Transmission slippage

[larry dtimothy]

Derek,
I once bought a used van very cheap because the dealer said it would
require a
new transmission. She'd shift and drive fine for 15-20 minutes then
slippage
would begin and actually get to the point that it seemed to be in
neutral. After sitting a while she was good to go another few minutes. I
got it home and found the screen was 75-80% clogged. Replaced the screen
and fluid, and wah-lah, no more slippage!
I don't yet know how the GMC trans fluid is filtered, but faced with the
problem You describe, I think I'd first service it with new filter(or
screen?) and fluid, and see if that makes a difference.
Tim Timothy
'73 NW FL

> ...shifts fine,without any slippage,but at higher RPM seems to slip or start
> racing....any ideas?Torque converter,pumps,or vacuum lines?..Just hoping its
> nothing major..any help will be appreciated....Thanks
> QUECON
> Derek
> 76 Palm Beach

 

[chuck will]

I am no transmission ecpert by any means but get down on your hands and knees or
back slide beneath the GMC on the drivers side and you will see the linkage to the
transmission. There is a linkage coming down from the engine and one going back
to the transmission where it does the shifting. It is joined with a bolt. Mine
was worn out and the adjustment was out quite a bit. It would not shift into any
gear for a while then all of a sudden it would. The bolt holding the two linkages
together was replaced and it seems to work ok now. It takes two to adjust one in
the drivers seat working the gear shift and one beneath doing the adjusting. Need
to probably block the coach so you don get run over. Mine was on a lift. Chuck

> Derek,
> I once bought a used van very cheap because the dealer said it would
> require a
> new transmission. She'd shift and drive fine for 15-20 minutes then
> slippage
> would begin and actually get to the point that it seemed to be in
> neutral. After sitting a while she was good to go another few minutes. I
> got it home and found the screen was 75-80% clogged. Replaced the screen
> and fluid, and wah-lah, no more slippage!
> I don't yet know how the GMC trans fluid is filtered, but faced with the
> problem You describe, I think I'd first service it with new filter(or
> screen?) and fluid, and see if that makes a difference.
> Tim Timothy
> '73 NW FL
>

> > ...shifts fine,without any slippage,but at higher RPM seems to slip or start
> > racing....any ideas?Torque converter,pumps,or vacuum lines?..Just hoping its
> > nothing major..any help will be appreciated....Thanks
> > QUECON
> > Derek
> > 76 Palm Beach