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Need c4 help asap. Car is on the lift

3K views 40 replies 4 participants last post by  dads67coupe 
#1 ·
Been having shifting issues with my brand new tci streetfighter trans. It was purchased about 5 years ago by my father and he never got the car running.

It has first and reverse, those work fine it seems.

will shift into second, sometimes in drive, sometimes manually shifting it into 2, no third at all. Sometimes when trying to upshift from 2 to 3 via manually moving ratchet shifter, it hits a "neutral like" thing, just revs until it slows down back into 2nd

I have valvebody out right now to check valves, currently googling a diagram of who is where. Is there a way to check band adjustment with valvebody out?

vacuum module seems to work, I put vacuum to it via small handheld vacuum pump/gauge and the valve assy, can be slid rearward gently. When vacuum is released, the valve moves back seemingly freely.

Pulling my hair out at this point..... any pointers
 
#3 ·
looks like you found it!! it's normally that or the governor is stuck.

so "new" tranny but sitting for 5 years? assume you are going to clean everything and change the fluid?
 
#4 ·
If you still have the valve body out do an air pressure test on the transmission. There is a Bad Shoe video on YouTube that is very good. Use regulated air pressure at 30 - 40 psi. If the air pressure test checks out ok the fault is within the valve body.
 
#5 ·
so I got it all back together and took it out for a ride. Still no third. Will only shift to 2nd if shifter is in "2" in drive it only has first. If I start in first I can shift it into second pretty easy, but when I click to drive I get a neutral position..
 
#7 ·
just to make sure did you perform the correct shifter linkage adjustment when you installed it? I recently installed my rebuilt c4 and forgot to do that and it did the same thing....until i adjusted the linkage and set the neutral safety switch correctly.
 
#8 ·
Do you have any issues with reverse? There are 2 clutch packs in the transmission. The rear clutch is engaged in all forward gears. As you can get 1st & 2nd that means the rear (forward) clutch is ok. The front clutch is only engaged in 3rd & reverse gear. If you have no problems with reverse, that means the front clutch is being engaged. In 3rd gear both front & rear clutches are engaged giving the 1:1 ratio thru the transmission. I still think the Problem is in the valve body. If it was in the govenor you would have an erratic or no 1-2 shift.
 
#9 ·
I just pulled governer and it had trash in it. I am thinking the dipstick may have been out for awhile while sitting. I am going to put tailhousing back together and air test the valve body.


1-2 was erratic, sometimes would upshift in "D" sometimes would not. It will shift when "2" is selected, but if clicked forward to drive, no engagement.


Revers is mint. works great, so looks like clutches are good thankfully. Would an out of adjustment band cause this? Maybe I should pull valvebody again and remove filter and cover to look for more "trash" in it. maybe something plugged
 
#11 ·
if you have found "junk" that caused the servo and gov to stick I would def drain the torque converter, radiator cooler, lines and flush everything out and start over with with new filter/fluid.
 
#15 · (Edited)
If you can hear a hiss of air escaping instead of the thud of a clutch being applied, you may have an internal hydraulic leak. When the pump is out look on the rear side. This is the stator or reaction shaft support. There are 4 steel sealing rings on the shaft. The 2 nearest the pump body are for oil supply to the front clutch. They must be in perfect condition. I cant really imagine them being damaged, because you say reverse is good. The only difference between 3rd & reverse as far as the front clutch is concerned is the apply pressure. In reverse it is 2 - 3 times higher than in 3rd. This is controlled by the reverse boost circuit in the valve body. Obviously more torque is required for reverse gear than in 3rd hence the boosted apply pressure.
I didn't mention to check the transmission filter for crap because you said this was a brand new transmission 5 years ago & not ever run. But I had a 66 Falcon earlier in the week that wouldn't upshift. The filter was so clogged that the pump had tried to suck up the mesh in the filter. New filter fitted, problem solved. I dont think the problem is a band adjustment issue. as the front band is only applied in 2nd gear(which is ok) & the rear band is only applied in Manual 1st & reverse (both good)
Please post your findings. Maybe with a couple of photos.
Cheers. Gaz
 
#17 ·
Yes Sir. That can happen with the pump. I always fit the pump & clutches with the transmission vertical. I have the tail shaft housing supported on an old wheel rim so the tail shaft is not loaded. The pump should fall into place with a little wiggling & no force. If your B.i.L. tried to pull the pump into position with the bell housing bolts, he may have done more harm than good. I've got my fingers crossed for you & hope all goes well.
 
#18 ·
OK, DIAGNOSES:
Second clutch in from the pump has a washer/spring, and behind it is an aluminum plate with an o-ring. That plate (not sure what its called) does no come forward when air is applied to corresponding hole for valvebody (the air check hole) I imagine its stuck from sitting. I removed it and lubed it up good with light grease, still sticking. I ordered a new set of internal seals for the whole thing. Will try a new oring and see if it airchecks.

If not I guess I am looking for a new one of those plates (anyone know the exact name?)
 
#20 ·
its back together for now, just so I dont lose anything til the parts come in. The second clutch back from the bellhousing side of trans, in the bottom of the "cup" its a round aluminum plate/disc with an oring around the outside of it. It would be the critter that engages those clutches.

If I feel frisky later on I will snap a pic or see if I can find a diagram online
 
#21 ·
OK. A picture would be really helpful. The second clutch back behind the bell housing is the forward clutch. It is engaged all the time the car is moving forward. This is why I am a bit confused.Because you say 1st & 2nd gear are OK, I naturally thought the forward clutch is not the problem. The clutch nearest the bell housing is the one I was concerned about, as this is the High/reverse clutch & it is only engaged in 3rd (high) gear & reverse.
If you mean the clutch piston seals on the forward clutch there are 2 of them. A large O-ring on the outside diameter & a smaller one on the inside.
 
#23 ·
Yeah, it must be the clutch piston on the forward clutch thats sticking. The clutch closest to the pump was also sticking (no "thunk" when air was applied to the correct hole, but it freed itself up when it was taken apart. I am thinking the o-rings throughout the trans have gone bad from sitting, including the 4 pump seals that engage the two clutches. Kit should be here today and gonna try to get it back together over the weekend

The front pump area seems to leak a bunch of air when checking, but with pump removed and air applied directly to the hole that the pump seals mate to, things seem to move in a more proper manner. I am just gonna go ahead and do a minor rebuild on it and see what happens.
 
#24 ·
Took the trans to a local shop to check out the parts. He said TCI has been using rubber pump seals instead of the factory steel ones. He bet that was the cause of the trans not air checking due to the pressure loss. I got a set of new steel seal rings while I was there. He also said that TCI transmissions with the exception of the full tilt race models are crap and he see's a ton of them come in brand new or low miles with all kinds of quality control issues.

He gave me a few pointers on assembly and things to look out for etc. gonna give it a go tomorrow and report back
 
#25 · (Edited)
Well that seems to concur with what I have been hearing about TCI & quality assurance, not just with Ford transmissions but also with 727s & 904s from Mopar. It seems a great shame that one time reputable companies let customers down on workmanship & quality control. Up until about 3 years ago I had nothing but praise for TCI. They helped me out with a C4 around 15 years ago here in Germany. But now I just hear one horror story after another. Shame.
When you get the transmission back together & before you put the valve body in, you are obviously going to do an air pressure test. Before you apply air, just put a squirt of transmission fluid from a syringe into the necessary ports in the transmission case. It helps seal the steel rings.
 
#27 · (Edited)
Seems to upshift ok 95% of the time. Sometimes a lazy upshift, when cold, and if I wiggle the shifter a little it will upshift, so a linkage/cable adjustment should fix that. But it WILL NOT downshift at a stop. seems to stay in either third or 2nd, not sure. If I click it donw into 1st on the shifter it will drop down fine and as soon as I take off I just put it back in drive and it goes about its upshifting business as usual.


Governer is out and seems to be free, so I am not sure where else to look

Also, anything else to check before I put it back together and test drive?
 
#28 ·
You have to make sure both the primary & secondary govenor valves are absolutely free to move their entire travel. A no downshift situation means govenor pressure is too high. Either one of the govenor valves is hanging up or the downshift valve in the VB is sticking.
 
#31 ·
Got it back together and it downshifted. for now...... thing seems to fight me badly. Is there a way to adjust where is downshifts as far as speed goes. feels like it has to be about 10mph to get back into first..

But I drove it home and stopped twice and it took off in first! so I am atleast getting somewhere with this damn thing
 
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