C4 no reverse

J's 67

Founding Member
Nov 27, 2000
561
0
16
Southern Illinois
It takes more than 30 seconds 'til the reverse gets engaged.... When it's cold, forget it.
Does anyone know what's wrong? All forward gears are fine.
Do I need a complete rebuild? If so, is it managable for a guy who's never worked on any trans?
 
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I would check fluid level first. Fluid level is critical with automatics. If that's good, may be a band/servo problem. C4s are not really that hard to rebuild, make sure you have a good manual with good illustrations of the breakdown in parts. Also keep track of where all the little check balls go in the valve body.

I have no hands on with c4s, only th350s and th125s.
 
If the level is ok, I suggest borrowing a pressure tester to help diagnosing problems. The C4 has a test port near the bellhousing just in front of the neutral safety switch (1/8" pipe fitting)

Proper specs for a C4 are (transmission warm and engine idling):

Neutral: 50 to 90 psi
Drive:60 to 90 psi
2 or 1: 90 to 110 psi
Reverse: 150 to 180 psi

If its too low or high in all or any gears then you have to start looking further. For low pressure in reverse only check for a leak in the high/reverse clutch or servo.

This info was emailed to me by another guy here on Stangnet as I'm in the middle of my own C4 grief except my car has no drive when it's cold. I've traced it down to a bad forward clutch actuator...sadly this was after I tore the whole thing apart and replaced the clutches/steels...the actuator piston was the one thing I didn't rebuild :doh:

I bought a rebuild kit and manual from oregon performance transmissions on Ebay.

Here's another site that can provide what you need:

http://www.bulkpart.com/cgi-bin/miv...Screen=CTGY&Store_Code=MDITP&Category_Code=C4

And a forum on Ford transmissions:

http://www.fordmuscle.com/phpBB/viewtopic.php?topic=9911&forum=13&25

Good luck :)
 
Thank you so much for your input.

The fluid level is good, and I serviced my C4 about two month ago (new fluid & new filter).

I'll try to do the pressure test whenever I have time but what kinda pressure tester do I need?

I'd appreciate your help.
 
When you did the service what condition was the fluid/filter in? Was there a coating of a sticky grey/black film and/or was there any chunks or flakes in the pan? I think a little discoloration/film is normal but sludge and or flakes is not.

I noticed a lot of this in mine, the small flakes were pieces off the clutch discs...not a good sign :(

As for the tester, it's basically just a gauge that can handle up to 300 psi pressure. Mine is made by MAC tools and is labelled as a transmission fluid /engine oil pressure gauge. I'm sure any gauge capable of handling fluid at those pressures will be fine. Make sure to get one with at least 7' of hose (also pressure rated). This will let you watch the gauge while your in the car. If it's too short you would have to crawl under the car to read it while someone else is switching it from gear to gear. Too risky for my tates!

Good luck,

Francis
 
Turbo II,

Thank you for the info.
When I serviced my C4, found no chunks/flakes. Just some film. The fluid didn't stink like burned.

The reverse still engages after 30 seconds or more. If the reverse pump is bad, that would affect forward gears as well, right? Since I don't have any problems with forward gears, I can eliminate the possible reverse pump failuer. Am I right?

Mac tools expensive....and I'm not a fan of Mac. I'll talk to Snap-on guy about the tester though.

How difficult to replace reverse clutch or servo? As I said, I've never worked on any trans so I'd like to get some kinda idea before I do anything by myself.

Thank you again,
 
Yeah, a transmission tester is really something I wouldn't buy (I just got mine in a box of junk at an auction). Should be able to find a place to rent or borrow it.

I doubt that you have a problem with the front pump as you don't indicate any problem with the forward gears. My hunch is worn discs in the high/reverse clutch. (exact same systoms with my forward clutch). The question will be if there is anything that is causing them to have worn prematurely. In my case I have a problem with the actuator piston itself as I just fried a brand new set of clutches. I'll be pulling the tranny out again this weekend to do it right this time.

I've never rebuilt a transmission before myself, this one is my first. I really didn't find it all that difficult but it is very important to have a manual or at least a good diagram to follow. I found a manual on Ebay for $15 and it was worth every cent as it stepped through the rebuild process.

Now that I've opened up mine once, I'm not scared to do it again (which I will be :( )
 
J's 67 said:
The C4 has more than 60,000 miles on since the last rebuilt. Do you think it failed prematurely?
How long did it take you to rebuilt one?


60,000 doesn't sound like a lot for a C4 (they're pretty dependable) mine started going bad at 85,000 which I thought was too soon but every tranny is different. I went through three on a Aerostar before it had a 100,000 miles but I've heard I was luck I only went through 3! :D

My rebuild took about 5 hours (which is slow I'm told) but I took my time to wash out every part thouroughly with varsol, let them air dry and then dipped them in fresh fluid as I put each assembly back together. If you decide to do the rebuild make sure you soak your new clutch discs in fresh fluid for at least a couple of hours, if you put them in dry or fresh they won't last long.

I'll be picking up some fresh parts for mine next week, I'll take some picks as I disassemble everything. I can email them to you when/if you do yours if your interested. :)

Francis "Turbo II"
 
5 hours doesn't sound too bad at all. Is it after you drop the tranny?
Yeah, pictures helps. I'm planning to get a manual for C4 as you mentioned, and do it on weekend. However, it's been wasy too busy, and I haven't spent any weenends at my place more than a month. I've been alwasy out of town on weekends for gigs. Well, I still planning to take care of my C4 someday.

I appreciate your help.
 
No problem, I get my help and encouragement here too :)

The 5 hours was with the transmission out, it took me about 4 additional hours for pulling it and re-installing it.

The biggest factor is the space your working in, I did it in a nice heated garage with huge stands that could let me get under reasonably well. This next time around I think I'll rent some space with a hoist to make it go even easier. I did some work one time on one of my cars in the driveway laying in mud and wet snow..slows down the process considerably :(

Things are far too busy here too, sadly I'm still driving the car and doing even more damage (it's my only registered vehicle). Should be picking up the parts this week and working on it during the break. I'll PM you the pics when I'm done.

Merry X-mas!
 
I can use my shop lift & tranny jack so there shouldn't be any problem as far as working space goes. Our shop doesn't do any tranny work, except the tranny service, and I've never worked on any tranny. The shop owner has worked on tranny long time ago, and he's got tons of experience but it's not his speciality. His son did take a part and assembled C4 about 15 years ago. I'm sure i can get some help but I'll get tech manunal before I do anything.

Yeah, I'm driving mine as well. She's the only vehicle I have. Hope you can find a nicee working space this time, and be safe.

I appreciate your help.
Thank you.
 
go get you a Ford Automatic Transmission book from autozone for like 15 bucks. Follow every picture and transmission specs and you will have no problem. Piece of cake. Now would be a good time to put in that shift kit for about 30 bucks.
 
I had the same problem, C4 slow to get into reverse, I just rebuilt mine last winter so I put it up on a lift and Stupid me left the reverse band lock nut loose and it backed out. Maybe you just need a adjustment.