915 Transmission pinion bearing

[Wew]

Having a tough time identifying these two bearings. I want to purchase two new ones but the ones carried by our hosts do not look like the two I pulled off of my transmission pinion rod for 1st & 2nd gears.
Below are the pictures of the two bearings. If anyone can confirm the names or part numbers of these bearings it would be much appreciated. Maybe the bearing design has changed and it just looks different now. Having a tough time getting confirmation of that. Please advise.
Thanks,
Gary

[Wew]

Here are the bearings based on the below diagram.

Thanks again,

Gary

[Trackrash]

What year? There were two changes in bearing design over the years.

[Wew]

It is a 1980 Transmission.
Thanks,
Gary

[KTL]

They look like the correct bearings to me, based on the diagram. The cylindrical roller bearing goes on the shaft first, all the way to the end near the pinon gear/head. That cylindrical bearing rides in the race that is contained within the final drive/differential housing. The 4 point ball bearing goes on next and is captured by the bearing retainer plate (called a tensioning plate in the Porsche diagram description) and the studs in the main case. Maybe you think it looks improper because your 4 point bearing is still contained in the retainer plate?

By the way those bearings aren't actually for 1st & 2nd as you've stated. Each of the two transmission shafts carries all gears 1st thru 5th. On the pinion shaft, 3rd and 4th happen to be the fixed/splined gears adjoining those bearings. So those two bearings at the end of the shaft are mostly supporting 3rd & 4th. The rest of the gears on the pinion shaft are "loose" gears and they're primarily supported by the needle bearings running within the ID of those gears.

Conversely the main/output shaft contains the fixed 1st, 2nd and 5th gears along with the loose 3rd & 4th gears.

[Trackrash]

Have you read this? Porsche Wiki

[Wew]

Thanks Fellas, I appreciate the the knowledge. Shows you what a rookie I am. I just jump in and work on stuff and I don't even truly understand how it works. One foot in front of the other.
I am still struggling with the actual part/bearing numbers for the two bearings shown in the drawing with the two red arrows.
Yes I have read the wiki page... my eyes start rolling into the back of my head if I read more than a page a day. so detailed.
I need to replace those two bearings, and I was hoping someone could tell me definitively that those two bearings are called x and these are the part numbers for them.
If you have that information, and believe you me I have looked. I just want to be sure I am ordering the correct bearings.
thanks a bunch,

Gary

[Wew]

I found them. Holy smokes. It's just a different bearing now. At least it looks different. It has a housing around the outer bearings now. As long as it fits.
Thanks for the support.

[Peter Zimmermann]

Originally Posted by Wew

I found them. Holy smokes. It's just a different bearing now. At least it looks different. It has a housing around the outer bearings now. As long as it fits.
Thanks for the support.

LOL! Porsche reserves the right to supersede a part/part number at any time!

The numbers used to be:

P/S bearing w/flange = 999 052 043 00
P/S bearing - roller = 999 110 071 00

Sorry it took so long to get back to you. Call your local Porsche dealer and have their parts dept provide you with the superseded numbers - good for peace of mind!

[KTL]

Originally Posted by Peter Zimmermann

The numbers used to be:

P/S bearing w/flange = 999 052 043 00
P/S bearing - roller = 999 110 071 00

First part number is still good- no superseding
Second part number has been superseded to 999 110 146 01

Any time you replace bearings, especially in this case where the bearing has changed type, you ought to check the ring & pinion backlash and make sure your shim thickness is proper.

[Wew]

Thanks a bunch gents!