Wanted: Crownwheel and pinion set 1972 3.0 CS 33121203086

eb88

Well-Known Member
Messages
93
Reaction score
50
Location
London
Wanted: Crownwheel and pinion set 1972 3.0 CS, we believe the oem part number is: 33121203086.
Many thanks in advance.
 

Attachments

  • Screenshot 2023-08-19 at 20-01-22 RealOEM.com - Online BMW Parts Catalog.png
    Screenshot 2023-08-19 at 20-01-22 RealOEM.com - Online BMW Parts Catalog.png
    89.9 KB · Views: 99
It looks like you are seeking a 3:45 set, correct?

You may have better luck seeking an intact differential. Most folks here don't disassemble differentials out of concern for our ability to properly reassemble them.
 
WN list this as good for 2800cs & CSA. I can't be sure it's also good for a 3.0cs.
 
WN list this as good for 2800cs & CSA. I can't be sure it's also good for a 3.0cs.
It's all about your current differential type - early vs. later.
Eearly have 8 bolts crown gear & later have 10 bolts crown gear
W&N have the early one;

You can check it by that bolt on the half shaft mount - early side-loader have that additional bolt, later doesn't.
Main mechanical parts - early vs. later are not interchangeable, even the case itself is slightly different.
 

Attachments

  • $_57 (7).jpg
    $_57 (7).jpg
    478.4 KB · Views: 88
Thank you Chris and Wladek for the indepth information that's very helpful indeed.
 
Just buy new?

WN list this as good for 2800cs & CSA. I can't be sure it's also good for a 3.0cs.
Only because 3.45 was standard on 2800

No, because the WN crown gear has "M10 holes" for earlier 2800 models.
The 3.0 models use M12 crown gear bolts.
 
No, because the WN crown gear has "M10 holes" for earlier 2800 models.
The 3.0 models use M12 crown gear bolts.
This Jon, turned out to be the correct answer as I can confirm and experienced first hand. We used the earlier M10 crown gear in our later differential using larger bolts. Both had eight bolts.
We have now setup a smooth and quiet final drive as road tested, very pleased to have found the parts.

20231006_084045.JPG
20231006_084031.JPG
20230830_083140.JPG
 
This Jon, turned out to be the correct answer as I can confirm and experienced first hand.
We used the earlier M10 crown gear in our later differential using larger bolts. Both had eight bolts.
How did you use "larger bolts" with the M10 crown gear?
Did you re-tap the M10 crown gear for M12 bolts?
 
Back
Top