Changing tranny/differential fluid

[CoastieJ]

Any advice for a newbie on changing tranny and differential fluid, including which type & amount of gear oil to use? I recently bought a '96 Cherokee Sport, 4.0L 4WD, auto tranny with what I believe is a Chrysler 8.25 rear and a Dana 30 front. On the differentials, there doesn't appear to be a fill and drain plug...do I have to take of the whole diff cover to change out the fluids? Any help is appreciated.

 

[5-90]

You're in luck - the AW4 usually has a drain plug. Service fill (a drain and fill job) is usually listed as four quarts - but I buy by the case anyhow. I'm getting ready to start buying fluids in 15-gallon drums - as soon as I can stomp up a "drum caddy" to sit in the corner. The AW4 is refilled via the dipstick tube - get a funnel and pour slowly.

Axles seem to like 75-90 - plan on two quarts for each axle (you won't use it all, but you'll KNOW - for next time.) Check the rear axle carefully - if it has a tag on the cover, or you can see clutch packs inside the differential, it's got a Limited Slip and requires "friction modifier" - which keeps the clutches in shape. As I recall, GL-5 series lubes carry friction modifier already (having it won't hurt if you don't need it - but not having it will wreck LSD clutches.) The axle is drained by pulling the cover, and refilled through the fill/check hole. You'll want one of these...

(Check around - a well-stocked local should have them. Made by Plews - it's called a "Suction Gun.")

For filling the axles and transfer case - makes the job a WHOLE lot easier!

The transfer case like the same fluid the transmission does (don't know why - they're separate units and sealed apart...) about two quarts' worth, IIRC. Drain through the bottom plug, fill through the top. Check wrench sizes - on all my RENIX XJ's, they're 1-3/16" - but I'm sure ChryCo changed that as well.

When you check your axle, the rear will probably have a rubber plug. If the hole it's in is threaded, you can probably stick a pipe plug in there - I use brass so I don't have to worry about rust or siezing (and it looks nice with my "bloo" axle covers.) You shouldn't have any trouble finding plugs at your hardware store - in brass or iron. If it's not threaded, get some spare rubber plugs now so you aren't hanging by your shorts if - when - you lose one somehow.

Engine oil is about six quarts, usually, so no trouble there. You should have the filter with "inch" threads - the early ones were metric.

Filter Numbers for 1996 XJ/4.0/AW4:
51085 - Oil
46077 - Air
33486 - Fuel
58936 - AW4 (This one's usually just a metal screen - I'll take it down and clean it the first time, then I only pull the pan if my magnet comes out "fuzzy." I drain fluids over a magnet to check for metal particles.)

All clear now? Clear as mud?

It really isn't so bad, once you get used to it! :laugh3:

5-90 :lecture:

{edit - got the image tag wrong...}

 

[viperbaron]

5-90, is there a drain plug on the torque converter for the AT?
I've had a replacement trany filter ever since I bought my XJ a couple of months ago. Have been meaning to do a oil & filter change, but just can't find the time.
On my F-150 there is a small drain plug in the torgue converter that requires me to manually rotate the flywheel into position. Same on the XJ?
Thanks.
Karl...

 

[5-90]

Nope - it takes a flush machine to change the fluid in the TC. Either that, or pull the TC, drill a hole, drain, braze the hole shut, rebalance, ... It's too much of a pain to put a drain plug on a TC, since it has to be dynamically balanced so it won't shake itself apart.

In my experience, a drain plug on the TC is a rarity - but I'd only be worried about a "full" fluid change if the fluid is already burnt (smells nasty, looks brown or black. Red tranny fluid is healthy tranny fluid.)

5-90

 

[noresttill]

Check the rear axle carefully -

if it has a tag on the cover,

or you can see clutch packs inside the differential, it's got a Limited Slip and requires "friction modifier" - which keeps the clutches in shape. ...}

Sorry to bring this thread back up , but Im converting my 2wd axle to a d30 tomorrow and im changing the oil in it too. It has a tag on it. Does this mean it has a LSD? Or does it say LSD on the tag.

Its covered in grease and i didnt read it, the tag is a metal piece about 3 inches long and held on by 2 of the diff bolts.

 

[5-90]

The tag will say something to the effect of "Use LSD Lube Only" or somesuch, and will probably be held by a single bolt.

If it's a long, narrow tag with bolt holes in each end - and a whole boatload of numbers on it - that's an ID/build tag and will have the Bill of Materials number, the gear ratio, and a few other things on it.

The LSD tag is pretty clear - if I had a pic, I'd show you (but I don't...)

5-90

 

[Ray H]

Your D30 wont be a limited slip unless someone put it in after it left the dealer. If youve got a LS, it will be in the rear diff only.
The tag on the front diff states the gear ratio.

 

[noresttill]

thank yall kindly

 

[dizzymac]

LSD....now that explains a lot of the weird things that go on with my XJ....the damn thing is tripping its brains out.
Dr. Leary...Dr. Leary..paging Dr. Leary....lol