Imperial Home Page -> Repair -> Rear Axle -> Drive Shafts
Question from Chris (1960):
Does anyone know of a good source to replace/repair the center support bearing assy for the driveshaft on a 60 Crown? Mine isn't bad yet, but I would like to be prepared in case I need to replace it in future.
Lowell Howe (my favorite) and Damper Doctor are two. To be technical, you are probably looking for the mount and the bearing. The bearing is a $10 job from the parts store.
To answer the other question regarding the one-piece replacement driveshafts -the frame has a structural cross-member that the carrier bearing mount mounts to that would interfere with a straight-line from the output shaft of the trans to the rear-end.
Having a center bearing and center bearing support and just putting them in now would make a lot of good sense. They all go when they start to get used as the 40-year old rubber disintegrates under load.
Had ours rebuilt by the Damper Doctor, great job and very timely. He advertises repair of harmonic balancers, but also reworks the driveshaft center supports.
I keep an extra housing on hand, and purchase any that I see available from swap meets if they are reasonable. I currently have one good one as a spare for all of my Imperials (as long as they are the same). The bearing is easy to get, but the rubber in the housing will eventually come apart allowing the drive shaft to bang on the floor under acceleration. I believe that the housing can be refurbished, and that you could most likely purchase a used one from Bob Hoffmeister at Imperial Heaven. I also believe that they are the same for many years.
The bearing itself went bad on my parents '60 when it was two years old. It made a loud squealing noise and was easily repaired. I just had the one in my '63 replaced last summer. The housing had gone bad, and I fortunately found a new one at a swap meet for $70.00 a couple of years ago. I don't know the name of a resource for repairing the old housing, but I bet that there is a reference to it in the website for the club.
Replacing the center bearing assembly is a snap.
Question from Allison (1963):
When I get on gas hard in my car (from a stop) the rear end seems to shudder. Anyone care to speculate on this? It doesn't seem to "clunk" when I shift it into into reverse from park.
There are three things that I can think of as possibilities right off, others will chime in with more I'm sure. The easy one to check is to make sure that the drive shaft center support is in good shape, and that all the u-joints are without free play. Next easiest is to verify that the rear axle mounting hardware is all in good shape, so it cannot "wind up" the springs when you accelerate. The tough one to scope out is the transmission - it is possible that the transmission has begun to slip in low range, and the vibration you are feeling is the friction material alternately grabbing and slipping. This does not mean that there is a rebuild in the near future, but it does mean you should avoid full throttle starts, don't get on it until you feel it shift gears. If this makes the problem go away, I'd just drive it that way, it will go for years like that.
Look for a broken rear axle strut or bushings, worn or broken rear springs causing drive shaft misalignment, worn drive shaft center bearing housing causing misalignment, broken left motor mount, bad rear motor mount.
Check the center carrier bearing housing over the U-Joint. If it's just the bearing, those are readily available, but if you continue to drive on it, you'll risk blowing out the housing, which, because it's vulcanized rubber, and very rare, is both hard to find and expensive. Believe me, I speak from experience! Does the shudder happen between 14 and 18 mph? That's when it was for me.
The bearing insulator is now being reproduced. Mr. Howe in California sells these but they are fairly expensive, $129.95 I bought 2 originals from Mitchell Motor Parts. I was lucky enough to get 1 of them at $ 69.95 before he raised his price.
Re-bonding (re-vulcanizing) - The Damper Doctor, 1055 Parkview Ave. Redding, CA 96001-3314; phone 530-246-2984, fax 530-246-2987 confirmed that they can re-bond motor mounts: "I not only do motor mounts - which by the way have gone to $99.95 each or $170.00/ pair, these things use a lot of rubber - I also do harmonic balancers and drive shaft supports for these cars. http://members.aol.com/damperdoc/
I would suspect the drive shaft center support bushing. If it does it upon application of serious load-like going up a steep hill- that would tend to confirm it for me. I doubt it is either the transmission or the rear end. Check your motor mounts too.
Question from Bill (1964):
Our '64 has an 8.75" sure grip differential. I have the car on jack stands and the drive shaft removed. When I rotate the rear wheels I get almost instant movement of the pinion flange, but when I rotate the pinion flange there is much more "slack" before the wheels begin to turn. It seems to me that the amount of "slack" should be the same regardless of which "end" I am rotating. Is this behavior normal for the sure grip rear-end, or do we have a problem?
I am trying to find the source of a "clunk" in the driveline, when I shift out of neutral into reverse or a forward gear. The "clunk" is kinda loud, and has a sort of bell ring sound to it. The front U-joint is a bit lose, but side-to-side not rotational, as though the ends of the "cross" were worn. I will replace it anyway. Also sent the center support bearing insulator to the Damper Doctor for rebuild. The rubber was intact, but sagging due the car sitting idle for 12 years. Any advice?
I just had my differential and rear axle bearings replaced in my 67 coupe - non sure grip- the only problem was a bad pinion bearing , had I known this I would not have had the rear bearings replaced. My car also sat for a very long time (20 + years) the spline that inserts into the drive shaft going into the differential seemed to have slack or play in it, in both the bad differential and the one with which it was replaced. If you have a bad part in your differential do not panic and buy another - these things can be overhauled and re-installed. I held onto my old one and will have the pinion bearing replaced which will make it good as new.
That bell ring clunk is a classic symptom of a bad u-joint, check all of them and replace any with detectable play. As for the latency of the wheels turning when the pinion is turned as opposed to the pinion turning immediately when the wheels are turned, you have to bear in mind that there is a gear ratio at work. Most 60's IMPs have roughly a 3 to 1 ratio in the rear axle. That means that for every one turn of the pinion the wheels only turn one-third of a turn! And for every one turn of the wheels, the pinion turns three times. My point here is that it is a lot easier to detect the pinion turning by turning the wheels than the other way around, especially since the wheels and tires are ten times the diameter of the pinion flange! The only real way to detect slack is to have one hand on a tire while your other is on the pinion.
Try replacing the u-joints & see that makes the clunk go away. It doesn't take much play to make a lot noise. Not sure about the rear axle, seems like there shouldn't be much play there either.
Question from Alan (1965):
I wonder if anyone with a parts book can help me with a number. I need to find the # for the rubber bushing for the center support bearing (drive shaft). I'm putting in a new carrier bearing and the old busing that houses it is pretty well worn out.
Reply from Gene:
Propeller Shaft Center Bearing insulator pt. no. is 1945 831 except conv. cpe , 1856 942 for conv. cpe.
Question from Dan (1966):
Is the driveshaft the same for all the '66 models? meaning will a driveshaft from, say, a 4-door fit a convertible? or how about from a coupe to a convertible?
According to the 1966 Master Parts Catalog, there is only 1 driveshaft: part #2533201, 61 5/8" long, 3 1/4" diameter. I should say that this is listed as an assembly including shafts with center joint, rear yoke and flange only. The MPC lists 2 different front yokes: a 9" length and a 7 1/8" length. No qualifier given, and since the 9" is also shared with the B and C bodies this may be a misprint.
NOTE: the 1965 MPC shows exactly the same number for the shaft assembly (but you'd have to change the front yoke) to fit a 66.
I have used the rear half of a '66 coupe drive shaft in a '65 convertible. Slip in - bolt on - no problem. Coupe + convertible do not share the same carrier bearing or insulator.
I believe the driveshaft is the same, but the convertible uses a different center hanger.
Question from Wayne (1966):
The driveshaft support bearing for my '66 LeBaron has died. The two sources I can find for them are Lowell Howell and Damper DR. Has anyone had experience with this? Whom should I go with?
We used the Damper Doctor, he rebuilt ours. He has the bearings, but we supplied one (cheaper) bought from NAPA. Fast service and a good job.
Lowell's hard to beat for personality. Says his are better and has his reasoning. I think it had to do with higher quality materials, but can't remember. He will be pretty easy to deal with if you come up against any "issues".
Question from Brad:
I have a question about the axle end play adjuster. I'm going to have to pull my differential apart to change the pumpkin case gasket and of course I have to pull the axles. The right axle has an adjuster on it to adjust the end play. There is a given measurement of .013 - .023 inch. Unfortunately I don't own a dial indicator. My question is, if I don't disturb the thing when I pull the axle out, "Will I need to readjust the adjuster upon reassembly?" I wouldn't think so but has anyone done this type of job?
Reply from Mark:
No matter how hard you may try, the adjustment will slip. For whatever reason(s), it just does. However, it doesn't seem to be that critical. I, for one, have never set it with a gauge; always done it by feel. Tighten the adjuster, just a little at a time, until there's no play, then back it off, one or two "notches", till there's just the slightest detectable amount of play. Drive it for a week, and check it again.
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