[DeTomaso] ZF m1 gear box

[jderyke at aol.com]

In a message dated 1/10/10 11:07:57 AM, detomasoregistry at gmail.com writes:

> One must wonder why the case was cast differently where it slops up to 
> the bell housing.
> That is not an area prone to cracking or failure.
> 
The GT-40 cast-aluminum side covers I run on our street Pantera (in place 
of the later iron ones) were dropped by ZF when they began producing ZFs for 
DeTomaso. According to RBT and others, in LeMans-length events with 
high-power engines, the aluminum covers expanded enough with heat that the 
differential bearing preloads went away, and that led to premature diff-bearing 
failure. My speculation is, bolted behind a high-torque turbocharged M-1 engine, 
the ZF company may have had hints of the same thing happening on long runs 
even with iron side covers, and further reinforced the diff case. Remember, 
there was a short-lived Euro spec-racing series for the M-1 in the early '80s 
when the M-1 ZFs were being built, and who knows what tweeks came out of 
that. 
'Course, on the street, that much heating never happens, so the 
unreinforced case and alloy side covers work fine on our 300-horse Pantera. My best 
guess- J Deryke