Trasmission gear wear

apbright

Senior Member
Hello,

I am wondering whether the gear wear as shown in the attached pictures is acceptable. Back story: These gears came out of a car that had a lot of growl noise when driving in first and second gear. The growl had some rattly-noise to it, with about about a 4 to 6Hz modulation to that... a kind of rurr - rurr - rurr sound to it. (I had at first supected bad universal joint, but growl was gone in 3rd gear; I then suspected transmission bearing problems, but upon dissassembly found them fine.) These gears have about 40,000 miles on them, subject to daily hill climbing FWIW.

Note also wear on the cluster gear shaft; the wear is down about 0.007" from the unworn part of the shaft.

Any thoughts on whether these gears are OK to use? Could the problem be only with the shaft - meaning it would be enough to replace that?

-Andrew B.
 

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I would not use those, too many pits/wear. Its a lot of work to change a transmission, I would go with new gears/shafts.
 
I would not use those gears; in my shop they are candidates for replacement. Always replace the cluster shaft and the reverse idler shaft. Most are available with an O-ring modification that will eliminate oil leaks out the back. Also replace the front and rear ball bearings and the bearing spacer on the nose of the input shaft. Look the three roller bearings over, and if they look good re-use them. The junk Chinese roller bearings all the suppliers are selling have a service life of about three hundred miles.

Tom Endy
 
Yep, all needs to be changed with a quality gear set and shafts. Concur with Tom's recommendation to go with shafts that use O rings - good system that minimizes leakage. Also recommend domestic bearings if you can find them. Look close at the U joint while everything is apart - again, only replace with a quality unit. Might also consider one of those adpater units that prevent oil being pushed past the shifter plate on to the clutch - simple bolt-in. Needless to say, do it all and do it right to avoid dropping the trans again in the near future. Good luck.
 
Consider the Mitchell synchromesh transmission. Whether you do that or rebuild the old transmission, use a modern transmission oi. SAE 85W-140 GL5. The modern oils have additives to reduce the wear on the gears and bearings.

The synchromesh transmission is a joy to drive. Simple to down shift. Quick shifts with no double clutching and no grinding. Not synchro in low or reverse.
 
Consider the Mitchell synchromesh transmission. Whether you do that or rebuild the old transmission, use a modern transmission oi. SAE 85W-140 GL5. The modern oils have additives to reduce the wear on the gears and bearings.

The synchromesh transmission is a joy to drive. Simple to down shift. Quick shifts with no double clutching and no grinding. Not synchro in low or reverse.

FYI, Mitchell is about 6 months out according to a friend that ordered one the first week of January 2022. But if I didn't have a rebuilt trans in the wings I would consider ordering one.
 
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