Rear Diff Smells like a Sewer PLUS: ID these diff parts???

[wired1000]

The bearings will not be the problem. Without lube the gears will be what gets damaged. The ring and pinon slide across each other. you need to make sure they are not scored or they will go away fast. The bearings roll on the race and in one mile probably have no damage at all.



What should I look for to be able to tell if they are scored or not? Is this going to be pretty obvious?

 

[mobileauto2000]

The gears should have a smooth surface. If the surface is rough or a dark blue it could become a problem.

In one mile of driving the gears may or may not be damaged. But if the shop is willing to stand behind their mistake I would be more concerned about the gears.

Just a thought. If this is a long established repair shop. Not likely to go out of business any time soon. Just ask them to give you a written year warranty on the carrier bearings and ring and pinion gears and pinion bearings. If you are going to have a problem it will show up within a year.

Luke 18:42 Then Jesus said to him, "Receive your sight; your faith has made you well."

 

[wired1000]

I'm taking it in on Tuesday morning of this coming week. The shop has been around 30+ years, so I don't think they'll go out of business, but we'll see just how willing they are to stand behind their mistake. The guy called me yesterday and was giving me some BS about how they *must* have put oil in, because their computer inventory was showing 3 quarts had been used. I replied with something like "Do you think I'm making all this up? I just want to be able to drive around... I have no interest in pulling off some elaborate hoax..."

Anyway, I'm gonna take it there Tuesday and actively participate in pulling it open again, examining the gears and bearings, and getting as much warranty as possible, as well as my money back for the tow and shop #2's inspection.

 

[mobileauto2000]

I would not be surprised if the employee that did the job took the oil out of inventory.
You can't tell the boss you put oil in it if the oil is still on the shelf.
I have been real lucky in that my employees will admit their mistakes.

But in today's world most won't and that can put the owner in a bad place.
Does he believe the employee or the customer. He should believe you one you show up with an invoice from the other shop.

Most important. Don't take the attitude that they are incompetent but present it as the mistake it was. The old catch more flies with honey.

If you have a good attitude when you come in even if you have already been short with them will go a long way.

I am speaking from how i react to customers with problems and how their attitudes affect me.

Pro 16:7 When a man's ways please the LORD, He makes even his enemies to be at peace with him.

 

[wired1000]

I've been very positive and professional through the whole process. Like I said before, I've made mistakes before as well. The important thing for me is to resolve it in a way that doesn't result in me having to go through another rear-axle swap again anytime soon.

 

[mobileauto2000]

I figured you had a cool head from your post.

I was giving just in case advice.

I hope all goes well and looking forward to Tuesdays update.

Pro 16:9 A man's heart plans his way, But the LORD directs his steps.

 

[wired1000]

OK, so I went in this morning and they put it up on a lift (wheel lift, unfortunately, so we could not operate the diff while watching it).

Opened it up and got more of that sewer smell. I've been trying to put miles on the truck before taking it in and have driven maybe 50-70 miles, about 10 of which were at highway speed. Haven't been getting any weird noise from back there.

Anyway, the bearings had not turned blue. The gears also had not turned blue. I did notice that the gears looked slightly worn-down, though the shop people were telling me this is normal and is what happens when breaking it in. I was warned to look for "scoring" and I didn't see any scoring, it was just a sharp edge worn smooth. As far as metal shavings, there were maybe 1/4 teaspoon in total, all pretty fine-ground.

The shop seemed to think everything is OK. I still have to fight with them about getting my towing/2nd shop inspection money back (the owner wasn't in yet), but I guess I won't worry about it leaving me stranded. I'll open it up again and have another look in 1000 miles or so.

So my questions are: The diff fluid turns from clear yellowish to brown/sewer smell in a pretty short time (50-70 miles?). Should I be concerned?

My plan is to: 1) Get my money back for the towing / other inspection. 2) Try to get a written warranty on the gears from them. How long? Maybe a year?

 

[wired1000]

In other, possibly-related news, the truck is experiencing a "shudder" when accelerating. Felt mostly in 2nd and 3rd gear in the higher-half of the rpm range. It seems to be a function of engine load. I'm worried that this is related.

http://www.steelsoldiers.com/cucv/73832-shuddering-above-25-mph.html

This post describes pretty much the same problem and I suppose I will go through to check all these things but I'd appreciate any help on how to check the rear axle as I'm worried that something this shop did is the cause. Need to hold them accountable sooner rather than later.

 

[wired1000]

Well, I guess I got a year and 4 months out of it... The rear diff started whining maybe a month ago, and now it's a full-on howl. Taking it somewhere Thursday morning to have them check it out.

 

[wired1000]

I don't suppose anybody in Madison WI has a spare rear axle? or knows a good place to take a differential to get fixed? I'm hoping it's something like a bearing... something cheap...

 

[o1951]

Just seeing your posts first time.
When you said they found metal dust in the bottom of second rear, I knew it would not last long.
Anytime you find metal in bottom of anything - axle, transfer case, engine, trans, it is on it's way out.
Sewer smell and discoloration means problem - lubricant really overheated.
I have done changes on vehicles with over 100,000 miles, and oil came out clear amber, no rotten egg smell.
Changing parts means should set rear up again.
I have done it on Civy veh. need special gauges, takes time. Gears are expensive.
Suggest 3 options:
Buy NOS rear and install it yourself.
Tell competent shop where to buy it, let them buy install and warranty it. Generally shops will NOT warranty customer purchased parts, even though they buy same thing because if it fails, they often have recourse with supplier.
Bring it to a place that specializes in rear axle and driveline repairs and get an estimate.

 

[wired1000]

Yeah... this is what's so infuriating... is the whole reason I bought the NOS rear axle assembly (had it shipped via freight) was because I figured that'd be the last time in my lifetime I'd have to bother with the stupid thing. New brakes, new axle, new everything. Should've installed it myself, however difficult. I will say that I've put a **** of a lot of highway miles on this truck in the last year and 4 months. easily 40k (my odometer doesn't work quite right, so who knows really?) but yeah, darn diff should last like 200k or more

 

[o1951]

For civy paved road service, you are right - barring leaking seal they usually last life of vehicle.
Extreme service -Off road & rock climbing or deep water fording takes a toll tho.

 

[Skinny]

For starters...no 10 bolt will last that long. Sorry to hear about your axle failure but I hope you learned your lesson from all of this. One, you should have taken it back to the original shop and had them pull the cover to discover they didn't put oil in it. Some way back in the thread said they are not responsible for checking oil level...I call BS. Any pro would check for proper oil level, inspect the driveshaft ujoints, and check/adjust the brake shoes as well. All of that is part of installing an axle whether brand new or from a junkyard. They would have eaten some crow and made good on the repair being that they screwed up a perfectly piece of junk 10 bolt. Two, finding pro's is so difficult these days...you should have invested in some tools and done it yourself.

Skip the 12 bolt swap, you gain nothing except installing an older axle assembly which has been out of production since 1979. Either have a good driveline shop install all new gears, bearings, and a real diff (get rid of that gov lock) or upgrade to a 14 bolt.

Sorry to hear about your luck with a new axle but some of this could have been avoided.

 

[o1951]

GM used the "corporate" 10 bolt 8.5 inch diff in full size and smaller Chevys, Buicks, Olds, Pontiac, 4wd Jimmy and blazer, bronco, camaro, Z28, firebird, K1500 and K2500 pickups and 1/2 and 3/4 ton pickups.
They replaced the 8.2 inch about 1970, and continued to use 8.5 10 bolt to late 1990's. It was put on performance cars, pickups and 4wd, and was known as an axle that would take abuse.

The only problems I know of were axle shaft bearings. It is semi-floating, so there is only one bearing pressed into axle tube, and they occasionally go bad. We drained and flushed diff, replaced bearings, no issues. Do not know of any diff failures. Even the posi clutches held up on Z28 app.

 

[Skinny]

You're kidding right???

10 bolt as "an axle that would take abuse"



I wouldn't run a 10-bolt in a riding mower...

 

[rsh4364]

In the gm G-body world the 8.5 10 bolt is a much sought after rear,usually go for 1k-1500$,they were used in Buick GrandNationals and Olds 442s,not trying to start an argument,

 

[Skinny]

Yes, much better than the smaller 7.5" 10 bolt. They still have massive limitations in the truck world. There are many people with blown up open diffs, gov locks, destroyed axle shafts, etc. in stock form. They are money pits. I'm just stating if you are going to invest money into an axle, a better choice is to upgrade for the same amount of cash.

 

[rsh4364]

agreed if you can upgrade for same cost,do it,but the 8.5 is a pretty healthy rear,gov-lock maybe not,on a street/strip car they handle 500-600 hp and equal ft.lbs. easily...

 

[wired1000]

Skinny: Well, if you've got an upgraded axle with 3.08 gears that'll drop right in, selling for a couple hundred $, available in madison, WI or Chicago, IL, or somewhere along I-90, this weekend. I'm all ears.

Also, hindsight is 20/20. "should've taken it back to the original shop". Well... the problem with that is that these guys were total slimeballs who would've just put some oil in it, ****ed it up some more, and told me I'd bought a faulty axle. I guarantee it. Should've done it myself? Yeah, probably, but I had other obligations at the time that prevented it. And I needed a vehicle. So I didn't have a lot of options. What I should've done was check their yelp reviews first.

I can't wait until the day I stumble across a shop that actually has pro's, doing good to excellent work. Then, when I'm weighing paying $80/hr to somebody to fix something, I don't also have to weigh the risk of them screwing it up so completely.