High Perf 4L80E Rebuild Short Lived

[DA BIG ONE]

Well, My so-called high performance tranny rebuild is no more. Tranny case cracked at bellhousing, and case cracking is not covered under the warrantee. So, I dump more $$$$$$ into another, but stock tranny at GM dealer.

I now wonder if the case was cracked in the first place when I got into some deep water?

Anyone else have this type of issue jump up at em?

Anyway, &^%!@%$#@!^&%^%!%^&^% it!

Happy, turkey day everyone.

[More Power]

There was a GM TSB produced some years ago about porous case castings used in some 4L80-E's. I've not spoken to anyone who actually had one of these, but you might investigate the cause of your case crack. Might be a casting flaw.

Secondarily, there is supposed to be a steel bracing rod used on the bottom of the torque converter cover to anchor the transmission to one of the motor mounts. This helps mitigate the bending (sagging) loads on the engine/trans bellhousing.

MP

[DA BIG ONE]

Originally posted by More Power:
There was a GM TSB produced some years ago about porous case castings used in some 4L80-E's. I've not spoken to anyone who actually had one of these, but you might investigate the cause of your case crack. Might be a casting flaw.

Secondarily, there is supposed to be a steel bracing rod used on the bottom of the torque converter cover to anchor the transmission to one of the motor mounts. This helps mitigate the bending (sagging) loads on the engine/trans bellhousing.

MP I will dig into it some more.

[JoeyD]

It could be like MP said or an improper install.How many miles on it? Why not get a case and have them swap out the guts and put it back in?

[DA BIG ONE]

Originally posted by Joey D:
It could be like MP said or an improper install.How many miles on it? Why not get a case and have them swap out the guts and put it back in? Actually, been having many problems with the quality, or lack thereof of all work done in this area.

Example: Last week I felt that my steering was getting sloppy, turned out to be the pitman arm was ready to fall off, because someone did not tighten and torque it!

[DA BIG ONE]

Any of you have a copy of TSB 02-07-30-024 (cracked transmission case)?

As it is only the bellhousing that is cracked, I will try to determine how it cracked, then have it welded by someone who welds aluminum all day, and keep as a spare. If the welder says it may crack again then I will get a case and change out everything, as usual big $$$$$$$.

[catmandoo]

if it's a 2wd they don't use those extra braces,at least my 94 c2500 sub doesn't have the flywheel cover or braces.but my 94 gasser 4x4 sub does.

[DA BIG ONE]

Originally posted by DA BIG ONE:
Any of you have a copy of TSB 02-07-30-024 (cracked transmission case)? Well, Add another $1,000.00 for core charge which is turning out to be maybe the most costly 4L80E fix ever! Can't find a good core in the bone yards.

But, I get the GM coverage nationwide, instead of local only...

[DA BIG ONE]

It now appears that broken motor mounts may have led to the cracked bellhousing, the L/S mount has a brace to the bellhousing.

Still getting the unit at GM cause it is covered at all their stores, good when traveling.

The tranny with the cracked housing will go back to the shop that did the build so they can try to weld it, if that fails they will give me a case at cost, and minimum labor cost.

How do you say spare? Costly indeed, but cheaper that a wife, or?

[DA BIG ONE]

Call me impulsive, but, I just needed to get away from the stock trans GM was installing, so, its a highend off road/towing setup again w/ all the aftermarket goodies.....

This Burb is actually a deeper money pit than a boat now, but I can't resist it! Is there, or should there be treatment of this illness?