Attached is a picture of a modified VW289d tool to allow use for 911, 914 and 915 transmissions. The dial indicator setting block has been modified to provide references at R=63.20 and 66.30. Could accomplish the same results by using some spacer blocks between the mandrel and the block. Also a picture of an unmodified tool for reference. Click to view attachment Click to view attachment

Any drawings or dimensions on how much material had to be removed behind the carrier bearings for clearance?

@oldie914

The spacing should be about 120mm; same as the length of the differential carrier. Then use spacer rings to take out bearing play in the case. Carrier bearings should have a very light fit on the tool. Just enough to keep them from falling off.

@oldie914

Thank you so much.

I'll be tearing down a 901 case over the holiday for another member to have the case. Will take a close look at all the other info out there (factory manual, pelican links, etc.) and look forward to modifiying another one for 914 trans work!

If I were making another one of these tools, I wouldn't modify the 289d setting block but would make or buy a 5mm plate used in the VW 385 tool set. It is held by magnets to the pinion face.
I happen to be working on a 901/13 now that has an R&P with R=63.36. Taking account the 5mm plate thickness, the setting distance is 58.36. If you have a modified 289d with known setting distance of 57.71, then 58.36-57.71=0.65.
Adjust the dial indicator in the mandrel with the setting block to read 1.65; then put the mandrel in the case and read the dial indicator against the pinion face (including 5mm plate) with the goal to have it read 1.00. If it is more than 1.00, that is the gasket thickness needed to move the pinion away from the differential. If it is less than 1.00, bad luck because you have to disassemble things to put more shims by the pinion roller bearing.

I recently had a 901 /911 open differential housing modified to accept a dial indicator in the center. I'll be using it this winter to set the pinion depth in a 915 box. It should work in mag 901/911/914 boxes as well. Another option.

That’s very cool
Can you post a pic
Brant

Yes, very cool.

Any chance you have a drawing with the dimensions of the modifications? I bought a 914 open diff a couple of years ago, with the intent of doing the same thing. Just haven't had a chance to get around to it, and a drawing with dimensions would save a bunch of time reinventing the wheel. Thanks!

I considered using a differential carrier to make a tool but couldn't figure out how to make a calibration block with the necessary accuracy. The VW289 is made to a tolerance of +/- o.oo5mm. I also would like to see what you did.