901 Transmission Reverse Noise
 

This is my 914 transmission (5 speed side shift) but I know there are similarities so posting it here hoping to find a tranny expert.

I can't seem to find the cause of my tranny making noise in reverse. I have replaced the cage and needle bearings on the reverse gear idler. It does not make noise in first or any other gear. I put the tail cone back on without the idler gear to test - no noise. The gear teeth on the idler are a little grinded on the side from nicking reverse when shifting to 2nd a couple times over the years but the gear teeth that engage the 1st/reverse slider look fine to me (see photo below). The 1st/reverse slider gear teeth look good. 1st/reverse slider seems to be sturdy on the guide sleeve. The car shifts fine in all gears.

Here is what it sounds like turning the wheel by hand: http://www.patssle.com/trans.mp3

Any thoughts?

http://forums.pelicanparts.com/uploa...1437875031.jpg

Bump!

That gear looks hammered. Have you filed off the edges of the damaged areas at all?

I may have a reverse gear in my box of bits and will look later in the day. Dr. Evil (Mike Lesniak) is the 901 expert and may also have parts for you.

Straight cut gears are noisy. That wear on the leading edge is fairly normal, being it's not syncronized.

Yeah that's what I thought with the edges being nicked a few times. But the area that the gear teeth mesh with the slider are fine - I wouldn't think the edges have an impact when the gears are together?

Straight cut might be noisy but this sound started after I nicked reverse when going to 2nd gear - the car makes a noise when reversing that wasn't there before.

I've tried to get in contact with Evil but it seems he's been offline for a while.

No syncro on reverse. Most if not all whine in reverse.

When you had the end cover off, did you check the clearance between the reverse gear and the slider teeth when the trans was in neutral?

I don't think that's possible in the 914 901? The reverse gear idler comes out with the tail cone as do the bearings and shaft.

You have to hold the reverse gear and it's spacer against the intermediate housing when you set up your shift forks. Probably didn't do that, eh?