Hey Everyone.

Was finally getting some progress made tonight on my swap. Bolted the trans up to the engine finally, and as i went to lift the motor into the air, i heard a nasty crack noise, and theres a massive crack down the side of my bellhousing on my trans now

The trans is a '95 Impala 4L60e with the non-removable bellhousing. Ive already modified my flexplate to work with the convertor and everything.

What can i do about this? Is the trans garbage now? Will tig-welding it ruin it? If i could tig weld it, what would the massive amount of heat do to the internals?

Ive been excited to finish this up, figured id aquired all the parts i need, but i feel like im ready to throw up. Dont think i can afford to buy a new transmission.

Thanks everyone,

Sheldon

massive crack does not sound good, pic?

its cast, im a pretty good tig welder and i wouldnt try tiging that......sorry.

here are some pictures:





Dad thinks i overtorqued it, then when i went to lift it, the cast gave out.

I had a crack like that behind an ear on my DSM tranny before.
Had it welded no problem.

yeah im not saying it cant be welded i would just recomend stick welding it not tig....

i have seen repairs done that where great . i have seen ones done that turned tranny into POS . get a good welding tech , listen to dad . good luck .

Hmmm, I would call your welding skills into question as you are telling someone to stick weld an aluminum bell housing.

I would say tig that no problem at all.

You can use MIG with the right wire but if you have access to a tig welder that would be the way to go.

Remember, heating metal will warp the case a little but its not going to matter that much where your welding. What is of vital importance is that the weld penetrates deep into the metal and not just a surface weld.(It will just crack again right next to the weld) You really want to make a deep pool and shove that tungsten rod in there a good 1/4'. You can do this with good results by using a smaller electrode and staying in one place longer so that you don't effect the surrounding area as much. (Which will warp the case)
Take your time and let the metal cool often, you can supplement a deep penetrating weld by welding the inside and then flipping to the other side and thus getting full penetration which will also give the material a chance to cool and help with distortion a little bit.

3 College Years, metallurgy and welding technology.
Hope that helps.
Seth
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Just took another look at the pics, make sure that the inside of that bolt hole the crack runs into gets welded as well. It can be chased by a drill afterwards.
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Looks like there are two bolts that go in were the crack is, if the upper bolt was over torqued then that was most definitely what caused the crack, Dad is probably right. On the other hand its not uncommon for casting defects to go undetected. Or both...

wow no your right crap totally slipped my mind that it was aluminum thinking cast iron what the hell its not some old powerglide my bad i wasnt thinking to great, o well everyone makes a mistake least i can admit it....

hell I'd just run it like that.. hehe

i wouldnt worry about it, thats a spot where the crack is negligible. It shouldnt mess up your alignment. BOP's dont have a bolt there but they have two on either side of the top one.

The way you described it, it sounded like you had a crack running along the length of the thing. THAT would suck!

duct tape it! or jb weld it just kidding. I thought the pictures were going to be worse... tig it and forget it ever happened

Whats with all those aluminum shavings there? Was it binding as you bolted it up? Looks like you may have alignment problems with your dowel pins or something. I think if it were me I'd drill the bolt holes ( NOT the dowel holes ) out a hair to free up some room to avoid bind. One thing to keep in mind here guys is he is already going to be running five bolts instead of six so having one more go down with a crack only leaves him four healthy ones.

I'd definitely get it welded by someone good. I would'nt worry about the heat its far enough away from any goodies you should be fine. Only thing I can say about welding aluminum? Clean clean CLEAN is the trick. Clean that thing like its the Stanley cup and it'll be strong as new when its done.

Sorry to hear about your set back Shel. Good luck

I absolutely agree, one of the most common causes for weld failure is contaminants that were not cleaned off of the surface of the welded parts. This tends to cause pitting and often small fissures which lead to cracks.

The heat most likely wont effect the internal components in the transmission but it can distort the bell housing, this is my main concern.

Youd better make sure that ur not jamming ur convertor in there, make sure its spaced properly cause there no reason that should have cracked

Look at where the crack is? Its most likely he over torqued the upper bolt then when it flexed it cracked...