Driveshaft, Driveline, Rear Axle                                                                    FAQ Home
 Volvo Maintenance FAQ for 7xx/9xx/90 Cars                                                                                                                     Version 5.0
 
Driveline Vibrations

Center Support Bearing Noise

Vibration in Drive Shaft

Driveshaft Out of Alignment

Driveshaft Removal Tip

Differential Exchange
 

Automatic Locking Differential

Automatic Locking Differential Lubricants

Failing U-Joints

760 Independent Rear Suspension Vibration

Pinion Seal Leak

Pinion Leak: Vent Plugged

Re-Filling Rear Axle Lube


Driveline Vibrations.  [Query:] My 740 has developed a nasty vibration. First of all it acts as if it needs a tune up and I just replaced the plugs and wires. But the vibration that I was experiencing before the plug and wire change did not go away. The car vibrates the most when it shifts from 2nd to 3rd. I can't tell if its the engine or the drive train.  [Response:] I have an '87 740 - same problems. Here's what cured them: Done. quiet. finally. Sounded like an old tractor before. now a car again.


Center Support Bearing Noise.  [Query:]I have an '88 740 GLE Turbo with 113K miles and a 3 speed auto with electronic overdrive.  Just the other day, I started noticing a faint whiny noise coming from the front of the car (it _wasn't_ the turbo!).  Over the next day or two, the sound became more apparent.  It ranges from being a faint whiny sound to a loud howl that turns heads on the street with no apparent pattern.  It comes from directly beneath the shifter.  It is not related to engine speed, and is just as audible while coasting in neutral as it is in any gear.  If I drive for more than about 10 minutes, it seems to go away until the next time I drive.  I can't get in to have a mechanic look at it until Monday, but in the meantime, perhaps one of you kind folks might have some suggestions as to what it might be?  [Response 1: Mike Froebel]  Classic hanger bearing noise.  This is located just in front of the center universal joint on the driveshaft.  There is a plate that is bolted to the frame rails with 2 bolts per side, the hanger bearing support is bolted to this plate with 2 bolts.  The bearing lives in this support.  It is generally a good idea to replace bearing and support together, especially when the bearing is going bad.  It is quite an easy job to do yourself, but you need some kind of puller or press to remove/install the bearing from/to the driveshaft.  Do not pound on the driveshaft or new bearing or you could damage the splines so you won't be able to put the two halves back together, or the ujoint, or maybe change its shape just enough to put out of balance.  You could easily remove it and take it somewhere to have the bearing pulled off/pressed on if you don't have those tools.   Just to make it more fun, your car could have 2 different driveshafts each of which take a different bearing and support.  Measure the distance between the hanger bearing and middle u-joint and use the following Volvo part numbers:
     if the distance is:  4" -->  1340501 support and 183265 bearing
                                8" -->  1209820 support and 181549 bearing
[Response 2: Zippy] It probably is the carrier bearing.  Often they don't act up until they get warmed up from driving. The only real way to pinpoint the problem is to put the car up on a lift and let the car run in gear (wheels are hanging free) and listen with a stethoscope for the noise.  Drive train howl is usually the carrier bearing, often a rear wheel bearing and if you have had a differential pinion seal replaced recently, incorrect pinion to ring gear preload.

Vibration in Drive Shaft. [Note 1:] Even with the 2-piece driveshaft, rear axle pinion angularity is very critical to smooth operation. If the nose of the rear axle is too high or two low, the rearmost U-joint will be extremely "busy", and you often can get this kind of thundering at specific speeds. It's very fiddly to get adjusted correctly, but often paying careful attention to this will solve such a problem. [Note 2:] My first take on all of this is that the driveshaft was re-installed "out-of-phase" when all of the axle work was performed. There is a specific orientation shown in all Volvo service manuals. The driveshaft is balanced as a two-piece unit from the factory...so the orientation between halves must be preserved when servicing is performed.   See Driveshaft Out of Alignment


Driveshaft Out of Alignment.  [Query:  I dropped the driveshaft to replace the center bearing and failed to mark the alignment.  Now it vibrates. What do I do?]  [Response: Dennis Hamblet:]   The front section must be kept in the same alignment with the back section.  The only approach I could suggest if yours appears out of whack is to remove the center bolts and rotate the rear shaft 1/4 turn then try it again.  If it cures the vibrations you're home free, if not, rotate another 1/4 turn till you've tried all 4 combinations.  [Response 2: Warner Bowles ] I believe that the yokes of the universals at the centre bearing have markings on them from manufacture which indicates the correct alignment.  You will have to clean off the paint and any other build up which has accumulated on the yokes to see them.  A second alternative is to ensure that the yokes on the universals at the centre bearing are parallel, (ie in the same plane). This will result in the universals working together rather acting against each other. If worse comes to worse you may be 180 degrees out but should still reduce the vibration.  [Response 3: John Yuristy ] Since you pulled the centre connecting spline apart, and there are about 17 teeth on there, you could have got it back together haphazardly in almost that many different orientations.  Only one is right, and you can probably find it again by knowing how the yokes should be oriented w.r.t one another.  If you did not take apart any U joints while you had it out, and therefore also possibly rotate the half-shafts in the process, then you get to try once or at most twice to get the original position. The vibes come from both the U joint yokes not operating with the right geometry, and also if you have lost the shaft mass balancing which was done originally.
So, orientation of U joint yokes should look like this if text can make an image.

[]-o]--------[]---[o-----------------o]-[]

1  2   3    4   5        6        7  8

where 1 is the front flange, 2 is U joint, 3 is front half shaft, 4 is centre bearing and spline, 5 is U joint, 6 is rear half shaft, 7 is U joint, 8 is rear flange.
Put it together this way, and if it still vibrates, take it off again, and reverse one half shafts 180 degrees on the spline so it still looks the same as above.  If you think about it, those are the only two positions where the orientation looks the same.
Remember when you get it right, mark the shafts with a paint stripe or punch for next time.  I would also mark the yoke arms as well, i.e. the ones not welded to the shaft.  I expect the balancing allowed for weight imbalance in these too, when they were in the original configuration.  You can`t be too careful.  I have never found any factory marks, and the rust and crud I have seen would hide them right up until when you obliterate them removing the rust and crud! FWIW I spent over $100 getting two half shafts balanced at a shop here, not easy to find a shop with a lathe that can do this, had to go back twice, and a couple of new U joints died from re-assembly before the day was done.  Still not perfect.



Driveshaft Removal Tip.  [Tip from Bill D. ] I had to unbolt my drive shaft yesterday to replace the transmission bushing. I couldn't get a good angle on the wrench to unbolt it from the differential so I needed a impact wrench or a longer handle. Since I had neither I used my socket handle and was able to use my hydraulic jack to lift the end of the handle thus loosening the bolt enough to ratchet them off by hand. I had to roll the car back and forth and do this four times to get all the bolts. Would have been easier if the rear end was up on jack stands.


Automatic Locking Differential.  [Query]  In which cars was the Automatic Locking Differential fitted?  Do they require special lubricants?  [Response 1: Abe Crombie] Volvo came out with the ALD in 91 as std equipment on Turbo engined models and then std on 960 the next year. I believe it was std on all 940's 94-95. It was fitted to S/V90 as part of the "cold weather" pkg. in 97-98.  If the Id tag on a Multi-link version 1 says 1045 it's an ALD. If the solid rear axle on a 91 or later is marked 1041 it's an ALD. If the label on a multi-link version 2 (95-98 with leaf spring) is marked 1065 it's an ALD. ALL cross-country or 70 series AWD are ALD in rear. The LSD was a dealer installed accessory and never fitted in factory to my knowledge. Those can be detected by the jack-one-wheel-up-and try-to-turn-it method. Usually they are tagged as LSD if the installer and subsequent servicers don't discard the tag.  Response 2:  Ceferino Lamb] They are called locking differentials rather than limited slip diff (LSD) because they lock up entirely. In old muscle car lingo I believe this design was called a Detroit Locker. There are no clutch packs as in LSD, so the gear oil required is standard gear oil, not LSD gear oil. I supposed synthetic hypoid gear oil would be best.  They have internal dogs that catch when one wheel spins, locking left and right wheels together 100%. It's not the most subtle device, and can cause some pretty amusing powerslides if you're running elevated turbo boost. Above about 25mph centrifugal force keeps the dogs from engaging. But if you start spinning at a lower speed the rear end will stay locked up no matter how fast you spin, until you let off the go pedal.  [Response 3:  Michael Sestina]  Eaton Corp makes the axle. it works great on our 93 945. I donít believe they require special fluids.

[Notes from Eaton on their at http://www.torquecontrol.eaton.com/prodinfo/specs/index.html]
How the Eaton Automatic Locker Works:

During normal driving conditions, the differential operates as a conventional "open" differential. But as soon as wheel slip occurs in either forward or reverse, the locking mechanism engages. A flyweight governor in the differential responds to differences in speeds. During normal driving, the governor does not influence differential action. But whenever one wheel's speed substantially exceeds the other's, which only occurs during wheel slip, the governor spins rapidly causing the flyweight to open. The flyweight then catches a latching bracket and begins lockup. During lockup, a self-energizing clutch system causes a cam plate to ramp against a side gear. This ramping compresses the disc packs that are inserted between the side gears and the case. The ramping increases until both axles turn at the same speed (full lock) which prevents further wheel slip. The entire locking procedure takes a fraction of a second and is unnoticed by the average driver. Unlocking occurs when both wheels regain traction.
How the Limited Slip Differential Works:
Carbon discs behind each side gear are pre-loaded with a central spring assembly. This spring force, added with the pinion/side gear reaction forces, increases the clamping load on the carbon discs as input torque increases. The bias torque of the differential increases in proportion to the input torque. Pyrolytic carbon with a texture of cloth is bonded to steel discs. These discs are then alternated with non-patterned steel discs creating a clutch pack that's virtually indestructible under abusive testing and operation. Due to the texture of the carbon discs, special lubrication requirements are eliminated and there are none of the chatter or noise problems associated with paper and steel friction materials.


Automatic Locking Differential Lubricants.    [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.]  We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended.  As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
[Comment from Castrol:] Thank you for contacting Castrol regarding Syntec 75W-90 GL-5 gear oil in your Volvo differentials with an Eaton Automatic Lock.  You may use SYNTEC gear oil with full confidence.
[Comment from Mobil:]  Mobil 1 Synthetic Gear Lubricant meets the GL-3, GL-4 and GL-5 API ratings. If the manufacturer requires the use of a GL-4 rated lubricant ONLY, then you should not use Mobil 1 Synthetic Gear Lubricant.


Differential ExchangeGear Ratios.  [Query] I have a 1986 740 non-turbo with a manual transmission and the differential is shot. I have purchased a differential from 1986 740 turbo automatic to put on my car. I know the bolt pattern is the same but wonder if the gear ratios are the same and whether the engine will rev higher or lower and any other possible side effects.  [Response 1:  JT Charger] Using a little gasoline or solvent, you can clean the left side of the axle tube, so the sticker can be read.  it is probably covered with undercoating now.  the part # & axle ratio is printed by Volvo on this sticker.  With the car up in the air, the sticker will be on the left side outer tube of the housing, visible from the rear of the car, after being cleaned with solvent.   [Response 2:  Paul Grimshaw] The gear ratio for the US-spec manual transmission cars is 3.31:1.  Autobox equipped 700 series cars will have either 4.10:1 (Aisin Warner 72 equipped B2304 engines), 3.73:1 or 3.91:1 -- the latter two ratios used with Aisin Warner 70/71 and ZF 4HP 22 transmissions.   Your shift speeds will be different if you have changed the rear axle ratio, but if you have a tach that should not pose a big problem.  Fuel economy -- particularly during highway cruising will suffer from the shorter rear axle ratio too.  A benefit, however, will be quicker acceleration.
Carrier Compatibility. [Query]  I have been looking for a limited slip differential for my 83 760 GLE. I have been told that this differential is a Dana 30, which is also used on some Jeep models. I have a chance to purchase a limited slip unit that was an OEM for the 200 series. Can anyone confirm (with a great deal of confidence, since I may base my purchase on the advice) that the 200 and 700 series differentials will interchange?  [Response: Abe Crombie]  On the back side of axle tube on left (driver's ) side is a label covered by undercoat. Clean this off and see if your model is a 1030 or a 1031. Then determine (label in same place on 240's) if the 240 is the same model. IF they are the same model then the carrier will interchange.


Failing U-Joints. [Symptom:] Vibration in 90 745, AT, that is sort of a low moaning sound. It varies with road speed but not engine speed. It's almost like (snow) tire noise, but doesn't change with road surfaces (and I don't have snow tires!), or a bad wheel bearing, but doesn't change with turns, etc. It's gradually (very gradually) getting worse. If I let up on the accelerator, it disappears for a moment, then returns on deceleration. Finally, the groan virtually becomes a grind with deceleration to a stop. So, U-joint or driveshaft bearing, maybe? {Diagnosis:] Just went through the same thing. I think you're right about the U-joint. In my case, seized rear UJ; all four trunions/needle bearings dry and trashed. Only way to check is remove rear portion of driveshaft and check UJ for smooth taut movement. In my case, the rear portion of the two piece driveshaft can be separated from the pinion flange (in order to check UJ) without loosening anything else. 14mm?Interestingly, the bad rear UJ was also causing a rear end vibration, similar to warped rear rotors, under brisk deceleration at less than 10mph.


760 Independent Rear Suspension Vibration. [Symptom:] I have a 760 Turbo with independent rear suspension. When I start off from a stop with a heavy load, there is a fluttering in the drivetrain that feels very similar to worn U-joints or CV joints. The U-joints are new and the CV joints feel fine as far as I can tell. [Diagnosis:] Probably slightly worn CV joints. Not worn enough to snap/click/knock yet but enough play between the balls and "grooves" to allow the load based "flutter." In my experience, unless there's an obvious knocking or the CV boot has been ripped awhile, it's tough to determine CV condition without removing, disassembling, cleaning and
inspecting. If the inner and outer CV joints are identical, as a temporary fix, swap the axles end-for-end so that load wears a different part of the joint.


Pinion Seal Leak.  [Query:] 90 740 GL wagon, manual trans. with 197,000 miles. Recently noticed small drip puddle below rear differential, originating near the U joint/drive train. Seems like a pretty heavy weight oil. Is this a pinion seal? What's involved in replacement/repair?
[Response: Abe Crombie] Replacement of this seal will require removal of driveshaft, marking it so as to preserve original relationship as it may have been balanced in-car at assembly. Removal of pinion flange that the drive shaft bolts to, marking it in relation to pinion so as to preserve its position since it may have more throw (run-out) if not put back into position. Removal of it needs to be done with a puller, no hammering allowed. Seal can be removed by any reasonable means that doesn't scratch the opening in diff housing where seal fits. The new seal will need to driven in evenly to be just below flush with front of diff housing unless it is one with a lip that stops it when the lip contacts the diff housing.  Re-install flange as marked and then refit nut (volvo recommends new nut) to a torque of 145 lb-ft. NO IMPACT WRENCH ALLOWED, TORQUE IT!!!  Failure to torque it properly will result in the pinion bearing being overloaded which will kill the bearing and place the pinion/ring gear relation ship in a new, different, and noisy relationship that will result in replacement of a bunch of parts ($$$$$).  Oh, don't forget to fill it up with gear lube when you're done.
[Tool Tip from Dave Farrington]  You need a good little home-grown tool to remove the pinion flange! The job's really pretty easy, but the trick is to get off the u-joint flange to get at the pinion seal. I took a piece of angle iron around 28 inches long when I cut it down. Then I took the rear drive shaft that I had just taken out of the car and marked two holes of the u-joint flange near the edge of one leg of the angle iron. I then bolt this length of iron to the pinion u-joint flange, but I still have a problem. That is I can't get at the center nut holding the pinion flange in place. Easy to fix: just mark some clearance around the socket you plan on using - it presumably fits that nut. Then grind some of the angle iron off.
The tool looks something like this:
 ____
 | |
 | |
 | |
 | o|
 | <
 | o|
 | |
 ----

Bad representation, but hopefully it gets the point across.  I now bolt this tool to the flange attached to the rear end and bracking it against the ground, I have something to work against to loosen that nut. With the nut off, I can pull the pinion flange off and get at the seal to replace it.



Pinion Leak: Vent Plugged. [Tip: Ted Tatham]  My recently acquired 93 945 with 79k had a pinion seal leak. Seal was replaced under warranty. After 1000 miles the leak was back. I removed the fill plug and tried blowing into the axle vent hose by mouth, but air wouldn't flow. I removed the hose and found it packed with mud right where it goes on the nipple on the axle. My guess is the mud was placed there by a small wasp or other insect. Just thought this might help someone.


Re-Filling Rear Axle Lube.  [Tip: Editor]  I make a habit of every so often spraying a little cleaner on the rear axle housing just aft of the pinion seal, as well as the gas tank near the seal, and washing the car in one of those car-bottom automatic washes. This allows me to see a clean axle housing when I inspect it occasionally and know at once when the rear pinion seal is leaking. The seal is a wear item and I have gone through them most frequently when the car is used in short trips on bumpy roads.
Sure enough, I looked underneath last night and found the telltale spread of dark oil being blown both aft
under the axle and sideways onto the gas tank. These are prime indicators of a leaking seal. Since time is real short these days (heavy work and travel schedule) I thought I would just refill the axle to let wife use the car for the week or so it will take me to fix this.
Anyway, someone made off with my oil suction gun and I didn't want to pay mucho $$$ at the only auto
parts store open on Sunday around here, so I bought a quart of axle lube for $2 at Walmart and an
eight-foot piece of 3/8 inch vinyl tubing at a hardware store. Got back home, hooked the oil bottle up to
the tubing, routed the tubing over the rear wheel, went under the car, had wife hold the bottle in the air
while I put the other end into the fill port, and slowly the oil siphoned down the tube into the axle
housing. It took a little while, made longer by wife complaining about the smelly oil, but it didn't leak and
was a quick and easy way to refill the axle. For $1.80 worth of tubing, it is also a throw-away. I will
replace the seal next week and refill the axle with Mobil 1 synthetic.
[Tip: Abe Crombie]  I've pumped hundreds of quarts of diff/gear lube at home by cutting the screw on top to a size that will take a piece of clear vinyl 3/8" tubing with a very snug fit. The you puncture a small hole near top of gear lube jug. With tube on very bottom of container and sparing application of air from your compressor via a blower nozzle, you can make quick work of adding the lube w/o assistance. Don't rush it or you'll rupture the gear oil jug.
[Tip: Peter Cohen]  StaLube sells small pumps ($5) that afix to gear oil bottles; visit NAPA.


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