Leaking axle shaft seal on rear end, need help finding parts

[BigBadJohn]

I have a '98 K1500 Silverado Z71, extended cab, 3rd door, shortbed, 5.7l engine, automatic transmission. I looked up the RPO codes and I have a 3.73 ratio locking rear end.

I was in a parking lot driving a few days ago and hit my brakes and heard a metal on metal grinding sound coming from the back. I took the drums off when I got home expecting to see my shoes worn down to the plates. The driver side looked fine but on the passenger side when I removed the drum the small springs that push on the shoes fell out. The pins and keepers were nowhere to be found either. One other thing that fell out was the cylinder puck. The shoes aren't being kept in place and the self adjuster is locked up. The shoes were pushed outwards more toward the inside of the axle and less toward the outside. The drum also has some decently deep grooves worn into it. I'm guessing all of this was caused by the self adjuster locking up. I also noticed that the brake dust was soaked with a thick oil which couldn't be anything other than gear oil or brake fluid and it definitely didn't smell like brake fluid. I looked at the axle seal and it appears that it could be deformed or scarred, possibly by brake hardware ricocheting everywhere inside.

I'm going to replace the shoes, all brake hardware, the self adjusters obviously and one if not both of the drums while I have it all torn apart. Especially at RockAuto's prices. Brakes are one thing I can handle and have done plenty of times. However I've never worked on an axle other than changing out fluid, gaskets, and an inspection cover. I'm having a hard time finding the parts on my own for the axle without tearing the rear end apart to measure so I can be for certain that I'm ordering the right parts.

I already have the inspection cover and seal and I have whatever gear oil the Chevrolet dealer in town sold me last year. I believe it's the same for the rear end, front end, and transfer case? I can't remember. I just remember I bought enough to change the fluid in two if not three things. I'm replacing the C clips on the inside since they're cheap and I don't want to risk one breaking while going down the road. I also want to replace the bearings on both axle shafts and the seals. The bearings and seals are what I'm not so sure about.


It's a 10 bolt pumpkin cover so from what I'm seeing I have 8.5" gears. And the drums are 10" drums. If I'm taking both axle shafts out of the rear axle to replace bearings and seals what else should I replace while I'm in there? It's harder to find free schematics on google images now due to these paid schematics websites flooding the search results. And RockAuto seems to have the same type of part in more than one place depending on how they word the part type which complicates things for me and makes me second guess myself while trying to find the right part. I could really use some help narrowing down to the right parts if you could. Thank you.

Also, what brands of brakes, bearings, and seals are brands to stay away from on RockAuto's website? Some are common brands I've seen before and other brands you don't see at brick and mortar places like O'reilly or AutoZone.

 

[Schurkey]

Is the adjuster just under the wheel cylinder, or is it at the bottom between the shoes?

>>>If your adjuster is just under the wheel cylinder, do yourself a REALLY BIG favor, and shitcan that entire brake assembly.<<<

I would no more put money into that crappy Twin Leading Shoe design than jump over the moon. When it was me, I slapped a 14-bolt semi-float rear axle assembly in place, which got me the better (and bigger) Duo-Servo rear brakes.

If your adjuster is at the bottom, between the shoes, you've already got the better-design rear brakes.

Rear axle grease when you have G80 Gov-Lock must be the sort with NO POSITRACTION ADDITIVE. If the bottle says it's got posi additive, you've got the wrong stuff for the rear axle. It'll work OK up front. My transfer cases take ATF or "Auto-Trac II" not gear lube. If there's a model of transfer case that still takes gear lube, I don't know about it.

Brake drums and rotors are all Chinese. Therefore, they're all exceedingly questionable. Same goes for any discount-priced bearings and seals. I'd be looking for Timken or SKF and hoping they're not junk.

I've been buying Performance Friction Carbon-Metallic brake pads. Made in America. Don't know if Rock Auto carries that brand.

If the C-clips and the axles and axle bearings aren't worn, I wouldn't replace 'em. It's too likely the "New" parts will be lower quality than what's in there already. Look at the C-clips, the C-clip grooves in the axle shafts, the bearing surface near the outer end of the axle shaft, and the center pin of the differential.

If you INSIST on rebuilding Twin Leading Shoe rear brakes--and I don't recommend that--be sure the park brake cables are in good condition, and that you USE THE PARK BRAKE. Failure to use the park brake means the rear brakes won't self-adjust.

 

[delta_p]

When I replaced rear wheel bearings, axle seals, and rear pinion seal recently I used these part numbers. This was on a '96 C1500 but may be same for the '98 K1500. At some point in during these years the rear pinion seal was different because I had to go back in years to get the part number and take measurements to determine the old years seal worked.

R Wheel Bearing GM 12479031 or ACDelco RW20-10
R WB Oil Seals GM 12471686 or ACDelco 291-315
Pinion Seal National Oil Seal 710506 or GM 26064028

 

[BigBadJohn]

Thanks for your replies. It’s greatly appreciated. I should have included the general state of my truck and my intentions with it. Other than my wife’s town and country I have the Silverado and a diesel Jetta. The Jetta is my daily driver and I only use the truck when it’s necessary. I pull my utility trailer (6.5’x12’ tandem axle) on rare occasions. Sometimes not even once a year. I use my truck anywhere from twice a month to twice a year. When I remember to I try to start it and drive it every few weeks around town for a few minutes to keep the battery up and to keep the cobwebs out of it so to speak. I bought the truck with supposedly 62k miles. If it really was that low then they were really rough miles. I knew going into buying it that it had some problems (headliner sagging, previously painted, etc). I was also aware the truck had either been rear ended or backed into something kind of fast as the bumper and trailer hitch are quite noticeably angled downward (I have to use a 5” drop ball hitch upside down when I pull my trailer). The frane is kinked pretty good where the hitch bolts to the frame. Since buying it my cab extension has rusted out at the bottom on both sides. I hit a deer last year going 75-80 mph without slowing down (late for work) and have been driving with a bent bumper, grille barely being held on, bumper to body filler, right filler panel, both lower right light assemblies, and all three lower right bulb sockets completely obliterated. My exhaust has also been slowly falling off for the last year. First was my tail pipe spout dragging down the road, then the last 3 feet of my tail pipe dragging down the road, two weeks ago I discovered my muffler recently broke off and is missing. I have a problem, when stopping and almost completely stopped, going only a few miles an hour, rather than continuing to a stop my ABS module/motor engage and I can no longer control my brakes. I’ve grown accustomed to maintaining a more than safe distance behind people. This was an issue before the shoes failed. One last noticeable problem I’ll mention is the cab is obviously rusted out at the top right where it meets my windshield. If it rains a little bit water barely drips from the top. But when it pours down a puddle forms on the rubber floor mat and I’m assuming my drivetrain control module gets wet because I lose overdrive, my speedometer, my tachometer if I recall correctly, and my transmission is also very sluggish to shift.

That said, all problems aside, I can’t afford a different truck or even a loan for one. My wife stays home with the kids and I wouldn’t have it any other way, but due to that money is kind of tight. Would I like a 14 bolt differential? You bet, I’d love to have hydro boost brakes too. Unfortunately this truck is a far cry from being a good candidate to fix up. I’ve had to replace all of the brake lines other than the coil wrapped line on the rear axle, all of which has been routed in a rather crappy and crude manner due to every time I’ve done the work it was out of necessity and in Oreilly’s parking lots (I’ve learned to keep a flaring tool in the truck) due to lines rusting out and bursting. And even the axle line probably needs replaced soon. The fuel lines and transmission cooler lines are starting to look scary in some spots.

I am planning on getting AC Delco seals and Timken bearings. I had actually arrived to that decision before anyone replied. I’m going to go with the Bendix shoe/hardware/cylinder kit due to halfway decent truck forum reviews on the shoes as well as the fact that the kit on RockAuto for $55 closeout I also stumbled across it on Amazon for $11.87 and it was prime (free shipping) and it also had a $5 coupon so I got it for $6.87 shipped plus tax. Amazon and that place Rock auto ships from must be the same because both only had one in stock. I’m planning on getting Raybestos drums at $28 each.
When I buy and install the new brake hardware I plan on putting a very small amount of anti seize on the threads. (And I have every intention of using the parking brake when I do my occasional drive in it to keep everything freed up, thank you very much for that suggestion) if I recall correctly I replaced the front to rear parking brake cable and both rear whip sections a few years ago when I replaced the shoes due to cracks in the plastic sheathing and wear marks.
As far as the c clips go I’m going to buy a 10 pack of AC Delco clips just in case the old ones have noticeable wear as they’re only a few bucks. I’m also planning on replacing the pinion shaft lock bolt because it’s only $1.53 and I’ve heard of it snapping on people some tome after working on the differential and not replacing it.

As far as the lube goes I’ll have to see what GM sold me and how much I bought to remember what it was for. I’m going to research it all again to make sure I know what everything was for so I don’t destroy my drivetrain.
I just need my truck to reliably start, run, drive, and stop. Some day I’ll hopefully get the

 

[BigBadJohn]

3/4 ton or 1 ton diesel pickup I want so I can pull the boat and camper that I’ll someday hopefully get. Until then I don’t have any other option than to keep this one running

 

[Schurkey]

I have a problem, when stopping and almost completely stopped, going only a few miles an hour, rather than continuing to a stop my ABS module/motor engage and I can no longer control my brakes.

I've heard of this happening, but I don't know what causes it. Someone here does, though, and I hope they'll reply.

I plan on putting a very small amount of anti seize on the threads.

On the threads of the adjuster? Or on the threads of the lug studs?

Anti-seize is the wrong product for the adjuster threads. You're looking for "white grease".

As for the lug studs, everyone will tell you anti-seize is a no-no there, too. I have used it, but I adjust lug-nut torque downward by 20% so I don't stretch the studs due to the reduced thread friction.

 

[delta_p]

The low speed ABS could be the wheel speed sensor drop out. Here's a video diagnosis but it's a long one.

xc_hide_links_from_guests_guests_error_hide_media

 

[BigBadJohn]

I've heard of this happening, but I don't know what causes it. Someone here does, though, and I hope they'll reply.



On the threads of the adjuster? Or on the threads of the lug studs?

Anti-seize is the wrong product for the adjuster threads. You're looking for "white grease".

As for the lug studs, everyone will tell you anti-seize is a no-no there, too. I have used it, but I adjust lug-nut torque downward by 20% so I don't stretch the studs due to the reduced thread friction.

Are you talking about white lithium grease? If so I have a couple spray cans of that. I used to use it on the window tracks in my GTP before the transmission went out.

 

[Schurkey]

That'll work.

 

[BigBadJohn]

Got the shoe kit I paid $6.87 for. It’s exactly as the picture shows. Both hydraulic cylinders, the shoes, and full hardware kit including the adjusters