Another C4 went

[Mesozoic]

Not sure if you're trying to keep your car as original as possible, but a good option in lieu of the C4 would be a 4R70W. I'm loving mine!

What company did you get it from and how much did it run you if you don't mind me asking?

I am pretty sure this is a fixable problem, I just want to be able to fix it before I think about bringing it to a transmission shop to fix it. I don't want to spend over five hundred for a shop to fix it when I could put that toward a new tranny. (Have looked at the C4 Performance Automatic transmissions like the "Super Street Transmission" which runs about $1700)

As a college student, I really REALLY have no money like that.. the car would sit for years before I could even think about buying a transmission. Or maybe I would take out a loan or something from the bank.

Wish me luck tomorrow! Pulling valve body and I hope to find a stuck 2-3 shift valve. At least that is an easy fix!

Hmmm... I do understand the starving student situation; I was once one of those as well.

The 4R70W is more of a premium upgrade and comes with its own computer controlled pain in the arse, so in lieu of that I would look for a '93 Mustang GT/LX 5.0 with an AOD transmission. Those are supposed to be the toughest AODs Ford ever put in a passenger car and I've had one in a '93 5.0 LX coupe and was never able to kill it, despite putting a B&M shift kit in as well.

You should be able to find a functioning used AOD from a '93 for around $300-500. You could find a reasonable 4R70W from a '99 and newer V6 Mustang for about the same. You could actually run the 4R70W without issue if you weren't abusing it too badly. However, you'll need a Baumann controller to do it right, so the AOD would probably be a better option if you're looking for minimal investment and time to install.

Also, don't forget that if you run one of these overdrive transmissions you'll probably need to change your driveshaft too...

 

[Precision Transmission]

If I may be permitted to offer a few suggestions.

First off, the factory service manual is the best deal for the money you will get in this hobby. Please consider purchasing one.

Secondly, your problem of no upshifting in "D", and of shifting 1-2-1 when manually going through the positions is not uncommon. The causes of this can be a stuck governor valve, blockage or leakage in the governor circuit; stuck throttle valve, defective or misadjusted vacuum modulator; vacuum leak to modulator; stuck pressure regulator valve, stuck or worn pressure boost valve, stuck cut-back valve.

The design of the hydraulic system in the C4 is such that increases in line pressure can delay or prevent upshifts. Nearly every shifting problem in a C4 requires performing a control pressure check in order to properly diagnose. Only once you verify that the pressures are correct and respond properly to manual valve position, vacuum pressure, and output shaft speed, can you go on.

 

[Elizabeth73]

Percision Transmission,

Thank you for your suggestions! It is good to hear that this 1-2-1 shifting is a common problem and that it seems to be fixable. I see a lot of the possible reasons are stuck valves. Valve body is coming off today. I did not completely disassemble it when I rebuilt the trans, I only replaced the check balls and puck. Maybe the valves got sticky in the two weeks that it was empty of oil sitting in a humid garage..

I have a ford manual but it does not offer anything in as in depth as transmission diagnostics. I did find the "1973 Ford Car Shop Manual" this is probably the one I will get.

Thank you everyone. I will update if I get everything back in the car today.

 

[Elizabeth73]

Took the valve body off yesterday. When I took the plate off for the 1-2 and 2-3 shift valve I was expecting them to pop out from the spring pressure. Only the 1-2 valve came out easily. The 2-3 valve was pretty stuck in there so I am hoping that my problem was just a stuck valve in the valve body.

It is raining right now so I am not sure I want to take the car for a quick ride to ease my mind.. If this doesn't work it will be off to the transmission shop to the guy who gave me a free valve that I broke.

Wish me luck, I NEED it!!

 

[imusa76]

hope fully that's all it was!!

 

[72HCODE]

the first replacement trans i got the valve body was so stuck and gummed up that it was beyond repair.

carefully clean everything with brake clean and get everything moving perfectly before reinstall.

also if the valve body is gummed up then good chance the governor is the same. the Governor and the most important valve in the transmission so you want to make sure that valve is perfectly clean and working. to get to that valve the rear tail has to come off the trans case. that means dropping the drive shaft and trying to get the tail case off. then you have to unbolt the gov from the plate and try to get it off. the torque specs are CRITICAL on the governor and are in Inch not foot pounds. you will need a inch pound torque wrench for reinstall. 80-120 inch pounds for the governor to plate bolts, double check your manual for these specs also.

do air checks on the C4 also

 

[Elizabeth73]

Thanks 72HCODE, you have a lot of knowledge on transmissions.

It is funny because I used that exact video to do air checks on mine and everything checked out but I didn't get that noise for the governor.. I hope it is not that, I don't feel up to pulling the tail end off the transmission. However, I do know I bolted the governor pretty tight being unaware of the low torque specs..

 

[72HCODE]

if you didn't get that fart noise then that governor is most likely stuck or sticking which is going to get you no where .

if you over torque the governor to the plate the body warps and then the valves get stuck.

you might be able to get to the tail, since you have the trans open and drained now to clean the valve body, (remember careful torque specs on the valve body bolts also) you can put the pan back on and stick a jack under it. loosen the trans mounts and get the cross member out, and lower the trans slightly to get to the tail bolts. pop the tail and if you tore the gasket replace it, with the drive shaft out of the way, there are the 4 bolts on the governor i think its very similar to the C6, pop the 4 bolts and the governor body should come off and out from the tail splines. look at the governor plate on the tail shaft and see if it has junk on it, you want that base clean also. next take the governor to the bench and you can take it apart and clean it really well, reassemble and install on the plate hand turn the bolts and then to be sure get a inch pound torque wrench and set it for 100 in pounds and torque the bolts across from each other evenly. reassemble the tail, i would pull the valve body and then retest for that fart noise. if everything is torqued right and free the governor should dither during the air test. also the governor installs on the plate 2 ways but you must install it one way.

the rounded side of the governor body goes to the rounded side of the plate. i can take a photo of the c6 version if needed.

the tail might be the easiest thing to pull off because it is just a cover like the trans pan, since the trans is empty all ready you can go for it.

 

[Elizabeth73]

Actually, my trans is full of new fluid and I cleaned and reinstalled the valve body yesterday, it is just too rainy outside to take it for a test drive..

The emergency brake is in the way of the tail coming off, I guess I can figure out how to take it apart so I have enough slack to pull the tail off. I am hoping it was just the valve body.. Ill let you guys know as soon as I can get it on the road.

 

[72HCODE]

the brake cable is really easy, on the drivers side you see the spring coming down on the parking brake pedal cable, use a 1/2" wrench and on the end is a nut, undo the nut and the cable holder comes off you can then drop the cable off the passenger side holder clip and then toss the parking cable cable back out of the way. on the drivers side infront of the rear axle the parking brake is attached to a block with bulbs you can pop the cables out from there also or just leave it, the long cable from the passenger side is the parking brake that runs from the backing plate all the way around through the holder on the passenger side through the parking pedal assembly and around to the drivers side, the drivers side cable is short and the both meet in that junction block. should take you about 5 minutes to pull that cable you can even reach it with the car sitting on the ground if needed. ford made it easy to adjust.

worse case you will be dropping the pan again the tail will have fluid in it.

 

[Elizabeth73]

UPDATE!!!

 




Took the car for a ride after freeing up the 2-3 shift valve. IT WORKS GREAT!

The only thing that is not perfect is that the car revs a little before the shift, so I need to go back and adjust the modulator a little bit, but for right now I can go for a cruise and enjoy my car!

I want to thank everyone for suggestions. I don't think you guys realized it but you all saved me a lot of money. I was getting a bit frustrated at one point and was ready to just bring it to a tranny shop.

Thank you so much!!

 

[72HCODE]

Awesome glad it worked out

 

[midlife]

UPDATE!!!

 




Took the car for a ride after freeing up the 2-3 shift valve. IT WORKS GREAT!

The only thing that is not perfect is that the car revs a little before the shift, so I need to go back and adjust the modulator a little bit, but for right now I can go for a cruise and enjoy my car!

I want to thank everyone for suggestions. I don't think you guys realized it but you all saved me a lot of money. I was getting a bit frustrated at one point and was ready to just bring it to a tranny shop.

Thank you so much!!

All right! Elizabeth is our new tranny expert. She'll soon be accepting orders for repairs. Congrats!