C4 pan options

[pinenuts]

My c4 is leaking around the pan. This tranny was recently rebuilt and has a new gasket. It leaked before it was rebuilt. I have torqued the pan bolts about as much as I dare. The flange on the pan looks a little deformed. Before I take it back to the shop that rebuilt it, I would like to know what my options are. If the problem is the pan, should I get a new or used stock pan, or get an after market aluminum pan? Do I dare put some kind of sealant on the gasket and try and use the old pan? Any ideas?

 

[Nova]

B&M aluminum pan

I was having the same problem with mine after I rebuilt it. I tried everything to seal it and it didn't work. So I bought a B&M aluminum pan from Jeffs Bronco Graveyard. It has cooling fins and holds 2 extra quarts. It also has a spot you can drill and tap for a temp sending unit. Ever since I put it on I have had no leaks. It came with a new filter and gasket. I didn't put anyting on the cork gasket and it sealed great. Hope this helps. ;D

 

[fire bronc]

c4 pan

Look On E-bay Under Tranny Pans,i Bought Mine On E-0bay,alumminum,extra Thick It Is Made To Stenghthen The C4 Case,and Holds 2 Extra Quarts,is Finned For Cooling,has A Drain Plug,and Hole For Dip Stick,i Got Mine For 110.00 With An Anidized Locking Dip Stick.if Not On There Need To Check Back Theres A Guy Who List Them About Every Couple Weeks. Great To Deal With And Fast Shipping.

 

[fire bronc]

C4 Pans

Heres The Pan I Was Talking About In Above Post,i Have One, Very Well Made And Sweet,this Pan Come In Pan Fill And This Guy Also Sells The Nice Dip Sticks To. E-bay Number 7972591262,you Will Not Find A Better Made Pan And The Price Is Great.

 

[daddyg]

You could try and straighten yours. Usually the pan will deform if the pan bolts are over tightened. I straighten mine back out. Also if you use a cork gasket it's more forgiving. I bought a new filter from O'Reily's and it came with a rubber like gasket. I changed my filter and put the new gasket on and it started leaking as soon as I started putting fluid back in. I took the pan off straighten it a little and put it back on with a cork gasket and it sealed alot better.

Also be careful buying a used pan, because they are probably deformed too.

 

[72_EB]

Like the others have said straighten and flatten mounting surface of the pan. Sometimes you'll even be able to look at it when it is mounted up and see where it is leaking and needs to be flattened (I did. Mine needed to come up in back when I last did my filter).
And, yes, the gasket you usually get with the rebuild/filter kits are thin and junk. Don't even try using them. Find a good tranny shop that has thick cork filter laying around. Don't overtorque. My experience is these take about the same amount as valve covers. Don't over do it or they will leak.

 

[Skipdevil]

If you go with an aluminum pan you may have to do some dipstck modifications. I used the TCI C-4 pan with the pan filled adaptor and the dipstick ended up hittting my long tube headders. I ended up shortning and reflaring the pan end of the dipstick tube and it fit great after that.

 

[Sabas]

I picked up that same pan this week. It's a deal for an aluminum pan
Sabas

 

[BwoncoHowie]

You could try and straighten yours. Usually the pan will deform if the pan bolts are over tightened. I straighten mine back out. Also if you use a cork gasket it's more forgiving. I bought a new filter from O'Reily's and it came with a rubber like gasket. I changed my filter and put the new gasket on and it started leaking as soon as I started putting fluid back in. I took the pan off straighten it a little and put it back on with a cork gasket and it sealed alot better.

Also be careful buying a used pan, because they are probably deformed too.

That's it !
Using the wrong gasket material usually causes you to overtighten the bolts and at the same time distorting the gasket surface...

Heres my solution for C-4 pan service and Leaky stock pans;

Pan Gasket:
When removing the pan use a 7/8” flarenut wrench to get the dipstick tube loose first before loosening the pan bolts. Make sure all the pan bolts are the Ford flanged type. The incorrect pan bolt can also cause leaks due to improper or uneven clamp load in the areas surrounding the bolt holes. Choosing the right type of gasket is important. Paper gaskets are not as friendly when used with older vehicles and usually require overtightening of the pan bolts to make them work. I have never seen a rubber pan gasket that didn’t leak on a C-4 no matter how tight it was. As far as I’m concerned, any C-4 pan gasket that comes folded inside a box from a part store is absolutely worthless. Go to a transmission specialty repair shop and buy a cork gasket, and any other supplies if needed. The best way to prevent leaks is to spend some time preparing the gasket surfaces. The trick to making the pan seal is to make sure the pan surface is flat and free of any stray gasket material. I have a wire wheel on my bench grinder for getting these clean. A dry gasket surface, free of oil and dirt is important. Most all transmission pans on trucks this old will be distorted on the gasket surface. You will likely need to straighten your gasket surface on the pan before reinstallation. The pan can also get distorted by using a paper gasket because you have to over tighten them in order to get them to seal. I usually straighten pans with a special punch that is larger diameter than the bolt hole but ground to a very shallow cone. The back of a ball pean hammer also works well for this. Brace the pan rail from behind with a straight block of wood or the edge of a workbench. By using a hammer with this punch you will cause the bolt hole to go beyond being flat and just a little concave on the gasket side. But when you tighten the bolt it will draw the gasket surface on the pan flat again. When tightening the pan, the same torque spec will not work with all gaskets because of different gasket manufacturers. For this reason I tighten them by feel and by sight. When the gasket starts to bulge just slightly around the bolt that you are tightening, that is usually enough. The important part is to get them all even torque. Draw the bolts down evenly, and do not over tighten. You might need to go over them 3 times to get them all evenly torqued. A speed handle is my favorite tool to do this. Use no sealer with a cork gasket, if you managed to get the pan surface straight with a hammer and the punch that I mentioned, and it is clean, dry, and free of oil, it will seal properly without a problem. I have the best success installing cork gaskets dry. If you must use sealer, use Gasgasinch. Apply the sealer to both sides of the gasket as well as the sealing surfaces and let it dry to a haze before positioning the gasket and installing your pan. Whatever gasket type you decide, care must be taken when installing it.

~bh

 

[pinenuts]

Thanks for all the great information. I have ordered a new aluminum pan from JBG. I will use the cork gasket and be carefull to not overtighten the bolts. I HATE leaks!