VW521 Required Components

[dennisO]

Hi All,

What are all the components required to use the VW521 tool for measuring backlash on a 72 915 trans? I don't see the information in my '72 Factory manual. The components that I believe that are required are:

VW521/4
VW388

Which sleeve/bushing is required?
VW521 /8, /11, /12, /13, 9145 or ?

Thanks,
Dennis

[JackkTheMackk]

I have 6 or 7 different sleeves for 521. Let me confirm which is correct for 915 this evening.

[dennisO]

Thank you!!

Originally Posted by JackkTheMackk

I have 6 or 7 different sleeves for 521. Let me confirm which is correct for 915 this evening.

[kevingross]

For your '72 915, you'll need the VW521/4 locking sleeve and the 9145 sleeve. The 9145 works with pretty much all differentials that use either a 50x80 or 50x90 differential carrier bearing. The VW 388 measuring lever is also what you want. (Some transmissions with wider ring gears swap the VW 388's arm for a longer version, but not your '72.)

To get accurate, repeatable backlash numbers you must lock the pinion shaft. There is no factory tool available these days to do the job. But you can fashion a simple one with a couple pieces of angle iron, works great. Photo below shows mine, and you'll notice it has a few different holes for the case studs, which are spaced differently for the 915, 930, and other transmissions.



(Photo shows the tool in place with a recent Wevo 356 5-speed project I completed.)

Just a friendly reminder that the pinion shaft has to be assembled to the point you have torqued down its end nut. The tightening moves things a bit, and you want everything where it will ultimately be.

Hope this helps, GL!