Hold on a second Chuck, this may not be your clutch slipping. It could
well be the overdrive.
A few years ago, I had a similar condition. If I tried to take off
quickly from a stop (stock engine at the time), the engine would rev as
though the clutch was slipping. This was usually soon followed by a
really strong odor of hypoy gear oil. I assumed the front oil seal on
the tranny was blown, allowing hypoy to spill on the clutch. In any
gear, if I applied too much throttle, the "clutch would slip".
However, disassembly showed that the clutch was fine. I couldn't
figure out what was happening, until a few weeks later, at the TRF
summer party. I engaged the overdrive in 4th gear and suddenly heard a
horrible thumping noise coming from the gearbox. Removed the tranny
and pulled the o/d unit off, the o/d was toast! The friction bands in
there were shot (which is why it slipped so badly) and everything else
had progressively fallen apart. Luckily I was at TRF (great place to
break down in a TR6!!), and they had a rebuilt A type O/D in stock.
Bolted it on (that in itself is another story, what a pain in the @$$)
and everything has been fine ever since.
You see, an overdrive equipped gearbox never has a "hard" connection
all the way through from the input shaft to the output shaft. The
friction linings in the o/d unit come into play even when the o/d is
not engaged. Therefore, if these linings are badly worn, the gearbox
can slip in any gear if enough power is introduced. With 170hp on tap,
and in a racing environment, this could be what you are experiencing.
Tim Holbrook
1971 TR6
--- Chuck Arnold <chuck.arnold@oracle.com> wrote:
> Have installed the Toyota TO bearing and the Sachs Disk Cover. Just
> blew the clutch plate [I assume, as the clutch now slips]. Am
> pulling
> the transmission tonight, so will be able to see why the clutch only
> partially engages [car will drive, but step on the gas and it just
> revs].
>
> Am looking for recommendations on a stronger plate than the Borg and
> Beck that has been in for 4000 miles.
>
> Note, car is modified to about 170 HP and, besides road driving, is
> used
> for club lapping days on the race track. The event that lead to the
> demise of the clutch was: I spun out hard, the differential locked
> [knew it was going, already bought a replacement]. Presume, because
> I
> was at 4000 RPM or so, that the locking of the diff caused the disk
> pressure plate to slip.
>
> Also, the OD will not stay engaged in 4th under full throttle [we
> engage
> it at about 4500-5000 RPM so as to not over rev on the long
> straight].
> Since the tranny is coming out, I will rebuilt whatever is needed on
> the
> J type OD [presume this is primarily o-rings in the pump]. Would
> appreciate any advice as to what parts may typically need to be
> replaced.
>
> Thanks Chuck
Make international calls for as low as $.04/minute with Yahoo! Messenger
http://phonecard.yahoo.com/
|