DFI, Batch Fire, and other myths

[Greg Hermann]

>Greg Hermann wrote:
>
>> Did the rear have a crush sleeve for preload, or positive shims?? The
>> latter is a lot harder to do that to, conversions are usually available.
>
>    I never even bothered to pull out the pinion to look.  The was like .75" of
>play at the driveshaft side of the thing, it made me sick.  I figured out why
>it all happened now though.
>
>    The previous owner got the VR TH-400 and swapped it in, but the tranny
>musta been 1" or more longer than the previous tranny.  When I got the car, the
>tranny mount wasn't bolted down and the threads were stripped.  So I put a bolt
>on the other side and bolted the thing down, I didn't even think about it.  I
>figured the last guy just forgot or something.  Soon after my rear end went.
>So I guess that the driveshaft  would buckle enough at the tailshaft and
>u-joints to soften the blow at the pinion.  When I bolted it down, it must have
>just pounded the poor rear into oblivion.  And I thought I was doing myself a
>favor by hooking up the mount, damn.
>
>James Ballenger

Betcha it was a crush sleeve. The too long driveshaft pounded the companion
flange on the pinion into the sleeve hard enough to smush the sleeve beyond
where it was supposed to be, and the rest was history. No doubt the too
long shaft was what got the rear mount bolts too (before you fixed them!

The crush sleeves are cheap for the mfgrs to use in a production
situation--beyond that they are not worth a #@$% !!!! For any performance
application, or even just for a quality rebuild, a conversion to positive
pinion preload shims is HIGHLY recommended for ANY rear axle!!!

Regards, Greg