Hi All


New Dmax/Zf - checked the rear diff and the oil level was 1 1/2" below the fill plug. I went back to the dealer and they wouldn't add any saying that if the factory filled it that full then it must be right. I'm not connected to gm so I don't have the books to check and see what the level is spec'd at. Does anyone know of an public internet site or paper source (title/page#) to get a spec in writting.





Dinger

My Owner's manual page 5-59 has that info.

Per Roy C's post here is quote form the owner's manual (page 5-7 in the 03 manual)

"How to Check Lubricant:
To get an accurate reading, the vehicle should be on a
level surface….
The proper level for the 1500 HD Series,
2500 Series, 2500 HD, and 3500 Series is from 0 to
1/2 inch (0 to 13 mm) below the bottom of the filler plug
hole…"

Also, you can download various GM owner's manuals in pdf format from This Link. (http://www.mygmlink.com/pdf/go2content/manual/US/en/chevrolet/)

http://www.dieselplace.com/forum/smileys/Geek.gif

Thanks Guys


The comment from the dealership about the owner's manual was "the owner's manual isn't always right, the factory has it done that way, lets leave well enough alone."


The service manager is also saying that if I fill the differential up to the fill plug I may cause extra pressure in the differential and wind up blowing out a side axle seal $$$ or at lease having one leak.


It would be nice to get my hands on something more offical -


Dinger

Here is the most official your gonna get.. Its from SI-2000, Doc id# 860221



<H1>Lubricant Level Inspection - Rear Drive Axle 11.5 Inch Axle</H1>

<LI ="1">Raise the vehicle. Refer to Lifting and Jacking the Vehicle (http://service.gm.com/servlets/CellHandler?CellId=47852&amp;RefDoc=860221&amp;evc=sm) in General Information.
<LI ="1">Make sure the vehicle is level.
<LI ="1">Inspect the rear axle for leaks. Repair as necessary.
<LI ="1">Clean the area around the rear axle fill plug.
http://service.gm.com/engif/000/000/665/665917.gif
http://service.gm.com/tif.gif (http://service.gm.com/servlets/RetrieveTif?pic=665917)

<LI ="1">Remove the rear axle fill plug and the seal.
<LI ="1">Inspect the lubricant level. Specification


The lubricant level should be between 0-10 mm (0-0.4 in) below the fill plug opening.
<LI ="1">If the level is low, add lubricant until the level is even with the bottom edge of the fill plug opening. Use the proper fluid. Refer to Fluid and Lubricant Recommendations (http://service.gm.com/servlets/CellHandler?CellId=53256&amp;RefDoc=860221&amp;evc=sm) in Maintenance and Lubrication.



<H4>Notice</H4>


Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.



<LI ="1">Install the rear axle fill plug and gasket. Tighten


Tighten the rear axle fill plug to 33 N·m (24 lb ft).
<LI ="1">Lower the vehicle. </LI>Edited by: dmaxalliTech

The plot thickens


I gave the service manager my vin (1GCHK24264E361522) and he phoned me back and said the spec is 17 - 21 mm below the plug. Go figure!!


Maybe it's not a 11.5 inch rear axle in my truck?


Dinger

The plot thickens


I gave the service manager my vin (1GCHK24264E361522) and he phoned me back and said the spec is 17 - 21 mm below the plug. Go figure!!


Maybe it's not a 11.5 inch rear axle in my truck?


Dinger





Dinger you have a 11.5'' rear axle. Go to a different dealer as this one is jerking your chain. My truck also came with the oil at 1.5'' below the fill holehttp://www.dieselplace.com/forum/smileys/Angry.gif I took it back to the dealer and they looked at me like wtf are you doing looking and do you really know how to check it. I had to show them how I checked the level befor they would even look at my truck. Between the front and rear diff they added 2liters of the gm synthetic axel lube.


Greg

Dinger, your vin says its an 04 2500 truck with a LLY.. That means you have a 11.5" axle. Show him the procedure I posted above and see what he has to say.. Other then that, find a more cooperative dealer

Make sure your report this to GM customer service...just get it documented that they are jerks.

the problem with that is customer service is usually the bigger jerkhttp://www.dieselplace.com/forum/smileys/Disapprove.gif

In another thread I noted how the tech neglected to check mine in PDI as I had asked, from day 1 and told them why. Anyway...I checked it, and as it turns out it was 1 2/3 qts low. Imagine that. http://www.dieselplace.com/forum/smileys/Ermm.gif I told my guy about it and that I was pissed 'cause it was the only thing I asked for. I went out to the truck a couple days later and there were 2 qts. of grape juice standing on the back bumper of the truck. We talked about it another day, and he said the tech got reamed because it was pointed out to him to check mine at PDI more than once. Also, they supposedly have added checking HD's rear axle level to thier PDI regimen because I proved to them definitively, for the first time apparently, that they are often little more than half full to-spec. I tow a 13,000 lb powerboat/trailer/fuel/gear and I want the damn thing full http://www.dieselplace.com/forum/smileys/HiHi.gif ...4 qts vs. 2 is most likely a significant temp reducer in the axle, and would make for fewer potential axle issues down the road...especially if you tow big # alot. I'm gonna do Mag-Hytec anyway at some point, but I don't want break-in temps any higher than designed or necessary. http://www.dieselplace.com/forum/smileys/Approve.gif Edited by: Rippem

Dmaxallitech...I haven't had a problem with my truck yet and I pray I never have anything major but what is the best way in your opinion to deal with these types of problems if customer assistance can be of no help, the dealer is of no help etc....?http://www.dieselplace.com/forum/smileys/Confused.gif

The Saga Continues


The Service Manager here was taken aback by the 860221 (how did you get that - you must have a password) , however, he insists that the number is for a 2003 rear end and that the 2004 differentials have a different spec, 17 to 21 down from the fill hole. He refused to tell me the Doc id# he used to get the 2004 spec. saying that he wasn't sure if he could give the info out. He is holding to the idea that the owners manual is wrong.


I have measured the present diff fluid level again - leveled the truck with a framing level in the box both ways - let her stand overnight - then using an Allen key held as level as possible by eye, dip down and back up. I got 25/27 mm down - that's below any spec so far - not by alot if the service manager is to be believed and by a fair bit if the owner's manual/860221 is right.


Maybe the best I'm going to be able to do here is put her to the top of one spec which almost the bottom of the other.


(What a mess)


Dinger

I changed out my fluid at 1400 miles with Mobil 1, before I pulled anything, I thought a break-in fluid change was the way to go, so I don't understand the big concern about a quart low. If the gears are running in fluid, and you don't tow a heavy load, and change the fluid after a few hundred miles anyway before you pull a heavy load, does it harm anything to be a little low? Just wondering.I suppose some people want to keep the factory fill in there for a long time.

I just checked for 04, here is procedure for them... Looks like your SM is correct:
<H1>Lubricant Level Inspection - Rear Drive Axle 11.5 Inch Axle</H1>

<LI =1>Raise the vehicle. Refer to Lifting and Jacking the Vehicle (http://service.gm.com/servlets/CellHandler?CellId=47852&amp;RefDoc=1381049&amp;evc=sm) in General Information.
<LI =1>Make sure the vehicle is level.
<LI =1>Inspect the rear axle for leaks. Repair as necessary.
<LI =1>Clean the area around the rear axle fill plug.
http://service.gm.com/engif/000/000/665/665917.gif
http://service.gm.com/tif.gif (http://service.gm.com/servlets/RetrieveTif?pic=665917)

<LI =1>Remove the rear axle fill plug and the seal.
<LI =1>Inspect the lubricant level. Specification


The lubricant level should be between 17-21 mm (0.6-0.8 in) below the fill plug opening.
<LI =1>If the level is low, add lubricant until the level is between 17-21 mm (0.6-0.8 in) below the fill plug opening. Use the proper fluid. Refer to Fluid and Lubricant Recommendations (http://service.gm.com/servlets/CellHandler?CellId=53256&amp;RefDoc=1381049&amp;evc=sm) in Maintenance and Lubrication.
<H4>Notice</H4>


Refer to Fastener Notice (http://service.gm.com/servlets/CellHandler?CellId=10105&amp;RefDoc=1381049&amp;evc=sm) in Cautions and Notices.
<LI =1>Install the rear axle fill plug and gasket. Tighten


Tighten the rear axle fill plug to 33 N·m (24 lb ft).
<LI =1>Lower the vehicle. </LI>





Now, dont ask me whats different about it, but sure enough, its want them that low.





Just for kicks, here is the fluid capacity rating for an 04:



<TABLE width="100%" border=1>
<T>
<TR>
<TD vAlign=top align=left>
<UL =NONE>
<LI>Rear Drive Axle (11.5") </LI>[/list]</TD>
<TD vAlign=center align=middle>


3.0 liters</TD>
<TD vAlign=center align=middle>


3.17 quarts</TD></TR></T></TABLE>


Same for 03:



<TABLE width="100%" border=1>
<T>
<TR>
<TD vAlign=top align=left>
<UL =NONE>
<LI>Rear Drive Axle (11.5") </LI>[/list]</TD>
<TD vAlign=center align=middle>


3.62 liters</TD>
<TD vAlign=center align=middle>


3.83 quarts</TD></TR></T></TABLE>





Now I am confusedhttp://www.dieselplace.com/forum/smileys/Confused.gif

Thanks dmaxallitech - nice to know I'm dealling with a straight shooter.


I'm almost afraid to ask about the front end differential, but now that we know the owners manual is duff. Any changes for '04? or is it still 0 / 3/8 down?


Dinger

Wow! That is not what I expected at all.

I just checked for 04, here is procedure for them... Looks like your SM is correct:


Now, dont ask me whats different about it, but sure enough, its want them that low.





Just for kicks, here is the fluid capacity rating for an 04:



<TABLE width="100%" border=1><T>
<T>
<TR>
<TD vAlign=top align=left>
<UL ="NONE">
<LI>Rear Drive Axle (11.5") </LI>[/list]</TD>
<TD vAlign=center align=middle>


3.0 liters</TD>
<TD vAlign=center align=middle>


3.17 quarts</TD></TR></T></T></TABLE>


Same for 03:



<TABLE width="100%" border=1><T>
<T>
<TR>
<TD vAlign=top align=left>
<UL ="NONE">
<LI>Rear Drive Axle (11.5") </LI>[/list]</TD>
<TD vAlign=center align=middle>


3.62 liters</TD>
<TD vAlign=center align=middle>


3.83 quarts</TD></TR></T></T></TABLE>





Now I am confusedhttp://www.dieselplace.com/forum/smileys/Confused.gif





I can't see any reason other than the extra dollars GM makes by not putting as much of the spendy "Grape Juice" in the rear ends. The chances of anyone catching it are slim since checking the diff's is not on the regular PDI from what I've found out.


If you cook the thing down the road, or break it, don't you think GM will try to blame you for improper service? If you've done it, or someone else then it's your problem. If they service it, all they do is fill it up and you pay for the extra. If the guy who does the PDI's is the lube guy as well, do we think he's going to check the spec?


This just looks to me like a continuation of the no glove box light, no underhood light, type of cost cutting gone further bad...http://www.dieselplace.com/forum/smileys/Dead.gif

Does anybody have a connection at AAM that would know if anything changed between 2003 and 2004?

My personal spec is 4.0 quarts for my 02. http://www.dieselplace.com/forum/smileys/Approve.gif It has worked well for 50K. I have serviced several 03 differentials. None had more than 3 quarts. One was right at 2.5. Later! Frank

so are we risking axle seal trouble by supposedly "overfilling"? http://www.dieselplace.com/forum/smileys/Confused.gif

BTT

I hate to open old wounds here but it's time to change-out my rear axle diff. fluid.



My manual for the 2005 states proper level is 0-13mm (0-1/2") below the
hole. Should I follow it or go with the 17-21mm (.60-.80")
standard???



On edit: Question answered by Eric on another recent post - thanks!


Edited by: skoryaro2

Here is my theory (for what it is worth). GM has a history of leaky pinion seals on their RWD cars and 1/2 ton trucks. They also have a problem of leaking axle seals on our trucks. So they lowered the level of diff oil to reduce the occurance of these various seals leaking. Instead of vairous distances below the filler hole, they should have just moved the darn hole so that all anyone has to do is just fill it to the bottom of the hole like we used to in the old days.


My wifes 01 Yukon XL is the first intance I came across the xyz distance below the hole. There is actually a blue tag that is rivited right below the fill hole on the 8.5" axle on her truck that says to only fill to "so many MM below the hole". I don't know the exact number from memory, but the first thing I had to do was to find something that measured in MM's. Give me something in fractions of an inch and I can do it........ give me metric and I'm lost.

It is interesting that the AAMs in the Dodge's have had the same
issues, not coming with enough oil. Some people lost their
differentials because they were not checked before being sold. I had
heard of this and asked the dealer to double check mine before
delivery; both were low.

To complicate the matter a little further, the owner's manual for my '03 6.0 gasser had EXACTLY the same specs for the rear end as my '04.5 LLY with the Eaton rear-end.


While I'm still confused over the whole deal, what's the bottom line?!


I'm planning on continuing to run it level with the bottom of the fill hole.

Coulda swore I saw a label under the truck that said how much to put in it.


It can't be that big of a deal between 20mm and 7mm to me. I would suspect that it would last as long as my 84 dually has by just keeping good oil in.Edited by: jefro

They may be trying to minimize leaks at the rear axle seals by running the oil level a little lower. The exact level is really not that critical in an axle.

It has to be the rear seal leaking. How can you say that running lower amount of oil is bad. Look at the aftermarket covers that increase the capacity--not sure of the level relative to the stock level.


I bet that is why my parking brake still does not work--I'd better go check it--leaking rear seal.