1994 chevy burban's K1500 Torque converter crack

[seza]

Hi All,

I have had no end of trouble with 4L60E trany box on my 1994 chevy burban K1500 with 6.5TD,
the vehicle has been loosing ATF fluid for few months and only today I figured it was coming from a welded piece that fix
onto the flexplate! what a b@stard!
That mean I will have to take down the tranny for the third time! am not relishing the job at all.

 

[stutaeng]

So the trannie rebuild was successful? I mean, beside this issue? Why did you remove it the second time?

You can't order a replacement converter from the a US vendor for it? How bad is the crack? I've heard of TC cracking, but I can't remember the cause...flywheel problem? Is the torque converter spaced correctly? I honestly don't know.

Recall from your other post we mentioned the 6.5TD wasn't mated to the transmission you have from the factory (at least in the US.) And since you mentioned the engine on your truck was swapped from the previous owner: I wonder what flexplate they used?

 

[seza]

Thanks Stu, you and many others have been very helpful on this great forum,
yeah ... long expensive story with this: you right - pairing a 6.5 with a 4L60E wasn't smart I agree
but the real cause was driving such heavy vehicle over speed-reducing ramps that are placed on fast Interstate highways!
in this country [Algeria].
basically - the bell housing (admittedly not the strongest) broke in two places and was held by only the two lower nuts!
Not knowing - I dove it like it for many weeks before the issues started showing: initially a intermittent shudder esp on rough surfaces and incessant fluid leak that won't stop [now I know where it was coming from].
So the break in the bell housing caused a misalignment between the engine and the trany that caused various breaks inside the box as well as
cracked TC which lead to fluid leak which burnt what remains of the box!
to answer your questions: it is prohibitively expensive to get a new TC and the rebuild was done by a local guy, very good job he did, so far so good
We will have to take it down to weld the TC, we ll probably have to balance it as well.
as the flexplate - unless you can tell from the pic - I don't know what it is?

 

[stutaeng]

Ah, ok. I had forgotten about the cracked bellhousing. I'd be weary of running the same TC on a freshly rebuilt transmission, but it seems like you don't have a choice.

Yeah, I can't really make much of what is seen on the picture. Maybe snap of photo of the flywheel when you remove the transmission and just to a visual inspection?

 

[seza]

Sure - will do, Stu.

 

[seza]

We dropped the tranie - we found a hairline crack behind one of nut fixings on the TC,
we welded it, my only concern is is that the unit will go out of balance?
is it a common issue on these units?

 

[Erik the Awful]

Seeing as the torque converter spins at engine speed, I'd replace it rather than try to weld it.

 

[seza]

Thanks Erik, unfortunately - there are none to be found in this part of the world,
getting it sent from the US of A is extremely expensive - so will have to make do with what we have.

 

[Frank Enstein]

Grind as much of the original weld away as you can. Flush the converter thoroughly. Make sure to get it squeaky clean.

For the final flush use something that leaves no residue like acetone.

Any fluid in the crack area will ruin the weld.

Fill the converter with a non flammable gas and reweld trying to make the bead as large as the original weld to minimize balancing issues.

Make/buy/borrow a balancing fixture (one used for motorcycle wheel/tires would work) to get it as close as possible if you can't get the convertor balanced locally.

Good luck!

 

[stutaeng]

Seeing as the torque converter spins at engine speed, I'd replace it rather than try to weld it.

OP is in some foreign North Africa country (per his previous posts) and can't get a replacement torque converter.

I agree with you though...

I was thinking if he grooved the crack and weld it in, then grind it flush he'd hopefully be okay on the balance part? That still risky; I don't think the torque converter front over is that thick to begin with?

I really don't know, but that's what I would try given the circumstances.