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C4 Transmission Issue - Help!

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
My C4 transmission pan was leaking by. I went ahead and replaced the filter while Inhad the pan off. After refilling, during test drive, it started to slip. I lost drive and had to return home in 2nd. Now it will only engage in reverse. I have no forward gears. I realized I had picked up Meron by mistake. I immediately pulled out 2 quarts I had put in, but no change. An6 ideas?
 

Rightpace

Jr. Member
Joined
Aug 26, 2019
Messages
114
So, you put two quarts of mercon fluid in, was the fluid level low at this point? was the engine running when you did this?
 

Rightpace

Jr. Member
Joined
Aug 26, 2019
Messages
114
It's the mixing of fluid types that causes foaming to occur. Transmission clutch material is relying on the fluid for lubrication and heat dispersion. Clutch material life is degraded in minutes witch leads to filter blockage and failure.
 

c0astie31

Jr. Member
Joined
Jun 27, 2015
Messages
157
Could be that you tighten the filter bolt too much,
Flush out the fluid and recheck the bolts on the filter housing
 
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
Update on the issue: Sorry for the delay but, I’ve been working on this thing all day. I managed to get some forward gears back working after a little effort. I jacked up the rear wheels, put it in reverse and let it roll for about ten minutes, then go through the gears a few times, then repeat. Next I was pumping out a quart at a time from the dipstick tube and replacing it with F type. I would then do the same process over again. I finally got it back to about 60% normal. I spoke with a guru at a Transmission shop. I learned that the filter that came out of it was for a Mustang C4/ shallow pan. The one I installed was the right one, but no sump-tube. I removed the pan, installed a tube, I had to fabricate one, and am right back where I started. The transmission works in reverse, but nothing forward again. I checked the fluid after buttoning everything back up. After adding two quarts, it didn’t even register on the dipstick. I added another quart, while idling and normal temp, but nothing worked in forward gears, again. I believe it is due to the draining of the fluid, again. I am thinking the torque converter is air-bound, for lack of a better term. Tomorrow I plan to put it on stands again and run it in reverse, just like today. Can someone please tell me if I am on the right track? Also, is there a better way?
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
48,109
Are you saying that you're still not reading fluid on the dipstick? If so, is there any reason you don't want to keep adding until you do? Do you know exactly how much you've put in so far?

Paul
 

56f100bbw

Contributor
Bronco Guru
Joined
Feb 3, 2008
Messages
2,313
Loc.
Tucson / lakeside AZ
Had my c4 rebuilt 25 k miles ago and my trans guy told me to use Mercon fluid no problems as I remember about 13 qts aluminum trans pan and trans cooler in radiator
 

rydog1130

Sponsor/Vendor
Bronco Guru
Joined
Jun 19, 2014
Messages
4,068
Had my c4 rebuilt 25 k miles ago and my trans guy told me to use Mercon fluid no problems as I remember about 13 qts aluminum trans pan and trans cooler in radiator

These c4's be thirsty... i remember filling mine and being astonished at how much fluid i put in it. i was like man this cant be right, lol BUT it was :eek:
 
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
I have put 3 quarts in it since dropping the pan the second time and adding the tube. I haven’t started it yet today. Last night I added another quart and it registered between the arrows, but wouldn’t move. I only let it run about ten minutes after that because it was so late and I had been working on it all day. I am about to go crank it up to warm up. I will cycle it through the gears and see what happens. I just checked the fluid while cold and it is registered about an inch above the arrows. I am hoping once the fluid gets pushed through the system everything goes back to normal.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
did you get the little pressure valve and spring under the filter tab going into the valve body in. the pressure valve and spring have to be put in only one way or it doesnt work properly. once you remove the the filter these 2 parts just fall out.
 
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
did you get the little pressure valve and spring under the filter tab going into the valve body in. the pressure valve and spring have to be put in only one way or it doesnt work properly. once you remove the the filter these 2 parts just fall out.

I did. I put the valve in first, then the spring on top. The spring is against the filter.
 
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
It is getting better, but far from right. I added another 1/2 qt. After it warmed up longer. I can get it to move, but have to start out in 1st gear and it takes a minute to build pressure.
 

DRBRONCO69

Chicago Mike
Joined
Jul 26, 2006
Messages
2,146
Loc.
Chicago, Illinois
Is fluid level registering on the dipstick while the truck is running in park??? If not, Add fluid until it does....keep checking it. If you are not aware, fluid level needs to be checked while the vehicle is running and warm.
 
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
Is fluid level registering on the dipstick while the truck is running in park??? If not, Add fluid until it does....keep checking it. If you are not aware, fluid level needs to be checked while the vehicle is running and warm.

Vehicle is running and warm. It registers at the full arrow. I just cranked it up and immediately drove off in drive. It drove fine until it warmed up. It started slipping after it was warm. That tells me it is low on fluid. Am I right?
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
48,109
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DeepC73

DeepC73

Jr. Member
Joined
Dec 25, 2020
Messages
224
Dipstick and pan are stock. The pan is the deep pan with sump. Full is at the full arrow. When I say warm, I mean normal operation temp. 150-170 degrees. Thanks for your help.
 

sprdv1

Contributor
REBEL
Joined
Mar 8, 2007
Messages
81,845
Dipstick and pan are stock. The pan is the deep pan with sump. Full is at the full arrow. When I say warm, I mean normal operation temp. 150-170 degrees. Thanks for your help.

well hells bells..

does sound warmed up
 
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