5 Seed Transmission

[jac912]

My 5 speed works great since the engine rebuild as we replaced the gland nut and throw-out bearing. Now that the engine is so quiet I hear gear whine / humm whenever accelerating (silent while decelerating). Think it is the pinion gear needs replacing or adjustment. What's the procedure and cost?
Jim in Ma.

[jac912]

Anybody have this problem?

[914Ghost]

Jim-
eehh....I dunno about the pinion gear wearing faster than other more likely things. Usually chips of the pinion gear will break off rather than wearing, from what I've seen.
The pinion gear is a pretty sturdy chunk of metal, and runs against the ring gear which is ever sturdier. It's in the realm of possibility that the backlash between those gears has changed and would cause a whine- but I think it would be more of a rough growling noise. And i think it would be louder when decelerating due to the lack of power applied holding the gears tight.
Try changing the gear oil? Maybe with Swepco? I know people swear by that stuff. It might do it.
Bob O

[lapuwali]

Probably not the pinion gear, but the pinion BEARING. These gearboxes are now old enough that it's becoming common for the bearing races to be loose in the case from wear. Unfortunately, the only good fix for this now is a new case ($700 or thereabouts), and a new pinion bearing. No one seems to make oversized bearings that fit this application.

In addition to the pinion bearings, the two bearings in the intermediate plate, esp. the upper one, are subject to wear.

[jac912]

Thanks guys. I changed the gear oil with no perceptible change in the noise. The old oil was really bad, black-brown broken down, with a lot of particle matter on the magnet. No idea how many miles on it. I've driven it maybe 25 gas tanks in 3 years . 10k probably. Suppose the problem will take awhile to go critical. Oh... just remembered. On a warm day I put my hand on the case after a hard drive and it was hot but didn't burn. Should it be hot?
Thanks ,
Jim