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Re: [oletrucks] TH350 & pinion angle questions

To: "BORDER,RYAN (HP-FtCollins,ex1)" <ryan_border@hp.com>,
Subject: Re: [oletrucks] TH350 & pinion angle questions
From: "joe" <chevy1@jps.net>
Date: Fri, 27 Apr 2001 14:37:10 -0700
I set up all my engine to be level side to side and front to back with a
level and that automatically set the transmission angle.  I then take a
dummy yoke and slide it into the tailshaft to take my angle measurement.  If
it's pointing say 1 degree down then I angle the rearend 1 degree up and
weld in the spring perches.

If you say the transmission is leaking out the rear now with a higher than
normal rear tranny mount then a shorter one will lower the tailshaft and
increase the angle and leakage won't it?  I have bought a few polyurethane
short mounts from Jegs that are shorter than a stock tranny mount and come
with 2 or 3 metal plates to act as shims.  Each plate is at least 1/8"
thick.

You may want to check the yoke for a worn spot that's tearing up the rear
transmission seal or possible you have a worn u-joint causing added flexing
and wear.  Although if you pinion angle is really off, you'll have a
driveline that's sliding in and out of the tailshaft due to spring wrap "on
acceleration and deceleration" and wearing out the seal faster then normal.

Joe
-----Original Message-----
From: BORDER,RYAN (HP-FtCollins,ex1) <ryan_border@hp.com>
To: 'oletrucks@autox.team.net' <oletrucks@autox.team.net>
Date: Friday, April 27, 2001 10:52 AM
Subject: [oletrucks] TH350 & pinion angle questions


>Hi guys-
>  I believe that I want to set my engine/tranny combo into my new chassis,
>such that the bottom of the transmission is level.  The idea is to stop the
>transmission pan leak problems that I have now... which are being caused by
>the somewhat sub-optimal (nose down) position of the motor I can thank my
PO
>for.  It's not the bottom of the pan that I care about, but rather the seal
>surface between the pan and the transmission housing; which if I recall
>correctly, is pretty close to parallel with bottom of the pan anyway.
>  If I am successful at this, I'm guessing that my tailshaft will also be
>horizontal.  I need to take a first stab at my rear-end pinion angle, and I
>think I want it to be zero... that is, parallel with the ground (maybe
>that's called 90 degrees), because that's what I think I want to shoot for
>with the motor.  I don't expect, or want them to line up, but I if I read
>all the articles correctly, getting these two parallel is what I should be
>shooting for.
>
>So: on a TH350, is the tail-shaft parallel with the bottom (pan surface) of
>the housing?  Or is the housing setup such that the tailshaft is pointed
>down somewhat (~3 degrees?) when the pan surface is level?  It seems that
>most (stock) motor installations are a little bit tail-down... and I
>wouldn't be too surprised if GM accounted for this by angling the
>pan-mounting surface just a bit.  Maybe I'm just over-estimating them ;-)
>
>Lastly, I have, and (for now) plan to keep a rear transmission cross-member
>from a ~mid '70s Camaro.  The rubber mount that goes between this
>cross-member and the tranny is part of my problem: it is thick and raises
>the rear of the tranny more than I'd like.  Does anybody know of a thinner
>(than the stock Camaro) rubber mount that would mate the TH350 with this
>cross-member?
>
>Thanks-
>Ryan.
>'55 2nd
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

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