Ford C6 transmission leaking

[crazyhorse]

My 72 Ranger XLT with 429 and C6 transmission is leaking automatic transmission fluid where the transmission bolts to the engine block.

The transmission works perfect except for the leaking.
The fluid looks like new.

I have thought about putting in a "mild street" shift kit.
Is it worth my time ?

I plan to install the front and rear seal, filter & pan gaskets.
Where should I purchase them?

I would appreciate any and all advice you have .
What are the things I need to do or be aware of?

Thank you in advance.

[Donnie]

Transgo & Superior both make nice shift kits...they modulate the shifts (that is, the harder that you throttle it the more firm the shifts become)
Not all kits do this.......some just block the accumulator's & ALL shifts are firm...I would go with Transgo. Shop on line for this.
As far as changing the filter, it is not really a filter, just a screen, wash it & blow it dry....Stop by any trans shop & ask if you can buy a pan gasket only...Duraprene is the best gasket material, it will not crush like cork/rubber...Should be tan in color. Any good trans shop should sell you one as they buy in bulk............flatten the pan area where the bolts have it pulled out of shape...Sit the pan on a flat floor & go around it with a small hammer.
Be aware of: there is 1 long bolt in the filter bolts, watch where it comes from....install in the same hole..Don't muscle in the filter bolts.
If you have average strength, use a nut runner on the 5/16 bolts....one hand tight
If you are installing the seals w/o a correct seal driver....put some Vaseline in the area where the garter spring is to keep it from popping out from the hammer shock.
Check down in the lower corner inside the bell housing.... there is a welch plug in that area that can sometimes leak..clean with brake clean & silicone it shut..there is no pressure there...or screw in a pipe plug if you feel like it.
Also when you have the seal out..look in at the bushing...also check the converter where the seal & bushing ride..should be smooth
You can stand the converter on edge, wrap a piece of 400 paper around the hub, hold it with your hand & roll the converter back & forth, this will polish the hub....Try for a National black front seal....Don't use a grey seal here......HTH..Donnie

[crazyhorse]

Mr Donnie, thank you sir for taking your time to give me that information.
I appreciate you doing that .

I will try to do exactly as you said.
Thank again.
You sir are one of the people that make

[crazyhorse]

Well I put in new seals , front & rear, new filter & gasket, new pan gasket, new type f fluid.
Put transmission back in and it STILL LEAKS just like before.
It is coming from the front of the transmission , where it comes in contact with the block.
This is 1969 Mercury C6 transmission & 1969 Mercury 429 motor both came together from factory.
The transmission is very clean and works perfect, it just started leaking several years ago
and has gotten worse.

What should I do next?
I know I will be removing the transmission again.
Thanks in advance.

[Donnie]

If you did everything right, I'm at a loss as to where your leak is. VERY seldom does the pump to case gasket leak, unless the bolts are loose.
I didn't address those as I thought that you would just tweak them . The bushing was good, the converter hub nice & smooth as glass? Sometime, but rarely the converter will crack at the stud mount on HIGH powered engines.. Hard to find on the bench.
Before you pull it again, hope that it is 2WD, I would add a bottle of leak detection dye from your supplier & just run it enough to create the leak, you don't want fluid with the dye in it to be all over the place, you want to see where it is coming from..
Ask around any mechanics that you know if they have a black light detection system.....pull your trans & see if they will light it up for you.
These mystery leaks are a PITA to locate.......I used a Spectronics system when I had my shop.....but there are less expensive lights on the market now.......Any black light will actually work.......Sorry for your bad luck.......donnie

[crazyhorse]

Mr Donnie, thanks for your reply.
Inside the bell housing , where the trans bolts to the block is where the fluid in leaking.
The front seal looked like new( the rubber part). the pan gasket was rubber and looked like new.
I put in the new screen filter, (old one looked like new)
Torque converter shaft is as smooth as silk ( no burrs, ridges.)
I can still see some factory letters on the torque converter.
I am pretty sure the transmission , torque converter and 429 motor has not been worked on.
I am second owner .
Trans in very clean inside pan and very clean overall except where the leaking fluid has blown back from front of trans.
Is there a pump seal in front of trans?
If so, is it complicated to replace?
If I remove the front shaft area, will every thing fall out or is that best left to experts?

Now I'm thinking of having it completely rebuilt, even though it works perfect.
It just leaks.
It will leak when it is sitting too.
In a week it will leak about 1/2 to 1 quart of type F fluid.

What is my next move?

Thank you for taking your time to give me this advice .

Please give me your advice.

[Donnie]

Hello, this may be redundant thinking, but are you 100% positive that the fluid is not coming from a faulty dipstick "0" ring or a crack in the dipstick tube right where the "0" ring seals & showing up as a front trans leak, the fluid can migrate around to the front of the bell, especially if that is where you are seeing it drip from...Yes, there is a gasket & a large "0" ring that seals the pump to the case, but there is seldom a leak here when sitting overnite, as there is no pressure involved, pressure only when engine is running, in or our of gear...
Removing the pump can be done, but it takes some careful planning so that you don't separate any of the drums...
You will need an assistant to help you do this....It can get involved if a drum, that is what you will see if you pull the pump, moves foreward...
Look below a few posts at another fella that puled his pump & got in trouble....I told him what to do, but never heard back..
I WOULD STILL ADD A BOTTLE OF LEAK DETECTION FLUID BEFORE PULLING IT AGAIN>>THIS STUFF IS FOR HARD TO FIND LEAKS..Donnie
check that dipstick area real close ! ! !

[crazyhorse]

Mr Donnie, thank you again sir for taking your time to give the good information.
You are much appreciated .

I will do what you said, but it will be a little while before I get to do it.

Can it leak while sitting around the dip stick o ring ?

Maybe it is some thing beside the front pump .

Putting the new front seal in did not have any effect on stopping it from leaking.

I will get this done as soon as I have a little time.

Thank you again.

[Donnie]

If the 429 / C6 came from a Mercury, it may have been necessary to bend the dipstick tube or reform it a bit to get it into your truck....
You bet, it could be leaking at that point...I would check it close....B4 pulling it again...respond whenever you can...good luck...Donnie

[crazyhorse]

Mr Donnie , thank you again sir for your reply.

I have pulled it back out and added fluid and watched it and the dip stick is NOT leaking .

The leak is coming from the "plate gasket" that is bolted back in the transmission bellhousing.
Where the shaft goes into the transmission.

I comes out at the very bottom of the plate gasket that bolts in.
I hope I am making sense.

I have contacted a transmission shop and was quoted $500 for complete rebuild & new torque converter, 12 months or 12,000
mile warranty since the transmission is al ready out.

The transmission is a factory stock from a 1969 Mercury Marquis with a 429 motor that I put motor and trans in my 72 Ranger XLT short bed in 1990 or 1991.
It has 72+ thousand miles, works perfect, (has not given one minute of trouble,)
but now I'm thinking this is a good price and it should last for many more years with a new rebuild.

What do you think .
Please let me know tonight if possible because I need to make a decision by 11 am tomorrow, (Thursday October 3).

I would like to have a six speed transmission in my truck, either manual or auto, any thoughts/advice/information on this would be appreciated .

Thanks again. Sorry, didn't mean to be so long.

[Donnie]

Hi, although you probably don't need a complete rebuild, $500 is pretty reasonable if you are getting a rebuild & not a repair. Plus a converter.
It is pretty uncommon for a leak in that area, especially with the engine off.....There is pressure there when it is running.
I would stop by the shop when it is apart just to see "how it is going" if possible...Ask whose converter they are using..
& whose rebuild kit..Tell them that you just like to keep records on that sort of thing... They should NOT be offended when answering you...
& ask for a warranty on your receipt. I could walk you thru the replacement of this gasket/ seal..but it may be a easier for you to have it done
and be on the road......Donnie

[crazyhorse]

Mr Donnie, thank you sir.
I appreciate you taking your time to give me the good information/advice.
Thanks again.

[colnago]

I also think $500 is a very fair price for a reputable shop. I am planning on rebuilding mine, but that's just so I can learn something and have bragging rights. Even so, it will probably cost me $200 - $250 in parts/kit, plus my own labor. And another 50 bucks for tranny fluid. If I could get a rebuild, plus converter, plus the installation for 500 bucks, I think I'd be willing to give up my bragging rights.

On edit, my cross-member goes right underneath my tranny. The only way I can get my tranny out is if I pull my engine, or maybe move my engine all the way to the front. I don't _think_ that I can move the cross-member back far enough to clear the tranny, but I could be wrong here.

Donnie,

Would it be worth anything to keep his current converter, or is it a good idea to have this replaced at the same time? Just wondering, since I'll have to make this choice as well. Nothing wrong with my converter, but as long as I have the tranny out, ...

Joseph

[crazyhorse]

Mr Colnago, he does NOT install the transmission, I will do that.
He will NOT give a warranty with OLD torque converter, must be a new torque converter.

I took my cross member out to drop my transmission.

I hope you have good luck with yours.

Mr Donnie, he told me I was welcome to come watch him take it apart and put it back together,
only problem I will be working and would have to drive about 50 + miles.
It is a rebuild and not a repair.
I just hope and pray he does a good job.

[colnago]

Any pics of the uninstall process? If so, I'd love to see anything you have. I'd also love seeing pics of the re-install process, if you can manage any. I tried removing my cross member to install an exhaust system. I could not remove it, but I think I could slide it back a few inches - but not lots, as I recall. Again, love to see some photos, or read a step-by-step.

Interesting about no warranty with the old torque converter. I'd still be interested in what Donnie has to say about old vs. new torque converters. One of those "if it ain't broke" questions, I guess.

Thanks for the feedback,

Joseph