Escalade Rear Diff, how to change fluid tips

Patrick7997 · Jun 12, 2008

Okay, this is a continuation of the "Front Diff and Transfer case" Thread.... Review that one to see some of my methodology, my pump, and some details...

This is the Fill Plug on your Rear Diff. Looks rusty. This is going to be fun. This picture is looking from the passenger side rear tire, across the truck, towards the driver's side rear tire.

This is another square plug, so again, use your 3/8ths drive to remove that...

Thru the magic of photography, the plug is out. What you missed were about 5 soakings with PB Blaster (all the wet stuff on the side of the diff), then some torching with a MAPP Gas torch, and then the bolt came out. Piece of cake, right?? Right...

Now, there is no drain plug on this case.

Now, this might not be "According to Hoyle", okay, so my apologies to real technicians out there... but I was shown this years ago by a friend, and if you're patient, and careful, it will work.

This is the backside of that rear diff. That bowling-ball shaped rear cover plate is held on with bolts all the way around. The bottom 5 are visible in this photo.

If you loosen (do not remove) the bottom 7 bolts, and then very carefully and gently pry at the bottom, the case will open a little.. and fluid will drain.

You do not want to jamb the screwdriver way in there. You're just cracking it open a little... there's a gasket in there that you are trying not to damage.

Like so. It was hard to get the picture, and do it at the same time, but a lot will come out when the case starts to open. Obviously, you will have your drain pan under there... and eventually, the case will be empty.

Then, retighten the 7 bolts you loosened, and wipe the excess off the diff, from the area where it was slobbering out of the case...

Having done that, you now will set up your pump again, fill this case with 75w90 Mobil 1, and when full, replace the fill plug.

This is a big case. Took me almost 6 quarts to fill it.

And you're done!

DLE · Jun 12, 2008

Re: Rear Diff, how to change fluid

Once again, awesome write up! This def helps us members out! Let this be a sticky! :thumbsup: :thumbsup:

The Factory Man · Jun 25, 2008

Check your Owners Manual for the proper differential fluid level. I don't have ready access to Cadillac information today but I will say on my 2005 Silverado 1/2 ton pick-up the correct fluid level is no higher than 1/2" below the fluid fill hole. Differentials on 3/4 ton and HD truck use a differant fluid level spec. Overfilling your differential can cause leaks and aeriated fluid which inhibits proper lubrication. The fluid level spec on my truck is in Section 5 of my owners manual.

cadillac_tech · Jun 28, 2008

I whack a prybar in right at that same bolt, but at a downward angle. It stays there by itself until drained. Never had one come back leaking. Far better than those suction hoses that can't reach the bottom. Nice tip for all.

Rolex · Jul 4, 2008

Nice. :cool2: I copied and stuck both threads in the Lade forum. :thumbsup:

digitalcaddie · Oct 28, 2008

There was a little plastic tag above my fill hole that said the level should be 15-40mm below the fill hole. It took just under 4 qts to reach that level. I put a 90 degree bend in a cable tie (you could use almost anything) with 20mm of length below the bend and used that as a dipstick to see how full the diff was getting. Fill slowly as the stuff takes a little while to settle...after 2 qts some started flowing back out of the fill hole and I thought I had overfilled the case. 5 minutes later the level had fallen and I was able to slowly add almost 2 more quarts. The dealer also said that synthetic is REQUIRED for these differentials. Kinda stinks cuz AZ only had Mobil 1 Syn which cost $9/qt. Oh well...a couple quarts of that and doing the change yourself is sure cheaper than replacing the differential.

Cliff8928 · Oct 29, 2008

digitalcaddie said:
Kinda stinks cuz AZ only had Mobil 1 Syn which cost $9/qt. Oh well...a couple quarts of that and doing the change yourself is sure cheaper than replacing the differential.

Just be happy you don't buy it from the dealer.. List price for the Quadrasteer limited slip fluid for my mom's Denali is over $30/qt.

g9s8r · Jul 4, 2009

so the fluids in the front and rear have to be synthetic? did OP use syn? why wouldnt GM put a drain plug on the rear? if i remember correctly, even my old z71 had a drain plug.

sk7 · Jul 20, 2009

My 02 has a drain plug on the rear diff. Same on my dad's 2000 sierra. Maybe it got removed as a cost saving measure? My older blazer didn't have one.

box986 · Nov 16, 2009

Patrick7997 said:
This is a big case. Took me almost 6 quarts to fill it.

What size ring gear would an '03 have?

According to this, here are the capacities:
Differential, With 10.50 RingGear Rear..........5.5 pints
Differential, With 11.50 RingGear Rear..........7.7 pints
Differential, With 8.60 RingGear Rear..........4.3 pints
Differential, With 9.50 RingGear Rear..........5.5 pints

Seems 6 quarts is very high.

Here is the link: http://www.amsoil.com/mygarage/vehiclelookup.aspx?url2=2003+CADILLAC+ESCALADE EXT+1

hamkan · Oct 10, 2010

I couldnt open the bolts on mine, was able to open the fill one but the ones at the back are stuck, any suggestions!!!

Gale Hawkins · Oct 23, 2010

I noticed the fluid draining out looked totally clear.

Being over 100K miles I thought about changing too but GM states only to top off every 50K miles if required but nothing about replacing it.

PU trucks may have a drain hole to let out water that might get in when in extreme off roading use.

ESV_Platinum · Jun 20, 2011

Anyone know the torque specs for the rear diff cover bolts for the 8.625" size cover???

BlownEscalade · Jan 15, 2012

Are all rear diffs 8.625" for the escalades? Mine is a 06 would that be the case? Thanks

TMoNeE · Nov 2, 2012

Any reason not to just pull it off and change the gasket, or just trying to avoid a step?

Nice Ride · Sep 4, 2014

Old but thought I would add 2 Cents. There is a magnet in the Diff that holds metal shavings. It is always better to remove the cover and clean out all the sludge and shavings. Lots of people also say the spray out the housing with Brake Cleaner. New gasket is only a few bucks.

Nice Ride · Apr 26, 2015

Finally got around to the Rear Diff. 60K on fluid was pretty clear. But the magnet was covered, no big filings, just gray powdery crud, as well as Fill bolt had some on it too. There is a magnet in there also.
Took 3 bottles of Mobile Syn. for sure fill slowly.... When it starts to flow out when re-filling, stop, place the plug in, hand tighten, wait 5 min then continue filling. I had to do this 4 times. What is the torque settings for these bolts?
Also on the 09 ESV, the gasket was the rubber type with metal inside and could be reused. I installed a new one since I was not sure what was on there.

Mr. B · Nov 5, 2015

Drain Plug (All Except 9.75 Inch Axle)
33 N·m
24 lb ft

Rear axle cover bolts are 30 lb ft.

"They are "torque to yield/torque to spec" bolts. Essentially they stretch a little as they are finally torqued. However, since they aren't under pressure such as the head bolts (as they're also "torque to yield") it isn't as crucial to replace them after removing them.

I'd simply re-use them too."

Polack8120 · Jun 3, 2017

I know i am late to the party, but is it difficult to remove the rear diff cover and is there any type of thread locker that anyone can recommend that i should put on the bolt at the end or should i avoid that?
Thanks

lukehaugland · Aug 10, 2017

Hi, was just wondering if you had the pictures anywhere to look at?
It looks like the photobucket link is dead

Escalade Rear Diff, how to change fluid tips

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