Noise in third gear under load

B

Bruce VA

Junior Member
Need some advice before I start to work.

Car is a stock 1929 Tudor.

No noise in first or second gear. In third, gear shift vibrates & a very noticeable growl under load. Let off the gas, no noise.

A good friend & experienced A Model owner & I figured transmission.

Pulled the transmission down for a rebuild; the cage bearing under the cluster gear fell out in pieces & the shaft was scored. Replaced all bearings, seals, shafts, etc.

Put it all together & got the exact same result.

Message below is from a reply on this board to a poster w/ the same issue.

Your thoughts?


If it is the pinion nuts, what's the fix?


(If I pull the rear out, I’ll replace all the bearings, seals & anything else you tell me that needs fixing. )

Tnx

Bruce



[FONT=&quot] " I think when you pull apart that differential you will find the two thin pinion nuts have come loose. Here is why I say that. When you aceelerate, the pinion is pushing in to the ring gear and you have no noise. When you decelerate the ring gear is pushing the pinion forward causing the noise you hear. We rebuilt a couple differentials that had this problem earlier this year."

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It's possible that the two large pinion gear nuts have loosened. Those sound like the symptoms, which are more noticeable in 3rd gear. 'Been there with a friend's Model A and that was the problem. The repo lock washer with all the ears was too shallow to allow the tabs to be bent over the two nuts to lock them in place. The forward-most nut had worked loose, and had worked its way forward on the threads quite a bit, followed to a lesser degree by the one closer to the pinion gear, allowing the driveshaft and pinion gear to wobble a bit. This is what creates growling noise and vibration. Don't drive until this problem is repaired, or the pinion gear could damage the ring gear teeth = $$$$$$. Unfortunately, the only way to check/repair this condition is to remove the rear end. The torque tube can then be pulled off and the parts inspected. The rest of the rear end can stay together, i.e., no need to take off the rear spring or other parts.
Marshall
 
Just to follow up.....and to say thanks to everyone who replied......it was indeed the pinion nuts. They were loose, which (of course) ate the bearing & race. All new bearings, races, seals, etc, preloads set & it's all back together now. Runs great.

Tnx again.
 
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