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C4 shifting problems

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
Gentlemen, I am having some issues with my C4 shifting from 2nd into 3rd. Situation: relatively newly rebuilt C4 about two years ago but I probably haven't put a thousand miles on it. New TC, fluid is full, and it has a new aluminum radiator with trans cooler and an additional thermostat controlled, electric fan cooled trans cooler under the driver's seat floor board. It shifts perfect from 1st to 2nd, nice and solid but when going from 2nd to 3rd it hesitates and slips for a few seconds before shifting. This isn't very noticeable on the first few shifts when it is cold but, the warmer it gets the worse the slip. And, if I drive it for more than fifteen minutes it doesn't want to shift into third at all. I either have to let off the gas or shift into neutral and back into drive to get it to shift. Thoughts?

Thanks for the help
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,312
Bad direct clutch seal. The slipping will soon cause the clutch to fail completely and you'll lose 3rd gear and reverse.
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
Awesome, I was hoping you would say don't use a rubber hose all the way from the manifold to the modulator or that I over adjusted the modulator when I was trying to raise the shift points. But I guess those things would also adversely affect the shift from 1st to 2nd which is working fine.

Thanks and Merry Christmas
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
Any reason this would be happening to a newly rebuilt transmission with relatively low miles and no off roading?
 

Viperwolf1

Contributor
electron whisperer
Joined
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Messages
24,312
There are 2 seals inside the direct clutch drum. The outer piston seal is easy to see and replace. The inner hub seal is difficult to see and difficult to replace correctly. It's a square cut seal that can roll easily when putting it in. I suspect that inner seal either wasn't replaced or it was done incorrectly.
 

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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
I'm gonna guess that this part/area is dead in the middle of the transmission? And thus require me to pull it out to fix of course? I should have just figured out how to do it myself the first time, would have been way cheaper and longer lasting. Thanks Phil
 

Viperwolf1

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Actually it sits right behind the pump, but the trans still need to come out.
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
You were right Viperwolf, it finally crapped out on me. I was driving it Friday across town and it sounded like ice in a blender then started slipping and ultimately nothing. No forward or reverse gears. I drained it and pulled the pain to find a lot of fine metalics, I went ahead and pulled the whole thing out yesterday. I'll break it open when I get a chance, but I am guessing I'll need a complete rebuild at a minimum. If it is going to cost me upwards of 700 bucks wouldn't I be just as well off with a new transmission from Summit for a few dollars more?
 

lowbush

Bronco Guru
Joined
Sep 13, 2010
Messages
1,807
Loc.
Summerland Key, FL
You were right Viperwolf, it finally crapped out on me. I was driving it Friday across town and it sounded like ice in a blender then started slipping and ultimately nothing. No forward or reverse gears. I drained it and pulled the pain to find a lot of fine metalics, I went ahead and pulled the whole thing out yesterday. I'll break it open when I get a chance, but I am guessing I'll need a complete rebuild at a minimum. If it is going to cost me upwards of 700 bucks wouldn't I be just as well off with a new transmission from Summit for a few dollars more?

They are very easy to rebuild and you can build a whole lot more than you can buy dollar for dollar. Honestly they are harder to get out of the truck than they are to rebuild. Personally I would/did rebuild it myself.
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
Roger, I spent the better part of my Sunday using equal parts sweat, motorcycle jack, and swear words getting it out. I'm afraid that it will need more that the run of the mill rebuild though. It was rebuilt in 2010, but they did a shoddy job. Either way, it is tango uniform for now. More to follow.
 

lowbush

Bronco Guru
Joined
Sep 13, 2010
Messages
1,807
Loc.
Summerland Key, FL
Roger, I spent the better part of my Sunday using equal parts sweat, motorcycle jack, and swear words getting it out. I'm afraid that it will need more that the run of the mill rebuild though. It was rebuilt in 2010, but they did a shoddy job. Either way, it is tango uniform for now. More to follow.


Get this:

http://www.broaderperformance.com/ford-c4/28-c4-500-horsepower-rebuild-kit.html

this:

http://www.broaderperformance.com/ford-c4/33-c4-number-9-needle-bearing-kit.html

this:

http://www.broaderperformance.com/ford-c4/52-forward-clutch-upgrade-kit-red-frictions.html


and this:

http://www.broaderperformance.com/ford-c4/47-direct-clutch-drum-6-red-frictions.html


and you will have a good middle of the road performance C4.
 

Viperwolf1

Contributor
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Messages
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If it is going to cost me upwards of 700 bucks wouldn't I be just as well off with a new transmission from Summit for a few dollars more?

A Bronco C4 is the best one to start with (rebuild). Summit starts with something else.
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
A Bronco C4 is the best one to start with (rebuild). Summit starts with something else.

TCI via Summit has what appears to be a decent, pan fill C4. They appear to be designed for a car or at least I assume they are by the looks of the tail section. I think you also have to provide the bell housing.

http://www.summitracing.com/parts/tci-511638/overview/

Am I still better off to pay the ~$1,000 +/- to have mine rebuilt? How big of a pain is it to swap out the tail sections? Thanks for the help, I want to make a better decision this time around. The last rebuild cost me about $700 for 4 years worth of mostly easy driving.
 

Viperwolf1

Contributor
electron whisperer
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Aug 23, 2007
Messages
24,312
It would have to be completely disassembled to swap the output shaft. Not worth it. Rebuild what you have.
 

Justafordguy

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Sep 26, 2009
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It shouldn't cost $1000 to rebuild it you remove it and take it to the shop.
 
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Lunar-tic

Lunar-tic

Sr. Member
Joined
Sep 28, 2009
Messages
629
Loc.
Brentsville
I've only checked one place here in Northern Virginia, County Transmissions of Vienna, VA. They quoted me $900 and change for a bench rebuild. Seems high to me but the guy said that would cover any of the busted innards. I'll get a second opinion, but the last place (Cottman and not recommended) charged me in the neighborhood of $700. Labor charges are a bit higher here, but if anyone has any other recommendations for this area, I am all ears.
 

lowbush

Bronco Guru
Joined
Sep 13, 2010
Messages
1,807
Loc.
Summerland Key, FL
I've only checked one place here in Northern Virginia, County Transmissions of Vienna, VA. They quoted me $900 and change for a bench rebuild. Seems high to me but the guy said that would cover any of the busted innards. I'll get a second opinion, but the last place (Cottman and not recommended) charged me in the neighborhood of $700. Labor charges are a bit higher here, but if anyone has any other recommendations for this area, I am all ears.

$900 to a grand sounds about right.
 

Justafordguy

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Bronco Guru
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We sure did em for a lot less back when I was in the business, but that's been a looong time ago.;)
 
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