Aluminum Transmission Housing crack

[joetho]

Does this look weldable?

This (photos below) is an automatic transmission pan in a 97 Honda CR-V. The pan does not remove like a regular transmission pan- you have to remove the entire transmission (and engine, I think). It has a drain plug like an oil pan, but as you can see it has a crack.

I thought I would ask the pro's (I am not a good welder at ALL and I wouldn't even begin to try this job) because there are several kind of dicey problems:

-it is still dripping transmission fluid, a little. That has pretty much stopped though.

-it would have to be welded upside down.

I am thinking just a little bead along the outside of the crack would do it. Maybe add an aluminum patch under the threads to beef it up.

Any ideas? I am hoping that since this is at the bottom of the sump and is such a short crack, things won't get too hot inside and I can get it welded in place. After all, if my alternative is to take the thing out then tear it apart, I would be money ahead to find a used transmission somewhere instead. So, I am willing to risk a little extra heat to get it going, and start shopping for another transmission.

Thanks, Joe







Thanks, Joe

[denrep]

Greetings Joetho,

No problem. That is just sump oil and not under pressure. The plug seals with a gasket on the flat surface, that will have to be closed too.

While working on it, the car should be tipped a bit to drain oil away from the repair.

Do you know what split the case?
Is it possible that the case was split by a tapered pipe plug being threaded into the straight threads of the drain?

Thanks for the nice pictures, they help a lot.

Good Luck

[smithboy]

Originally Posted by denrep

Greetings Joetho,
Do you know what split the case?
Is it possible that the case was split by a tapered pipe plug being threaded into the straight threads of the drain?

Thanks for the nice pictures, they help a lot.

Good Luck

That was exactly what I was thinking. Someone lost the original and stuck in a pipe end plug. There doesn't appear to be any other damage, like from a rock or whatever...it shouldn't be too tough for someone who does aluminum.

[Rojodiablo]

Grind out the crack, acetone clean the area, and weld it up. I like the idea of tipping the car a bit if practical.

[joetho]

Originally Posted by Rojodiablo

Grind out the crack, acetone clean the area, and weld it up. I like the idea of tipping the car a bit if practical.

I thought about that too, and I am thinking about tilting the car up sideways and drilling a little separate sacrificial drip hole on the low side, then sealing it with a screw and washer when it is all said and done.
_____________________________

Originally Posted by denrep

No problem. That is just sump oil and not under pressure. The plug seals with a gasket on the flat surface, that will have to be closed too.

Do I need to know what alloy this is? How do I find out?

Also, I am worried about transmission fluid burning inside. I am draining out as much as I can. Just how hot is this likely to get?

Removing it requires taking off the front wheels, axles, back driveshaft, transfer case, and lifting the engine. Then to get the pan off requires pretty extensive disassembly of the transmission.

So whatever the solution is, will have to be as is, in place.

Thanks for all the comments and advice!
-Joe

[zapster]

Believe it or not you may want to go thru the draining and cleaning and "v" ing..

Forget the heat..
This just may be a "JBWeld" moment..
There is no pressure in it its just a pan..

As far as the plug goes get the correct one and use 2 fiber washers behind it..
You will need very little squeeze to get it to seal and won't crack the cold weld..

That's what I would do..

...zap!

[tresi]

I'm liking JB weld also. Metalset, aluminum Devcon or any of the dozens of structural epoxies that they have out these days if you don't like JB weld. Jb weld will be the cheapest and easyiest to find. Might be a place for low temp aluminum brazing rods and a propane torch if epoxy doesn't work.

[zapster]

I would stay away from the heat..
Oils and such wick to the heat and doing it upside down??
You'll have a way bigger mess than you have already in no time at all..

That will just make you

...zap!

[JWC]

I agree with tresi and zapster, an epoxy would be much easier. Once you start to weld it is going to pull all that fluid up to the surface and be very hard to weld without being able to clean both sides. I run into this problem at work all the time. Most of the time I have to run a bead, and grind it out until I have enough clean new material to work with. As far as the alloy goes if you do decide to weld it, a 4043 rod will bond to pretty much any kind of aluminum alloy as far as I know.

[David R]

I would vee, clean and weld. Who cares if its upside down?

You HAVE to make sure no oil gets into the crack when you are welding it. Tip the car so it ALL drains out, then tip it the other way so none runs back. Watch out with spray solvents, it can get inside the tranny and give a little POP when you strike the arc. 4043 is what I would use.

Good luck

David

[Me!]

Is it that hard to take the tranny out?
I would pull it from the car and do it on a bench. Ya, it might take longer but it will be a lot easier to do.

Or if I cant get it out than the JB weld it would be!

No matter what you do drill a small hole at the end of the crack, and V it out. The hole will stop the crack from progressing in the future.


Good luck!

[malich]

I had a deep transmission pan on a T-400 years ago that I had someone weld in the trans temp sensor plug. Well it leaked after they welded it so I just took off the pan, cleaned the weld and JB Welded it and it never leaked again.