Trans Bearings, bearing numbers Options

[cwpeden]

Original question is the part numbers for all the bearings. I work in heavy industry and have direct connections to some major bearing suppliers. Might be able save some coin?

I have been trying to get rid of a noisy driveline. After rebuilding the engine and replacing trans with another the the noise is still there.
The trans I put in I took apart and re-sealed. I question is wheather that may have resulted in a 'gear alignment' issue if the trans wasnt shimmed correctly with gaskets? Kit only came with one set of gaskets.

I'll list the symptoms for clairity:
When first started from cold, everything is reletively quiet.
After warming up there is a growl of sorts. Not like a wheel bearing that has gone bad, the noise is inconsistent.
It is affected a little by the clutch engagement and through the shifter a bit.
Same sound traveling or not, in gear or not.
Take off Alt belt and noise remains.


Engine is rebuilt with all new bearings and rings, rods resized and bushed.
Only thing that might be suspect is the oil pump but I havent had any oil pressure issues.



I'm open to any suggections to help track this down.
I may have left out a few things.

Ask questions! I have an open mind.

[brant]

Interested in any bearing details you might figure out

[cwpeden]

I suppose I could take one of my cores apart and get the info from there. But I'm a believer in not doing work thats already been done. (IMG:style_emoticons/default/wink.gif)

[Dave_Darling]

You have to measure the gaskets between the intermediate plate and the main trans case. Because those set the ring and pinion clearance. If you just threw out the old gaskets and used "whatever was in the kit", you have potentially caused a significant problem. Measuring what the gaskets should be is a rather more involved process than just measuring what was originally in there...

--DD

[cwpeden]

I measured the old and new gaskets and there was maybe a couple thou diff.
But if the kit from Pelican only comes with one gasket then....how is there an adjustment to be made?

[Dave_Darling]

I don't remember the tolerances, but a couple thou might be more than you want...

The single gasket in the kit might be for the other side of the intermediate plate; I'm not really sure. I do know that usually more than one paper shim is used between the plate and the main housing, though if the proper clearance is the same as the thickness of one shim, then it's OK to have only one.

The paper shims should be purchased separately, after the old ones are measured, or after determining what their total thickness should be. Not all thicknesses are available from all sources, as I recall.

Time to ping Doc E, I think!

--DD

[OU8AVW]

Pinion depth is critical.....



This tool approximates a diff and uses the same bearings. A dial indicator is held inside that can be seen inside the hole. It bears on the tip of the pinion shaft. This tells you the depth of the shaft so it's within spec. The ammount of gaskets used determine the depth. Mine needed two to hit with spec. Don't assume the original was correct, both transmissions I was using for parts were wrong.

[Mueller]

Silly/stupid question....

Can you not just look at the wear pattern on the gears like a conventional rear diff
and measure breakaway torque?

That is what I did when I rebuilt my Ford 8.8 rear diff. assembly

[Mark Henry]

Silly/stupid question....

Can you not just look at the wear pattern on the gears like a conventional rear diff
and measure breakaway torque?

That is what I did when I rebuilt my Ford 8.8 rear diff. assembly

Dykem blue and valve grinding compound (IMG:style_emoticons/default/smile.gif)
Also use you MARK II eyeballs to look for abnormal wear.


Gasket kits come with two paper shims IIRC.

[oldie914]

914 transmission bearings are metric size; some are available from bearing suppliers and some are Porsche only. The 901 and 911 mag case transmissions use the same bearings as the 914. The 901 aluminum case differential carrier bearings are smaller and inch size.
914 carrier bearings are 32010X
Mainshaft roller bearing is N2205
Pinion roller bearing is 510848
The intermediate plate bearings are specially made for the 901 transmission. The inner race is split to allow a greater contact angle between the balls and the races. This increases the axial load carrying ability of the bearing but reduces the radial strength. The mainshaft intermediate plate bearing was always a weak point for the transmission. They would often fail after less than 100K km back in the days. Failure mode was spalling of the inner race on the thrust side. Now, the races on the thrust side break apart.
You can look up the bearings on the internet; FAG and other suppliers have sites with tech data.

[Dr Evil]

There is a tolerance in setting the pinion. It is not an all or nothing. The R/P that you are using is used, it is missing material over the last 40 yrs. Also, as Mueller mentioned, in almost every other diff the method to set things is just by checking contact pattern. Ours is attached right behind our heads and makes a nice racket if out a little. As for the setting being out and causing the carnage above, it would have to be way out. The usual suspect is metal fatigue from 40 yrs of ass whooping and likely neglect (oil starvation/dirty).

As for the bearings, good luck. I and friends of mine have been trying to find a ready made alternative for 10yrs. The sizes with the flanges are proprietary. I have been connected with a supplier that makes them for much less, but I only use them in builds that I do to save folks money and so I dont need to stock them.

Some simple diagnostic parameters:
- If getting worse with tire speed; Diff bearings/pinion bearing in intermediate plate. Less ofter, roller.
- Worsening with RPM; Input shaft bearing in intermediate plate. Less often, roller.

That is a quick and dirty. Sure, there are finite things, and nothing is always.

Typed on the fly, may have spelling and grammatival errors, going out to the shop to set 2 diffs and pinions (IMG:style_emoticons/default/smile.gif)