73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: team39763 on September 15, 2009, 12:22:58 am
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I bought an Eaton LSD and I'm about to install it in a few days. I had planned to install it tonight, but one of the new bearings fell apart in my hand. I was standing there in my living room and holding the diff and spun one of the bearings, then the outer shell and all the little rollers came apart. Anyways, I'm taking the diff to a nice shop in the next town to have the bearings pulled off and new ones pressed on. Any suggestions on what brand?...I'll need a specific part# because none of the auto stores seem to know what I need. We have an O'Reilly and an Autozone. The bearing that fell apart on me was the "National" brand made by MOOG and Federal Mogul(MADE IN CHINA).
I'm using the same ring and pinion. There were no shims when I pulled the G80, but I have a install kit with shims and gear paint. I didn't touch the pinion, so it's still in place. It's an 8.5 10bolt with Richmond 4.56 gears.
So here's my questions:
1. What bearings do I need for the diff?
2. Which way do the bearing caps go? The rounded side towards the center or the to the outside? I know which is left and right, they just fell and I don't know which part is the top/bottom.
3. I don't have a dial caliper or anything, can I set up my gears by looking at the pattern on the gears with the paint?
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Kudos to you dude for attempting this yourself! I've been looking into if I could attempt this and it looks kinda much to me, but that's just me. Go to ringpinion.com and check out their FAQ and Tech section, then read the installation instructions for a set of Yukon gears. It's pretty informative on what to expect and why you would want a dial indicator.
One thing that apparently was pretty imporant is if you are reusing the same R&P, you would have wanted to measure the backlash it was at, since you would want to reset your R&P back to that when you put them back in. If you don't, you run the risk of wearing out your R&P because a wear pattern has already been established. I wish you luck though and a successful, quiet Eaton installation! I'm out $2k for my rebuilt Eaton and R&P install and it's STILL not right :-\
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If I ever want a gear change or to do another car, I'm definitely gonna try it myself. My take is the main cost you are paying for is the tedium of pulling/reinstalling the diff/pinion until you get the shims right. But I wouldn't be interested in attempting it without my own press (for pinion bearings).
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Just look up the bearings for your rear end application. Witness marks are important so don't mix up the caps. Get a dial indicator with magnetic base and digital caliper before you do the swap. Harbor freight has them cheap.
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Thanks Vile, I'll check out HF and go ahead buy the tools I need.
Kudos to you dude for attempting this yourself! I've been looking into if I could attempt this and it looks kinda much to me, but that's just me. Go to ringpinion.com and check out their FAQ and Tech section, then read the installation instructions for a set of Yukon gears. It's pretty informative on what to expect and why you would want a dial indicator.
One thing that apparently was pretty imporant is if you are reusing the same R&P, you would have wanted to measure the backlash it was at, since you would want to reset your R&P back to that when you put them back in. If you don't, you run the risk of wearing out your R&P because a wear pattern has already been established. I wish you luck though and a successful, quiet Eaton installation! I'm out $2k for my rebuilt Eaton and R&P install and it's STILL not right :-\
For some reason I didn't even think about checking the lash or anything on the old carrier(not that I had a way to check at the time). I may need to get a pro to help me do this.
If I ever want a gear change or to do another car, I'm definitely gonna try it myself. My take is the main cost you are paying for is the tedium of pulling/reinstalling the diff/pinion until you get the shims right. But I wouldn't be interested in attempting it without my own press (for pinion bearings).
I would gladly pay the price for a professional install, but the shops around here won't stand behind their work, not only that, they seem just as new to posi/gear installs as me.
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get your self some "blue" oo any off color grease if not supplied for contact pattern. or use the stuf supplyed.
measure back lash BEFORE removing the carrier. then reset the new carrier and ring back tot he previose back lash seting. this will allow and is critical to maintianing long R&P life.
you will need this to measuer back lash.
http://www.summitracing.com/parts/SUM-900016-1/
(http://static.summitracing.com/global/images/prod/large/sum-900016-1_w.jpg)
bearings get pressed on to the carrier ends..
no press..
here is a trick place the bearing in the over heat to ~350*F this will case the bearing to expand. about .001-.002"
place carrier in a bag. set bag and carirer in ice water. this will case the case to strink .001-.002"
then drop bearing on case allow everything to warm up/cool down nauturally ore palce a fan on it.
i would get this going before you start draining the diff and what not..
race. that is the part that slips over the bearing. the bearing goes on the carrier.
and yse you will need a dial indicator and base. see above link :)
caps.. if they dont have arrows. (they should they both face the same direction) fit them up on the axle housing they should be flush on the in-board side.
and most important take your time or you will be re-doing it ;)
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I took out the old carrier and sold it weeks ago, so I'm already in trouble. Can ya'll tell me this...how long will the ring/pinion last with the wrong backlash? The truck isn't running yet, I just need the truck to roll back and forth so I can install the motor. Once the motor is running, could I make one or two track passes to see how this gear works with the new trans/motor? I may want to change to 4.88's or 4.30's. This is a race truck and it's seen less than 50 miles over two years...in other words, it won't be driven much.
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Well, I can only tell you my experience. My original 3.40 gears were re/re when my rebuilt Eaton was put in, and it lasted 4 days. But, that was about 100 miles of driving back home from the shop (about 50 miles) and then back and forth to the dragstrip (about 50 mile round trip), and then 5 passes that night at the drags. It wasn't even making any noise until the next day after the drags when I went for a rip up through the gears. And then once they do start making lots of noise, you could still probably get a few hundred miles out of it before a tooth breaks or something. You'll basically know if it's okay or not whether you have very audible gear howl.
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Well I only plan to put about 5 miles or less on them and that's over a period of 2 weeks...driving to my test spot on the farm road. I'm pretty convinced that I'm gonna need new gears anyway. I just would like to test with the 4.56's before spending money on a new set.
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You need the correct pinion depth and the correct backlash or you won't only trash your ring and pinion you'll trash the differential too. Do it right the first time.
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OK, you guys convinced me. I'll do it the right way.
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I need to install my motor/trans, can I slap the wheels back on and roll the truck about 3ft without doing any damage to the rearend(without the differential in there)?
EDIT: I just did it and everything seems ok.
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I just ordered the tools, I guess it'll be a week or so before I get to mess with the gears.
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I need to install my motor/trans, can I slap the wheels back on and roll the truck about 3ft without doing any damage to the rearend(without the differential in there)?
EDIT: I just did it and everything seems ok.
yep as long as you are not apply power to them freewheeling them wont hurt them IE moving them around the shop and drive way.
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Ok, I got all my tools from Harbor Freight. I installed my gear on the carrier and oiled my bearing caps(they rusted while sitting in the cab of the truck). I sanded them down with really smooth sandpaper. I have been reading several sets of instructions/write-ups, but one thing they don't mention is how things go as far as the shims/retainer(looks like a really thick shim). Does it matter which direction that thick retainer thing goes in the axle tube? I'm assuming the shims would go between the retainer thing and the bearing race? I know I should have payed better attention when I pulled it all out, but it all came falling out when I took off the bearing caps.
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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.
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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
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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.
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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.
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That is a replacement for the factory installed THICK shims
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Ok, these are thick factory looking pieces.
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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?
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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.
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HaHa! My wife came and helped me get it done. The gear pattern looks similar to the ones I seen on the net.
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Nice! So what was the problem? I sure hope it works out well for you.
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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.
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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?
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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.