406TPI

iTrader: (1)

Anybody ever seen a 700R4 tranny take out a thrust bearing? Reason I ask is because I ate up a thrust bearing after only 4000 miles last year... and after a recent rebuild it appears that I might be losing the thrust bearing war AGAIN witnessed by copper colored glitter in the oil filter! The block was rebuilt with a new crank and the endplay was .005. Nobody could figure out why I lost the thrust bearing the first time....thought it might have been a fluke. Well looks like it wasn't a fluke. The only thing I can think of that might be causing this to happen is a forward force coming from the trans. I talked to Dana at probuilt (he built the trans) and he said it was highly unlikey. I have about .200 clearance between the flywheel and converter before I slide it forward to bolt it up. The converter has an anti-ballon plate so I ruled that out. I am out of ideas here.

[This message has been edited by 406TPI (edited May 16, 2001).]

FlashGTA

How long after the engine build until the problem. In other words did it happen after the engine work or after the tranny work, or can you tell?

406TPI

iTrader: (1)

Well the tranny was actually run behind my old 305 for a summer before I put in the 400.
I never really checked the contents of the filter on the 305 because I was never really worried about it, nor did I really care too much if it was healthy
I don't think it's the trans causing the problem. I mean, how much pressure could it have put on the thrust bearing just sitting there for 20 mins. while the cam was being broken in?

Matt87GTA

Definately an engine lower end problem. I've never seen an automatic trans that was properly installed, take out a thrust bearing in an engine.

I'm not sure what could cause it. I assume that you checked all the clearances for the bearings during reassembly of the engine and they were within specs. In that case I am not sure...... maybe just a bad crankshaft - warped or something.

Just an idea......

------------------
Matt

1987 GTA L98 MD8 GW6

"Stop Lights timed for 35Mph are also timed for 70Mph"

Guest

Ive been trying to follow this...

You said you had the mains align honed right? There is the possibility that they screwed up the block in the process. Or maybe the flange on either the block or trans isnt square and you have an alignment problem that way.

406TPI

iTrader: (1)

The first time the engine was rebuilt, the mains were never align honed because apparently it wasn't needed. The second time, I had a different machine shop do the rebuild. They align honed it and installed a brand new crank. All the clearences were in spec.

I hadn't thought of the rear trans flange maybe not being square, that's proabably pretty rare?

Here's another odd note, the oil temp runs abnormally high, like it will get to 250 after only 10 mins. of easy driving. It did that last year too so I put on an oil cooler to help out. The machinist who rebuilt it the second time said that if the short block was built correctly that I wouldn't need a cooler, so I never re-installed it after the second rebuild....seems like something has to be binding up in there to create all that heat?

Guest

You are thinking right IMO.

It really sounds like something isnt lined up right inside the block, and thats what the problem is. That really sucks, I sure hope thats not it even though it would solve your problem.

The rear trans flange being misaligned is very rare. More common is debris/damage to the mounting area that causes misalignment, but I have seen both before.