Mark:
Let me preface this note by saying I have not worked on an
A-type, so I am merely drawing on my J-Type experience. For that reason,
you may wish to hit delete now, before I feed you a line of well
intended rubbish.
Somewhere I have a PDF A-type manual that I will send you
separately for your perusal. Just gotta remember where I put it. You can
also go here for maintenance instructions from the VTR web site:
http://www.vtr.org/maintain/TransRebuild/
Anyway, it sounds like your clutch may be worn out (or as you
suspected you have low hydraulic pressure due to a clogged filter, a bad
piston, or low fluid).
I would certainly check the fluid level first. I would also
clean out the sump and the filters, then top off with 80WT gear lube.
Some people recommend 30wt non-detergent oil as well. Both work, so pick
one and stick with it.
If that does not do it, then you are looking at dropping the
tranny and opening the OD. My experience is that the clutch sliding
members wear out. They have friction material on them just like brake
pads, and like brake pads the surface is a wear item. Unfortunately, the
clutches are no longer available new. You can have a local brake bonding
shop rebuild it for you (it will be expensive because the clutch member
is aluminum, and so the friction material must be cold bonded, which is
boo-hoo-hoo hard to do. At least that is the local gang bangers told me
when I tried to get mine rebuilt).
You can also get rebuilt clutches from Rimmer, Quantum, etc. My
J-type clutch was $225US rebuilt from Quantum. Before you replace it,
measure the friction material (both sides of the clutch). It should be
about 0.100" thick new, and is completely worn out at 0.040" thick.
Cheers,
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Mark Campbell
Sent: Sunday, July 02, 2006 6:00 PM
To: 6pack@autox.team.net
Subject: A-Type OD Problem
G'day Listers.
First time I've contacted you. Just purchased my first classic car, a
1970 TR6 (Damson) with A Type overdrive, and immediately have a problem.
Perhaps I should have just stood out in the rain and got my wife to beat
me with a large piece of tree.
On the drive home after picking up the car the overdrive was fine to
start but then would not stay engaged. Only started happening after
about 15 minutes at freeway speeds so I presume when the gearbox and OD
unit were fully warm. OD would engage on a VERY steady throttle but as
soon as I squeezed the pedal it would drop out. Sometimes would only
engage for a fraction of a second and then out again.
I've checked the workshop manual (always a bit of a worry when you buy a
car and the DPO hands you the manual as you drive away) and it suggests
the problem could be accumulator pistons worn or sticking OR oil level.
I hope it's the oil level but I wonder if anyone out there has any words
of wisdom to pass on. The car did mark its territory as soon as I got
home and I had noticed a "weeping" oil leak from the OD rear oil seal
when doing my under car inspection prior to purchase but it certainly
didn't look bad.
I contacted Penrite Oils and they recommend using their 30 weight gear
oil. Any suggestions?
Anyway, you guys seem to be the "experts" so I'm entirely at your mercy.
Please be gentle with a newbie. Happy Independence Day weekend from
Australia.
Regards,
Mark Campbell
70 TR6 Damson
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