About to do my own differential install...any tips?

[VileZambonie]

Let's get this straight, you aren't swapping the ring and pinion, just replacing the carrier right?

If so install the carrier and bearings/cups and measure the thickness you need on both sides to get you in the ball park. Check the backlash and end play (this is your carrier bearing preload). Get the correct preload and proper shims.... here I'll copy you the procedure. (remember the carrier is usually referred to as the differential case)

 


To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed.


Ensure side bearing surfaces are clean and free of burrs.
Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used.
Install differential case in carrier, with bearing outer races in position.
Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment.
Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers.
Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing.
At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary.
Check case for zero endplay using a suitable dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6.
Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs.
Fig. 4 Gear tooth contact pattern check
 
 
 
 




If pinion was not removed, check backlash and tooth pattern as follows:
Apply suitable marking compound on ring gear teeth.
Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required.
After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them.
Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload.
Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16---29 inch lbs. if new bearings are installed or 10---16 inch lbs. if original bearings are installed.
If total rotational torque is not as specified, repeat steps 4 through 10.
If drive pinion was removed, remove differential case and shims, then proceed to ``Drive Pinion & Bearing Shim Adjustment'' procedure.

[malibu795]

another tirck to doing this..

when adjusting then carrier L-R dont do the "preload" till after you got the desired back lash. then adda  .002" shim to each side bearing and tq then main caps for a total of .004" pre-load.  this will make removal and installation of the carrier ALOT easier

[team39763]

I'm gonna tackle this in the morning(Saturday).  Thanks guys.

And no, I'm not replacing the ring and pinion.  I'm just throwing in an Eaton LSD.

[team39763]

I don't seem to be doing something right.  Is a service spacer the same thing as a shim?  There were no shims in there when I pulled out the other carrier, just two large spacer type things(maybe they are shims?).  One was .231, the other was .240.

[VileZambonie]

That is a replacement for the factory installed THICK shims

[team39763]

Ok, these are thick factory looking pieces.

[team39763]

Here's what's happening.
1. I install carrier with bearings(no shims).
2.Install left bearing cap and leave bolts loose
3.I measured the old spacers .231 and .240
4.I remove bearing cap because spacers/shims won't go in with it installed.
5.I install spacers on both sides.
6.I do my best to measure backlash which comes out to be .08 or .09.  I'm pretty sure I'm not setting up my dial indicator correctly.
The sideplay is about .20(estimation).  But like I said I'm not setting up my dial indicator correctly, because I can't seem to get a good reading for the backlash.  How should I set it up?

[team39763]

Alright, here's where I'm at now.  Got the backlash to .038 and preload I'm not too sure, but the carrier doesn't move at all.  I'm thinking I need to remove some of the shims I added to the right side and put them on the left and see where I'm at then.

EDIT: That didn't work out...I guess it was too much preload.

[team39763]

HaHa! My wife came and helped me get it done.  The gear pattern looks similar to the ones I seen on the net.

[SUX2BU99]

Nice! So what was the problem? I sure hope it works out well for you.

[team39763]

The problem was me...I was so worked up and nervous about this part of the project that I just couldn't wrap my mind around the directions/advice.  I was reading the words, but not understanding any of it...like my mind was blank.  My wife got me focused and we threw a huge tarp over the truck to block out everything, then we went under the bed and got it done.  It actually wasn't that hard, but we still gotta see if they howl...we'll see in about a week when I get my new driveshaft.

[SUX2BU99]

Yeah that's funny how that can work out that way, eh? Glad it worked out for you. So did you G80 fail on you or was it still okay?

[team39763]

The G80 still worked perfect, but I was warned that it wouldn't last long under drag racing conditions, which is all my truck is used for.  I sold my G80 for $70.  I plan to buy another G80 in the future for my 4WD S10.