Rear axle rebuild

[Wgesnerjr]

Starting in February, I noticed a howling coming from the rear of the truck. I did change fluid and seals during my build but otherwise left the axle alone. (so I'm not surprised it needs attention)

I have called two local rebuilders, Doraville Driveline and North Atlanta Driveline. Both quotes are out of my budget right now.

Anyone have a good experience with another service in Atlanta? If so please let me know.
Thanks.

[MikeB]

If you're even semi-mechanically inclined, I suggest you pull the diff cover and look for anything suspicious. All you have to lose is the price of a gasket and some gear lube. Also, push and pull on the pinion yoke to see if it moves up and down or fore and aft.

[Wgesnerjr]

When I did the seals, I found the axles were rusty. Just half the length had rust like it sat half in and half out of the fluid. Looks like the truck sat outside for a long time without being driven before i got it.

There were no chunks of gears so I cleaned what I could before.putting back together with the new seals and fluild. My guess is the bearings probably got rusty as well. Pinion felt fine at the time too. I figured this would eventually happen, so been expecting a rebuild

Just didn't expect 1700-2200 dollars. I know I want a posi unit and different gears but damn, I don't have that much especially right now with COVID.

Just looking for other options in the area so when this COVID thing is over, I can hopefully get it done a little less expensively.

[MikeB]

I'm not in the Atlanta area, so can't help. But if you have any performance/hot rod shops nearby, ask them for recommendations. And you might as well call the Chevy and GMC dealers. They typically have at least one guy who knows differentials, because Camaros used to eat them up back when they used the 7.625" diff.

$1700-$2200 is not a bad price for all new gears, bearings, posi, and labor, but "howling" may not mean all the parts are bad. Is this an 8.5" 10-bolt? And do you really need limited slip? That can easily add $500+ to the price.

[TrybalRage]

I just paid $1400 for new gears and a new limited slip in PA. So you're a little higher, but like MikeB said if you're in a financial pinch you can save a bunch by dropping the limited slip until later.

[Wgesnerjr]

Thanks guys.
Yes, this is a 8.5 10 bolt open rear with 2.73 gears.

Why I wanted a limited slip is in the rain with the 5.3, the truck has a terrible time leaving a stop light if there is even a hint of uphill travel. Wheel spin is almost a given and modulating the throttle is the only way to gain enough traction to eventually get it moving.

I would hate to do a rebuild and not do the Posi, (seems like double work to go back and redo later) but it looks like I'm headed in that direction. The truck is not a daily driver. Just occasional use. Right now I have been on the same tank of gas since 3/14 and it's still over 3/4 full. So not urgent but probably needed in the near future.

I will contact the local dealer and see what they have to say. They have not been helpful in the past, but worth a try.

The local hot rod shop on my side of ATL was "Sam's Garage" (yes, the TV show guy) But he closed his shop in December to concentrate on other things. The only other guy I know about is a Mustang guy. Guess I could see if he would do it.

Thanks again,
Jay

[blazer2007]

Mine did the same and I had no money to get it done. Mine was the pinion bearing even thou there was no slop.I watched alot of u-tube videos and bought a bearing kit and got it done in a afternoon. checked wear pattern and was close enough for me with the old gears. I don,t have a dial gauge. Be working for 3 yrs now with the odd howl on coast on a hill or a corner on coast . Is a 12 bolt 80 truck. Or check with some local drag racers,they always doing rearend work and probably know a good person. With all the things going they could use some extra cash

[Ziegelsteinfaust]

I tried rebuilding my axle, and here a few pointers to help with success that are not usually said.

Clean the hell out of the housing, and pull it out of the truck if you can. If you dont you will wish you did.

On the pinion there is a shim set up under its bearing. Get a bearing puller, and for the love of God get it. Otherwise you will play hell chasing your tail.

Order a metric ton of the pattern grease, and flux brushes.

Beg, borrow, or buy all the tools. Regret will be in the air if you dont.

When I finished my 8.5 rebuild I took it to a competent shop for a quicky check. Yes it cost $250. But the rear end was out of the vehicle, and clean. He adjusted my shim stack as I was a bit tight. I paid LA prices, but hard labor was done.

[MikeB]

Different tires might help with the slipping. Had a new Ford pickup that slipped on moderate acceleration in the rain, especially on right turns after after stop. Ended up ditching the OE tires and went with some Continental Cross Contacts. Problem solved.

Depending on the type of posi unit, you could actually slip sideways a little when going around corners in the wet. Been there, done that with an Auburn diff that I put in a 69 C10 12-bolt rear end. It would also cause one of the tires to chirp-chirp-chirp a little when going around a totally dry corner.

An old racer I once knew said limited slip diffs are for drag racers and off-roaders, but don't work as well as a standard diff for everyday driving, because of what it can do in corners.

[sweetk30]

take it out of the truck . do as much labor as you can clean / wash inside / then ask if they want you to pop the old guts out or leave them . some guys like the old so they know were to start there shim pack at .

u-bolts are cheep new and out of the truck loose might get you a better deal price in the end . find a good shop or person who does gears . 1 wrong setup and its all smoked . check some local 4x4 guys our or shops there always swapping in bigger / better stuff . you might find a good take out rear with what you want already done .

[Wgesnerjr]

Never thought about a 4X4 shop. Should be able to find a few still left in ATL.
Thanks for the idea.

[MikeB]

Which of these best describes your symptoms? Comments in red are mine.

https://www.knowyourparts.com/techni...rential-noise/

Diagnosing Differential Noise

Vehicles make many sounds. Most are normal while the vehicle is in motion. But there are times when a noise coming from under the car can be a serious matter. Here are a few common “noises” that may come from the rear axle that need immediate attention:

• A “whirring” noise while decelerating at any or all speeds is most likely caused by bad pinion bearings or loose pinion bearing preload. This condition is typically (and wrongly) diagnosed as a bad ring and pinion gear.
Did you by chance install a new pinion seal?

• A “howl or whine” during acceleration over a small or large speed range is usually caused by worn ring and pinion gears or improper gear set up.

• “Rumbling or whirring” at speeds over 20 mph can be caused by worn carrier bearings. The noise may change while cornering or turning.

• Regular “clunking” or loud “clicking” every few feet may indicate a broken ring or pinion gear tooth.

• “Banging, clicking or clunking” while cornering can be caused by broken cornering gears commonly called “spider gears”, lack of sufficient positraction lubrication, or worn positraction clutches.

• A “Rumble” while cornering or turning may indicate bad wheel bearings.

• A steady vibration that increases with the vehicle’s speed can be caused by worn u-joints or an out of balance driveshaft.

• “Clunking or clicking” when starting to move or getting on and off the gas might be loose yokes, bad u-joints or worn transfer case or transmission parts.

[sweetk30]

Originally Posted by Wgesnerjr

Never thought about a 4X4 shop. Should be able to find a few still left in ATL.
Thanks for the idea.

also 10bolt to 10 bolt same vintage if its 6 lug just swap the shafts and drums . this would make it a 5 lug .

just watch out tho last few years got 30 spline over 28 spline .