Last Fall, on a post-Carlisle excursion on 476, I noticed that I was getting a vibration when I got up to around 55 mph. I could continue to accelerate to 70 or so and cruise without vibration, but as soon as I accelerated, it was back.
A local mechanic suspected a broken motor mount and replaced them, but that was not it; nor, the transmission mount. He said the ball and trunnion joint seemed solid to him (the rear universal had been replaced a couple of years back), but I had my suspicions…
So of course, I put the question to (Fury) Jim Rawa:
Is there a way to diagnose a trunnion if I get it up on jacks and get under it - or will only dropping the shaft tell the tale? If it is the joint, what are the prospects a rebuild kit will do it, or do the housings get chewed up too? Or are there other culprits I should be looking at?
Jim sagely advised:
Before you pull the shaft out. Put it up on stands out back, so the suspension is still at ride height. Go hard on the B&T in all directions feeling for play. Also is your ride height low? If your springs are weak you can be winding them slightly under accel and throwing the pinion angle off. But feel for play at the trans end.
To which I replied:
Will do! It’s the universal at the pumpkin that got replaced a coupla years ago - I’ve never touched the B&T, which makes it suspect. Leaf springs are from Espo, maybe 20 years ago - ride height is solid.
This past winter being what it was, and because of the “Honey Do” list, and because my feet hurt, and the sun was in my eyes, and…
OK: No more excuses. Today I finally got Faulkner up on all four corners, and crawled underneath. And doncha know:
While the trunnion housing doesn’t budge a bit, the driveshaft slops around inside of it as I torque it back and forth. I think I’ve found my culprit.
Next step is to drop the driveshaft, and have a look inside. I’m hoping the balls have taken the worst of it, and there’s little wear in the housing, if any.
Who’s the best source for a rebuild kit? And if push comes to shove, and I’ve got a bad trunnion body: My parts book shows 1739 920 as the correct P/N. Does anyone know of a NOS source, if I need one?
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