Differential self-service?

SBosco · **Posted:** Wed May 07, 2008 1:40 pm

I just dropped my liberty off at the dealership because both the passenger front and driver rear windows got stuck down/came off the track. I already had the driver side window regulator replaced under warranty months ago. I think the assembly line worker who installed my windows was on drugs or something.

Anyway, they called me and told me that I was overdue for differential service (@27,000 miles) and wanted to charge me $299 to "inspect" and "replace" the differential fluid. I always thought that diff fluid was good for atleast 75k miles. Regardless, I was thinking of doing the fluid change myself and saving about $250.

Can anyone offer me insight on this issue? Is it simple enough to do, do I need any special tools, special fluid, etc.?

Any comments would be greatly appreciated, thanks.

Sir Sam · **Posted:** Wed May 07, 2008 2:20 pm

It is very easy to do, and I think only needs to be done about eveyr 75k-100k miles, maybe once at 50k for break-in, but after that I think its good for a long while.

crd liberty · **Posted:** Wed May 07, 2008 3:47 pm

SBosco wrote:

I just dropped my liberty off at the dealership because both the passenger front and driver rear windows got stuck down/came off the track. I already had the driver side window regulator replaced under warranty months ago. I think the assembly line worker who installed my windows was on drugs or something.

Anyway, they called me and told me that I was overdue for differential service (@27,000 miles) and wanted to charge me $299 to "inspect" and "replace" the differential fluid. I always thought that diff fluid was good for atleast 75k miles. Regardless, I was thinking of doing the fluid change myself and saving about $250.

Can anyone offer me insight on this issue? Is it simple enough to do, do I need any special tools, special fluid, etc.?

Any comments would be greatly appreciated, thanks.

-----------------------------------------------

The manuel says to change the front and the rear diff's every 12,500 miles which I think is
a crock. I had mine changed at the 13,000 mile by the dealer and they charged me 69.95
each diff., plus the usual shop charges, towels, etc.
I have since than done my own changes.

Steve

SBosco · **Posted:** Wed May 07, 2008 4:16 pm

that's good news to me. what kind/grade of fluid is reccomended? How involved is the procedure? Is there a drain plug or do I need to purchase new gaskets for the diff covers? Thanks again for all your help.

crd liberty · **Posted:** Wed May 07, 2008 4:51 pm

SBosco wrote:

that's good news to me. what kind/grade of fluid is reccomended? How involved is the procedure? Is there a drain plug or do I need to purchase new gaskets for the diff covers? Thanks again for all your help.

--------------------------------------
Rear diff. is 75w-110 or 75w-140, depending on towing there.
Front diff. is 75w-90
All are synthetic. Mobile 1 or contact our friend for Amsoil. He flys above as
Hot rod oil. Delivered to your door and cheaper than the local auto stores.
Front change is easy. Drop the skid plate, remove the drain plug and the fill
plug. Please have a pan under it as it drains. To refill this, a pump is a good thing
because there is not a lot of room in there. Hand pump 1.2 Qts and that one is done.
Rear diff. a bit harder. Pan under, loosen all the bolts leaving the top bolt in place,
remove bottom bolts and let the fluid run into the pan. Remove cover and clean
scrape Permatex gasket maker off both cover and diff. Reseal diff with Permatex gasket maker,
put cover back on, tighten, refill with 2.4 Qts syn.
Good to go.

I do have to add though, at age of 62 years, I am looking at rear diff's with a drain plug
because of the laying on belly and back trying to get this darn cover back in place
with the Gasket sealer letting the cover sag and holes not lining up.

Give me a car lift and I would be set :lol:

dgeist · **Posted:** Wed May 07, 2008 4:58 pm

crd liberty wrote:

SBosco wrote:

that's good news to me. what kind/grade of fluid is reccomended? How involved is the procedure? Is there a drain plug or do I need to purchase new gaskets for the diff covers? Thanks again for all your help.

I do have to add though, at age of 62 years, I am looking at rear diff's with a drain plug
because of the laying on belly and back trying to get this darn cover back in place
with the Gasket sealer letting the cover sag and holes not lining up.

Give me a car lift and I would be set :lol:

Some suggestions:
- I buy a little 10-15 fluid pump that fits in the diff oil bottle. It'll save your back from trying to "pour" the oil into the diffs by simply allowing you to hand-pump it.
- to center the diff cover, get a bolt with the same threads as your diff bolts at the hardware store and cut off the head. After you put the silicone bead around the perimeter, thread it into one of the top holes loosely, then place the diff cover over the exposed stud to hold it in place while you start the other bolts. Once you have a few of them in, you can back out your stud and replace it with the normal bolt. No messy sealant smeared all over the place.

Dan

crd liberty · **Posted:** Wed May 07, 2008 5:06 pm

dgeist wrote:

crd liberty wrote:

SBosco wrote:

that's good news to me. what kind/grade of fluid is reccomended? How involved is the procedure? Is there a drain plug or do I need to purchase new gaskets for the diff covers? Thanks again for all your help.

I do have to add though, at age of 62 years, I am looking at rear diff's with a drain plug
because of the laying on belly and back trying to get this darn cover back in place
with the Gasket sealer letting the cover sag and holes not lining up.

Give me a car lift and I would be set :lol:

Some suggestions:
- I buy a little 10-15 fluid pump that fits in the diff oil bottle. It'll save your back from trying to "pour" the oil into the diffs by simply allowing you to hand-pump it.
- to center the diff cover, get a bolt with the same threads as your diff bolts at the hardware store and cut off the head. After you put the silicone bead around the perimeter, thread it into one of the top holes loosely, then place the diff cover over the exposed stud to hold it in place while you start the other bolts. Once you have a few of them in, you can back out your stud and replace it with the normal bolt. No messy sealant smeared all over the place.

Dan

----------------------

Hi Dan
You could be the Man. Darn, I never thought of that, but yes it would work.
Thanks
Steve

dgeist · **Posted:** Wed May 07, 2008 5:18 pm

crd liberty wrote:

Hi Dan
You could be the Man. Darn, I never thought of that, but yes it would work.
Thanks
Steve

I admit I stole the idea from Audi. My wife's old A4 uses wheel bolts (as opposed to wheel lug nuts). The jack kit came with a heavy plastic rid threaded to the bolt size on one end for sticking into your brake rotors to allow you to position the wheel without slamming it into things and eyeballing it. Thank the German Engineers (which I guess technically I am, but again, it wasn't my idea...)

Dan

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

I just did both diffs and my transfer case last weekend.
Having a bottle pump is well worth the $8 from Wal-Mart.

BTW - a great side effect that I noticed is how much more willingly the Jeep rolls.
I live at the bottom of a hill. I often times will put it into neutral and coast down. Before last week, I would actually slow down - even in neutral - going down hill. After replacing the fluids, I can now coast down the hill - in gear - and gain speed.
I figure the loss of friction has to improve my mileage a few mpg. I always thought the Jeep had way too much engine braking, but now it is quite a bit better.

I used RedLine synthetics for each and a LubeLocker on the rear.

JJsTJ · **Posted:** Wed May 07, 2008 10:04 pm

crd liberty wrote:

SBosco wrote:

that's good news to me. what kind/grade of fluid is reccomended? How involved is the procedure? Is there a drain plug or do I need to purchase new gaskets for the diff covers? Thanks again for all your help.

--------------------------------------
Rear diff. is 75w-110 or 75w-140, depending on towing there.
Front diff. is 75w-90
All are synthetic. Mobile 1 or contact our friend for Amsoil. He flys above as
Hot rod oil. Delivered to your door and cheaper than the local auto stores.
Front change is easy. Drop the skid plate, remove the drain plug and the fill
plug. Please have a pan under it as it drains. To refill this, a pump is a good thing
because there is not a lot of room in there. Hand pump 1.2 Qts and that one is done.
Rear diff. a bit harder. Pan under, loosen all the bolts leaving the top bolt in place,
remove bottom bolts and let the fluid run into the pan. Remove cover and clean
scrape Permatex gasket maker off both cover and diff. Reseal diff with Permatex gasket maker,
put cover back on, tighten, refill with 2.4 Qts syn.
Good to go.

I do have to add though, at age of 62 years, I am looking at rear diff's with a drain plug
because of the laying on belly and back trying to get this darn cover back in place
with the Gasket sealer letting the cover sag and holes not lining up.

Give me a car lift and I would be set :lol:

"Our Friend" Thanks!!

I, JJsKJ, am HotRodOil.com

I use dgeist's trick of using a long grade 5 bolt w/ head cut off to hang the diff cover on while centering it to start the bolts. Works like a charm.
My rear KJ diff takes less than 2 qts to get it to w/in about 1/2" of the fill hole. Much more than that and it starts to flow out.

SBosco · **Posted:** Thu May 08, 2008 1:31 pm

All great information and advice. Thanks guys.

Hearing about how much of a pain the rear diff sounds like, provokes a thought...does anybody make a diff cover with a drain plug? I don't know much about the type or model of the rear diff but could probably find one if I did.

Also, I have heard great things about both Redline and Royal Purple products. I have wholesale access to both product lines and was wondering which you guys would reccomend; they both exceed the API GL-5 rating of the mobil 1 gear oil.

SBosco · **Posted:** Thu May 08, 2008 1:49 pm

Does the CRD have the "Chrysler 8.25""/"Corporate 8.25" rear, or a Dana 35 or 44?

Sir Sam · **Posted:** Thu May 08, 2008 2:27 pm

SBosco wrote:

Does the CRD have the "Chrysler 8.25""/"Corporate 8.25" rear, or a Dana 35 or 44?

8.25

SBosco · **Posted:** Thu May 08, 2008 2:38 pm

what do you guys think of this?

http://www.yourcovers.com/dc_9864.shtml

MOSFET · **Joined:** Sat Feb 25, 2006 11:40 pm **Posts:** 295

I got this from http://en.wikibooks.org/wiki/Jeep_Liberty/Chrysler_8.25%22

Quote:

Differential Covers
The Blue Torch Fabworks 8.25" Differential Cover is constructed of 1/4" plate steel with a 3/8" plate steel ring. It's built to resist peel up and features a protected fill plug.

The Crane High Clearance Differential Cover is made of 8630 chromolly steel and features a lipless design.

Moe's Metalworks 8.25" Differential Cover

The PML 8.25" Differential Cover is constructed of aluminum, features both a threaded fill plug and a threaded drain plug, and holds 3/4 quart more oil than stock. The cover also comes with heatsinking fins, but they must be ground off if the cover's to be used in conjunction with a fuel tank skid plate.

Ruff Stuff Specialties 8.25" Differential Cover. The Ruffstuff 8.25" Differential Cover is the only fabricated cover known made of 3/8" plate with a 1/2" ring. A 1" fill plug is standard with $10 options of a drainplug or countersunk bolts. Many companies make 1/4" covers but Ruffstuff is the only company known for a 3/8" thick cover. Very fairly priced.

hatchetman · **Posted:** Thu May 08, 2008 3:06 pm

The PML cover does fit on my Jeep with the fuel tank skid left on and no removal of heat sink fins. :evil:

flash7210 · **Posted:** Thu May 08, 2008 6:06 pm

Do we have both front and rear locking diffs?
Just front?
Just rear?

CATCRD · **Posted:** Thu May 08, 2008 6:40 pm

Neither one is locking. Limited slip was an option on the rear for 05 only.

JJsTJ · **Posted:** Thu May 08, 2008 7:03 pm

SBosco wrote:

All great information and advice. Thanks guys.

Hearing about how much of a pain the rear diff sounds like, provokes a thought...does anybody make a diff cover with a drain plug? I don't know much about the type or model of the rear diff but could probably find one if I did.

Also, I have heard great things about both Redline and Royal Purple products. I have wholesale access to both product lines and was wondering which you guys would reccomend; they both exceed the API GL-5 rating of the mobil 1 gear oil.

Read this:
http://www.amsoil.com/products/gearlube ... Paper.aspx

You would be better off w/ several different brands over those two but between the two, Redline is better than RP for gear oils.

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

JJsKJ wrote:

SBosco wrote:

All great information and advice. Thanks guys.

Hearing about how much of a pain the rear diff sounds like, provokes a thought...does anybody make a diff cover with a drain plug? I don't know much about the type or model of the rear diff but could probably find one if I did.

Also, I have heard great things about both Redline and Royal Purple products. I have wholesale access to both product lines and was wondering which you guys would reccomend; they both exceed the API GL-5 rating of the mobil 1 gear oil.

Read this:
http://www.amsoil.com/products/gearlube ... Paper.aspx

You would be better off w/ several different brands over those two but between the two, Redline is better than RP for gear oils.

Asking people to recommend an oil is like asking who you should vote for in some elected office.
If you have a brand you trust - use it.
I like Red Line and have used it successfully. I know nothing good or bad about AMSOIL (though my dad has drank the kool-aid), nor Royal Purple. I have heard good and bad things about all 3.

Differential self-service?

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