Sealing up the transmission - RTV? Something else? Lots of questions!

[jonnymopar]

Hi all,

I did a chrome moly plate install last year and things did not go well. It held together and took a good beating, but it leaked like crazy. Is there something other than RTV that should be used to seal up the trans? Maybe Indian Head sealant? Is there a specific type of RTV I should be using? I have the trans out right now with the plate taken back out so I can clean it. Should I take the actual bearing plate out as well and seal up all 3 seams?

Just to throw this out there, I used the red Mopar sealant on the differential housing and that sealed up great. I only did that because it's all aluminum (other than the steel housing on the driver's side).

Sorry for all the questions.

[cordes]

Clean the surface well and use RTV.

[GLHNSLHT2]

Anerobic sealer or nothing.

[turbo84voyager]

It might be leaking from the bearing plate. It is not difficult to remove. I have used both anerobic and rtv. For those side plates I have had the best luck with black permatex. Check to make sure end cover fill hole lips fit inside support plate. There were a few floating around where they won't because hole is too small and end cover does not fit right. I had one of these and caught it after installing.The only thing to remember the bearing plate effects end play / preload. I have yet to find out if the bearings should have preload or endplay. I have books that say either way. So I have always set to 0 endplay / preload and no problems plus every tranny I have had some endplay. Honestly if you are going to remove the bearing plate it wouldn't be a bad idea to throw new bearings in especially the intmediate shaft roller.

[jonnymopar]

Good info. Last year when I did the moly plate and OBX install, I shimmed the input shaft bearing to 0 endplay. The intermediate shaft doesn't feel like it has any endplay right now (trying to move it side to side by the now-exposed 5th gear end).

It sounds like I just douched up with the RTV bead last time and I need to do it again. After going through the triumph of machining the 555 gear to fit an OBX and getting it to work, I was pissed to find out the project wasn't a complete success because of something so stupid. It was tough to tell exactly which seam was leaking because they're all so close together, but it's definitely there and not on the diff housing.

Justin, are you going to Carlisle this weekend?

[turbo84voyager]

I'm planning on going to Chryslers @ Carlisle this year. Unless the weather is bad.

[thedon809]

Mopar Three Bond RTV seals really, really good. Only problem with it is if you have to take it apart you might need a heat gun to loosen it up.

[turbo84voyager]

Mopar Three Bond RTV seals really, really good. Only problem with it is if you have to take it apart you might need a heat gun to loosen it up.

Sounds a lot like the great stuff. A pain to disassemble. I used some once on a 3.5 upper intake because some idiot used a cookie on it and the intake had an air leak from the marks in the metal. It worked but when I had to remove it at a later date I swear you could have pulled the engine with it. A lot of guys I know like permatex gray rtv. It's the import stuff. I've used it with good results. I might use it on the auto trans I'm putting together.

[jonnymopar]

I'm planning on going to Chryslers @ Carlisle this year. Unless the weather is bad.

I have no idea why I said "weekend". I meant to the Chrysler show. It will be my 9th year in a row, regardless of the weather. Hopefully I'll see you there.

Mopar Three Bond RTV seals really, really good. Only problem with it is if you have to take it apart you might need a heat gun to loosen it up.

Never heard of the stuff, but I'll have to check it out. I'm pulling the entire trans apart this time around, and re-sealing everything. I pulled the bearing plate off and I think that's where it was leaking. I must have broken that seal when I was popping the old bearing retainer off to install the moly plate. I've got everything out already except for the differential and the input shaft seal/bearing cup. Bonus of pulling everything completely apart: found out tonight that I had a broken pad on the 3/4 fork and never knew it! Now to try my luck and see if anyone has them available.

Thanks for the help everyone.

[turbo84voyager]

Black pad? Last time I needed them they were still available.

[jonnymopar]

Yep, black pad. I emailed Cliff to see if he had any more of the complete sets.

[135sohc]

I have some and yes they should still be available from the dealer. The black pads were used on stuff besides the FWD transmissions.

[supercrackerbox]

A lot of guys I know like permatex gray rtv.

That's the only kind I use, although I use very little RTV on our engines.

I could look to see what the FSMs say for the 555, but for the 568 it says anaerobic for all the end plates. RTV is only used on the differential bearing plates.

[jonnymopar]

I've wondered if I could use the red Mopar anaerobic sealant on the whole thing. It says right on the squeeze tube that it's for ALUMINUM. However, the reason that I have it is because the 1998 Stratus FSM called it out by part number to use to seal the 2.4 bedplate to the block - neither of which are aluminum. Building the 1998 2.4 that's in the car, I followed those instructions and it is not leaking after 40k hard miles.

Again, I used it where the diff cover meets the case and it's not leaking at all.

[shackwrrr]

Mopar Three Bond RTV seals really, really good. Only problem with it is if you have to take it apart you might need a heat gun to loosen it up.

Three bond ftw!

[johnl]

Three bond - nearly JB Weld.

[jonnymopar]

I have some and yes they should still be available from the dealer. The black pads were used on stuff besides the FWD transmissions.

Do you know the part number off-hand? Just for kicks I'd like to see how bad a dealer would bend me over to get one of those. If Cliff still has some, I'll gladly pay what he was selling complete sets for.

[Rrider]

Are you guys using 3bond 1184?

[135sohc]

Do you know the part number off-hand? Just for kicks I'd like to see how bad a dealer would bend me over to get one of those. If Cliff still has some, I'll gladly pay what he was selling complete sets for.

4295519

[bgbmxer]

I sealed mine up with blue recently. I take a little wire brush on a drill and it scuffs it up pretty good so it sticks better.