FAQs about Drivetrains

Replacing/repairing the center support on the driveshaft.

From: southern@neit.cgd.ucar.edu (Lawrence Buja)
Subject: Re: Drive shaft question and Boge T Gas
To: V093P9MD@ubvmsb.cc.buffalo.edu
Date: Tue, 20 Apr 93 15:58:55 MDT
Cc: swedishbricks@me.rochester.edu

}First of all I want to ask a question about the difficulty or ease
}of replacing/repairing the center support on the driveshaft on an
}'84 240 GL (120,000 miles). The shaft shudders a bit when I put the
}car in reverse. I would like to do the repair myself if I can

}since I have no desire to "give" any unneccessary money to my
}mechanic.

It was rather easy on my '74 142. It's been almost a year now, but this is how I remember it...

- Order the bearing, a new rubber support donut, and consider ordering new U-joints. I believe Herm had a mod welded to the center support to keep the donut from popping out of place.

- Park the rear end up on ramps and a couple imbibables in the fridge.

- Paint matchup marks on both ends of the driveshaft (DS) and around the splined center portion where the DS comes apart.

- Look for directional dependencies in the rubber support donut (if any).

- Unbolt the support for the center bearing

- Unbolt the DS at either end. My DS bolts were locktite'd and wouldn't come apart even when heated. After an hour struggling with the stuck bolts, I simply cut them off in a couple minutes with a fiber masonary wheel mounded on a hand drill and replaced them. I had to jack the rear end off the ramps and rotate the DS 1/2 turn to get at the bolts on top.

- Mark where the bearing is on the DS and observe if there are any directional dependencies in how the bearing goes on.

- The bearing I pulled came off rather easily with a small gear puller.

- Find something tubular to help you pound the bearing down the DS if it becomes necessary. Lubricate the outer sfc of the DS.

- Pop the DS in the freezer and the new bearing in the oven under mild heat.

- Consume an imbibable and wait awhile.

- Push the warm bearing on the frozen DS, down to the mark you made earlier on the DS.

- Reassemble it all.

Since you'll have the DS off, this is a good time to replace all the U-joints. I highly recommend having a machine shop do this as it was an extremely unpleasent job to do with hand tools that would be relatively easy job to do with large presses.

/\ Lawrence Buja Climate and Global Dynamics Division

\_][ southern@ncar.ucar.edu National Center for Atmospheric Research

\_________________________Boulder,_Colorado___80307-3000__________

Date: Tue, 20 Apr 93 17:08:07 -0400
From: alfred@nyquist.bellcore.com (Alfred Kwan 21342)
To: V093P9MD@ubvmsb.cc.buffalo.edu, swedishbricks@me.rochester.edu
Subject: Re: Drive shaft question and Boge T Gas

Andre'

I did one of those U-joint/center-support-bearing on my 242GT. I bought a $99 hydraulic press years ago and it came in real handy for the center-support-bearing. A large jaw vise or a large C-clamp is real useful for the U-joints.

Go real easy with the U-joints, check the movement of a new joint constantly during installation. Press the end cups back just enough so the C-clips can go back on. I pressed one in too much and it was too tight. The rollers or the pins like to fall out of place. In addition, there are 4 little plastic thingy inside each of the end cup; if any one of these plastic thingy is off center, it will get flatten, hang up the end cup, and you can't put the C-clip back on. If that happened, you have to take it apart, find a good plastic thingy from an old U-joint and start all over again.

You might want to replace the center-support rubber boot also. There is a little spring at the bottom of the rubber boot. It broke on my 242. You might check that also.

Good Luck

Vibration during slowing down.

Date: Fri, 20 Mar 92 09:10:48 EST
From: wiegman@orion (Herman L. N. Wiegman)
To: DEBOER@sask.usask.ca, volvo-net@me.rochester.edu
Subject: Re: vibration during slowing down

>Yesterday I noticed that when I slow down from high speed (let's say 100 km/h) there is a very noticable vibration which seems to originate in the rear of the car.

Dirk and netters, [ commom problem, simple fix ]

I'll pin this one on worn U-joints in the drive shaft. They should be changed after 140km's. When the lubrication leaves the U-joints, you should feel a disturbing vibration when the car is slowed ( The rear end comes up just a hair, which is enough to cause the U-joint rotational angle to change to where the internal roller bearings rub. ).

best `o luck,

herm

p.s. There are three sizes of U-joints you probably have the large size and two medium ones on the '78. Measure all three U-joints for overall width before ordering. If you are not familiar with the job, it is probably better to have a mechanic do the work. It is not a difficult job, but one which requires some finesse (big hammer).

p.p.s. The O/D switch and gear shift lever are "in the mail."

____ ____ ____ ____

| / / / / | / / / / // /

| / / / / | / / / / \ //--- /

|/ /___/ /____ |/ /___/ o / \//____ /

U-joint size.

From: cblmarti@ihlpo.att.com
Date: Fri, 4 Jun 93 11:22 CDT
To: att!wiegman@orion
Subject: U-joints...
Cc: ihlpo!cblmarti

> Brain,

> I am not sure if the diameter of the drive shaft (tubular sections between the U-joints) has any impact on the U-joint size. I think that the Yoke
> width is the real measurement..

Herm,

Thanks for the last email. The first two U-joints are small. The shaft size does increase as you travel backwards on the shaft. The rear U-joint maybe the wrong size. George at Toyota/Volvo of Keene wanted the shaft sizes... Larry at IPD told me he could tell me the U-joints needed, based on the driveshaft diameter of the front section. I said O.K., told him the front section's driveshaft size and he told me I needed two smalls and a medium. The rear U-joint shaft was 3.25. IPD's '92 catalog list sizes as follows:

4A5512 2 7/16" dia. yoke is 2 5/8" diameter 8.70ea

4A5514 3" dia. yoke is 3 1/4" diameter 15.30ea

4A5512 3 3/16" dia. yoke is 3 1/2" diameter 12.90ea

So, I don't know. Guess I will have to wait and see if they were right. I still don't understand how I can determine which U-joint is at fault. I couldn't get any of them to move at all with the car out of gear with the rear wheels off the ground. The emergency brake was set...and that would prevent the rear tires from moving...

David Martin
AT&T Network Systems
Columbus, Ohio
+614.860.7898
att!ihlpo!cblmarti
cblmarti@ihlpo.att.com

Date: Fri, 4 Jun 93 12:57:47 EDT
From: wiegman (Herman L. N. Wiegman)
To: cblmarti@ihlpo.att.com
Subject: Re: U-joints...etc
Cc: wiegman

David,

interesting.. i never knew that there was a correlation between shaft diameter and u-joint size.. you learn something new every day.. the yoke width (diameter) is still the best measurement.. i will put your summary into the Net wisdom driveshaft file..

u-joints can only be inspected once the shaft is out of the car.they should not be able to be shaken when the drive shaft is in the car..although if you rotate the shaft (hand brake off).. you may be able to feel some rubbing in one of them.. but the vibration may travel up and down the shaft making it difficult to determine the exact source.

once the shaft is removed the U-joints and yokes can be played with.. making them move through their whole range of motion will quickly determine which is bad (kind of like moving your ankle through its range of motion to determine if you have sprained it.. can't do that with boots on.)

I've got a ticking in my rear end.

Date: Sat, 14 Aug 93 17:59:34 CST
From: "Marvin Bausman" <bausman@mcc.com>
To: swedishbricks@me.rochester.edu
Subject: Tick in Rear End- Conclusion

Netters:

You may remember my notes to the net concerning a tick in the rear end of my relatively newly acquired 86 240GL Wagon.

To make a long story short--- I finally took the car to an independant foriegn car shop (after having the rear end open myself and not being able to track down the problem).

It ends up that it was the action of the wheel trim ring on a rusty right rear wheel (the wheels where transferred from the 76 wagon I sold) that was making the noise I was hearing while driving the car. Cost me $24.00 to find this out.

One can still hear the rear end "tick" when the car is up on the hoist and one spins the wheels, but this is supposedly "normal" and can not be heard while driving the car.

I felt pretty dumb missing this one, but would have felt worse if I would have changed the rear end out and still had the tick.

MORAL OF STORY-- DO NOT OVERLOOK SIMPLE SOLUTIONS EVEN IF LOGIC LEADS YOU THAT WAY.

Thanks for all the suggestions/help I received through the Net on this one.

Regards,

Are limited slip differentials available for most Volvos?

Date: Tue, 28 Jan 1992 13:19:22 PST
From: John_E_Werner.Wbst311@xerox.com
Subject: Re: limited slip differentials
To: volvo-net@me.rochester.edu

Limited slip differentials are available for almost all Volvos. (I am not sure about the ones with independent rear axles.) Many of the older volvos, especially the 140s and 240s use a Dana/Spicer Model 30 differential, which just happens to be what some jeeps use. There are both limited slip and Gleason Torrison differential available for these cars. (The Torrison differential applies power to the wheel that is not spinning.)

I know the 700 series cars can be fitted with a limited slip differential. Unfortunately, for you stock class autox'ers, it is a dealer installed option, and thus not allowed in stock class. Volvo does not recommend the limited slip with the turbo models. I am not sure if it is because of the ability of the turbo to destroy the diff, or because with all of the power of the turbo, they don't want drivers getting themselves in too deep. (Limited Slips let you get deeper into trouble, faster.)

-- John

Date: 24 Nov 1992 09:31:06 -0500 (EST)
From: V093P9MD@ubvmsb.cc.buffalo.edu
Subject: Re: limmited slip diff.
To: swedishbricks@me.rochester.edu

Here's a thought... The limmited slip differential Volvo has been selling can't deal with the stress of the Turbo engine, but in the latest 900 series with the Turbo or 24 valve I6, they now offer as standard equip. (if not mistaken) a limmited slip diff. this oe disengages above a certain speed (probably in the 15 to 30MPH range). Are they offering it yet as an aftermarket upgrade to the older 740/760T's, or has the rear differetial design changed?

Andre'

Date: Tue, 24 Nov 92 20:52:08 -0500
From: bw738@cleveland.freenet.edu (Ed Wetherell)
To: swedishbricks@me.rochester.edu
Subject: Re: limmited slip diff.

ias i understand it, the lim slip is not recommended for turbo cars because of the problems that can occur when the turbo kicks in.. not that the units can't handle the power, the dena axels and spicer lim slip units can definately handle the power of large v-6 motors so a turbo shouldn't be a problem..just that lim slips can be really wierd in bad traction situations with a lot of pwer increase in a short period of time.. i have nearly spun my 1800 w/ spicer lim slip rear end several times when road conditions are less than optimum.. they are great at low speedes and trying to get unstuck from snow/mud, but can be really tricky in the rain or snow.. i think that the volvo recommendation is primarily one of safety..

ed

Neat trick for diagnosing driveshaft vibrations.

From: southern@sage.cgd.ucar.edu (Lawrence Buja)
Subject: Re: driveline vibrations
To: kst@isdn.ncsl.nist.gov (Ken Tice)
Date: Fri, 4 Dec 92 14:18:51 MST
Cc: swedishbricks@me.rochester.edu

} I learned a neat trick for diagnosing (and potentially repairing)
}suspected driveshaft vibrations from a (of all places!) GM shop
}manual from the early eighties.
}

} The procedure is to clamp a lead wheel weight to the shaft with two
}hose clamps as close to the rear as possible. Put 4 chalk marks on the
}shaft and drive the car at the speed where the vibration happens with the
}lead weight at each of the four positions. The manual went on to say that
}you can "fine tune" the balancing effect of the weight after you get it
}to where it seems to have an effect. I used this method on my '70

}Camaro with success.

In talking to my parts guy about my driveline vibration, he related a similar technique that they used when he worked in a Volvo shop. It sounded so dangerous that I felt that it was best left unmentioned.

But, since the subject's come up, here it is:

They would put the car up on the lift with the wheels free. They could clamp two hose clamps on the driveshaft with the bodies 180 degrees away from each other. They would then start the car and run it up to 30-40 mph. They would touch the spinning driveshaft with a piece of chalk taped to the end of a broomstick handle. Stop the engine and examine chalk mark. The chalk mark would indicate the "heaviest" side of the driveshaft. Rotate the two hose clamps bodies towards each other to counter balance the "heavy side" of the driveshaft. Repeat the chalk test/hose clamps rotation until the chalk makes a circle on the driveshaft. Apply weights or just leave on the hose clamps.

Any volunteers?

/\ Lawrence Buja Climate and Global Dynamics Division

\_][ southern@ncar.ucar.edu National Center for Atmospheric Research

Chronic vibration caused by bent driveshaft.

The 240 is finally cured of its chronic vibration! After a little research I managed to cut out the middleman and located a shop in DC which does driveshaft repairs. It is called Washington Spring Works, they are on 1410 Church Street NW. Number is listed. I brought them the whole driveshaft, they diagnosed it as being bent. For $90.00 they straightened it and balanced it, and I had it back the next day! Considering that a used driveshaft of questionable integrity which undoubtedly needs a new center support and/or U-joints I priced at $100.00 at the junkyard this is a tremendous bargain. (For the hell of it I priced a new one at Volvo... would you believe $950.00??!) Removal & reinstallation of the shaft was a piece of cake... I even managed to put it back in w/o jacking the car. Don't try this on a full stomach. The road test proved 100 percent successful... the vibe is gone.

And on to my next question. I've been reading the thread about stress bars and body flexing. Someone commented that body flexing can manifest itself in badly matching doors & trunk seams. Within the last couple months I have noticed that the trunk matches badly on this 240. It almost touches on the left side and leaves a gap of about 1/4" on the right side. Is this likely to be the result of a twisted frame, or perhaps a sagging spring on one side? What, if anything, should I do? Thanks for any comments-