About to reassemble turbo, any advice / tips?

[ohlarikd]

After 6 months of no action on my car, I am finally going to start putting it back together. First up is the turbo.

Inexplicably, I decided to rebuild my perfectly fine working turbo. Seemed like a good idea at the time, but now I wish I just saved the aggravation. Anyway. It's completely apart and I have a rebuild kit (seals, journal bearings, etc.) Had turbo shaft/wheels balanced (debatable benefit)...

One problem is that I don't remember anything about when I took it apart, but I guess it may be self explanatory. Any advice and things to look for when putting it back together? Any advice on tips during reassembly?

Thanks!

Derek

[rampant150]

Put clean engine oil on EVERYTHING.

[turbovanman²]

Every turbo I've had balanced was out so its a good idea.

Just becareful assembling, use lots of oil and take your time, when you tighten the compressor wheel nut, you'll have to move the wheel away from the tightening rotation as it will move when you tighten it down, it might take a few tries. DON'T use any loctite on the nut. That's about it.

[ohlarikd]

Every turbo I've had balanced was out so its a good idea.

Just becareful assembling, use lots of oil and take your time, when you tighten the compressor wheel nut, you'll have to move the wheel away from the tightening rotation as it will move when you tighten it down, it might take a few tries. DON'T use any loctite on the nut. That's about it.

So basically, the wheel will move as I tighten it, so I have to make sure it starts at a position that ends up aligned with my marks when fully tightened?

And by fully tightened, I guess its a 'feel' thing? No real torque specs, not that I have a inch-lbs torque wrench anyway.

Derek

[turbovanman²]

So basically, the wheel will move as I tighten it, so I have to make sure it starts at a position that ends up aligned with my marks when fully tightened?

And by fully tightened, I guess its a 'feel' thing? No real torque specs, not that I have a inch-lbs torque wrench anyway.

Derek

Correct, I just go by feel, but tight, lol. I am sure there is a torque spec but dont' know where you would find it. I also put the turbine nut in a vise so you don't damage the fins.

[onerippinturbo2]

general rule of thumb was 20 inch pounds on shaft nut torque.

[puppet]

I'd buy a M8x1.25 tap and run it through all the holes on the exhaust housing. New bolts are cheap ... hit up Fastenal if the kit you have doesn't supply 'em. (Grade 8/Class 10.2)

One other thing you might consider doing is to tap the swing valve exhaust connection flange bolt holes. The hole size is just about perfect for an 8-24 thread ... no drilling required. Then, get (2) 8-24x3" grade 8 bolts ... (4) 5/16" hardened washers ... and a length of steel tubing 3/8" ID - 1/2" OD ... you'll be reusing the old springs.

What you do is mimic the standard bolt as far as stud section length .. the part that bottoms out the fastener to the swing valve flange ... with a cut section of the steel tubing. Vary this length depending on housing size (.48 vs .63) and on down pipe sizing with the flange (2.25/2.5 or 3" on a 2.5 housing) Adjust tubing length accordingly because donut sizes for 3" don't seat as far into the flange as it's native donut will.

Example: I cut tubing 1/4" longer for a 3" downpipe connected to a 2.5" SW. The donut I used (aftermarket Caddy with copper mesh because some vendors sell cheap "steel" filled donuts that rust out quick) sticks out about 1/4" farther. The (2) washers stacked on the bolt with the steel tubing length adjustment cleared the .63 turbine housing I use. At any rate, bolting up the DP is way easier.

[turbovanman²]

I'd buy a M8x1.25 tap and run it through all the holes on the exhaust housing. New bolts are cheap ... hit up Fastenal if the kit you have doesn't supply 'em. (Grade 8/Class 10.2)

One other thing you might consider doing is to tap the swing valve exhaust connection flange bolt holes. The hole size is just about perfect for an 8-24 thread ... no drilling required. Then, get (2) 8-24x3" grade 8 bolts ... (4) 5/16" hardened washers ... and a length of steel tubing 3/8" ID - 1/2" OD ... you'll be reusing the old springs.

What you do is mimic the standard bolt as far as stud section length .. the part that bottoms out the fastener to the swing valve flange ... with a cut section of the steel tubing. Vary this length depending on housing size (.48 vs .63) and on down pipe sizing with the flange (2.25/2.5 or 3" on a 2.5 housing) Adjust tubing length accordingly because donut sizes for 3" don't seat as far into the flange as it's native donut will.

Example: I cut tubing 1/4" longer for a 3" downpipe connected to a 2.5" SW. The donut I used (aftermarket Caddy with copper mesh because some vendors sell cheap "steel" filled donuts that rust out quick) sticks out about 1/4" farther. The (2) washers stacked on the bolt with the steel tubing length adjustment cleared the .63 turbine housing I use. At any rate, bolting up the DP is way easier.

Nice tips,

[4 l-bodies]

general rule of thumb was 20 inch pounds on shaft nut torque.

Derek,
My assembly manual for T3 Garrett says 18-20 inch lbs PLUS additional 1/3 turn for shaft stretch. IMO, 20 inch lbs is way too loose by itself. That torque can be easily reached with a nut driver.
Todd

[onerippinturbo2]

you have to watch, trying the 1/3 turn could result in a broken or twisted turbine shaft, the debate could be ended by the o.p placing a call to gpopshop and simply asking what he should torque it to.

[4 l-bodies]

Derek,
Trust me you don't want to torque to 20 inch lbs. That is less than 2 ft lbs! I guarantee at that torque that nut will come off in a hurry and be ingested into the turbo. I'll bet the bank on it
Lets do some common sense math
std. turbine shaft is approx .250" That is 1/4". 1/4" fine thread bolt torque is anywhere between 13-18 ft lbs. That would be 156-216 inch lbs. depending on what grade (material) the bolt is made from.
Todd

[onerippinturbo2]

like i said, i would watch when turning the additonal turn, that is how shafts get twisted and broken, i didnt say that i didnt do it. i did say that 20 inch pounds is the torque they want on it, my bad that i omitted the additonal 90 degrees.

[ohlarikd]

Thanks for the torque info guys. Now... apparently, this seems pretty important. I don't currently have an inch-lbs torque wrench, as they seem to be $250. Does anyone know of a less expensive source of an inch-lb torque wrench?

I usually have a decent calibrated wrist for torque, but this is scaring me a bit. I really don't want to take this all apart again after the nut falls off and gets eaten.

Derek

[4 l-bodies]

Thanks for the torque info guys. Now... apparently, this seems pretty important. I don't currently have an inch-lbs torque wrench, as they seem to be $250. Does anyone know of a less expensive source of an inch-lb torque wrench?

I usually have a decent calibrated wrist for torque, but this is scaring me a bit. I really don't want to take this all apart again after the nut falls off and gets eaten.

Derek

Derek,
Craftsman micro-torque wrenches in inch lbs are much cheaper than that. Although they don't get down accurately to real low torque #'s (like 10" lbs.) that is where the big dollar wrenches shine.
I like to use the snug, then 1/4-1/3 turn method myself. I also like to use a sliding t-handle & socket on this nut as well, to evenly distribute the load on the bolt. As Simon mentioned do this with the turbine shaft secured in a vice. This is a delicate step and I don't feel comfortable using a torque wrench with all that leverage on one side of the shaft. IMO, too easy to bend the shaft. Call me if you have any questions.
Todd

[cordes]

Thanks for the torque info guys. Now... apparently, this seems pretty important. I don't currently have an inch-lbs torque wrench, as they seem to be $250. Does anyone know of a less expensive source of an inch-lb torque wrench?

I usually have a decent calibrated wrist for torque, but this is scaring me a bit. I really don't want to take this all apart again after the nut falls off and gets eaten.

Derek

You should be able to go to sears and pick one up for a reasonable price.

[mr glenn]

you can also rent one for 5.00 a day

[ohlarikd]

you can also rent one for 5.00 a day

I had asked Autozone, they did not carry them. Anywhere else?

Derek

[cordes]

I had asked Autozone, they did not carry them. Anywhere else?

Derek

I don't know how much you want to spend.

http://www.sears.com/shc/s/s_10153_1...orque+Wrenches


http://www.harborfreight.com/hand-to....html?limit=30

[ohlarikd]

I don't know how much you want to spend.

http://www.sears.com/shc/s/s_10153_1...orque+Wrenches


http://www.harborfreight.com/hand-to....html?limit=30

There are only two craftsmans that have inch-lbs. One is 25 - 250 in-lbs. I skipped this initially cause 25 is usually too high for the application. TODD - you recommended higher torque on this shaft nut, what would that number be? $70 is certainly great.


But there is that torque screwdriver that I overlooked before that goes from 2 to 36 in-lbs. Not bad... and I wouldn't have that issue with the arm leverage bending the rod. Of course, maybe that is too little now?

http://www.sears.com/shc/s/p_10153_1...3&blockType=G3

Price is not terrible, still $150 is a lot. But most torque wrenches I see in this range are $250, I assume due to the precision needed for such low numbers.



Derek

[turbovanman²]

Is there no one you can borrow it from? Any shops you could bring some donuts and they'll do it for you?