5 Speed Transmission Gear Question

[canuck750]

I have a spare set of 5 speed gear and shaft clusters and a complete 5 speed for the 750 S3 project. 

Are the gears 'matched sets' from the factory or can I mix and match from two sets to build a 'good' transmission?

Thanks

Jim

[Vasco DG]

If you haven't got a matched set they'll howl!

Pete

[JoeW]

As far as I know, you can mix and match as long as the clusters have the same ratios. There are differences from year to year and model to model.

[canuck750]

One of the gears on the 750 S3 transmission is a little iffy, not terrible but I wouldn't mind if it were better, the spare set came off a 1973 Eldorado. I don't know if the ratios are different from the 1975 S3 (basically a 850 T3 in all mechanical components with the exception of the cylinders, pistons etc.).

Would the verdict be leave it alone and not to bother with a gear swap?

I could live without a howling transmission!

Thanks
Jim

[Muzz]

If you haven't got a matched set they'll howl!

Pete

Agree completely. I was told by experienced mechanics to not even contemplate putting in a new gear to mesh in with an old one. Had to do it once and they were right. ::)

[Rolf Halvorsen]

I agree with JoeW.

Mix the good parts together and you will get a good gearbox.

If I find parts that are too worn - I buy new parts from TLM or anyone else. (Used good parts are also fine.)

Rolf

[canuck750]

Thanks Rolf
Good to have your input

Jim

[Dick]

At this point if your still concerned with mixing gear sets, you could always keep them paired up, as long as the pair your changing out is good. Fifth gear set is easy enough. First/second and third/fourth will require separation of the mainshaft and swapping two gear sets together, assuming they're good. Also, there was an early change to five speed boxes involving the layshaft and gear bearing inner races. The update of the inner race included a thicker flange. Easy to see the difference. Good luck.

[rodekyll]

I did a mix-n-match on a convert gearbox and sure 'nuff got something that sounded like a garage band tuning up for an acapella set.  It was most noticeable on the slow end of a decel-to-stop.  It sounded like heck -- I got some comments from bystanders here and there -- but aside from the noise it worked good.

[Aaron D.]

They won't always howl. I stuck in a gear in a Land Rover transmission (I was too poor etc) and it sounded the same as the others. I wasn't too deaf back then either.