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GM-8 rebuild?

bubbatexas

bubbatexas

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Location
San Antonio, Texas
I picked up a GM-8 turbo from the salvage yard this past weekend. They let me have it for free because the bearings are shot. The shaft has some side to side play but it doesn't look like the compressor wheel has contacted the housing. My question is is it worth it to try and rebuild it and use it on my truck, or should I look for another one. I'm on a very limited budget and the truck I got this one off of is the first 6.5 I've seen in a junk yard in about 6 years so GM-8 turbos are not really abundant around here. Thanks in advance for any advise.
 
You can sometimes find rebuild kits on ebay or try gpopshop.com. pretty easy rebuild assuming the shaft is good
 
It's really at your own discretion. If you rebuild it, and it works out, you have a cheap turbo, and you know what has been done to it. I am sure you could pick up a good used one (GM8) for about 300 bucks or less. Then there is the ATT option, but as you said, if your on a tight budget, the GM8 is a big improvement over the GM3(?) you have on the '93. We can give you all kinds of advice, but in the end, it's your cash.
 
I have installed new bearing and seal kits in these turbos.

As long as the compressor wheel has not been into the housing and chewed that up your one step closer.

Then once you get the shaft out (Undo the little nut on the compressor wheel and the thing comes apart easily)

If the shaft is not scored then your good to go.

Installing the bushings takes care as they are Bronze.
The seals look like a little piston ring except the ends lock together.


Missy
 
Thanks for all the advise. I think I'm gonna try to rebuild it. It will be a little while though, got to put a clutch in the daily driver first...... so much fun.
 
I'm hoping to install my ATT this weekend or next. I'll have a GM 8 with Turbo Master up for sale. Whats a fair price to ask or should I just put it on the great "auction house" and let the bidding begin?
 
A fair price would depend on miles on the turbo and it's overall condition, I've priced mine to about 1/2 of what a ATT is worth to folks I know, for e-bay etc. listing I'd start there and let it go to where the market takes it.

I also have been known to barter for something of similar value; ammunition or firearms come to mind for me, one caveat trade only if you know your trading partner "VERY WELL", you'd hate to trade to somebody something that was stolen or had been used in commission of a crime somewhere, or do a trade and you not get a true in kind value trade item.
 
Not having had much experience with turbos, a question comes to mind regarding general wear and tear......... The turbo charger is esssentially a pump. Do the vanes on a turbo eventually wear out? If so, at how many miles would this occur, and what would be the symptoms?
 
dms4x4 said:
Not having had much experience with turbos, a question comes to mind regarding general wear and tear......... The turbo charger is esssentially a pump. Do the vanes on a turbo eventually wear out? If so, at how many miles would this occur, and what would be the symptoms?
Click to expand...

Generally unless fed something they aren't designed to digest, bearings-seals-& WG shaft/bushing are what go bad with the turbo, when it goes bad is determined in a large part to oil quality, and air filtration, clean oil keeps bearings happy, though not a requirement according to some sites, I still like to give my turbo a cool down period before shutting down after a hard pull or long drive, air filtration keeps airborne grit from working on seals and also making it's way to the engine oil.
 
i just put my old GM-4 up in the FS section. it has some miles on it, but was cooled down to below 300F EGT on the pyro EVERY TIME. (as TD says) It ran perfect until i took it out.

will post up pics in a sec...

http://dieseltowingresource.com/showthread.php?t=14523

... i would have tried and keep it as a spare since it really did run fine.
 
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