TH700R4 gremlin on my 89. see sig

[simon]

I posted this before, but I think everyone was gone for lunch.
I looked trough all tranny post but did not find what i needed to know.
So i try again, here it goes.

The tranny seems to shift up and down between third and OD going around 80 km.
By shifting manually back to third, the shifting prob stays, so i think it has to be the converter lock up kicking in and out.

also when starting out the tranny wont shift to second, only when i let up on the trottle it will shift up, or when i really step on it it will shift.

when in cruise everything is acting just fine.

The brake light is flickering constantly as soon as i turn the key on , and when driving. that started a few weeks ago , after the TR probs .I don't know if this is related?

The oil is getting brown, so something is amiss. I took the pan and filter off , there are no filings or other debris in the pan or on the magnet.

The tv cable is tight and seems to be working well, I can't find where it goes in the tranny? there is only 60.000 km on the tranny since rebuild.

is it the TPS ? can I bypass it ? the TPS has 3 wires on it.

Could it be a sensor inside the TR , i like to know before I put the pan back under.

Any suggestions are greatly appriciated.

Thanks Simon

[DmaxMaverick]

Start with the brake switch. It is essential for the tranny operation, for the year you have. If the brake switch is failing, it will prevent the TC from locking, and overheat the fluid when you are under load.

Don't mess with the TV cable. Modify it, and you'll burn up the tranny. If it was right, it will be now. The throttle valve itself may have issues, but it doesn't sound like it. The TPS probably has no tranny influence, but I may be wrong about the '89. I think it is only for the EGR.

[HillBilly2]

IF the brake light is flickering you need to find and correct that problem. The TTC will unlock whenever the brakes circuit is energized. btw, the cruise will kick off when the brakes are applied so if its on cruise, the brake circuit is not energized. Just to confirm it is the TCC and not a shift unplug the 4 pin plug from the tramsmisssion and give it a test drive. This will disable the TCC entirely. If it still shuttles it is not the TCC.

What year model 700r4 are we talking about? Later models are computer controled. (edit) OOPS, did not read the header, Sorry.

The TV cable is on the front passenger side, it comes straight down almost above the front corner of the pan. If you have the pan off you can see the linkage.

Did all these problems start at the same time? Have you adjusted the TV cable at all?

I'm not an expert on these, but have been thru similar problems and had to diagnose. Give us some more info and maybe somone with more knowledge will take over from there.

[Robyn]

The TPS is used to help with the control of the TCC.
Th earlier ones were slightly different but still used the TPS.

The shift is controlled by the throttle pressure cable and it goes into the tranny right by the dipstick up on the right front of the pan rail.

If your shifts are goofy its got to do with either the governor or the TV system.

Try taking the governor cover off and inspecting the governor.
left side rear of the tranny. Roynd bulb type steel cover. Use a screw driver and a small hammer to remove it. The cover is like a wheel bearing cover on a 2 wheel drive front wheel and it just taps into the tranny with an oring between it and the tranny.
Slide the governor out and be sure the plastic drive gear is in good shape and not worn out. Also make sure the weights and the valve work freely.

If this is all ok then its in the TV system and then
TRANNY GONNA HAFTA COMAPART

The 700 with everything right should do a 2-3 shift under light throttle at 15 MPH and a 2-3 at about 25 and 3-4 at maybe 30-35 and lockup and 45-50 depending on gearing and a few other factors.
If the TV is working properly a light throttle 1-2 followed by a stomp of the throttle should drop it back to 1st gear.

To set the TV you press the TV cable latch and slide it as far toward the firewall as possible then stomp the throttle clean to the mat and the cable will self adjust to the proper position.

Let us know

Robyn

[simon]

OK, I found the transm conn on tv cable, all checked alright, adjustment seems correct. I left the governor for now, i can look in that one anytime.

Put the pan back under, flushed all oil out by draining trough coolerline with engine running, going trough all gears, while adding oil steady till new oil was at the drain.

I looked in to brake light flashing issue, well for all i care front oil reservoir was empty. Stupid Me. Topped it of , bled the brakes, brake light stays off.
No leaks found, I had serviced the whole brake system 1/2 year ago, I wonder what happened? Could be leaking in the booster maybe.

Took the truck for test drive, Found all shifting correct, exept tcc still goofy.

I disconnected the TPS, test drove again and had to abandon drive for heavy rain coming down. I have twenty miles of gravel before I hit the highway.
Will try again later this week, if everything is Ok I wont post.

Can I leave the TPS disconnected If TCC locks in ???

Thanks for the help Simon