FAQs about Overdrive Transmissions.

  • Why do I keep jumping in and out of OD?
  • How to change out an OD unit.
  • Some thoughts on pulling your transmission.
  • Summary of overdrive work repair.
  • Here are some things I learned repairing my Overdrive.
  • I'm getting a 40 mph shudder in 3rd gear.
  • What fluid should I use with my overdrive manual transmission?
  • My transmission is making a metallic hissing noise.
  • Should I use Redline MTL synthetic oil in my OD?
  • How to sort out the M40/41/1400/410 transmission codes.
  • What can I do for a constant leak of transmission fluid?

  • Why do I keep jumping in and out of OD?

    Date: Thu, 12 Mar 92 10:37:29 MST
    From: ewethere@onyx.mines.colorado.edu (Wetherell Edward L)
    To: volvo-net@me.rochester.edu
    Subject: re: MTL in OD

    Thoes results are great!!! The noted experience (jumping in and out of OD) could also be due to a couple things. 1) low oil level in the overdrive. For a while, mine was leaking so badly that i knew the transmission was out of oil when the od poped out. Durring this expedition, i lost 6 quarts of trans oil in under 200 miles...finally found a place to work on it and managed to temporarily fix the problem so that i only used 6 more quarts for the next 1100 miles, much more dooable, but still annoying. Back to the point, low oil means that the pump sucks air, looses pressure, and od jumps out. Another thing is the solonoid. Bad o-rings that seal the solonoid can allow oil to bypass the pressure side of the system where it is really needed. The solonoid could be week, and that leads to obvious problems. I have done a lot of seal changes in the od, and it isn't too bad... just be extra careful w/ the planetary geers if you start digging... they are VERY expensive and im not sure that they are easy to reinstall... i was never that brave... remember that the od's run an oil pressure of 450-500 psi!!! MTL can probably handle that a lot better than std 30W oil... too bad the stuff is so darn expensive...


    Subject: Re: OD Experience
    Date: Thu, 21 Dec 1995 10:04:05 -0600
    From: jaos@pclink.com (Jared Aos)
    To: swedishbricks@me.rochester.edu

    >I want to share an experience I had while driving to DC from Pittsburgh last
    >weekend while driving my "new" 82 244 dl w/ 4sp/OD. Just as leaving PGH my
    >OD started acting up, suddenly dropping out of overdrive. I tolerated this
    >for a while the stopped at a quick lube to have the tm fluid checked. That
    >was full then I swapped OD relays and messed with the wires to the switch and
    >relay as I had recently connected them when installing the "new" tm. I
    >thought it was the relay because I noticed the car would not go into OD until
    >I had driven ~3 miles on the hiway. All to no avail. Anyway, once in DC I
    >checked the wire to the solenoid on the OD, it was loose and crimping it
    >down solved the problem. Just wanted to share this since OD problems are
    >frequently discussed here.


    >80 264 GL diesel (for sale)
    >82 244 DL
    >89 245

    I also had my 245 drop out of overdrive. I removed my relay (removed glove box, 1st relay on left) took the cover off and inspected the contacts. They we're not pitted, just a small black dot of carbon in the center of the contacts. I sprayed contact cleaner on a torn strip of card stock paper (not waxed or colored) and slid it through the contacts while holding them closed untill clean. This fixed the problem. I've been cleaning relay contacts for years (industrial machine repair) and was surprised that that little bit of carbon caused the o.d. to fail. Must be a low current device.

    Hope this helps someone,
    Jared Aos
    85 245TI 120kmi.

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    How to change out an OD unit.

    Date: Thu, 18 Jun 92 14:14:24 EDT
    From: wiegman (Herman L. N. Wiegman)
    To: wembley@mentor.cc.purdue.edu
    Subject: Re: O/D swap


    >I think it could be this stuff because...

    1. I had the clutch replaced less than 50K ago,
    2. I had the U-joints replced shortly before that,
    3. I just got the Plugged CAT fixed and I now have more HP than I have had in over 2 years.

    ah.. I see. The prodigeous amounts of torque are making the uni-dir clutch slip.. ca-chunk ca-chunk.. you need a rebuilt O/D unit.

    to change out an O/D unit.. start with a manual spray car wash w/ degreaser setting. spray the piss out of the underside of the tranny tunnel. Then spray with soap, then with water.. this is to insure a clean working environment before you tear into the tranny. usually 1 minute per setting is fine as long as you can get at the tunnel from both the driver's and passenger's sides.

    disconnect the drive shaft at the O/D output. (oops, drive the car home first :)

    next, remove the tranny cross brace member while supporting the motor (at teh oil pan) with a floor jack. once the cross member and tranny mount bushing are removed, then the motor can be lowered about 2".. so the O/D unit is looking towards the garage floor. Now all the tranny fluid can be drained via the O/D inspection cover. (NOTE: this lowering of the back of the motor can stress the exhaust pipes.. and the back of the cam cover usually touches the firewall, check for clearence and stray wires)

    loosen all the small 13mm nuts that suround the input side of the O/D unit.

    slide the O/d out (don't forget to disconnect the selenoid wires).

    Disassemble O/D and replace one-way clutch...

    reverse order with new O/D while being careful when sliding it on the tranny output shaft.. a new paper gasket may be necessary between the o/d and tranny ($1.25 at dealer).


    p.s. I would first inspect the filter for metal.. this would prove that the clutch is slipping.

    From: wembley@mentor.cc.purdue.edu (Brian F. Marten)
    Subject: Re: O/D swap out
    To: wiegman@orion (Herman L. N. Wiegman)
    Date: Wed, 1 Jul 92 23:21:22 EST

    Herman L. N. Wiegman writes:

    | how does the OD work?? well?? remember, don't whale on it in the first | week. feel your way into it and see if it can take the torque.

    I swapped the shims in the pressure regulator so I have the pressure of the "Turbo" model. Yours had one and mine had two. There is no other real difference.

    | Did you keep the inside of the O/D clean? .. new fluid? good.

    I cleaned every peice until shiny and gritless in petrol and then oiled them liberally. On assembly we poured oil on and through every part before inserting it, changing newspaper and using new paper towels every few sections.

    | p.s. see if you can make it to the picnic.. You S.O. and the other S.O. | will have a good time (neat crowd).

    When is it?


    Brian aka wembley@mentor.cc.purdue.edu

    Oh, Wembley, this is very self destructive of you... I mean, look at you! You are completely unconcious! What if we hadn't been here to help?

    Hmmmmm? Hmmmmm? -- Mokey Fraggle.

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    Some thoughts on pulling your transmission.

    Date: 26 Jul 1992 14:09:22 -0400 (EDT)
    From: "John W. Retallack" <JWRPPH@ritvax.isc.rit.edu>
    Subject: Re: Pulling the transmission
    To: jhenders@jonh.wimsey.bc.ca

    I agree with most of what's been said RE: pulling the transmission. Here are some additional thoughts:

    1- Safety! No matter how you get the front end up make sure it won't come down on you. I've known several professional mechanics... It's not a nice way to go. I use axle stands and place wood or concrete blocks under the car in some out of the way but secure spot to prevent the car from coming down all the way. Be especially careful if you are not working on a concrete surface. This is most important if you have the wheels off! (you won't if you are only doing a clutch).

    1a- You'll need something to support the back of the engine while the transmission is out. I use a bottle jack (hydraulic) and a 6" square block of wood under the oilpan. The wood spreads out the load, cut a hole in it to clear the drain plug.

    1b- Disconnect the shift lever and remove the boot from inside the car. Also disconnect the overdrive and back up light wiring.

    2- I don't remember seeing allen bolts (transmission to bellhousing) on anything later than an early 140. Allen sockets are available (Sears) or you can make one as previously described. 3/8" will work, actually, I think they're metric. Also fits B21 head bolts. A universal joint for your socket set is useful. Also a new (to me) gadget called a wobble drive is useful here (simply, a loose fitting extension bar). Plenty of room on 140's & 240's but a very tight fit between the transmission and the floor tunnel on 544's and 1800's.

    3- On earlier cars the transmission can be separated from the bellhousing leaving the bellhousing attached to the engine. Starting with the B21 and M45 & M46 transmissions, the bellhousing is attached to the transmission with bolts from inside the bellhousing.

    4- I don't remember any unusual problems when I replaced the clutch on my B21 ('76) but... The transmission is heavy. I used a floor jack with wheels. A bit touchy but it worked. Probably two strong guys could handle it. The bolts on top of the bellhousing are accessible from above. All Volvo's use metric bolts after 1975. I think these are 17mm. Disconnect the battery before you remove the starter! I suggest wearing gloves when man-handling a transmission.

    5- Rear main seal. If it shows signs of leaking, replace it. Otherwise I'd leave it alone. Note: there is always some oil inside the bellhousing. Sometime in the early '70s the felt seal was replaced with neoprene. When replacing this type they should be installed to "run" in a slightly different spot. IE: not in the groove they have worn in the crank. Printed instructions came with the seal I got from Volvo. The Haynes manual covers this too. Put some grease on the "lips" of the seal before refitting, soak the felt seal in oil (early models).

    5a Examine the old clutch. According to the Haynes manual; the clutch facings should look like smoothly finished wood, light in color. The grain should be visible. If oil leakage has been present the facings will look like varnished wood, darker and the grain may not be visible. Some oil is always present. Haynes says that if the finish is smooth and the grain is visible oil leakage is not a problem.

    6- Pilot bearing (input shaft): Always replace it when doing a clutch job. If it seizes it will keep the transmission input shaft turning even when the clutch is disengaged. You'll think your synchro's are bad.

    7- Flywheel surface: Check for deep grooves. It can be resurfaced at a machine shop. If you want perfect shifting, the surface must be good. If you just want to replace the clutch... I've seen some fairly grooved flywheel's that shifted OK.

    8- Centering the clutch. Can be done as earlier described. Also you can buy a centering tool (plastic) from a good auto parts store. Sometime about 1980 the number of splines on the trans inputshaft were increased so a different tool will be required for later models. I put a little grease on the splines of the clutch plate.

    9- Shift fork. Check for excessive wear where it runs on the throwout bearing. A little grease in this area too.

    10- When reinstalling the transmission it helps if it is in gear. When all is lined up you may have to turn the ooutput shaft to engage the clutch splines.

    11- I torque clutch cover (pressure plate in US jargon) to 25 ftlb (Haynes does not give specs). The flywheel gets 50 ftlbs. I also use loctite. A big screwdriver engaged in the starter drive ring will prevent the engine from turning.

    12- Parts suggested for a complete job: Clutch, clutch cover, release bearing, pilot bearing & possibly rear seal, rear seal housing gasket & possible machining of flywheel surface. I've done it with a lot less and not been unhappy.

    It's not as difficult as all this seems but you'll know you've done some work! Sorry for the long post:


    From: matula@cblpo.att.com
    Date: Mon, 27 Jul 92 09:06 EDT
    To: swedishbricks@me.rochester.edu (Volvo-Net)
    Subject: Transmission removal(s)

    My two cents, after others:

    >Yes you can pull the transmission without pulling the engine but the differance in work is marginal.

    I've done it both ways. To just do the transmission/rear seals, its easier to just pull the xmission. IF you also think you want to redo the coolant pipe, look over the engine, perhaps replace a oil pan gasket, etc., then prepare the hoist and pull the engine. However, if you have the following, you can do just the xmission without a lot of hassle:

    Jackstands for safety.
    2 1/2 ton floor jack, or something simiar with a large (~4") cup at the end of the arm.
    19mm 3/8 or 1/2 inch drive sockt for those three bolts at the top of the engine.
    1/2 inch universal
    3/8 to 1/2 adapter if you're 19mm is a 3/8
    2 foot long 1/2 inch extention bar
    1 foot or longer 1/2 inch drive breaker bar

    First, remove driveshaft connections. Note that they are 9/16" bolts (yes, on a metric car..)

    The idea is to get the jack under the transmission, place a block of wood between the engine and the firewall just under the camshaft, remove the rear xmission supports, and then lower the engine/xmission until the engine is supported against the firewall by the wood. If the camshaft on the engine touchs the firewall, get a bigger block. Additional safety can be had by putting a separate stand under the engine.

    With all this done, loosen the three top bolts, then the others, and then you and another person slide the transmission off of the engine.

    >I have done it from under and I had a pit to work in, it was as comfortable

    >as this job can get.

    If you have a concrete floor garage, you can do it.

    >If you pull the transmission (on a 240) you have to do some double jointed contortions to get the top three bell housing bolts and you need to get a friend to help you pull out the gearbox which - auto or manual - is both large and heavy.

    >Next time I pull the motor.

    Either way is not an afternoon job. However, if you don't have a hoist, and you decide to rent one, then you'll be under the time=gun to get it done before the hoist is due back. If you don't OWN/have unlimited time for a hoist, I'd recommend that for your first time out on this job, don't pull the engine. It always takes me longer than I think the first 3-4 times I do a job.

    (After that, it takes me a little less time, but I start to more properly estimate the job ;^)

    Tip: For a pilot guide, select the deep socket from your craftsman set that matches the outside diameter of the pilot bearing. Put a long 3/8 extension into the socket BACKWARDS, so the ext. is coming out past the 12 teeth. 9/16" is a size to select first. Now, just hold it against the bearing in the depression, and set up your clutch and cover.

    Val Matula

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    Summary of overdrive work repair.

    From: SiewSiong Tan <u883399@sol.surv.utas.edu.au>
    Subject: SUMMARY: OD Repair (1-way clutch)
    To: swedishbricks@me.rochester.edu
    Date: Thu, 30 Jul 92 19:59:46 EST


    I have several postings from the net requesting me to summarize to over-drive work repair. I must acknowledge that this work was carried out with many helps and encouragement from Herman. Ok here it goes..



    Will jump after using the od, ie you will feel some kind of knock coming from the transmission similar to someone slamming the back of your chair.

    Moving off on a slope is the worst regardless of gentle or steep one, it will spin so fiercely that you might think that your wheels are lossing grip on the road. Or you may think that your main clutch is on its way out.

    The best description of the symptom was posted by Chuck, see posting below;


    >Date: 12 Jun 92 16:45:00 EDT
    > Early M46 transmissions had problems with the one-way (sprague) clutch
    >in the OD. It would jump and make terrible noises when you were starting
    >in first or shifting hard. The clutch is only used when NOT in OD. This
    >may be your problem. Volvo sells a new and improved clutch for about $65.
    > Chuck Swepston


    If your OD made alots of noise when you use it you should stop using it further and if possible stop using the car before further damages will be done to your od and tranny components. I was stubborn to continue using it after the 1-way clutch had disintegrated, thus my od gearing components were badly damaged. I learn the hard way so I hope you do not have to go along the same track that I took.

    How to disassemble it

    See posting below from Herman.

    >Date: Tue, 9 Jun 92 10:01:09 EDT
    >Subject: Re: Slipping o-d clutch question
    >Status: OR
    >Stuff Deleted...
    > FIRST: wash under the car with a spray gun at the car wash. The cleaner the
    >underside, the better. (use the "soap" and "de-greaser" settings)
    > SECOND: lower the transmision cross member (by the O/D unit). Have a jack
    >under the tranny to let it down slowly. This will allow you to remove the
    >several bolts which hold the O/D onto the end of the transmission. Disconnect
    >the electrical wires and drive shaft and the O/D should slide off the end of
    >the transmision output shaft (this must be done in a straight line.. don't
    >wiggle it too much.)
    > THIRD: Take the O/D to a nice clean work bench (kitchen table :) and start
    >to separate the front half from the back half.
    > FOURTH: Replace the one way clutch with a new one and reverse the above
    >steps to have a nice new O/D... (clean the filter elements as this time.)
    > simple, isn't it? The whole tranny does not have to come out.
    > Stuff deleted...
    >If you have a decent tool box and like to work on Volvo's, this is a good
    >repair for you. It is not easy, but the repair is well within the reach of
    >normal owners.
    >best of luck,

    Removing old 1-way clutch

    1) When the rear casing is out, the circlip can be removed by a small screwdriver. The oil thrower will come off easily. I don't have to remove them because the circlip was already out and the oil thrower was in a really bad shape.

    2) The old 1-way clutch can now be removed by lifting off the central hub. MY was completely destroyed with the outer ring suppport, clips and bearing rollers grinded to pieces.

    Fitting the new 1-way clutch

    1) There are two design of these 1-way clutch, the old one has a steel ring on the external while the new has only some clips to retain the roller bearing which sit on a plastic holder. The new design is claimed by Volvo to be better, I agreed because in the event of its failure (self destruction) it has less metal to harm other gear components in the od unit.

    2) To fit in the new 1-way clutch. Note the side view of the 1-way clutch, the side with the shorter plastic holder will sit in the bore while the other londer side will face towards you or the planetary gear. See diagram below. The roller bearings are placed into the bore first follow by the central hub.

    Planetary gear and carrier is on this side
    This end will face you if you are looking down 
    This end with longer plastic holder
    |                           |
    |  |  |  |  |  |  |  |  |  |  |  |  |
    |  |  |  |  |  |  |  |  |  |  |  |  |  roller bearing
    This end with shorter plastic holder
    This face will sits into the bore towards the drive shaft
    Diagram showing side view of the  1-way clutch.

    3) Fitting will be just the reverse of the disassembly but require a new gasket. Volvo here wants $18 for it, so I made my own gasket using a roll of gasket paper that I purchased from K-mart.

    4) How to made a gasket. Place the gasket paper on a flat surface. Apply some ATF on the od rear casing joint and place it over the gasket paper. The shape of the casing will be printed on the paper which can be form using a small pen-knife. So my gasket only cost $5 instead of $18. With this roll I can make another 6 more gaskets Which is a huge saving.

    Hope this help



    1980 244GL 161000km

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    Here are some things I learned repairing my Overdrive.

    Date: Mon, 26 Oct 1992 12:48:31 -0500
    From: memsthd@prism.gatech.edu (MIKE WILEMAN)
    To: swedishbricks@me.rochester.edu
    Subject: Overdrive repaired - gory details

    Thanks to everyone who responded to my SOS for the overdrive problem. Here's what I learned during the process of repairing it.

    The wiring for the OD solenoid comes out of the harness behind the center panel of the dash and feeds into a relay. The control leads of this relay are wired to the switch in the shifter, and these wires pass under the carpet over the drive train hump. The output of the relay follows the same path into the shifter housing, then through a hole to the transmission beneath the car.

    Apparently, the solid-state relay fails fairly often, but this wasn't my problem. You can check this pretty simply by just pushing the shifter switch several times, but the relay requires a second or so to reset, so don't push the switch to fast. THe easiest way to access the relay is to remove the glove compartment. It's the big orange things right to the left.

    There is a three wire connector between the relay and the shifter housing, two green wires going to the shifter switch, and the white wire going to the solenoid. This is a good place to check for correct voltage from the relay to the solenoid.

    If there are twelve volts on the white wire at the connector with the overdrive switch set for on, check the path of the wire from the connector to the solenoid. The wire passes through the shifter housing through a hole in the front sealed with a rubber grommet (which is easy to remove but a real pain to get back in) down to a bullet connector just on the other side. This is where my wire had broken. On the other side of the connector the wire passes though a small clamp on the passenger side of the tranny, then over the top of the tranny to the solenoid, which is on the drivers side. As one netter warned me the wire was covered with gunk and brittle from the heat.

    After a couple of attempts at finding one of those darn bullet connectors (forget used ones, they all have the same brittleness problem) I finally just went to my local electrical supply and bought some high-temp gas resistant wire and butt-spliced it in. The hardest part of the job was getting that darn grommet back in. There is very limited clearance for fingers in the shifter housing, even after you remove the backup light switch.

    The OD works fine now, though, so thanks again to all of you Volvophiles for helping out.

    In other news, I just poured in my first bottle of Techron. I guess I'll know the results in a couple of days. My car had a pretty bad cold starting problem. Anybody have any suggestions as to how many bottles of this stuff I should try before I give up (I'm too pessimistic to really believe the first bottle will solve the problem).


    '84 245DL

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    I'm getting a 40 mph shudder in 3rd gear.

    From: jhenders@jonh.wimsey.bc.ca (John Henders)
    Subject: Re: still noisy
    To: swedishbricks@me.rochester.edu
    Date: Wed, 11 Nov 1992 22:34:56 -0700

    In <"11-Nov-92 8:31:51".*.John_E_Werner.Wbst311@Xerox.com>, John writes:
    >>My '74 142 is experiencing exactly the same symptoms and I've fixed
    >>nearly all the same parts... These fixes did help a great deal,
    >>but I'm still getting a 40mph-in-3rd-gear shutter.
    >A hint might be here. I have noticed what Is probably a similar problem, but
    >it is only when my 145 is in 3rd gear. I can go the same speed in a different
    >gear (i.e. 2 OD) and not have the problem. I have resigned myself to the fact
    >that it is probably something to do with the gear box. The car has been that
    >way since I got it, and it has not gotten worse.

    Sorry to take so long to jump in on this, but these last little bits of info pretty well nail it down from my exerience. The needle bearings in your transmission are going. These are where the front and rear shafts fit together, and if you look at the power flow diagram that was in one of the aftermarket manuals, you'll see ow the third gead flow puts more stress on the bearing than any other gear. I had this problem on a 544 years ago, and, having nothing to lose decided to chnange the needle bearings. It actually wasn't that hard, though I remember haveing to make a circlip spreader out of an old pair of plyers and a file.

    If you're time is worth a lot to you, it's probably a better idea to buy a used transmission. though. It's not fun the first time, as getting the countershaft back in is a trick that takes a bit of practice to master. The transmission will last a long time before it goes completely, as mine had been bad for a year before I got around to fixing it, and it never did quit.


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    What fluid should I use with my overdrive manual transmission?

    Date: Mon, 14 Dec 92 10:03:08 EST
    From: hwiegman@ASTRO.GE.COM
    To: moran@uxh.cso.uiuc.edu
    Subject: Re: transmission fluid

    Juan, [ and owners with Over Drive manual transmissions ]

    It is difficult to tell you which fluid to use, but it is simple to suggest several. Volvo has used several different types of fluids in their transmissions over the years. Now 'a days, they are mostly using Type F and thier own special type which, I believe, is compatible with Type F. (don't quote me.. I don't like voiding warrentees for others..;)

    The earlier 240's could be specified with many different types of fluids. I owned a `79 4-speed (M-40), which I later replaced with a M-46 O/D tranny from an '85. The '79 M-40 used 80W, the '85 M-46 used ATF Type F.

    Here is an INCOMPLETE summary...

    4 speed transmissions:
    M-40 B20/21 80W90
    M-45 B21/23? 80W90 or 30W
    4 speed O/D transmissions:
    M-410 B20 30W
    M-41 B20/21 30W or ATF type F (later units with the 'new' O/D)
    M-46 B21/23/230 ATF type F
    5 speed transmission:
    M-47 B230/B234 ? ATF

    Most Transmissions requiring ATF will have the letters painted on the side of the transmission by the oil fill hole. This is primarily the M-41 and M-46 O/D units. Good luck in reading the old white paint on the transmision with a flash light ... :)

    Note to O/D repairs on M-410/41 units:

    The O/D units are highly sensitive to the type of fluid used in the transmision. Most old Jensen O/D units are toast these days, if the O/D is repaired or replaced on the older transmissions, they may be the "new" type-J Jensen OD units. These REQUIRE ATF instead of the 30Weight oil. Inquire which type of O/D unit was used when the repair was made. 80W90 does not work too well in the modern Jensen O/D units... I know by experience.. fortunatly for me a quick flush and fluid swap gave the new unit life until I could propperly clean it.

    best of luck,


    Herman L.N. Wiegman
    hwiegman@ew0099.astro.ge.com or wiegman@orion.crd.ge.com

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    My transmission is making a metallic hissing noise.

    Date: Mon, 15 Mar 93 14:09:58 EST
    From: nick@meaddata.com (Nick Gough)
    To: marka@sol.metaware.com
    Subject: Re: tranny noise


    Sounds like OD problems.

    A little tranny noise is normal, plus a little vibration thru the shifter. But, if it has suddenly, or over a short period of time, has gotten louder, read on...

    BTW... change the trans. fluid every 30k miles, or so. It is cheap insurance.

    Before doing anything, have the mechanic put it on a lift, raise it up, start the car, get it in OD & check out the rear seal on the OD unit. If it leaks, you may have to replace only the seal. If, after checking, draining & replacing the fluid, you still have problems, you may be in store for rebuilt OD-units. Have your mechanic listen to the noise when the car's up in the air, with the thing in OD & running. If it comes from the OD, you may be heading for the same thing as I ran into last year with our OD... rebuild time. If the noise comes from the front of the trans, chances are it is probably the pilot bearing, which is a cheap part, but requires about 2-3 hours labor to yank the tranny/OD-unit & put a new one in, then button it back up again.

    If you have to rebuild the OD-unit, you may be better off getting one already rebuilt. Strandbergs has them (see the PPL for their #). If you have a place that can warranty the work for a year (rebuilt units usually only come with a 90-day wtty.) like I did, you may be better off having it rebuilt. My cost for just the OD-unit was around $350-400, which is about the same cost as the rebuilt unit (minus shipping). I had to replace all tranny & OD bearings, and opted for a new clutch, pilot bearing & rear main seal as well. Total bill was around $1300, but the labor for the clutch work & rear main seal was a no-charge item, since everything was already out of the car.

    Also, I had the guy use Volvo bearings, and a Fed-Expressed Sachs clutch assy., since we were going out of town about a week later & needed it done ASAP, so we could have it tested out prior to the trip. Everything was OK, after a valve was re-positioned properly. Totoal time to work on it was only about 5-6 hrs. labor, but the parts all had to be ordered. We didn't have the time to go to a local bearings supplier to locate the Volvo equivalents at a lower price. All trans/OD bearings cost about $350. One of them, in the OD-unit, was sitting in the bottom of the OD case when he opened it up. All gears & the OD clutch were OK.

    Good Luck.


    > From metaware!sol.metaware.com!marka@netcom.com Mon Mar 15 13:43:10 1993 > From: marka@sol.metaware.com (Mark Alexander) > Date: Mon, 15 Mar 1993 09:14:36 -0800 > X-Mailer: Mail User's Shell (7.2.5 10/14/92) > To: swedishbricks@me.rochester.edu > Subject: tranny noise > Content-Length: 1100

    > Both my 240s ('85 and '76) have 4sp+OD, and both are now making a
    > noise that sounds like it's coming from the transmission. It's a sort
    > of metallic hissing noise, a bit like the noise water makes rushing
    > through a metal pipe. The noise is related to vehicle speed and
    > nothing else; it happens in any gear or neutral coasting, OD or not,
    > clutch pressed or not, and disappears only when the car is stopped.
    > Fiddling with the rubber shifter boot while driving makes the noise
    > vary, so it seems to be coming from right below that point. The noise
    > seems a bit louder when it's warm outside.
    > The '85 (109K miles) just started doing it last week, but the '76
    > (160K miles) has been doing it for a few years now and is louder.
    > >From this I conclude that it's normal wear-and-tear on the bearings or
    > something in the transmission, but it would be interesting to hear if
    > any other bricksters have noticed this noise.
    > A possibly related question: the owner's manual for the '85 says you
    > don't ever have to change the transmission fluid, but Haynes says do it
    > anyway. What's the collective wisdom on this?

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    Should I use Redline MTL synthetic oil in my OD?

    From: "Ron Tewksbury" <ront@twg.com>
    Subject: Redline MTL in Overdrives?
    To: volvo-net <volvo-net@me.rochester.edu>
    Date: Thu, 12 Mar 92 8:07:51 PST

    A few weeks ago I asked if it was OK to put Redline MTL synthetic oil in the OD of my 1800 coupe. I got one answer back, in the affirmative.

    So, I tried it. This is what happened:

    The Overdrive used to be quite sluggish engaging- like 20 to 30 SECONDS to drop into OD, and this was when the transmission was warm. Also, the transmission would jump in and out of OD depending on the amount of throttle used.

    So, I drained out the old stuff (30w) and added the MTL. The difference is nothing less than astounding! It shifts into OD as soon as the switch is flicked. And even on long trips it NEVER jumps out.

    Before I tried this, I was sure I needed to rebuild the OD, but now it looks like its got some life left.

    Being a synthetic, I wonder if this would help any of those sluggish East Coast Winter OD's perform a little better?

    ron tewksbury

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    How to sort out the M40/41/1400/410 transmission codes.

    From: w2iy@hoqas2.att.com
    To: swedishbricks@me.rochester.edu
    Date: Thu, 27 May 93 09:20:20 EDT
    Subject: Transmission type codes

    Fellow netters,

    A few weeks ago I posted a note about how to sort out the M40/41/400/410 transmission codes. It turns out that what I learned years ago is mistaken and I wanted to correct my earlier misleading posting.

    This information comes courtesy of fellow netter Ray Parsons.

    M40: 4-speed box, used in lots of early models including 71-73 1800 (maybe up to 69 as well? Can someone fill in?)

    M41: M40 with overdrive stuck on the end, overdrive was Laycock-deNormanville J-type in 71-73 1800

    M400: Beefier 4-speed box used in 164 and 70 1800.

    M410: M400 with overdrive stuck on end, J-type in 70 1800.

    So apparently to indicate overdrive, you add 1 to the second place after the M.

    Ratios: M40 M400

    1st 3.41 3.14

    2nd 1.99 1.97

    3rd 1.36 1.34

    4th 1.0 1.0

    Reverse 3.25 3.54

    One way to tell which box you have is that the M40 has its fill hole on the right side (passenger side) and the M400 has fill hole on the left.

    Keep 'em rolling,


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    What can I do for a constant leak of transmission fluid?

    Date: Tue, 10 Aug 1993 14:44:49 -0500
    From: Juan Moran <moran@uxh.cso.uiuc.edu>
    To: merrill@stsci.edu, swedishbricks@me.rochester.edu
    Subject: Overdrive problems

    I was at least one of the persons who had problems with the Overdrive last month. It took some time to get it all back to work order. My thanks for the various suggestions I got.

    My problems were 2 of them: One was the gound wire in the selenoid broke off. This was easily fixed.

    The second problem was that there was a constant leak of the transmission fluid. In my case I traced the problem to the fact that the 2 top studs on the back cover of the overdrive unit did not have the plastic seal washers. The transmission fluid was leaking out through the top studs even though they had a spring washer and the nut tight. One must put in the plastic seal first and then the spring washer and the nut.

    The problem that Merrill described is seems like an electrical problem of sorts. It does not sound like a mechancial one or problems with the transmission fuild.

    If anyone needs to, I can make copies of how to diagnose and repair/rebuild the Overdrive unit. I would make the copies from the Volvo manual.

    Juan Moran

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