Re: 86 CGT Transmission Oil

[Ken <kkeith@qnet.com>]

John Graham <jgraham1@erols.com> wrote:
> 
> Jeffrey A Blanchard wrote:
> >
> > I recently replaced the transmission oil in my 1986 Coupe GT with
> > Valvoline Dura-Blend (synthetic blend) 80W90 which has a GL5 rating, but
> > is recommended for GL4/GL5 applications (according to their homepage).  My
> > Bently specifies 80W90 oil, GL4.  I don't know much about gear oil
> > ratings, etc. but it seems to me that I picked the right stuff.
> 
> The school of thought is never use a GL5 any thing in aGL4 spec.
> transmission. Any thing thats GL5 is too corrosive.

Yep.  It's supposed to eat away at the brass synchros.  (not Synchros)

> > The car shifts fine when warm, but it now shifts terrible when cold.
> > There is always some grinding between gears unless I shift really slowly.
> > I don't remember this happening before I changed the transmission oil.

Sounds exactly like my current problem.  Well, actually I think shifting 
really slowly doesn't even help that much.

(For those of you who remember my problem, I still can't get that tranny 
plug out.  It's really messed up now.  I hacksawed a piece off my
BigAss(tm) 
allen wrench, but I still couldn't get it off.  Can you picture a
6-sided 
allen (hex) plug, with two of the six "sides" broken off?  My next plan
of 
action is to get some JB Weld and "glue" the allen piece inside the
allen 
plug.  That should hold it in there enough for me to get it out.  I
hope...)

> > Any suggestions?  If it continues, I plan to switch to Redline oil since
> > it is spoken of very highly.  Which type should I use?
> 
> I use Redline MT-90. Thats a 75W-90 GL4 synthetic oil.

That's what's sitting in my garage, waiting to get into my tranny.

Ken