Vibration 57 customline

Blackpearleb434

Blackpearleb434

Member
Hi look looking for some thoughts... Recently replaced both front and rear uni joints and rear brakes on my 57 customline also pulled the left axel to re seal it, drives really smooth until I get to around 90km's per hour then I get a vibration which seems to be through the whole car it sort of disappears when you go faster but is still there, my question is which one do you think is causing it?... Tail shaft or brakes/ axle. I don't want to do the whole lot again so thought I would call on all you experience.

Cheers
 
Have you checked the tire balance lately? All 4 of them.
Even if the new u-joints are properly seated you can try separating the rear driveshaft joint from the pinion gear yoke, rotate either the driveshaft or pinion yoke 180 degrees and put it back together. Theoretically it shouldn't make any difference, but sometimes it does.
 
Norm don't know if you know Dom Staltari, but he chased a similar vibration in his 56 for quite a while with no joy. He ended up snapping the rear extension housing. This was a 3 speed manual 272 56 model. He originally thought the problem was in the clutch, but the tail shaft sounds like it is the more logical problem. His symptom was exactly as you mention it. If you don't find the problem give me a call and I'll give you his number. His problem developed gradually with nothing being changed. If your car didn't do it before you started to change things, you need to address each change one at a time and then retest it. If you replaced the unis check the manufacturer of them. It is hard to get good bearings here nowadays, especially for older cars.
 
Thanks for the info guys, all seems to point to unis, as rick has said it was difficult to find the rear uni down here in oz, I will try the 180 trick see if that works, hadn't looked much at the tyres as it didn't do I before but I will rule them out as well... Changing the tail shaft round or changing a rear tyre on these cars is about the same work so I'll do the tail shaft first

Thanks all
 
By any chance you didn't accidentally knock one of the counterweights off the driveshaft when you had it out to replace the U-joints, did you? If you lost a counterweight, it will surely be out of balance and cause vibration.
 
I once replaced the pinion yoke on the rear end because I went with a different heavier style of universal joint. I fought the balance problem for two years until I found the problem using a dial indicator. The replacement yoke was tweaked just enough to give me the out of balance. I replaced the pinion yoke again and the balance problem was then solved. The 50 % rotation of U joint was also a good answer.
 
My ranchero had a wicked vibration from 53 to 68 mph, I felt it in the seat not the steering wheel. Now I put brakes and seals on when I went over this car a few years ago, so I kick myself for not noticing this. At some point in its life the car lost an axle bearing, it kind of chewed up the rear end bearing area. Well the owner must have had access to another car or rear end he just swapped axles. The axle was longer than the original, when it bolted down it bottomed out on the round pin in between the axles. We just cut a little off on a lathe and that fixed it. I also replaced the axle bearings, so don't assume everything belongs in there, Mark
 
What did it do before you did the u-joints and bearing? I doubt the axle seal or brakes has anything to do with it.

I would look closely at the u-joints to make sure everything is well seated. You may have to pull the drive shaft for a good look, try the 180* trick as suggested above. I always put a crayon mark on the rear yoke and the shaft so it goes back in the same plane.

Look at the transmission mount while you're under the car. Tire balance could do it as well. You should feel it in the steering wheel if a front tire is out of balance.
 
jack up the rear of the car, put jack stands under the axle tubes, and as was said put a dial indicator on the drive shave and turn rear wheels by hand and check straightness of the drive line, also while rear end is jacked up put blocks in front and rear of front wheels as a safety measure, have a friend wind the transmission up to where the viberation starts, look at drive line to see if it is running true, could be a bent drive line, u joints installed incorrectly, or a worn tail shaft bushing
 
I once had to cut and join a tail shaft and as a temporary measure balanced it myself using two hose clamps. It worked that well I forgot about it. When I finally replaced the tail shaft I didn't notice any difference.
It's easy to do. Put two hose clips on the end of the tail shaft spaced 180 degrees apart. With the car on axle stands, put it in gear and take it up to about 40mph. Hold a piece of chalk close to the end of the tail shaft. If it is out of balance you will get a chalk mark in one place. Simply move the clips together opposite the chalk mark. With a bit of patience you will get it very close if not perfect.
 
Just an update, Jacked the car and ran in gear, the tail shaft has a little run out but nothing to significate (however I will get it balanced) but it looks like the left rear axle is bent ( tried a different wheel to eliminate) not sure how or why , so I'll get this straighten and go from there.

Thanks for you input.
 
Just an update so we all know the answer for next time... The tailshaft had a slight amount of run out as did the rear axle but the main cause was a problem with the new front uni I fitted having play on the yoke axis (manufacturering issue) fitted a another brand of uni and it is super smooth now.
 
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