'69 Thiokol "B" Spryte spitting up trans fluid

HI folks, starting a remedial maintenance project for a friend--1969 Spryte 1201B-55, S/N 1384 in South Lake Tahoe, CA.

I think it has the C4 automatic transmission, anyway he put a new trans cooler on it and it is still "spitting up" ATF on the ground, apparently overheating?!?

any ideas?

What is the proper fluid for this trans? I'm not sure about the ATF he is running now, Dexron or something. I am going to change the fluid and filter and see if that helps things.

(BTW it has the OC-12 rear end and I am going to get the Cat TO-4 oil for that)

also the rubber steering brake hose looks rough, is there anyone who stocks that part??

the guy at NAPA said it could be a clogged trans "vent" making it spit fluid--where might this vent be?

also trying to figure out all the chassis lube points. picked up a grease gun and a bunch of grease.

Have you checked the Vacuum Diaphragm Unit? It is on the outside of the transmission.

Have you checked the Vacuum Diaphragm Unit? It is on the outside of the transmission.

Click to expand...

Ok so I see that vacuum thing, has a little drip on it, what else do I need to do to check it??

It looks like most of the leaking is from the rear seal, but I have a hunch there is too much internal pressure somehow?!?

pics to follow tomorrow night after another day in the rain. . .

If you have a vacuum guage set it at 18 inches with the vacuum hose end plugged. Then connect the hose to the diaphragm unit. If the guage still reads 18 there is no leakage.

If no guage unhook the vacuum line to the diaphragm unit. If it has trans fluid in it chances are the diaphragm unit is bad.

Transmission fluid should be Type F.

Here are some links on your issue, but they are from auto applications. Hope they help. Later.

http://www.fordmuscle.com/forums/all-ford-techboard/418882-c-4-transmission-question.html

http://mmb.maverick.to/showthread.php?p=362762

thanks for the suggestions. grabbing ahold of the trans output shaft it looks like there is excessive play in the output bearing (maybe 1/8 in???). I think that's probably where most of the leaking is coming from. Is it possible to change the bearing in the output assembly without pulling the whole trans??

looking at the service records it looks like it had a different pan and dipstick added later. How many quarts should a C4 take? we will make sure not to overfill it. it's possible that was done in the recent past.

OK, so it looks like C4's in pre-78 Fords use Type F. somewhere I read that sometimes they are rebuilt to use Dexron? what are the odds. . . looks like I need to to a fluid and filter change.

this was a custom install as the cat originally had the manual w/reversing box (since removed) It seems the tranny guy could not fix the reversing box (~2004). so he just installed the automatic.

i don't have a vac gauge handy but I'll check the hose.

pic of the trans:



I'll start another thread for the main pics.

I am not sure about the bearing question. Are you sure it is a C4 and not a C6? (I do not know how to tell the difference) The C6 holds about 12 quarts, but that does not take into account the larger pan or trans cooler addition. The fluid you use in the OC-12 may be influenced by how your hydraulics are run. If they have a separate system / reservoir your choice seems prudent. If they are run from the OC-12 reservoir you may want to reconsider the TO-4 choice. L:ater.

unsure of a lot of things but this is pretty clear for the non-hydraulic OC12:



this "custom" C4 thing is a new animal for me . . . thanks again for your suggestions.

That auto trans is a Ford C-4. The driveshaft bushing is easy to replace. You will have to remove the rear mount and support the trans. Then remove the speedo sender. The tailshaft housing unbolts and if you have the room, will slide off to the rear. There is a gasket that will probably tear. there are no loose parts to be concerned about. The tailshaft itself will be loose in there but thats o.k. When you have the housing on the bench remove the seal and press or drive the bushing out, note the position of the oil hole in the bushing (if it has one) reinstall the new bushing with the same orientation. Then install the seal. Grease the space between the seal lips and it will last much longer. If you use a new tailshaft housing gasket use grease to hold the gasket in place while you install the housing.

Ford Vacuum modulators are notorious for leaking after a short time, I think trans overheating is a partial cause. If in doubt, change it out, but
watch for the little push rod in there it sometimes falls on the ground.

Another leak can be at the speedo cable hole. I see there is something mounted there, make certain it doesn't leak. there is an o-ring that gets brittle, again due to overheating.

The Ford C-4 holds about 12 quarts, don't over fill- your trans's volume may vary.

When climbing steep hills a C-4 tailshaft leak can drain a trans enough so it won't go into gear. (BTDT)

I still use type F fluid in the C-4, as I don't know what year they changed that. The dipstick markings are what I would go by but that has been changed on your machine so ...?...

-Pat

WOW!!! I knew the info was out there. Thank you, Pat, for sharing your expertise. That should be a piece of cake now that i know what to do.

almost forgot, hat tip to Snowcat Ops for the "Cat TO-4" pic above. it really helps to minimize the uncertainty!!

almost forgot, hat tip to Snowcat Ops for the "Cat TO-4" pic above. it really helps to minimize the uncertainty!![/QUOTE]

I like the illustration of the planetary gears!
-Pat

Thanks Snowcat Pat. Hard to get the wrong stuff when you have a picture!