OK, back in this thread I mentioned how I thought I missed the band when reinstalling the servo piston. I pulled the servo piston out and everything looked fine. After checking the band and making sure it was in the correct location, the servo assembly was reinstalled. Not to much surprise, the tranny still didn’t have second or fourth gear.

I finally broke down and pulled the transmission from the car. Upon initial inspection, my BRAND NEW band and 3-4 forward clutches were burnt to a crisp! This was after about 3 miles of driving. ***? Sounds like low line pressure, right?

I called up the (helpless) TCI customer service line and asked what was going on. The first rocket scientist I talked to said: ‘Sounds like your bands are bad… you need to replace them.’ Well… DUH!!! I then told the TCI associate that it was the manual valve body that caused the bands to burn up in the first place. After arguing for a few minutes, I realized I wasn’t going to get any worthwhile advice from this guy and hung up.

The next day, I make another call to TCI in hopes of talking to a somewhat more intelligent representative (shouldn’t be too difficult). The next guy I talked to said that line pressure is definitely the culprit. We walked through the instructions again step by step and verified that I indeed did everything per TCI’s (very vague) instructions. Still scratching our heads, the TCI tech suggested checking the pump assembly. Even though I had just rebuilt the pump with a high flow unit, I decided I had nothing to loose and agreed to check it.

Pump checked out just fine.

Later that same evening, a friend with a good deal of automatic transmission experience came by to take a look at it. His first question was: “Where is the throttle valve for the hydraulic pressure?” I told him that the TCI kit gets rid of the throttle valve. He called B.S. and said that would be impossible and that I would need to at least put the throttle valve back into the valve body even if I wasn’t using the linkage.

We must have re-read the instruction ten more times and never once did it mention reusing the old throttle valve in the new TCI manual valve body. I decided to make another call to NASA. The first call, I asked the TCI tech to confirm that the manual valve body sold in the kit was ready to drop in and that I didn’t need to transfer anything over from my old existing valve body…

“No sir, the TCI supplied manual valve body is ready to drop in and nothing needs to be carried over from you old valve body.”

Fifteen later, I make a second call to TCI. This time I asked a different tech if I needed to transfer the throttle valve from my existing valve body to the new TCI valve body…

“Yes so, the TCI supplied valve body does not come with a throttle valve. You will need to carry over the throttle valve from your old valve body before you can drop in the new TCI manual valve body.”



In closing, has anybody ever successfully gotten a TCI manual valve body to work in a 700R4? It is quite obvious that TCI has NO CLUE about this product of theirs. I would really hate to button everything up, reinstall the transmission and find out that I still missed something based on bad information from TCI.

Thanks in advance.

Go buy a Transmission pressure gauge (0-250 PSI min).
I don't care who you talk to or buy parts from, line pressure in an automatic WILL determine your success. If the gauge has stable, consistent line pressure with a manual valve body, the trans will work....

Hi Bayley, I guess your'e the guy who emailed me! Small world this internet place!

As the previous poster (and my reply, but I think you had left for the day) - check the pressures via the test ports.
You mentioned a torn gasket around the accumulators, yes - this could cause low pressure on the apply servos. Usage a test gauge to be sure.(I have a gauge hooked up to line pressure permanently)

Edit for the benefit of others searching: the 700r4 tci manual valve body doesn't use a TV assembly. I think the pictures on their instructions are potentially misleading. Photo 4 here:
http://www.tciauto.com/instructions/376015_inst.htm
shows it installed, but step 4 tells you to remove it!

Welp, with all new valve body gaskets, drum band, 3/4 forward clutches and 240 - 250 psi of line pressure...

The tranny behaved no different than when I first started all of this. Still no 2nd or 4th gear.

That's all for now. I have a sudden urge to destroy something beautiful right now!

Do you have reverse?

If you don't have 2nd, 4th or reverse, you have a broken sun shell...

Reverse works fine.

This truly a stumper of massive proportions. Nobody seems to know whats up. I'm trying a standard valve body tonight and see if that makes any difference over the TCI manual valve body.

since there is a problem only with 2 & 4th gears. I wonder if the 2-4 servo assembly is set up & installed ocrrectly?


Perhaps the band strut pin hole on the band has pulled through?

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If you can't fix it with a hammer, you have an electrical problem.

i have seen people miss the band anchor pin completly.

That was my original thought in all this. However, the servo is working fine (checked it with an air line) and is indeed lined up on the band.

Now what???

And you have the band anchor pin inserted the other end of the band - right? (Circled red, 7 o'clock below)

Attached Thumbnails

 

Yup. Sure do.

Any more guesses before I take old Yeller' out behind the barn with my shotgun?

So with the pan removed and pressing on the servo cover, you can see or feel that the band is clamping the drum? (wiggling the band)

Whith it all assembled and running, do you see pressure in the test ports when selecting 2 or 4 th?

Yes.



Pressure drops to almost nothing (20 - 30 psi) whenever the gear selecter >= 2nd gear. Reverse, Nuetral, Park and 1st all have 230 - 250 psi. However, as soon as I drop it into second gear, the line pressure drops a couple hundred PSI.

Last night, I reinstalled the original valve body and everything works fine. I feel 99.9% confident that I've reduced the problem to the control circuit(s) in the TCI manual shift valve body.

Elliot,
Did TCI give you a new plate with your valve body, or did you re-use your existing one?

TCI supplies a custom plate, it's red anodized.

The lack of pressure is your problem, on the test port for a particular gear, it should be the same as line pressure (i.e. well over 200psi) when that gear is selected.

You saying that you used your original separator plate?

The kit contents http://www.tciauto.com/instructions/376015_inst.htm states "1 Separator Plate"

...mine didn't come with a new seperator plate.

Also, I have the 376010 which is the valve body without engine braking. I'm going to call TCI right now and see what they have to say.

Thanks Eliot.