Turbo rebuild- anyone ever done theirs?

[rdixiemiller]

All
Went to swap my C turbo to Marksgarage for his D. Got mine off and found the bearings were worn to the point the compressor impeller was polishing the housing. Luckily, my spare engine in the can (LDT 465 1D) turned out to have an excellent C turbo on it. Go figure, the depot boys must just bolt on whatever turbo is at hand.
I am going to tear down the loose one and rebuild it. I am a qualified machinist as well as a mechanic, so I see no real issues. My question is:
Anyone here ever rebuild one? Or do you mostly just swap them?
If anyone has an old turbo laying around that might be rebuildable, let me know. I want to try a couple and see how they come out.

 

[cranetruck]

Hey Robert, I have this "change manual", it's not a complete TM, but has wear limits, tolerances and such for the waste gate turbos plus procedures for disassebly/assembly.
If you can use it, I can send you a copy (about 40 pages).

 

[CCATLETT1984]

I've been thinking about getting a turbo for my truck, but haven't seen one for the right price.


And before I do that I'll have to either get a different trans or bigger tires so the speed increase is worth it. I had found a source of Allison 1000 transmissions rebuilt for $1500 with no core charge, but haven't found an economical way of controlling the trans (damn computer controllers cost almost a grand).

 

[Jones]

I've seen the kits and there isn't much to them. If you're brother machinist, I think you should breeze right through it. At the NG we just change out the center sections, swap the housings over and put the turbo back on. I think the biggest deal is dis-assembly and re-assembly in a pretty clean environment, not a field shop workbench. Taking apart and handling the turbine and compressor wheel(s) and shaft while out so as not to damage them is critical. At 92K rpm, unbalanced part(s) = grenade. These parts are usually cleaned in an ultrasonic cleaner (McKay PartsDip or something similar should do the same) because Garrett and Switzer both warn against using wire brushes or bead-blast to keep from putting scratches or stress risers on the wheels.

 

[rdixiemiller]

I pulled mine apart today. Nothing to it. The bronze bushing had started to turn in the turbo bore. By the looks of things, this is the weak spot on this turbo design. The bushing is only held in on relatively small area on each end of the bushing. Because the drive end will get hotter than the driven end, the bore will expand slightly, allowing the bushing to move. This will eventually cause the bushing to work loose and spin. If you look in the drain port of the turbo center section, there is a fairly large area you can access with a drill and tap. I am going to drill and tap for a 1/4-28 grub point set screw. This will allow me to lock the bushing in place mechanically.
I was careful in the disassembly/re-assembly. As long as you don't bend or crack the impellers, you should be fine. This is actually easier to work on than a lot of things on the truck. I knurled the bushing and re-installed it just to see how it would work. No problems. Stay tuned, I may have a turbo rebuilding service for multifuels after a while!
I will have to find a source for the turbo bearings. I would imagine Memphis carries them.

 

[rdixiemiller]

Turbo tear down pictures

Here are some pics.

 

[rdixiemiller]

The TM number is:
TM9-2990-201-40 and P. I cannot access LOGSA at the moment. If anyone can check and see if it is there and download it to the tech section, I would appreciate it.
Mangus....Hint Hint Hint
If not, maybe one of you in the Service could post a copy......

 

[rdixiemiller]

Bjorn- If you can send me the TM I would appreciate it. You can e-mail it to me at: rmiller@hl-a.net
Jones- Is the TM for the turbo included on the military issue CD?

 

[Jones]

Will look for the Turbo TM when I get back to the NG. Some of the stuff is available to depot if not to us. If it's on a ETM I can access and post it. If not, somebody smarter than me will have to take it from a hard copy to a .pdf file.

 

[mangus580]

if it is needed from hard copy, someone just has to mail it to me, I will pdf it

 

[ken]

The bushings are sopposed to be loose in the bore, When it gets hot they will expand and fit tight in the bore. The bearings (bushings) are made from oillite. It's a brass compound that is pourous. The pores in the metal will hold oil so they won't wear too quickly when the engine is started and the oil pressure hasen't come up.
If your compressor wheel has rubbed the housing then the rotor assembly needs to be ballenced. Even milligrams of unballence can cause it to explode at 30,000 rpm's.

 

[rdixiemiller]

The bushing had spun out and was badly scored on the outside on the exhaust end. This tells me it was spinning freely in the case. I recognized the oilite material, I use it in my conveyor chain here at work. The compressor wheel was rubbing just enough to remove the oil and soot from the housing. There aren't any burrs on the wheel. I will however check the balance on the rotor assembly, that I can do without too much trouble.
I wondered if the bushing was supposed to be a tight fit or not, since I can't find the manual on these things.

 

[DrFoster]

If you need someone to rebuild it let me know. DIY is not that hard, given you have the proper tools and measuring devices.

That turbo looks hammered.

 

[rdixiemiller]

All i need is the tolerance list, and the bushings. The turbo itself is pretty simple. I will check the static balance and runout.

 

[cranetruck]

Robert, sent you a PM regarding the TM posted above.

 

[DrFoster]

Bjorn,

Can I get a copy of that tm? $$?

 

[cranetruck]

PM me your snail mail addy and I'll send you a copy. It's not a complete manual, just the changes to the original, but covers the waste gate turbos mentioned on the cover, as stated in the above post.

Please, don't send any money, I'll never have enough anyway.

 

[mangus580]

bjorn, send me a copy, I will scan it and upload it.... even if it doesnt have all the info, some is always better than none.

 

[builder77]

Any update on your rebuild? I have only about 6hrs seat time in my deuce, but on several occasions I though I heard something like a bearing vibration one or twice.

 

[emmado22]

That TM is not in the ETM disk. Doesnt look like it is on LOGSA either.....

Is the turbo charger a model Schwitzer M 5HDR?? If so, you guys are in luck.