I work at an independant auto shop in so cal.. I called up my local chevy wholesale pars dealer and ordered some gear oil and filters for my lb7... I didnt know that gear oil was so damn expensive! Censored! Is it because the improved grape smell or what???? for what I paid for the 3 liters ( 60 bucks my cost) for 25 more I buy a case of red line snyth. (case of 12) i am temted to take it send it back and get the redline.. anybody run redline? I know they have been around for years and have a good reputation.. what do you think?

Running Modil 1 90wt since 5000miles no problems. Now have 21000.:)

take the overpriced gape juice back. i also am running mobil 1 since 5000, now at 21K also. wil

buy the grape juice from gmpartsdirect.com, or dmaxallitech (eric) for much cheaper than the stealer. other fluid may work, but GM says grape juice

I used RedLine

gmpd wont ship it. I use the Schaeffers in mine, can do both axle for about 65.00

Whats Up With The Royal Purple Stuff? Any Feed Back on It?

I use Amsoil. Great stuff, too.

I use Royal Purple and have had no problems. Although it's a bit pricey, it works great and does it's job, in my opinion.

I use RP through out the truck and no problems.

I run Redline in the rear end (75w140) and the trans (Hi Temp ATF). I've had good luck with both. The gear lube was about 1/4 of the cost of the grape juice.

TC

Understand if you are still under warranty it has to be the grape juice. Outside warranty you are on your own anyway so use what you want. Grape Juice has some Special Locker additive specifically for the G-80, at least that's the pitch from GM.

Dmaxalli Tech can probably confirm if warranty can be voided when other than grape juice used and there is a problem with the Diff.

Better safe than sorry at least for the first 36K IMHO.

Regards,

No reason it has to be the grape juice. GM cant dictate it. As long as its meets blah spec your fine. I have no reason to believe that GM will give you grief wit non oem fluid. We use BG here at the dealership for 4x4 services. Any of the quality non oem lubes should be fine. That being said, most prefer to stick with the grape juice just as a precaution, but I dont think its needed.

I ran mobil 1 for about 20,000, and after about 5000 miles I started to get a locker clunk in the rear end! Swiched back to the GM grape and had no problems! Friend is a line tech for the phone company And he says GM does put a special locker additive in , And I think you can buy the additive only, after market!

I ran Mobil 1 and would also get a clunk every now and then--especially going into reverse.

Could be becaue it was break in period....about 15k miles. I switched to Amsoil---no more clunk...36kmiles.

you need to run a friction modifer with some oils. some do not havve it in them already...

Royal Purple in mine for last 27k miles. No clunks, no problems.

Any quality synthetic oil will have an additive package in it already to work with the limited slip. GM specifically says to NOT add an additive to the rear end.

I just did a fluid service to my truck yesterday, changed out both front and rear diff... I also was outraged at the price of the grape juice from GM, so I decided to go to wally world to see what I could dig up. I found Pennzoil synthetic 75w-90... It meets GL-5 requirements, which is what we need, and it says it is formulated to work with late model limited slip and locker applications... The BEST thing of all, it was $6.47 a quart... and GM's was $28 a quart. That means I spent $38.82 instead of $168!! Now I don't know how well this Pennzoil is suppose to work, but it says it meets all GM requirements, it's synthetic and designed to work the limited slip and lockers... that sounds good to me! Now I will find out if it really is good fluid or not, I will keep everyone updated.

Dan

Mobil 1 in mine for 40K now and no issues. Easy to find too.

I just did a fluid service to my truck yesterday, changed out both front and rear diff... I also was outraged at the price of the grape juice from GM, so I decided to go to wally world to see what I could dig up. I found Pennzoil synthetic 75w-90... It meets GL-5 requirements, which is what we need, and it says it is formulated to work with late model limited slip and locker applications... The BEST thing of all, it was $6.47 a quart... and GM's was $28 a quart. That means I spent $38.82 instead of $168!! Now I don't know how well this Pennzoil is suppose to work, but it says it meets all GM requirements, it's synthetic and designed to work the limited slip and lockers... that sounds good to me! Now I will find out if it really is good fluid or not, I will keep everyone updated.

Dan
We've had it in for about 10,000 miles or so. No problems with it at all.

I use Valvaline throughout the drivetrain and Royal Purple In the crank case. GREAT!!

Thanks Mrsspoolin, I was kind of curious about the quality of the lube, but I figured it was pennzoil and couldn't be terrible, and it was worth a shot since it was about $22 cheaper a quart than the GM grape juice.

Dan

pennzoil???? -:t in my opinion

i think penzoil is parafin wax based... beleive it has the ability to gum up with that kind of base.... I would not run penzoil either... I also heard it has alot of detergents in it which can cause permature sear failure.... but I am not sure on that..

Thanks Mrsspoolin, I was kind of curious about the quality of the lube, but I figured it was pennzoil and couldn't be terrible, and it was worth a shot since it was about $22 cheaper a quart than the GM grape juice.

DanI was mistaken actually. It's the valvoline that we used. Pennzoil didn't have enough of what we needed. I just pulled the bottle out of the back. Sorry.:o

I used valvoline on mine. That synthetic is way nicer than regular 90. It doesn't stay on your hand for days after when you spill it on you...

Mobil 1 75-90 syn front and rear.........no problems here. Rick

Redline 75-140 flawless in everything I have run it in. Dad's 02 Duramax just ate a carrier bearing at 37,000 miles with the stock GM oil. It is now running redline also.;)

At what point do we need to change the first diff. fluids? I have heard so many different things from so many different people. Running at 17,000 miles and usually get Rotella for normal engine oil. Its time for my yearly inspection and I wanted to get a full service done but I'm not dropping 168 bucks if I dont need to. I'll just go to Wally world and get gear oil for myself.