TH400 torque converter disintergrated

[nutwood]

I've a Chev 383 with a big block torque converter and a TH400 transmission in a Jeep J20.
I recently had the torque converter re-built. After a few weeks it developed a metallic rattle as though something was floating about inside. A few weeks after this the torque converter failed completely. Apparently the inside was like a washing machine bowl full of bits.
The company that over-hauled the converter are refusing to take responsibility, saying that it must have been fitted incorrectly as I did the installation myself.
Leaving aside the fact that I've had the vehicle 15 years and have always done my own work, please could anyone tell me if they know of any way that it could be possible to incorrectly fit a torque converter to cause it to disintegrate internally?

[MT-2500]

The convertor would need to be cut open to find the cause of destruction.
But.
The only installation thing I can think of would be no end clearance.
Or possiable a lot of metal from inside transmission or oil cooler.
What was the end clearance fly wheel to converter when you installed it.
Wascooler flushed out when converor replaced?
When a convertor shells out it throws metal all of the way threw the transmission.
Did you go all of the way threw the transmission when you replaced the convertor?

Always use a good quality rebuilt convertor.
One of my pet pee's is Dealer OEM parts does not furnish Brand new convertors.
There is a lot of cheap rebuilts out there but that is what you a cheap rebuild that does not have all parts replaced and rebuilt right.

I use a company in Ohio that puts a liftime warrany on there convertor.

If you want there name and address let me know.
But not at a cheap price.

[nutwood]

Thanks for the reply.
The converter was overhauled because of an oil leak where the spout was welded on. It was performing perfectly.
Apparently, so they say, the cause of failure was a synthetic thrust washer breaking, and letting loose a heap of bearings.
Thing is, there was a light metallic rattle, like a bit of tin can floating about, coming from the converter, for a couple of weeks before failure. I'd only hear it when stationary in drive, and then not all the time. At this point the converter was functioning correctly. I reported it to the company that built the converter and they insisted there could be nothing that could make that noise and it must be something else.
The next step was that it stopped torque multiplying and shortly after, stopped working. And you're dead right, it put metal right through the transmission and cooler lines!
When it was installed, there was 5 - 6mm (from memory) end float. That is, the distance the converter had to slide forward to met the flex plate. That's built in to the design of the TH400 housing and the flex plate.
The company that did the re-build are meant to be reputable. They maintain that there was a synthetic thrust washer broken through excessive end pressure. My question was, what on earth could I do wrong in the installation to cause such end pressure? Also what was the metallic rattle I heard initially? I would imagine that once the thrust washer broke, everything would stop working quite quickly. I had the rattle for a couple of weeks before there was any other symptom.

[MT-2500]

Originally Posted by nutwood

Thanks for the reply.
The converter was overhauled because of an oil leak where the spout was welded on. It was performing perfectly.
Apparently, so they say, the cause of failure was a synthetic thrust washer breaking, and letting loose a heap of bearings.
Thing is, there was a light metallic rattle, like a bit of tin can floating about, coming from the converter, for a couple of weeks before failure. I'd only hear it when stationary in drive, and then not all the time. At this point the converter was functioning correctly. I reported it to the company that built the converter and they insisted there could be nothing that could make that noise and it must be something else.
The next step was that it stopped torque multiplying and shortly after, stopped working. And you're dead right, it put metal right through the transmission and cooler lines!
When it was installed, there was 5 - 6mm (from memory) end float. That is, the distance the converter had to slide forward to met the flex plate. That's built in to the design of the TH400 housing and the flex plate.
The company that did the re-build are meant to be reputable. They maintain that there was a synthetic thrust washer broken through excessive end pressure. My question was, what on earth could I do wrong in the installation to cause such end pressure? Also what was the metallic rattle I heard initially? I would imagine that once the thrust washer broke, everything would stop working quite quickly. I had the rattle for a couple of weeks before there was any other symptom.

When the thrust washer starts breaking or comes apart it lets the turbines and other stuff in transmission flop around and start wearing down and may take a while to destroy the rest of converter.
Sounds like it was a bad new thrust washer or it was not replaced on converter rebuild.

[Blue Bowtie]

What the shop is apparently presuming is that the stator support splines were not aligned when the converter was installed, and the pressure on the converter damaged the thrust washer in the turbine hub. If the converter was correctly and fully seated when installed it would have to be slid forward slightly to install the flex plate bolts. If the converter were tight to the flex plate when you bolted it in, that would have been an indication that it was not keyed in correctly. Since you can remember that there was a 5-6mm float in the converter once the trans was bolted in place, it's likely that something else caused the failure.

Another possibility is that when the converter was installed and the turbine shaft was started through the hub it was slid rearward too quickly or aggressively. When the converter was slid back to engage the turbine hub and input shaft splines the resultant impact with the turbine hub damaged the thrust washer. The same thing could occur when sliding the converter back farther to engage the stator support tube and stator hub splines, and the impact may have flexed the stator hub forward into the turbine and done the damage. Unless the convert is slid backward slowly and it is gradually turned to engage both the turbine hub and stator support tube splines, this kind of damage could occur. Of course, once the stator is aligned the converter slides back the last few mm before the pump drive lugs are engaged. Impact on the splines before they are aligned and engaged can cause damage at either of the two steps, and pump rotor damage can occur at the third step. If you were reasonably cautions pushing the converter onto the shafts, that shouldn't have been a problem.

GM factory converters are usually remans, but they are done in GM facilities (so they are usually right) and include a global GM warranty. They only do stock converters, however, so are not a good source for custom stall speeds (K factor) and usually don't offer options for lockup clutch types (not an issue in front of a THM400). I like the carbon clutches for longevity and good bite (although they can dirty up the fluid quickly for the first couple of changes) which is why I mentioned the TCC options with remans.

I use a place called Midwest Converters for stockers and customs, and they are good and reasonable. There are many good custom shops around, and since you're on the other side of the planet you may be able to find one in your area. Asking around in some of the Holden performance forums may give you some ideas. Those guys tend to be about as hard on their equipment as many of us on this side of the pond.

Unfortunately, it sounds like you have even more work to do now that glitter has been spread through the whole hydraulic system.