Rear axle problem 98 Chevy

[Rooster_86]

Hey y'all here's what happened...I was out campin' a couple of months ago and was leaving after dark. I got a little turned around and ended up lookin' at this creek right in front of me. Cool...I know where I'm at now. The way out is on the other side of that creek. Now I'm not the kinda guy that likes to take a good truck through the mud because stuff breaks. But I had been through that creek before on my four wheeler and it wasn't very deep. So I decided to go ahead and save time and go on through the creek. It turned out that I got stuck. So I hit the gas to try and get out which ony made me sink more: with mud and sandy water over my rear bumper. So my rear axle was fillin' up with that junk. I was there for 30-45 minutes until a friend of mine could come and pull me out. When he got there he told me that he had been there with his mud truck a couple of weeks before and had dug that hole out...nice huh?

Anyway...to the point: I have replaced all the bearings including the wheel bearings, the axle seals, the pinion seal, axle shafts, and my carrier. I cleaned up my ring gear and my pinion gear as well as the rest of the inside of the axle, and re-shimmed the carrier. My truck is still making a god-awful noise when the thing is in drive and those wheels get to turnin'. The only other thing I can think of is when I drove it home with all that **** in there it messed up the gears (maybe so bad that they can't be used) like you can't get a good enough pattern on them or something. So I was thinkin' about buyin' a new set.

Any suggestion on what the problem might be before I go spend any more money? I appreciate your time and any comments you might have to help me out.

[75K30]

Couple of quick questions before we move on to trying to speculate on what is wrong.

Where is the vent tube? Why did it fill up the diff with water? How much water ran through it?

alright, more on this later. You mentioned that you replaced all of the bearings and such, and you also mentioned that this thing is still making a terrible noise. One has to assume that this noise is what prompted you to replace all sorts of stuff.
Alright, you "cleaned up" the ring and pinion, and what does that mean exactly? Did you have to do anything to the surfaces of the gears?
What did the pattern look like, before, and after you re-set up the gears?
Many common problems with noise is related to an improper crush sleeve pre-load.
This can be a major problem.
If this bad boy is noisy, then it is appearant that the gear set-up is not correct, or one of the bearings was damaged, or permitted to run dry.
How much carrier pre-load did you use?
Did you use a case spreader to obtain the proper bearing pre-load?
My first verification would be in the gear pattern. If you removed any material from the gear sets at all, then you will need to replace them.
Have any pics of the pattern when you set it up?
Is the noise under acceleration, or deceleration, or when the truck maintains speed?

[Rooster_86]

The vent tube is right above the rear axle on the driver's side. Maybe 6 inches up. It was completely under water. And when I pulled the diff cover off the oil looked more like gray grease. Once I got out I drove back to base (I live on an air force base in NM), it's about a 14 mile drive and I didn't start hearing anything until about the last 2 miles. This is my first time working on a rear axle so while I've learned a lot, I am far from expert status. So I had a couple of more experienced friends help me. We used the auto hobby shop on base to do all of our work. They've got all kinds of cool machines there. We washed the pinion and the ring gear in the parts washer with solvent. There weren't any missing teeth and we didn't see any nicks or chunks missing. Some of the bearings were bought online and a couple along with the pinion seal were bought at NAPA. We greased all the bearings after we pressed them on and we never ran it without gear oil. The carrier came out of a 93 Chevy truck and looked fine. The first time it was taken apart the pattern wasn't checked. I was ignorant and maybe my friends forgot...dunno. My friends set up the pattern and all they said was that it looked good. I know that a case spreader was NOT used-I don't think the auto hobby shop had one-so the bearing pre-load could be the problem. The preload on the crush sleeve is about the same as before we took it apart, but could also still be wrong. All the preload was done by hand: "Yep, that feels right..." I unfortunately do not own a digital camera since my old one broke, so I don't have any pictures of the work we did. If we can get back to the shop tomorrow after work, I will try to borrow someone's camera and get some pictures. There is a deep humming sound while accelerating up to speed that gets louder the faster you go. When I get up to 30 mph I let off the gas and it makes a high pitch whining sound. Everything in the rear end besides the ring and pinion is brand new which makes me think that maybe between the gear teeth is too worn. In my mind it's got to be either the gears or the way we got everything put together or preloaded.

[436'd skylark]

Originally Posted by Rooster_86

The carrier came out of a 93 Chevy truck and looked fine. The first time it was taken apart the pattern wasn't checked. I was ignorant and maybe my friends forgot...dunno. My friends set up the pattern and all they said was that it looked good.


I The preload on the crush sleeve is about the same as before we took it apart, but could also still be wrong. All the preload was done by hand: "Yep, that feels right..." .

Probably just typed your own answers. rent or buy an inch-pound torque wrench and redo the crush sleeve. I would redo the carrier shims as well once the crush sleeve is set. Tell me you set the pinion depth?

[stumpuller454]

sounds like a bad "setup", what size rear end you have?

[Rooster_86]

One of my friends set the pinion depth and I have an 8.5 10 bolt

[75K30]

I am back. I think the guys have hit the nail on the head, and, I also believe that you too suspect what the problem is.
A bad gear mesh will be as loud as can be, and will ruin the gears in a quick way. They will start to get sharp, and your troubles will only get worse.
Now, you mentioned that you changed the carrier, and I am wondering why. The carrier cant really be damaged, and probably did not have to be changed. Assuming that you have an "open carrier" it should not have been damaged. I am sure that the set-up is the problem, and this could be anywhere from the pinion depth to the lash in the carrier, and even the runout.
Now lets think this out loud for a minute. You said that this thing makes noise under both acceleration, and deceleration. I would imagine somewhere,,,,,you could feather the throttle and coast,,,and maybe get the noises to go away???? This would indicate decent bearings, and would direct the problem more to the set-up than anything else.
Alright, it is entirely possible that the pattern looked alright, but how was this verified? How did you mark the gears to determine this?
If you did not have a torque wrench, one can only assume that you did not have any type of dial indicator to determine the backlash.
It is my opinion that you have a set-up that is simply too loose. The pattern might indicate a decent depth on the pinion, but if you can move the carrier up and down more than just a small click, or .010" it might be that your problem is simply in the carrier shims. This can be fixed, and does not really require a case spreader. You have the luxury af having a set of used gears. I love to set up used gears because the pattern is already marked.
Take some marking compound, and shim this thing until the pattern is exactly over the old pattern. This includes the pattern not only on the ring gear, but the pinion too.
Might mean that the pinion has to come out again, but crush sleeves are cheap, and it would be a good idea to replace it, and get the proper torque on there.
Hard to believe that an AFB auto hobby shop did not have a torque wrench.
Good old AHS usually has pretty good stuff.
Find a flightliner and have him turn in a "CHIT" and check one out of the tool crib for you. Just jokin, you might not get away with that, but there are several sources for a torque wrench. Worse case, you could rent one (free) from your local auto supply house. Many have loan a tool programs.
If you get the set-up right, you will have a quiet axle again.
Hats off to you for your attempt, and unfortunatley many first timers ruin thier first set up or two, but hey, you have to start somewhere.
Keep at it, and pick up a book, books are great, and get the right tools. Some you can do without, but you are gonna need a torque wrench and a dial indicator at a minimum.
Lots of luck, and since you live on a base, I can only assume that your are active, so, thanks for your service!!!!

Here is a little pic of what the pattern should look like.

[Rooster_86]

They checked the pattern by puttin some grease on the ring gear and making one full rotation. I replaced the carrier because it had a limited slip in it and the clutches were toast. The open carrier I put in was free (donated by a friend of mine). Us E-3s don't make much money and I didn't want to burn a bigger hole in my pocket by buying another limited slip. You're right- when I coast there is no noise. I did order a book and it will be in the mail soon. My job in the military is in a PMEL as a calibration technician and I actually calibrate torque wrenches pretty often. Thank you for your appreciation...it's nice when you know some people care about us troops! Thank you for all you're advice too! We're gonna tear this thing apart again and giv'er another shot!

[75K30]

Alright, here is where the problem with using grease is. Grease does not adhere well to the steel surface, and it can move when compressed. If it moves, you may not be seeing the correct pattern. It can be close. but close does not cut the mustard when it comes to gears.
Again, this can be salvaged, and I hope youe book comes in soon.

As you well know, that the checklists and manuals that you use are specific for a reason, and believe it or not, you have the resources right down the road. Take a visit to the motorpool, and makes a buddy. This guy or girl will have the gear set up in a T.O. and can make a copy for you. As you know, T.O.'s will be very specific, and will provide you a step by step method to proper installation. Follow the T.O., and maybe borrow a dial indicator, and that thing will be as quiet as can be.
Oh yeah, I forgot to mention above, that the correct marking compound is going to be a real requirement. This stuff will stick well, and not move like grease on the slippery gear. The motor pool will have some yellow stuff that will work very well.
Again good luck.