trans shelled out... again

Chrisd91 said:
How would one go about checking this?
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I bolted the tc to the flex plate and mointed a dial indicator on the block, then positioned it so it was resting on the convertor hub, where the bushing sits.

I had already checked the flex plate with the dial indicator as well
 
12vCumminsFTW said:
Converter had to be pried off the trans, converter hub is ruined, scored and looks like it got hot. Pump bushing is reamed, tried to spin in the bore. Pump is destroyed. Metal shavings everywhere. The forward and direct clutch packs looked fine.

Any ideas on what would cause all this BS? I'm running a Suncoast flexplate, same one I ran on the last rebuild. Brand new converter. There was about 1/4" of play between the TC and flexplate so I don't think it was too tight.
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What was the final end play? Transmission wise.
 
12vCumminsFTW said:
Fairly tight, probably around .010. I have always run the end play on the tight side and never had an issue.
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That is very tight! Running that kind of line pressure and the heat involved I would say that the converter and the pump have no room to expand. That is tighter than factory specs and part of your problem right there. You may not have had a problem before that your aware of but I would say that final end play on that tranny would need to be .050 thousands to .080 thousands on a 4x4. Just my 2 cents to add in getting your problem resolved.

I have seen the same problem you just had on other transmissions an it was to to tight end play specs. Wiped out pump and converter hub.
 
Good points, I will look into getting more end play on the next build. I still don't see this as being the whole problem, something else had to be screwed up. I built the first trans with .010 play on the input and beat the crap out of the trans for a year and never had an issue. And then this trans takes a dump in less than 20 miles.




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12vCumminsFTW said:
Good points, I will look into getting more end play on the next build. I still don't see this as being the whole problem, something else had to be screwed up. I built the first trans with .010 play on the input and beat the crap out of the trans for a year and never had an issue. And then this trans takes a dump in less than 20 miles.




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You can set it at lets say .020 but as the transmission breaks in it will open up some. I usually increase end play based on hp being made. any where from 0.25 to .090. Better to be safe than sorry. Also leaves a little room for parts to slide a bit especially during hard shifts and to compensate for heat generated. On my temp gauge when I had it connected to the trans discharge line I would see trans temp hit 280* plus on a WOT run down the track. It gets toasty for sure.
 
I'm on the to other end of the spectrum, I like to set the endplay tighter on my high HP builds. I'm nervous when endplay is .050" or larger. I usually try to get them between .015" and .020". It is, however, extremely important to make sure there is adequate space between the converter and the flex plate so it can do it's growing and shrinking without adding a bunch of endplay stress to the transmission input shaft.
 
Just checked flexplate run-out, its about .005 out. What is acceptable run-out for a billet flexplate? I'm checking the converter hub next.
 
Ok, bolted up the converter and put a dial indicator on the hub, about .008 runout.

There was a sticker on the flex plate that the converter mounting pad was sitting on, I peeled it off before checking runout. Not sure if that was an issue, but anyways.

ImageUploadedByTapatalk1382309161.070604.jpg


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mathews8pt said:
I don't think so. I had like .060 on the one I was having problems with. Call a tc builder to be sure
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Damn that is a lot. I will call goerend when I get a chance. I would think the flexplate would be able to soak up .008 out.

If the TC/flexplate isn't the problem then I'm kinda stumped. Maybe I screwed up the bushing somehow during install. Or i got a bad pump?
 
12vCumminsFTW said:
Damn that is a lot. I will call goerend when I get a chance. I would think the flexplate would be able to soak up .008 out.

If the TC/flexplate isn't the problem then I'm kinda stumped. Maybe I screwed up the bushing somehow during install. Or i got a bad pump?
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How far was the bushing installed? Dimpled or Solid bushing?
 
Well I talked to Dave today, he said .008 total runout on the hub is OK. He also said input shaft end play would not have caused this. If it was too tight the thrust washers and stuff in the trans would wear excessively, but it would not effect the pump. It seems I might have got a bad pump. He said they have had a lot of new and reman pumps that had bad gears and stuff. So anyway, I'm sending him the TC, Vb, and old pump and he's gonna check out everything.:D
 
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