John:
Sounds like your pump is not putting out enough pressure.
Probably worn pump seals. Many of the Volvo ODs out there have a lot of
miles on them. Seals wear out, as do clutches. Before you panic, make
sure your oil level is correct on the tranny, and top it off if
necessary. You may get lucky and it is something simple like this.
The fact that the problem worsens as the car warms up tells me
that the thinner the oil, the worse the problem. Really sounds like bad
seals. The good news is that the seals are very cheap, and replacing
them is cake (once you get the tranny out of the car).
If you do in fact need to replace the seals, check the cone
clutch thickness (friction material). It should be between 0.100" (new)
to 0.040" (worn out). Might as well inspect/replace the cone clutch
while you are in there if it is heavily worn. John Esposito at Quantum
is the only person I know that is currently rebuilding the clutches. He
is a bit on the expensive side, but he is super to deal with and stands
by his work - so he is worth the price.
If it makes you feel any better, I had to yank my Volvo OD out
after installing it as the clutch was completely worn out despite it
being "rebuilt". In my case the rebuild consisted of new seals and
gaskets, but the clutch was not serviced, and it would slip in reverse
when hot. The OD is not engaged in reverse, but the cone clutch is still
transmitting torque, and in reverse the roller clutch is not engaged. So
if your clutch is marginal, it will show up first in reverse when the
tranny gets hot.
A new clutch made my OD work flawlessly, and I have been
enjoying it ever since.
Cheers,
Vance
-----Original Message-----
From: owner-6pack@Autox.Team.Net [mailto:owner-6pack@Autox.Team.Net] On
Behalf Of John North
Sent: July 29, 2007 11:26 AM
To: Triumph 6 Pack
Subject: [6pack] Overdrive engagement
My j-type overdrive won't seem to engage at lower RPMs... When the
motor
is cold and I flip the switch at 2700rpms the OD engages. Once the
engine
is hot, I can't get OD before 3300 rpms. I flip the swtich but the OD
clutch slips (I guess - I can feel something going on but rpms don't
drop)
until I flip the switch back again and continue sans OD. Basically
means
that once the engine is hot I can't get OD except on the highway
This is a Volvo conversion... I have 90 weight gear oil in there. I
hear
that various people who know a lot about this recommend 30 weight, but
it
seems like that would make things worse - wouldn't the heavier oil
create
higher pressure and result in earlier engagement?
For those with ODs, what is your experience? Is this normal behavior?
Am
I looking for something that isn't going to happen?
Any help appreciated
|