I have an upshift problem with my TH400 on my 89 model, and since I
always wanted to put an adjustable modulator on it anyway, I’m trying
that first before checking the governor.
Question is: what is the recommended procedure for setting to proper
adjustment?
The modulator I obtained is a Standard TM 50. It has a very small
valve with a slot for a very small screwdriver inside the vacuum hose
bib. I assume it is basically trial and error adjustment, like start
in the center of travel and back off to one end of the travel to see
what changes, and then repeat in the other direction?
What exactly is supposed to change with adjustment? Upshift point?
Kickdown point? Both?
George Balthrop, Clifton, VA USA
85 & 89 XJ-S Coupes; 89 XJ40 VDP
In reply to a message from George Balthrop sent Tue 28 Jul 2009:
George, I stopped by my trans.parts shop this pm and asked about
the TM50. It is supposed to be set (pre-adjusted) right out of the
box for usage. The ‘‘best’’ guy told me that you can cause shifts at
higher rpms/speeds by screwing the adjuster screw in (tightening-
clockwise) and create softer shifts at slower speeds by unscrewing
(counter clockwise). Both points evidently change in relationship
to each other. Hope this is of some help to you. Did you see my
question about pre-oiling an old stored V12 machine on the V12
list? Any thoughts would be appreciated, Best, JW–
The original message included these comments:
always wanted to put an adjustable modulator on it anyway, I’m trying
Question is: what is the recommended procedure for setting to proper
The modulator I obtained is a Standard TM 50. It has a very small
what changes, and then repeat in the other direction?
What exactly is supposed to change with adjustment? Upshift point?
Kickdown point? Both?
George Balthrop, Clifton, VA USA
Thanks for the adjustment information. I put the new Adjustable
Modulator in, and still no upshift. I still suspect the governor drive
gear, but with no access port on the transmission tunnel, I was
delaying dropping the mount in hopes the easier-to-change modulator
might be the cause.
I have started old engines that have sat idle for some years on several
occasions by simply (1) changing the oil/filter & coolant; (2) removing
the plugs and squirting some oil into the cylinders; (3) cranking the
starter (~200 RPM) with no plugs installed for several minutes to
circulate the oil (pressure gauge shows something in range of 20 PSIG);
(4) recharge battery; (5) then add another squirt of oil to the
cylinders and re-install plugs; (6) hope it fires and look for a bit of
smoke from the tailpipes related to the oil in the cylinders.
Virtually all other systems of course may have problems from passage of
time, or lack of use, such as all hoses & belts, the brake
cylinders/seals, transmission seals and governor drive gear (rust
builds up on worm gear that drives governor, wearing gear) front & rear
crank seals and water pump seal, A/C compressor seals & o-rings,
corroded radiator tubes, P/S fluid & trans fluid & filter, (ALL
fluids), etc., etc. (it’s the etcs. that kill you
George Balthrop, Clifton, VA USA
85 & 89 XJ-S Coupes; 89 XJ40 VDP-----Original Message-----
From: Dr.Quail jwk1953@hotmail.com
George, I stopped by my trans.parts shop this pm and asked about
the TM50. It is supposed to be set (pre-adjusted) right out of the
box for usage. The ‘‘best’’ guy told me that you can cause shifts at
higher rpms/speeds by screwing the adjuster screw in (tightening-
clockwise) and create softer shifts at slower speeds by unscrewing
(counter clockwise). Both points evidently change in relationship
to each other. Hope this is of some help to you. Did you see my
question about pre-oiling an old stored V12 machine on the V12
list? Any thoughts would be appreciated, Best, JW
// please trim quoted text to context only
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
4
What exactly is supposed to change with adjustment?
Upshift point? Kickdown point? Both?
The vacuum modulator doesn’t affect kickdown at all. It will affect
both upshift and downshift points relative to throttle, though.
Thanks for the adjustment information. I put the new Adjustable Modulator in, and still no upshift. I still suspect the governor drive
gear, but with no access port on the transmission tunnel, I was
delaying dropping the mount in hopes the easier-to-change modulator might be the cause.
In reply to a message from stephen sarmanian sent Tue 28 Jul 2009:
George in the past I have seen the bolts loosen up on the downshift
solenoid causing it to leak presure & not shift out of first.but
make sure the throttle switch is not stuck closed first.
Nick–
88&86 XJ-S 88 VDP[xj40] 73S1 last&least97xk8
scotts valley ca, United States
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