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Discussion Starter #1
what are the common spot for a c4 trans to leak? i know the one i pulled out of the car was leaking. i just dont know where from.

i already plan on...

changing pan gasket
front seal
tightening the modular if its loose

i read somewhere that the actual shift linkage leaks sometimes too. is this fixed by just undoing i think it was 1 big bolt or 2 small bolts (id have to go look at it agaiin) and cleaning the surface and puting it back on? is there a gasket/oring for it?

is there anywhere else that you can think of that might be leaking? oh i also dont think its leaking where the front case and rear case meet
 

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There's 2 seals at the shift linkage , the inner rarely leaks , the small outer o'ring type seal is most common and easily replaced by only removing the kickdown linkage .

Cooler lines ? There are o'rings under the case adaptor fittings also go pretty hard with age
 

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Discussion Starter #4
sorry if this is a stupid question but what is the case adapter fittings? and when you say removing the kick down linkage, do you mean just the bar or the actual "swivel" peice it hooks to on the trans?
 

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Discussion Starter #5
could you tell me where in this picture the oring is that i should replace? and is it a oring thats a normal size? i have a case of orings in hella sizes so im hoping one of those will fit

 

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The o-ring is under the lever held on by the nut in your picture.
 

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Thats the one , the correct seal is a square section o'ring but i have see a few just had normal o'rings worked ok.

Adaptor fitting are where the cooler lines attach, there is a fitting on the case for the line to attach
 

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Discussion Starter #9
oh ok. yea i know what fittings you are talkin about. i thought those were just cooler line fittings. thanks for the help. ill check out all these spots later today
 

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could you tell me where in this picture the oring is that i should replace? and is it a oring thats a normal size? i have a case of orings in hella sizes so im hoping one of those will fit

Is this the transmission you are working on? Doesn't look like a C4.
 

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Discussion Starter #11
no thats just a picture i pulled off the internet.

today though i did pull that nut off and replaced the oring that is behind it. i also pulled off the fittings that the cooling lines go into. the bushings on those look good but im going to replace the lines and probably the fittings with some AN fittings. i also noticed that i have a lot of play in the tail shaft. so it looks like ill have to pull the back housing off and punch out the bearing and also replace the tail shaft seal. then ill also replace the pan gasket. hopefully that will cover all my basis and it wont leak when im ready to re install it
 

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Discussion Starter #12
Is this the transmission you are working on? Doesn't look like a C4.
i see in your sig that you are a transmission builder. question for you. do i HAVE to pull off the tail shaft housing to replace the bearing thats behind the seal? i was going to jam the screw driver into the seal to pull that out and was hoping there is a way to punch that bearing out without taking the housing off. if not then i guess ill take it off. thats just 1 more gasket i would then have to replace
 

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... i also pulled off the fittings that the cooling lines go into. the bushings on those look good but im going to replace the lines and probably the fittings with some AN fittings.
The cooler fittings are a special 1/8" straight thread. AN fittings will not work. Some have gotten away with screwing NPT fittings in, but most weep or leak, and some have cracked the case. ckelley modifies AN fittings to the special thread at a nice price if you want to go that route. PM him.

David
 

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do i HAVE to pull off the tail shaft housing to replace the bearing thats behind the seal?
Unless you have a 1971 or earlier truck C4, there is no bearing behind the seal in the tail housing. All tail housings containing bearings had male threads on the end of the output shaft for a nut to retain the yoke.
 

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Discussion Starter #15
Unless you have a 1971 or earlier truck C4, there is no bearing behind the seal in the tail housing. All tail housings containing bearings had male threads on the end of the output shaft for a nut to retain the yoke.
oh damn. i did not know that. good to know. so i picked up the pan gasket and the rear seal today. tomorrow i will pry the old seal out. and replace it along with the pan gasket
 

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Discussion Starter #16
The cooler fittings are a special 1/8" straight thread. AN fittings will not work. Some have gotten away with screwing NPT fittings in, but most weep or leak, and some have cracked the case. ckelley modifies AN fittings to the special thread at a nice price if you want to go that route. PM him.

David
i think i saw a picture of his and didnt know he had made them i though they were just possible to use. thanks for the info
 

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mmerlinn - I presume he's talking about the tail shaft yoke bushing (part 121 in the pic below). Yes Kenny, take the housing off - like 7 bolts and not a big deal. Use a cape chisel to split the bushing inwards until it falls out, then replace using a bushing driver. Be sure the lube hole is placed at the bottom, as there is only splash lube to it. I did remove one once with a flat-hook slide hammer, but setting the tail housing front on the floor between your feet and the cape chisel straight down is much faster and easier.
:tup:
David

Typical car-style rear bushing for extended housings. The short truck housings use a roller bearing rather than bushing:
 

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i see in your sig that you are a transmission builder. question for you. do i HAVE to pull off the tail shaft housing to replace the bearing thats behind the seal? i was going to jam the screw driver into the seal to pull that out and was hoping there is a way to punch that bearing out without taking the housing off. if not then i guess ill take it off. thats just 1 more gasket i would then have to replace

Remove the housing and replace the bushing.

It isn't that difficult.

I think PSIG put a nice pic in here.
 

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Discussion Starter #19
thanks for the help guys. the local kragen has them in stock so i will pick one up along with a new gasket
 

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You will need though some sort of installer for that bush , you wont just knock it in + out with a hammer . .

Those fittings that Chris Kelly does are modified -6 fittings . I have done the same . Don't screw a taper thread in there , i have seen the tapers split the case .
 
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