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Bad torque converter!


cheese's Avatar
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11-06-03, 12:41 AM   #1  
Bad torque converter!

Hi!

I bought a rebuilt torque converter about 2 months ago to install along with the THM350 w/lockup transmission I put together. I installed it and it did fine...for about a month. Then in the mornings it starter to delay engagement, but after it engaged, it was fine the rest of the day. It got progressively worse and I have to rev the engine good to get it to engage, then it got to where it would do it even on warm starts, then it got to where it dropped out of gear at idle. That was monday, and I parked it so that I could pull the tranny back out. I jerked the pump out of it and it was wasted. (looked like brand new when I installed it). The pump drive gear chewed into the back side of the housing. Only the drive gear.

I was trying to figure out what did this, and all I could figure was maybe the converter was pushing it somehow, or the flywheel was bent. Checked the flywheel and all appears to be fine. I reassembled the pump and stood it up on the workbench and installed the converter. I spun the converter and it wobbles. The neck that connects the converter to the pump is installed crooked. It made the pump drive gear wobble in the pump housing and chewed it up. Even the converter bushing in the pump is wiped on one side...almost galled.

Has anyone ever heard of such a thing?

What aggravates me is that I went ahead and rebuilt another tranny to go in before I removed the bad one, and it turns out my tranny was fine...the pump was just bad. (because of the converter). All that work just because of someone's inferior converter rebuild. That chaps me. I guess I have an extra tranny now. I'll probably use it one day.

It's in a 1985 chevy truck, 5.0liter, by the way.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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11-06-03, 05:27 AM   #2  
jimmymc
It happens...but don't fret over the trans rebuild. All that ground up metal has to be cleaned out or more troubles are on the way...including contaminating your new torque converter.

Be sure to flush out the cooling lines too...

jimmymc

 
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11-06-03, 05:37 AM   #3  
converter failure...

...or should I say...inferiority! Have you contacted the rebuilder? Was there any warranty on the converter? If you can, you should mount the converter in something...a jig of sorts...a lathe perhaps...something that gives you true center and use a dial indicator to measure the runout of the hub...something the rebuilder should do with every rebuild! I'd be rasin cain and trying to get them to replace it and help with your other associated costs. it never hurts to try...

 
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11-06-03, 06:38 AM   #4  
Joe_F
What brand of converter? There are some bottom barrel parts out there. Stick with Daaco or an OEM converter for best results.

 
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11-06-03, 10:16 PM   #5  
mike from nj
a torque converter normally will flop around laying on an input shaft, it needs the support of the back of the crankshaft to hold it straight.

what i would do in the absence of a lathe, is bolt the t/c up to the flexplate of the engine and mount a dial indicator to measure actual runout of the 'oil pump drive' part of the converter, while slowly turning the crank bolt, it should be very close to zero 'thousanths' of an inch.


what will tear up a front pump bushing almost as fast as a bad converter, is missing alignment dowels between the two(engine to trans) as well as loose or missing bellhousing bolts.

but you knew this already, it was for the other folks reading.

 
cheese's Avatar
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11-06-03, 11:38 PM   #6  
Yeah, I knew it would move around on the input shaft as much as the bushing would let it, but this was obviously more than to be expected. The place I bought it from warrantied it today after some persistence on my part. I took the new converter and checked it the same way and had no wobble other than the tiny bit from the play in the bushing. I had probably at least 1/4" of run out on the old one.

I sure am glad I decided to pull my old pump before I installed the newly rebuilt tranny. I was going to use the same converter until I saw what happened to the pump. That's what made me take a look at the flywheel and converter.

The converter I got was made by precision. That is the brand that the reputable tranny shops in my area are using. They say they costs a bit more, but the quality is much better. Apparently I got a fluke. (I know 2 tranny shop owners and they both said that precision converters seldom have problems). Apparently precision is based in Pennsylvania.

I haven't contacted precision about my problem, and I probably won't worry about it. The tranny shop owner said that they won't warranty consequential damage anyway. I have a few of these pumps, and installed one. I put the fresh tranny in today and all is well. Hopefully it will stay that way !

I'll probably disassemble and clean the other tranny and set it aside. I have 5 vehicles that this tranny could work in if I happen to need it. (one doesn't really count since it is a parts truck...about to get cut up for scrap and hauled outta here).

Thanks for the input!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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11-06-03, 11:54 PM   #7  
mike from nj
i've heard a bunch of good things about precision on other boards, and they do make strong stuff if you want to really pay.

maybe it got dropped in shipping, who knows?

this is the precision i'm talking about
http://www.converter.com/

 
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