Well I took out my carrier today. I guess my pinion bolt backed off since i had really no measurable preload on the pinion and it was leaking fluid everywhere. Here are some pics. One of the two carrier races have these scratches on them. Also the inner pinion race has scratches. I can feel them with my nail. Do these need replacing? Shop installed everything about 10 years ago and maybe 10k miles. It was a ratech kit. Thanks

 

The pits bother me more than anything.
Replace.

 

what causes that to happen? bearings stamped Koyo Japan.

 

Did you have a lot of gear whine before you pulled it apart?
It's hard to tell from the pics, but I don't like the looks of your pinion gear.
Inspect your gears more closely.

 

No noise, just a leaky pinion.

 

Debris, probably casting flash from the new gears.

 

Do what will make you sleep better at night regarding reuse or replace.
If reusing, I would run some crocus cloth over those pitted areas.
Make sure there are no high spots. The pits will only hold oil.
After pinion seal is replaced, torque the nut to 150 ft/lbs and use red Loctite.
While you have it apart, remove 1 ring gear bolt at a time, clean the threads with solvent, dry with compressed air, retorque using red Loctite. Unless you know for sure this was done 10 years ago. Be aware, the RG bolts are most likely left-hand threads.

 

The gears are motive 3.42 and its an eaton posi.

I looked it up and the install was done in Nov 2008.

Heres what the gears look like.

 

Yup, that's destroyed.

Probably not debris. Looks like water got in the fluid and pitted the races while they sat.

Sometimes it's the little things that get you.

Can't run that for any length of time... every time a roller goes over it, it'll dig in a little more. Won't be long before you're back in there if you try to skimp on acoupla pennies. Not worth it.

Ring gear bolts are indeed LH thread in this model of rear, as they are in most.

Gears look fine.

 

Probably not debris. Looks like water got in the fluid and pitted the races while they sat.

OK. I'm not trying to start a debate here.
But doesn't oil float on top of water, even if the oil is heavy weight gear oil?
That would mean that if any water did get in there, wouldn't it be sitting at the very bottom of the housing?

Please explain if I am wrong.

 

Get another kit from Ratech and get their smart sleeve option. You will need a dial type inch pounds torque wrench. I did mine using the smart sleeve and was able to sneak up on the crush value with a cordless 1/2" impact. Your gear pattern is about the same as mine - aftermarket 370 gears. Just reuse the same shims and you should be fine.

Rick

 

Doesn't make any sense to me either. My 9 bolt sat for 11 years and had no such pitting. That's probably installation damage from knocking the races in and out during slimming etc. Or break in debris danage, or something like that.

Even if you emulsified a whole bunch of water into the oil (was it watery in there?) then the oil in it would still most likely prevent major corrosion.

I've never seen isolated pitting like that from water. There would be other, more extensive corrosion if there were enough water content to cause pitting like that. Also the pits would be black, and there would likely be water marking in various places. Like a ghost image of the where the water was pooling.

Rick

 

I agree.

 

It's hard to tell from the pictures exactly what damage is done to those bearings, but I do see some pitting. This will only get worse. I don't think I would use them again.

 

I didn't see any water when I drained the fluid. I'll go ahead and replace all the bearings and races, don't want to have to do this job again. I'll look into that ratech smart sleeve.

One more question, will i have to set the pinion depth and gear backlash when changing bearings?

 

will i have to set the pinion depth and gear backlash when changing bearings?

Technically, YES. But IF the replacement bearings and races are exactly the same, then just keep your shims in order, and put it together. When you check your backlash, you will then know if you are good to go, or if there is a problem.

 

There is a very good chance that it will go back together fine with no adjustments needed. In your case you have already disassembled it without checking the backlash or the contact pattern, so you will have no idea whether it changed or not. If backlash is within specs then your only choice is going to be to run it as is and hope for the best.

 

No, oil does not float on water. Water is denser than any kind of petroleum oil.

Problem of course is, when the rear is running, the oil is getting all churned up and circulated in there, and any water in the oil gets emulsified; then when it stops and sits, sure, the majority of the water sinks to the bottom, but what's trapped in the parts stays there.

Worst I ever saw was one I had in a car I used for pulling a boat many years ago. One of the axle seals developed a leak one summer, I noticed the fluid in the brakes. Needless to say, ALOT of water got in it at the boat ramp when it went underwater; the next spring when I went to use it the first time and out of the clear blue it roared like a lion and I pulled it apart, that photo up there is pretty much the same as what I saw.

4WD people have that happen all the time. I see it in those quite a bit as well.