oh boy, good luck!

My C4 has been dumping trans fluid pretty consistently. Took it to one shop and they claim I have a crack in the casing itself which is allowing it to leak.

Got a second opinion who told me that ALL C4's leak if you let them sit for too long without at least getting the torque converter to spin and move the fluid around inside. He made is sound like somehow there is more fluid in the trans itself than will fit... so when it sits and all of the trans fluid eventually settles to the bottom it overflows. I'm still looking for how to put a stop to this... if anyone knows please chime in!

 

Im gonna send you a private email.

 

My main culprit was a crack in the torque converter.Pushed the fluid right past the new seals.New converter , no leaks. (after a complete rebuild and a new converter)

 

I rebuilt my own with no experience and it runs great, shifts strong, and is leak free. Kit cost 75 the TQ was another 100. Special tools are torque wrench and feeler gauges... if you can call those "special" haha.

 

C4's are notorious for leaks. After a few heat cycles the seals will dry up and shrink when the trans sits unused for a while. If the trans works well except for the leaks, you could probably get by with an overhaul kit, which replaces all the gaskets, seals, and a few other parts, but not bands or friction discs. I've seen these kits as cheap as $60. The C4 isn't real complicated. Just get a repair book that has visual reference for a complete tear down, and keep everything organized.

 

When I had a C4 rebuilt the shop told me about the same thing. They said it still could leak as they are "notorious" for that. Even after a rebuild I guess. They told me, after driving, many times the Torgue converter will bleed back into the case raising the level and thus leaking out places it's not supposed to.
That's all this Company does so I tend to believe them I guess.
John

 

I got an estimate from a local transmission shop that has a very good reputation, (not one of those AAmco guys) they said the front seal was leaking on mine & it would be $250.00, mostly because they have to drop the dual exhausts and pull the tranny out. My tranny works very well, have had no problems with it in 7 years, but drops tranny fluid in the garage after it sits for awhile.

 

For all of you experienced C4 guys out there... is there a temporary fix for this that will work as a "stop-gap" measure?

 

For all of you experienced C4 guys out there... is there a temporary fix for this that will work as a "stop-gap" measure?

All I know is that, in my case I tried the low cost approach first. Had it completely re-sealed.One week later, after leaking, took it back and had it re-sealed again. That lasted a few months, took it to a good shop, they found the problem with the torque converter shaft, bit the bullet, paid the price and now everything is good. :thumbsup:

 

It's pretty common....My experience is that its a great transmisssion and pretty much bulletproof if cared for properly (no neutral drops, driving in 2nd gear all the time, etc.)in working condition, but I haven't seen one yet that does't leak something.. There is also an "Overflow vent" with the C4...so if you overfill it...It will drain to the proper level (i.e. All over your driveway)...So if you fill your C4, Make sure you do it somewhere else other than your home!!

Tony Kovar
1966 Sprint 200 Convertible
MCA#70001

 

The fluid level in the transmission should not even be half an inch past the fluid pan bolts. There is no reason for it to leak out the top vent. If it is leaking from the vent then you have a problem with the torque converter valve that keeps the fluid in the torque converter when the transmission is not working. Another problematic area is the fluid pan gasket. Again, there is no reason for it to leak here if the pan is straight and ALL the bolts are torqued down in the correct sequence and to the proper setting with a calibrated inch-pounds torque wrench. If one bolt is stripped this will throw everything off and it WILL leak.. ask me how I know this! Next is the shaft where the gear selector rod bolts on. This area is harder to get to as you need to drop the fluid pan, drop the valve body, and replace three seals. Once again, you need a good inch-pounds torque wrench to re-install the valve body. Other leaks may develop at the tail shaft and input shaft seals but are less common IMO.

BTW by "good" torque wrench I mean calibrated, it does not need to be an uber-expensive fancy tool. I built my transmission with a new harbor freight tool and it is running true and strong. I don't know if I will trust the wrench in a couple of years, but for the price I paid (20-some dollars) I can just as easily replace the wrench. There is no need to have leaks all over your driveway, replacing all of the non-internal seals (which requires you to drop the transmission) is relatively cheap and fast. The most expensive thing will probably be a new pan if you can't straighten yours out. I pounded mine with a hammer and a block of wood for about 10 minutes and then proceeded to working it with a flat file for another 20 minutes to check for bumps and nicks. Good luck and ask questions.

 

[quote} The most expensive thing will probably be a new pan .[/quote]
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I bought a new C-4 pan at NPD for $20.00. Just so I knew it was straight and smooth.

 

:deadhorse:

The complete rebuild kit costs about $50 and includes frictions, seals, O-rings, steels, gaskets etc etc etc... (bulkpart.com) :clap: how much do you think a pair of gear selector shaft o-rings and the seal needed will cost? :shrug: $3 max at your local transmission parts house?... Let's throw in the pan gasket and it brings us to a whopping $6 total. :loco:

A cheap torque wrench for tightening down the pan bolts will cost about $20 at harbor freight :thumbsup: :thumbsup: :thumbsup: . It is just as good as any for this simple task http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=2696.

Now, a new pan costs around $40 for a stock replacement, which I would recommend he get http://cgi.ebay.com/ebaymotors/1965...QitemZ290183338085QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_500wt_1367. But, I guess he could get a cheap chrome one that will probably leak for $35 or, while we are at it, I suppose he could also sprint for a high end B&M aluminum piece for $160 :swing: . http://shop.advanceautoparts.com/ProductDetail.aspx?MfrCode=BNM&MfrPartNumber=40281.

Is there something wrong with my math? Should I retake elementary math? Or can I safely assume the pan is the most expensive component needed to fix the leaks in donstang's C4?

irate: :ba:

hmm... I like how animated this post came out...