Transmission leak
 

Hello,

I'm new to this forum. I'd like to get some advice on how to go about fixing a transmission leak. Two bolts on the transmission pan of my Sebring 2001 are losing their threads. These two bolts on the lower part of the transmission pan simply turn and turn when screwed in. I'm thinking of getting a tap and die set and putting a helicoil in as a replacement. Is this a good idea?

The other option might be to put in a new transmission pan, but I've read a bit about that in the Haynes manual and it seems like a huge job, requiring a transmission jack and other exotic tools.

At the moment, installing a helicoil upside down while lying under my Sebring seems like the most doable solution. I may entertain the idea of bringing my car into a transmission shop or other repair shop, but I'd prefer to do the repairs myself and I'm concerned about the high cost of this sort of repair at a shop.

Any advice you could offer would be much appreciated.

To summarize: Two bolts on the transmission pan are too loose to properly torque the transmission pan at the lower bottom of it. I'm looking for a permanent solution, but perhaps something like leakstop or threadlock would do for now?

Thanks for reading.

Stripped threads in aliminum cases are very common, as is doing helicoils. I do them all the time. People will not clean the old silicone from the holes before they put the bolts back in and they strip the threads. But, the right way to do it is with the pan off. It's not that big of a job. You can change your fluid and filter while you're in there. The pan seals back up with black RTV. If you use one of those gaskets it WILL leak.

Thanks. I'm actually interested in learning how to do helicoils so I think I'll attempt this. Would you mind stepping me through the process of taking off the transmission pan and adding the helicoils? This procedure doesn't seem to be covered in the Haynes manual I have for my model of Sebring. Could you recommend an instruction manual for doing helicoils on transmission pans? As well, I'm going to do some test helicoil work beforehand, and perhaps you know of a good way to practice doing helicoils? I was thinking of going to a salvage yard and just picking up some crap parts to work on.

I'm using black RTV sealant and I try to do a fairly could job of removing all the guck on them before torquing them back onto the pan. Do you recommend a more effective way of doing this? I simply use a scraper after dousing the bolts in brake cleaner.

The Haynes manual covers removal of the trans pan in the first chapter, under general maintenance, not in the transmission chapter.

You won't be able to successfully seal anything with RTV if it's leaking and covered with oil. You have to have a clean surface to work with.

Don't scrape on the aluminum housing of the transmission except very carefully as you can gouge the aluminum easily and then you'll never get a seal.

go buy a tube of the Chrysler RTV it will seal anything even if wet

Re: Helicoils for Transmission case
 

I have to clarify: I always use RTV sealant. I don't know why a few of you are going on about this.

Additionally, the Haynes manual does not cover what I want to do. I need to repair the aluminum case and probably take it off of the Sebring to work on it.

The issue is the stripped threads in the aluminum case. So I want to repair them using helicoils. TNTech addressed the issue, and now I'd like to know if anyone has any further details about putting helicoils into an aluminum case. This is new territory for me: helicoils: but I'm interested in working with a tap and die set and doing helicoils. I want to learn. So can anyone guide me into taking these first steps into repairing the stripped threads on the aluminum case of my transmission?

Thanks for reading!

sebringhardhat, Check this out ...

http://www.youtube.com/watch?v=RFYa6sjhh_E

I'm sure you'll get the idea.

Don't know what I am talking about here, but I will give it a stab anyway. My mechanic friend is of the persuasion of "making things work" on older cars vs. making them perfect. I walk the fence on these issues.

Anyway.....he helped me fix a bad bolt on my daughters Sebring, but it might not apply in your case.

If it's an "open" bolt hole.....is there room to stick a nut on the end of the bolt?

If it is a "closed" bolt hole.....ends inside the tranny case (my situation), the original bolt was quite short and there were still plenty of good threads at the top of the hole. I cleaned it out carefully with a "stub/flat type tap and simply used a longer bolt!!!! It work splendidly.

read the instructions on the heli coil kit

"Additionally, the Haynes manual does not cover what I want to do. I need to repair the aluminum case and probably take it off of the Sebring to work on it."

Previously you mentioned that you wanted to remove the "pan", and that was the basis of my response.

Removal of the "case" entails complete removal of the transmission from the car. You don't need to do that to insert a helicoil. That's a major operation. Depending on the size of the hole in the pan, you may be able to insert that helicoil with the pan in place.

The youtube video of the helicoil operation could use a little polishing. When drilling by hand, you need to exercise care to make sure the drilling is perpendicular to the surface to get a straight insert. It looked in the video that he was off a few degrees. That may or may nor be important. Also, when using a tap, I always put some oil on the tap to make cutting easier and to help collect and carry the cuttings out of the hole.

It shouldn't be too difficult to do that under the car. Get some ramps to lift the front of the car up and you should have plenty of room to work. Wear eye protection as you'll be looking up at all that crap falling down.

Let us know how it works out.

Okay, well, I have purchased a HeliCoil Kit of size M8x1.25, and I'm preparing to go ahead with this operation on my transmission pan. I'm just wondering if it is necessary to drill the hole prior to tapping the hole? Is the only reason to drill the hole to get an adequate depth? That's my understanding. Perhaps it widens the hole as well? The drill bit is supposed to be 21/64(.328). I found instructions that match the job I'm about to do:

http://www.roadstarmagazine.com/modu...rticle&sid=233

But I'd just like to hear a little more about the drilling part prior to tapping and then inserting the helicoil. Does anyone have any advice, such as perhaps skipping the drilling part? If skipping the drilling part is a bad idea, I'll have to go out and buy a drill and bit set, which I'm prepared to do so long as it's necessary.

Thanks for all the help so far.

You need to drill the hole to make the proper diameter for the tapping operation. The hole you drill will be larger than the previous hole because the helicoil insert occupies the additional space.
You should buy an electric drill anyway. It's a very handy tool to have for many uses. My personal recommendation would be a 3/8" variable speed, reversible corded drill. Cordless drills have their uses but if you only use it a few times a year the battery will always be dead when you need it. When drilling metal, slow speed is better. Trying to drill at high speed in metal will dull the drill and cause the hole to elongate.
The tap requires a specific sized drill bit. Buy only that size and exactly that size. An ordinary drill bit set may or may not have the correct size. Drill carefully and don't enlarge the hole by working the drill in and out or you'll not get a good result with the tap.
Oil the tap to make the cutting smoother.

Well, I bought a 3/8" variable-speed cordless drill last night, and I've got a block of aluminium coming to me to practice on, so we'll see. Thanks for all the advice. I'll let you know how it turns out after I've done the work on the transmission pan and got some results.

Well, here's how things have gone so far. I temporarily minimized the fluid leakage from my transmission pan by using a longer bolt. I then set about practicing doing helicoils on an aluminum block I got from a local welder, which was excellent preparation for doing helicoils on my transmission pan.

Now, this past weekend, I actually went about replacing two non-adjacent, stripped bolt holes on the lower end of the transmission pan with helicoils. The job went well. I even sealed up the transmission pan to exactly 165 in-lbs using a torque wrench. I had previously been doing the criss-cross pattern with a ratchet and figuring out torque by feel. Now I relied on the clicks.

Unfortunately, the end result has been a bit of a disaster. The pan is leaking more than ever. I think this may be because I used a torque wrench (165 in-lbs may be too much). I'm also wondering if there may be some burrs on the transmission pan from the drilling, though I don't recall any. The helicoils seemed to have installed nicely, with the helicoils being about a 1/2 turn below the surface. I'm going to redo the transmission fluid change job next weekend, and I'll be installing at least one more helicoil.

So it's getting tough, but I insist on fixing this. For christ's sake, it's just a matter of sealing a transmission pan. I'm going to examine the transmission pan for any grooves or nicks that may be causing this persistent leakage. The pan always leaks at the lower/bottom of the transmission pan, but I don't recall any obvious grooves or nicks on the sealing surface there. I may avoid using a torque wrench: the Haynes repair manual says to work up to a final torque of 165 in-lbs in three or four steps, and last time I did this in two to three steps. Will a more gradual four step torquing process actually be the solution? It's a brand new micro torque wrench, but maybe it applies to much torque?

I would appreciate any advice that might help me to fix this problem. It's been a great learning experience, but ultimately I must finish this job.

ever thought about buying a transmission pan that hasn't been destroyed?

back to my original question what brand of RTV are u using and how do u apply it?

165 inch lbs is the correct torque, per the Chrysler service manual.

It hasn't been destroyed. The threads on the transmission assembly were stripped. Now it's all me, I think.

I'm using Mopar ATF-RTV, which is a silicone rubber ATV. I think the problem is that I smeared the ATF-RTV sealant onto the transmission pan last time, instead of squeezing out a "bead". Too little sealant is probably the problem this time...

As to torquing the pan, I normally ratchet the bolts snug and then proceed to apply torque. I'll probably go with 155 in-lbs this time just to be safe, but 165 in-lbs is what's recommended in the Haynes repair manual. The problem lies with me this time, I think. Not enough of a 1/8" bead going on the pan.

Which Chrysler service manual is this? I have the Haynes repair manual.

Daimler/Chrysler Service Manual. 2001

If you are still having trouble getting a proper seal, try installing a gasket. Auto parts stores carry them for your transmission. No sealer should be necessary.

If you still want to try the sealer-only method, try putting a nice even bead on the sealing surface and around each screw hole. Then install the pan, bringing it up to the case but only finger tight. Allow the sealer to cure before tightening the final torque. This should prevent squeezing the sealer out and then allow it to compress between the metal surfaces to make the seal.

Okay, and cure for about fifteen minutes? I normally apply a bead of sealant on the inboard side of the transmission pan which I've understood to be on the inside portion. Then I apply a bit of sealant on the underside of the actual bolt's head, separate from the transmission pan. You're suggesting apply that bit of sealant straight onto the transmission pan around the bolt hole instead, which sounds like a better idea, or as an additional bit of sealant?

Probably the best reason to put the sealer all the way around the bolt hole is to provide equal support for the force of the bolt bearing onto the pan. This is how a gasket is designed, partially for the same reason.
Yes. I would allow it to cure for at least 15 minutes, maybe longer, like an hour. You don't want to be squeezing liquid sealer out of the gap between the two metal parts.
Personally, I would opt for the gasket route. The gasket will be a much more uniform surface, and more likely to bridge the gap and get a good seal. The cost of a gasket is about the same as a tube of RTV.

No such luck. But I see I'm not the only one with this problem:

https://www.chryslerforum.com/forum/...ead.php?t=7386

I let the Chrysler RTV sealant cure for over an hour. I squeezed the tube all around the inboard side of the transmission pan with a nice 1/8" bead and afterward went around and squeezed another 1/8" bead around the outboard side of the bolt holes. Then I threaded in all the bolts with my fingers until the transmission pan was snug against the transmission assembly, applying a small amount of RTV sealant to the underside of each bolt head as well, per the Haynes manual instructions. After an hour, I went about torquing the pan in several stages. Still, it leaks. The next day, I decided that maybe the lower end of the pan needs to be torqued a little bit more than the upper end, 5 in-lbs more, because maybe the pan is a bit warped, but still no such luck.

I'm thinking of going the gasket route, but only after I purchase an entirely new transmission pan from Chrysler (they're 20-40$ usually, no?). What I'm now supposing is that the pan is slightly warped. The actual assembly it attaches too is unlikely to be warped right? Most probably the pan, right? I can't deal with this RTV sealant anymore, especially if a gasket is the better way of doing this. I'm going to see if I can get a gasket from Chrysler as well. It's so time consuming to clean off all the old RTV sealant from each bolt, but I do it. I meticulously remove the sealant, so there are no traces of RTV sealant that could be getting in the way.

One thing I noticed that I have in common with the above forum thread, is that there is always that little bit of transmission fluid that keeps flowing hours later after I've let the transmission fluid drain from the assembly and just before I put the pan onto the assembly I dab the mating surface clean, but it's not long before the trickle of transmission fluid returns. I don't know if this is a negligible issue or not. I should also note that the air where I am is very dry, it's the Canadian Rockies, close by Calgary. Could that be significant? Maybe the RTV sealant actually takes 6 hours to cure? I work outside, too. Maybe dry air, in an outdoor environment, will take 12 hours to cure?

Anyhow, the gasket route with a new transmission pan is the best option I can think of at the moment. Leak, leak, leak... it's maddening.

Any advice? Any old forum threads that might be helpful to read? Big thanks for all of the help so far! I want to give this one last go before I bring my car into a transmission shop.

OMG pay for my plane ticket up to where u are and I will do it

But what would you do different and which route would you take, sealant or gasket? Am I overreacting by replacing the transmission pan?

i dont think there is anything more anybody can say to help you out bud. If you can't do it then take it to somebody that can.

No, I'm pretty sure there's a lot more that can be said on this subject. Oil changes are easy, but this transmission fluid change procedure is difficult. Books could be written on the subject. I'm a little worried there is an art to it, rather than some significant mistake I'm making.

Anyhow, my next move would be to go the gasket route. Could someone provide a few hints on how this differs from the sealant route?

take it to some one u dont know what u are doing

I'll take it to someone if I really can't get it done after a few more trys. I'm having fun with this.

I'm just wondering how to go about the gasket route since the Haynes repair manual doesn't instruct on this procedure. Can someone advise me on how to go about doing this, compared with the RTV sealant procedure?

Go onto most any auto parts store site like Advance or AutoZone or O'Reilly's and drill down to a gasket for your car. They will have a picture. Like this:

http://shop.advanceautoparts.com/web..._1197404810___

They also sell replacement pans, like this:

http://shop.advanceautoparts.com/web...S_987324228___

It will be immediately obvious how the gasket goes in. Tighten the screws to the same specified torque and you should be fine. The torque specified for a particular screw is generally related to the size of the screw more than anything else. There's also a pretty good range of "tightness" that will still function acceptably.

Although allpar.com has gone downhill regarding tech. help, go there to see that lots of people have problems with the weeping fluid and RTV use, yet the pro techs. seem to have it nailed down. Also see lots of controversy on using gaskets.

Felpro (at AAP) makes the most robust gasket I have seen. It's packaged flat in a box and is made of a very stout material (not just rubber). I torqued mine to about 9 ft. lbs. initially, but had to snug each bolt up about 1/8 turn more a month later to eliminate a bit of weeping. Be careful not to over torque and deform the gasket. Using a torque wrench on a gasket is a bit funky....they keep compressing. Its better (IMO) to do it on the conservative side, then retighten if needed (something a pro doesn't want/need to deal with).

Chrysler makes a reuseable gasket for these trannys of metal and silicone. Most don't know about it, but it is very expensive.....$40+/-. Part #
1 05011115AA for 41te. I don't think it is cost effective.