rear axle lube..06/3500 4X4

[spongebob]

im ready to change the rear-end lube..
dealer sold me 3 qts of #89021677 and 1 4 oz.
bottle of #1052358..
is this enough? and the right stuff?

[DmaxMaverick]

4 oz. bottle of L/S additive???

I'm not sure of the part #'s, but if your dealer is selling you additive, I'd question the lube, as well. What do the labels read?

Your rear end DOES NOT have limited slip! If you have the G80 option (would be listed on the RPO sheet in the glove box), you have an Eaton Gov-Loc, which requires NO additive. The correct OEM lube should be 75-90 synthetic. Check the bottle volume closely. GM has a way of selling 13 oz. bottles that look like full qts.

In either case, 3 qts isn't enough. 3.5 qts minimum.

[spongebob]

yes the glove box sheet says "G80"..
the lube is 32fl.oz. of GM synthetic axle lube sae 75w-90..says it has a new "grape" scent tongue.gif

the additive is a 4 oz. bottle of "limited slip axel lube. additive".

what do you think??

[DmaxMaverick]

That's the correct lube, but get your money back on the additive. If the guy insists you need it, ask him to show you where in the book it is required for any GM truck since mid 90's. You will need more lube, though. The original (2001 M/Y) service was 4 qts, and was reduced to about 3.5 qts a couple years ago. The level should be about 3/4" below the fill hole (on level ground). Overfilling has been suspected of causing seal failure in some cases.

[spongebob]

"God i love this site"...

thanks for the info.... :D

[madmatt]

3.1 qts is the updated spec.

[spongebob]

OK, check this, i went back to the dealer told him what was up..and he looked cornfused..he went to his computer and punched in "RPO G80", this is what popped up: "1976-2009 AXLE, REAR, POSITRATION, LIMITED SLIP, POSITRATION L/SLIP R/AXL(G80) :confused:

[fanzdslpwr]

i have a 2003 dually. the only thing i no about the rear is that its a 3.73. does that take the limited slip additive?

[spongebob]

doOd, the 3.73 is tha axle ratio..look to see if you have a G80 code on your build sticker in the glove box.

i added 4 -32 oz. of the synthetic and
it still hasnt come out the fill hole..
but my little finger gets wet when i stick it in the fill hole.. :confused:

[DmaxMaverick]

Originally posted by spongebob:
doOd, the 3.73 is tha axle ratio..look to see if you have a G80 code on your build sticker in the glove box.

i added 4 -32 oz. of the synthetic and
it still hasnt come out the fill hole..
but my little finger gets wet when i stick it in the fill hole.. :confused: The level should be fine. The last print I have recommended 3.1 liters, or about 3.4 qts. Either way, close enough. Many OEM fills seemed to be at least a qt. low, anyhow. Interesting though, AAM's latest recommendation is still 4 qts.

FYI:
NO L/S additive is needed, regardless of which rear end combo you have. If it's an open diff (no G80), or a locker (G80), it will still require the same lube, and no additive. Older models that have L/S may require it, but nothing that's been built in the last 10 years.

[madmatt]

My papers say qts, but it wouldn't be the first Typo I've found in a GM document. I never measure it in anyway the bulletin also says 1-1.4" so I put it about an 1" low.

[Ranch55]

I just recently changed the rear diff. lubricate in my 2500HD. 4 qts. brought it up to 1/2" below the oil fill plug. Owners manual specifies filling to 0" (level to bottom of fill hole) to 1/2" below fill hole. I have removed the rear diff. cover on one of these trucks and they DO NOT have any need for the additive. There are no clutch plates for the additive to lubricate, only a positive locker assembly lubed by the 75W90 synthetic gear oil. If the dealer says it is required, he does not know what he is talking about, much less what the computer says. It is not needed or required.

[ 01-20-2006, 05:59 AM: Message edited by: Ranch55 ]

[Ranch55]

Also, please keep in mind that the oil level is crucial to the lubrication of the axle outer bearings. The oil level has to be high enough so that the lubricate can enter the axle housings and reach the outer axle bearings. If the minimum level is not maintained, there is the probability that the outer axle bearings will not be properly lubricated and eventually fail. The OEM & aftermarket repair manuals tell us this. I have also personally experienced this issue in my 1991 GMC 2500HD and had to replace the outer axle bearings.

[madmatt]

Heres part of the Service manual update/ TSB that your paper copies don't have....for those of you who plan on doing a lot of their own work, trash the paper backs and get yourself an online subscribtion to alldata (http://www.alldata.com) you'll get it done right the first time and you'll have all the correct info and updates.

Subject:
Rear Axle Fluid Level May Appear To Be Lower Than Published Specification

Models:
2005 Chevrolet Silverado 2500/3500 Series Pickups
2005 GMC Sierra 2500/3500 Series Pickups

with Four Wheel Drive and 8.1L Gas Engine (VIN G - RPO L18) or 6.6L Duramax(TM) Diesel Engine (VINs 1, 2 - RPOs LB7, LLY)

On full-size 2500 and 3500 Series Four Wheel Drive Chevrolet and GMC Pickups equipped with the 11.5" ring gear rear axle assembly, the factory lubricant fill level may appear to be lower than the published specification. This unit can be identified by the location of the fill plug on the rear axle housing cover, instead of on the front of the axle housing.

All axle assemblies are filled by volume of fluid during production. They are not filled to reach a certain level. On the 11.5" rear axle, the fill quantity is 3.0 Liters plus or minus 0.1 Liter (3.18 Quarts plus or minus 0.1 Quart). Testing has shown fluid level readings as low as 35 mm (1.4 in) below the bottom of the fill plug opening are acceptable, even with the correct amount of fluid in the axle, compared to the currently published specification of 17-21 mm (0.6-0.8 in) below the fill plug opening, even when the correct amount of fluid was installed in the axle assembly during production.

It is NOT necessary to add axle fluid to the axle when the fluid level is at or above 35 mm (1.4 in) below the bottom of the fill plug.

When checking the fluid level on any rear axle, variations in the readings may be caused by factory fill differences between the minimum and maximum fluid volume. Also, if a vehicle has just been driven before checking the fluid level, it may appear lower than normal because fluid has travelled out along the axle tubes and has not drained back to the sump area. Therefore, a reading taken five minutes after the vehicle has been driven will appear to have a lower fluid level than a vehicle that has been stationary for an hour or two. Remember that the rear axle assembly must be supported to get a true reading.