Lost all gear oil today, 1991 Testarossa

Check ebay auction number 153294313677 entering this number in search. Look at the bolt hole at the 11 o'clock position.

 

Is there a reason that particular bolt hole is counterbored as it is? I find it hard to believe it's a machining error but it could be.

 

Yours and the one one ebay both seem to have a counter bore machined in that one spot. I’m curious if theres a reason that becomes obvious once installed.

 

same I wanted to write just now. very bad work. but I not mean the piece at ebay, I mean this here in the photo, so where the hole edge is cutted. sorry, don´t know the right word and cannot find in the translator. in german: entgratet ( boned ?? )
also have a look at the other holes, most on this at 3 o´clock
and then see the part where the large O-ring belongs

 

Well that makes it clear. Must have some sort of bracket that mounts on the 512M at that hole. The pictures didn't make it clear that the hole had been counterbored. It just looked weird to someone that only has a Testarossa cover to compare with. Maybe, upgraded cover is a loosely used term for a cover that has one counterbored hole.

If there were NO covers available, this part can be made pretty easily out of a solid chunk of aluminum. But it appears there's an adequate supply of these. Maybe they're a little expensive, but there's a bit of work to make them.

The remaining passenger side shim, I see NO REASON the shim has to follow the original in having the outside diameter follow the contour of the cover. This could be a ring with the outside diameter round and concentric with the ID. At that point, this is as easy to cut out, as the drivers side shims. Very easy to turn and cut in a lathe, and have the ability to easily cut to within a few thousanths of intended thickness. Of course the holes would have to be drilled.

 

Great posts Versamil!

You broke down this process perfectly (post 579). I am also doing this job and sincerely appreciate your write up.

 

Responding to Turbo Joes critique of the part, I would say they machined the chamfer in the mounting holes TOO deep. It's one thing to remove the burrs, it's another to remove too much material off of the surface a nut and washer will bear against. Machining this too deep, means the bearing for the washer will be reduced, or cause the washer almost to fall into the angled hole. Stupid mistakes like this, most people don't catch or think about. By removing material, they caused more problems than if they had omitted that step.

 

Yes, I made my passenger side shims on Bridgeport/ rotary table. Sandwiched various sizes of shim stock. Them machined everything but outside. Then cut outside with snips, not critical. If you look closely at counter bore of side cover, it was CNC ed around and not using counter bore cutter!

 

not press, warm the bearings

 

Just a reminder you dont check preload with the crown gear on unless that was just a glamour shot.

 

You CAN do the bearings in the oven (or on the cook top) approach rather than find someone with a press.

 

Bearing in the freezer(-18°C) and cover in the oven (+250°C) ?

 

in the oven not more than 250°C for about 20 - 30 minutes, but first heat the oven and when reached the temperature put the bearings in.
but before clean the surfaces ( bearing and also diff ) with carb cleaner or equal cleaner.
no need to freeze the diff, the bearing just will fall down.
when both bearings are on the diff use both sides a steel pipe and give some pressure on those pipes with a screw clamp to avoid that the bearings during cooling down get back. this can happen sometimes. own experiences when puting other sleeves into the cylinder blocks of motorcycles.

remove the crown before heating ! ! !

he is talking about the bearing to the diff, not the outside bearing ring into the cover

 

Sorry my english is absolutely awful