Rear End Advice?

[McLeod]

We wanted and looked at lots of '03 2500HDs, hoping to find the "perfect" one for us...2WD with G80, for street/daily driver and occasional towing of our travel trailer. Unfortunately (...actually, fortunately) we found the almost ideal one and bought it, however it has an open differential. We "assumed" that it would be (relatively) simple to have a local shop install a G80 and properly re-set up the ring gear. Now, in the real world, we're having a heckava time locating anyone who seems to have the experience, expertise and tools to make the change for us (There are several who quickly say "you bet, I can do it!" but, when questioned, they admit that they have either "never actually done it" or have actually only worked on a "couple" of smaller rear ends. Of course, there are plenty of suggestions that we "find a good used rear end", but we hesitate to go that route as ours is truly like new and we'd rather avoid the axle assembly R & R. ...we really do want the "limited slip" simplicity of the Gov Loc, however, although we have considered the Richmond Gear PowerTrax No Slip as it doesn't require removal and re-set of the ring gear (there seems to be some driveability issues with the PowerTrax, though).

Whew! OK, if anyone has followed the rambling along this far, "all" we're seeking is advice and sharing of expertise. Is it unrealistic to hope to find ANYone who can do a good job of installing a Gov Loc AND correctly re-setting the backlash? (Is there anyone out there who may know/recommend a shop or individual in the central NC area who truly is qualified?). We'll greatly appreciate thoughts/ideas! Mc

[DwayneJ]

Have you talked to offroad shops? I do ring and pinion work myself but it is not an average shadetree project, few repair garages are capable and most dealerships don't even seem to have anyone on staff experienced much less willing.

 

I would STRONGLY suggest you look beyond the gov-loc, it is a completely idiotic design and frankly the biggest flaw I have found with these trucks sofar. A proper posi will turn both tires before one spins drastically.

[McLeod]

Have you talked to offroad shops? I do ring and pinion work myself but it is not an average shadetree project, few repair garages are capable and most dealerships don't even seem to have anyone on staff experienced much less willing.

 

I would STRONGLY suggest you look beyond the gov-loc, it is a completely idiotic design and frankly the biggest flaw I have found with these trucks sofar. A proper posi will turn both tires before one spins drastically.

Thanks, Dwayne -- info. much appreciated! I was zeroing in on the Gov Loc as it's what came in our '99 Tahoe and has worked well for 230,000 miles (4WD, all street use, little towing). On the other hand, we have an '83 C10 with an Auburn Posi that's worked great, too, so that may be a good or better alternative to the G80 (?). We're wanting to do whatever will last a long, long time and we sure don't want to have to "do over" because some inexperienced person tries to "learn" on ours. And, you're so right -- it seems almost impossible to find anyone, dealership or indy, who truly is experienced with this. Your advice on the Gov Loc is well taken -- we'll sure keep an open mind on an alternative to that for this "big" diff. (We did have axle bearings/seals on the Tahoe done by a local off road shop & they reused the old cover gasket so that it leaked fluid, and they failed to clean up the brakes where the fluid had leaked -- I had to fix that all myself. Sloppy work on their part.) We're still looking for a true expert. Thanks, again. Mc

[DwayneJ]

Something like a Detroit TruTrac will give good manners and since there are no clutches should not wear out. I don't understand how it does it but it uses gears to seemlessly split the torque.

 

The gov-loc probably is more bothersome to me than you because I actually live where we get a lot of snow. If you get one tire on ice and one on dry pavement and you don't notice the spin and lift off the throttle in time it about feels like you got hit at low speed from behind. That is also how they break, it is a LOT of shock to suddenly engage a stopped tire particularly if it is on a surface with good traction.

[cwendel4]

+1 on the true trac. I HAD a G80.

Have one in my 2000 1500 ext cab with 3.42. It is the best. I no longer have to worry about spinning that inside tire.

 

Now, to find one for my 07 silverado...............

[McLeod]

+1 on the true trac. I HAD a G80.

Thanks, Guys. Good info. and much appreciated -- thanks for sharing. Mc

[mkimber]

True trac is the way to go. Best mod I've done to my 2wd. It's been a long while, but seemed like it didn't require reseting the ring and pinion either. I changed gears at the same time so it didn't matter in my case.

[McLeod]

Thanks, Matt. The True Trac is sure sounding like the way to go. Now, if I can just find someone reasonably close here in NC to do the work (...and, do it right the first time;-). Mc

[DwayneJ]

When changing the carrier and reusing the original gears the pinion depth wont be disturbed but the backlash can change so it should be checked. There is a possibility that the backlash will fall perfectly in line but just a chance, no guarantee.

[Z45]

Any GM dealer can do this. Had it done myself before.

[McLeod]

Any GM dealer can do this. Had it done myself before.

...wish it were so around here. Most of our local dealers have been shut down and those remaining are loaded with new car service and warranty work. They don't even want to discuss this type of work as it's apparently more trouble than it's worth to them when they have plenty of profitable and "easy" work in the shop. The dealers I've contacted suggest finding a "good" 4WD shop...and, of course, they are around and willing to tackle the job. Again, though, when questioned specifically about doing the work on a 14 bolt full floater, few have ever been into one. I certainly realize that the most anyone can do is their best and "re do" if it doesn't work out, but I'd sure like to get it done right the first time. The more I get into this, the more it seems to truly be "rocket science" . In any event, the sharing of thoughts and ideas here is valuable and very much appreciated! Mc

[doverarjim]

Your are right it is almost "rocket scence" but not really, back years ago my brother and I would rebuild anything. man made it, man broke it we could fix it or fix it where no one else could!

We had two Chevelle rear ends to do back to back both gear changes to 4:88's set one when in like a dream we had it set up and back in the car in less than 2 hours, but #2 was a different story, 2 full days of setting pinon depth, and shimming the gears, and it still had noise it about drove us crazy, what did we do different who knows, finally put all new shimms in it and reset everything about ready to throw our hands up in the air and it worked like a charm who knows why!!

[McLeod]

Your are right it is almost "rocket scence" but not really.......finally put all new shimms in it and reset everything about ready to throw our hands up in the air and it worked like a charm who knows why!!

Yep, I'm actually amazed at how well most come in factory-new vehicles set up so well. I've actually been into a couple over the years, too, installing new carrier and pinion bearings..."thought" I had torqued the crush sleeve enough only to have the pinion bearings go out right away. Then, of course, the backlash turned out to be not exactly right either, so the whine was evident. It just seems that you have to do a LOT of them to get it right all (most?) of the time, although Dwayne's point (and, your experience) is well taken, too, that with minimum change the backlash can sometimes just fall right back into specs. In any event, there's good news for me on this, now, though -- I've found a truly experienced expert nearby who can/will do the install and re-set-up for me...as soon as he can get a "rountoit" in a month or so. So, I'm just gonna wait for him and get'er done right . Mc

[DwayneJ]

Far as the crush sleeve Ratech has a new one called a "smart sleeve" needs less torque to crush yet is supposed to hold up better than solid shims.

 

For those not familiar the standard crush sleeve takes several hundred pounds of torque to crush, I am talking grunting with a 3 foot bar. Most guys including myself do it the "wrong" way with an impact wrench.

 

Measuring pinion bearing preload can be a trick too since not many of us have a beam type wrench that will read down around 25in. lbs