okay, so i changed my dif. fluid in the rear end... or rather i changed the palmfull of tar that was in there...

it was black and REALLY syrupy... and smelled really bad guessing it was burnt...

no big chunks came out... except a very fine layer of shavings... but i dont know how long its been since the oil has been changed...


afterwards, i took it for a 10 mile or so drive reaching speeds up to 65, and it didnt make the grinding noise again... but it does still make the whooshing noise... Im gonna change it again in about 4000 miles when i do my next oil change just to be safe...

i also cleaned my dif. breather while i was there... it was sooo caked with crud that the little cap on it wouldnt even move...

Thanks to Grant, Slowstrike, and DC... you guys are awesome...

 

That sounds like the ring and pinion have a ton of slop in them. I would try and check that out.

That's interesting on the size. When i did mine, the 24mm was too loose. a 15/16" fit perfectly on mine and they were both the same size.

 

Pretty much all gear oil has that awful wreaking smell, new or old. Makes you gag almost. But it does worsen with age. Refill the diff. Pour in enough fluid that it's coming out of the check/fill hole and screw the plug in quickly.

If you ever go to top it off, don't forget to make sure you haven't been driving it for a while and everything is back to the outside temperature...gear oil expands quite a bit.

 

Do you drive in water up to the breather on your axle? that can make that fluid pretty nasty.

Im afraid thats what my front diff fluid is going to look like its sucked a little bit of water and hasent been changed in quite awhile.

 

no water...
and i only got about a quarter cup of black syrupy oil out of it...
but i will be extending the breathers up to the body because, hear tell, where i live its supposed to flood again this year... so, 2 feet of water will be my everyday cruising...

EDIT: Anyone know where the drain and fill plugs are on my transfer case???

 

another update...
im 100 percent sure that its the rear dif...
i need to change the pinion seal because its leaking there... a lot...
i know that the pinion seal is only about 15 bucks, but what gear oil do you guys recommend running? and what weight?
also, i bookmarked and memorized roger/4crawler's guide to replacing the seal, but do you guys have any other tips? should i check the seal on the back of the t-case too since it looks to be leaking from there a lil bit too?

also planning on greasing all the points while im down there...
any other cheap tuneup ideas i should do while im there?
thanks guys!

 

well, about 2 weeks ago, my rear end went BANG! click click click click...
i was pretty sure that i chipped some teeth off of the ring gear...

so, i got a hold of ZUK and ordered a set of 4.88 gears to replace the wasted 4.56s...
after waiting for the ground to dry, i pulled the rear dif, and lo and behold, the pinion gear shed all of its teeth into the bottom of the dif...

im kinda surprised that it even drove at all!
so, i still have to clean out the axle tubes and put in the new third, but thats gonna have to wait until tomorrow as will pics... school takes prescedent...

also, thanks to matt16 for his writeup as it was so easy to follow... one thing tho, might wanna add in a setp about taking off the ABS sensor... i forgot about mine and almost ripped it off!

 

so space-junk has junk in his trunk?

good luck. you got both front and rear gear sets, right?

 

Good choice on the 4.88'd

 

no abe, i could only afford the rears, so until i get my income tax check i am stuck in 2wd...

thanks jay... im actually building my runner based on your truck... only not blue

 

really? Thats awsume I like your progress so far

Being stuck in 2wd kinda sucks, but at least its not 1wd I ran with my 4.56 front and 4.88 rear for about 2 weeks, that was fun... I used 2wd low quite often

 

ITS IN!!!!

SHE LIVES!!!!

NO MORE STRANGE WHIRRING NOISES!!!

i havent driven in my truck and been able to hear the stereo on volume 10 in a year...

thanks so much guys for helping, and thanks to ZUK for the excellent work...

 

I'm surprised the gears made it that long with no oil bathing them.

Glad the writeup helped. I don't have ABS, and I haven't ever messed with a ABS diff before. Could you write a quick blurb on dealing with the ABS pigtail and I'll C&P (with credits) in to my writeup?

 

I love the smell of diff oil in the morning . And Matt16's rightup is great! Its what got me through my diff change. How do you like the 4.88's?

 

i feel like im driving a racecar...
and now i can start out in 2nd without it chugging/bucking on me...

and matt, no credit needed... all that is required to remove the pigtail from the housing is a 12mm socket to undo the 1 support bracket from the 3rd member outer ring, and 1 bolt holding the sensor down... then get a big long flat head screw driver and work your way under the sensor and slowly keep prying up on it till it pops out...
took me about 3 mins to pry mine out...

also, its prolly best to do that after you have the dif out on the jack... makes it easier to turn the wrench...

 

The gear oil when my old 4.10 was in there nearly made me vomit... Synthetic oil ins't nearly as bad a smell. I wonder why gear oil has that sulphur smell when engine oil smells so good?

Glad the writeup was helpful.

 

CONGRATS!!!!!!!!!! I'm glad to hear you got it fixed! If I'd of know you were doing it, I could have tried to come over and help. I can't wait to regear my truck!!!!!!!! : ) But I'm planning on doing it all at the same time. Which explains why I haven't done it yet.

With your front diff. You can remove the entire 3rd member and do the work on the bench if you would like. But that sucker weighs about 100lbs (Or MORE). I removed my buddies once. It wasn't fun. lol All to remove the oil pan. Go Figure!

Just a thought. I might not be a bad idea to remove your front driveline, until you regear your front diff too.

Good Luck!! Keep us posted

 

thanks grant... i didnt even think to call you for help... its cool tho... the hardest part was laying on my back on the concrete when it was 40 degrees outside and i was in shorts and a teeshirt... lol...

but, yea, i was thinking about just pulling the front dif out all together...
sucks that im stuck in 2wd, but hopefully i can afford a rebuild when i get my tax return...

ill ask for your help when i do THAT... :razz:

 

Ya, rear diffs are easy! I haven't actually taken a 7.5 apart. Just removed it from the truck. But I'll try to give you a hand if I can. One of these days I'll have the parts and ambition to tear my front axle apart and change the gears.

Did you purchase an already assembled 3rd for the rear? Where'd you get it? If you don't mind me asking

 

Reviving this thread. I've run into something similar, but not quite as serious yet. Mine is only whirring under heavy acceleration.

Who is ZUK & how can I order the same gears there?

I checked the links in matt16's sig, but I can't find this write-up. Link anyone?