Differential Service

[XRover]

I just had my Av in for the scheduled Diff service.(Z71) To my astonishment the price of the Diff oil is $33.00 a Pint. It take 3 pints. I know the oil is a Mobil 1 synthetic gear oil but $33.00 a PINT. I am in the wrong business.

 

[mrwishes]

Ouch! What's the service interval for the differential?
And I thought Redline was expensive at $9 a quart.

 

[XRover]

The service is at 7500 miles and once done is not needed again until 100k miles

not so bad..

 

[NJAV]

Isn't Redline supposed to be one of the better diff. oils..now that you mentioned it....my Av has about 5256k on it and will be due for a diff. change with the next 1500 or so.....

Inquiring minds want to know...

 

[mrwishes]

I used Redline MT-90 in the 5 speed of my 95 Maxima, worked great. Haven't yet put in the 00 Maxima.
I used Redline 75W90 in the transfer case and axels of the Durango, worked great
I used Redline C+ ATF in the transmission. Had the transfusion done at 38,000 miles or so. At 75,000 or so, I had a shutter at certain rpms, going uphill. Had the Dodge dealer do a transfusion with Mopar oil which resolved the issue. Don't think that Redline was to blame.

The stuff is expensive, and it may be hard to find a local dealer. Certain grades are specific to a certain make, and if the dealer happens to be a BMW service shop, then they don't want to order a whole case of Mopar.
Redline was helpful in locating an East Coast dealer to save me on shipping. I think in the meantime there are sites now that let you order by the quart.
www.redlineoil.com

 

[Carnac]

I paid about $17 for a quart of Moble 1 gear oil at Checker Auto. I needed two quarts for the front and rear differentials of my Durango. I also had to add friction modifier (for the limited slip) to the rear. The friction modifier was about $6 from Dodge. $33/pint seems a little steep. Cheers - Jim

 

[frule]

Am I missing something here?I don't see where a rear diff fluid change is called for.Ever!

But change out $75-$100 of fluid at 7,500??

 

[gandolphxx]

Absolutely change out the rear [and front if your 4x4] @ 5000. Then follow specs - i.e., 25000.

 

[Butch]

Just changed My rear Diff. at 2500 miles.., will do again at 5000.., then every two years..., I used Mobil 1 syn. Paid 8.95 a quart.., seems to be quite a price spread.., someone is making a lot of profit.., will do My new front Diff. at next oil change.., Id like to run synthetic in the front also., but Im hearing this is not a Good thing.., I need to look into this.., and find out Why.......

 

[MrBill]

All right!!!!!!!!! there is six different ways to go here. Does the manual say when to change it I must of missed it. If not, will the real answer please step forward.

 

[gandolphxx]

All right!!!!!!!!! there is six different ways to go here. Does the manual say when to change it I must of missed it. If not, will the real answer please step forward.

Trust Butch and I - change the rear and then forget it for two years or 25K miles unless you are towing the Queen Mary.

Butch, I too have heard that about the front - doesn't make sense - post if you find out anything on it.

 

[frule]

G-man,I'm not doubting what you say(change at 5K miles,then every 25K).

But my manual doesn't even MENTION a rear diff fluid change....At all....ever!No "25K specs.Nothing but "check level".

Is the Mobil 1 OK to substitute?Seems I read on a couple of other forums to use ONLY GM's "purple stuff".

 

[gandolphxx]

Have the dealer change it - they will use the right stuff.

Let me get some other references on other fluids, it can wait a day.


Turning loose the infobots as we speak....

 

[gandolphxx]

OK, 6 boards, only one with much of anything useful - I am not going to try to summarize other than to comment that the rear differential with the locker needs special treatment - synthetic.

Go to http://www.gm-trucks.com and search for "differential and fluid" - you will get about 15 threads - interesting stuff.

Best of batch is Rear Differential Lube Change

Another thread Differential stuff

Cheers

 

[gandolphxx]

More on this topic - protection and longer life - especially for you folks that tow - In researching this topic I came accross an old post that reminded me of the heat problems with towing. Looking into the following:
Mag Hytec Heavy Duty Differential Covers

Some reference reading:
Keeping your read end cool <-- not to be confused with butt warmers.

Off-Road article

Thoughts, comments - looks like a smart move for those of us in the heat zone and/or those that tow big boats.


Thread @ Gm-Trucks.com is also active.

 

[Butch]

gandolphxx..., I talked with My friend who owns the Tranny shop., about using Synthetic Lube in the Front Diff., He said there are problems sometimes with seal leakage.., and Foaming of the Fluid, and it being pushed out the breather tube.., He does alot of rear end work.., He says that Guys with Lifted Trucks.., who do alot of Serious Off Roading.., have Torn up this Differential, and because of the aluminum case.., its not the Strongest thing out there.., He hasn;t really Moded them much.., mostly has installed some Air Lockers in them.., said He would check to see whats available for Beefing them up.., but its not done much..., and thinks the problem maybe flexing of the case, because of the aluminum casting... Im not going to be running My truck at the Track very much., but the fact that one Failed on Mine already has Me abit worried.. Oh well., may just have to live with it., Well see.......

 

[gandolphxx]

Thanks, I will check with my guy in the AM on this issue.

 

[AVYNUT]

Thanx, Butch and gandolphxx for all the info. I'm still a bit confused!

My AVY (w/ rear locker) has 890 miles. Should I have my Chevy Dealer change the front and rear Diff oil at 5000 mi. and then every 25,000 mi.? Not to disparage any particular dealership, but is there any way for me to confirm that it was actually done I've had experiences with charges being made and work not performed. How about DIY? What would that entail. Do you need a special fitting?

Thanx for bringing this to our attention!

 

[gandolphxx]

If you tow or drive real hard and aggressive change the rear after 500 miles of the above abuse, make sure it meets specs, use GM's stuff or equivalent.

Normal use, I would reccomend 5000 then 25K+ after that.

 

[AVYNUT]

OK, gandolphxx! I baby my AV (for now). So, please complete answer to my question. Is this a DIY situation or do I need to take her to the Dealer? If so, how can I confirm the work was done and that the proper diff fluid was used? This is the kinda thing where a $200 can be spent and absolutely nothing is done.

Thanks for you help!

 

[gandolphxx]

If you tow or drive real hard and aggressive change the rear after 500 miles of the above abuse, make sure it meets specs, use GM's stuff or equivalent.

Normal use, I would reccomend 5000 then 25K+ after that.

I don't know which category you are in, you pick, there is no in between for all practical purposes, and have your dealer do the work - there is no reason for them not to do it based on the markup of the fluid.

How do you know, lurk around the shop, watch from the entrance, or find a dealer you can trust.

The rear differential, "pumkin" is pretty obvious, take a picture before, crawl under after - pretty hard to change with wiping up - should look different.

Ask the shop manager to see the drain plug when they pull it, tell them that you are curious to see if there are particles of metal on it - that will probably get you in the shop area - even if they bring it out to the waiting area it is drained and they will have to fill it with something, hence they will probably do it correctly.

You can do it yourself - messy and hard to get the stuff in - critical to only fill to the right level, overfilling can lead to problems.

I really don't have any other suggestions other than to just ignore it like most car drivers do and hope for the best.

Don't let the express places near it unless you are married to the pit person.

 

[Guest User]

When I took my AV in for the 8000 mile service I ask about the 7500 mile differential service. They told me it don't need any special service and only needed fluid level checked.
I checked the Eaton site and it said the G-80 is a maintenance free differential.
You may want to check out the link below.

http://automotive.eaton.com/product/traction_stability/lockingdiff.html

rogerh

 

[frule]

Apparently the factory thinks no service is necessary under any driving conditions(other than level checks).

The controversy apparently stems from posts on other boards(GM-Truck and pickuptruck) that refer to a fluid change at 500 if you tow.

AFA changing your own fluid,there is a drain-plug.Carefully measure how much you drain out and add that back.You will need a suction pump gun($10 or so) to add fluid.A bit messy,but easiy do-able.

There is a
definite question on whether other fluids(Mobil 1 synth?) are acceptable,or if the expen$ive GM "grape-stuff" is necessary!

 

[XRover]

The 7500 Mi diff oil change service on the 4x4 Av is a required maintainence item. It is listed on the GM site and a letter was sent to me by the dealer/GM reminding me of it.

 

[frule]

Hummmmm?It is not mentioned in the owner's manual.I have received no letter.Something is wrong here!

Sounds like they need to get their act together!!
Where on the GM site,XRover??