Jeep grand cherokee. Dif is FUBAR I think????? maybe????

[big black thing]

Well the old noggin is scratched raw here.. I have a Jeep grand cherokee and as much as it can be a pain in the arse, I do like the ohl lady. I'm not daft with a spanner but really only know what I've learned from my own experience with bikes and motors. Thats why I'm hear. I've had a few people give me advice but I live in Norn Iren so the jeep is not going to a main dealer as they are dam hard to pay and i'm not paying plus I'd rather do it myself.. Write enough ste here's the thing.

I think there's something fked in the rear diff. When she's cold there's no bother at al but when she gets a bit of a drive and some heat built up there's this sort of cracking crunching noise when you turn hard over either way which to me sounds like a big clutch slipping or jumping. Thing is I don't even know if the thing is limited slip or not or if there is a clutch in the diff or what.. I've had to put new harly spicers in the rear drive shaft which makes me think there's too much torque being put through it due to the lack of a slipping diff????? Well there's my thoughts.. Probably pure dung but I would defo take advice on it if there is anybody willing to give it..
What is it?
What do I do?
How do I do it?
Kinda thing..
Cheers folks!!!
Liam

[Ayahuasca]

No real idea, but I don't think rear diffs come with clutches. You might want to check the diff oil?

You can tell if it is limited slip or not by jacking up the real axle (both wheels), getting someone to hold one wheel tightly while you try and turn the other one by hand. If it turns easily there is an open i.e. not limited-slip diff. If it is hard because it wants to turn the opposite wheel too (the one your mate is holding) then it is a LSD.


Once you have figured out your Jeep any ideas about my Landcruiser ? - it drives normally for a bit, then no matter how maany revs you put on the thing goes nowhere. I would suspect a knacked clutch except that being an auto it doesn't have a clutch.

Yours in 4x4 problems empathy.

Aya.

[TUS 373]

I'm no expert but can only relay my experiences with our Cherokee (not a Grand). This has a LSD and it is necessary to put 'Friction Modifier' in with the diff oil. There are clutches in the LSD, and this stuff must somehow provide the optimum amount of lubrication to get it all to work properly (very untechnical). The Friction Modifier can sometimes be bought from Ebay for about £8 for a bottle. The whole lot is then injected into the diff.

As I recommended on another thread, loads of Jeep help available here: http://www.jeepforum.com/ . Can always ask on there - quite a friendly bunch all said, and probably one of the best places to go for Jeep help on the web.

[Fire99]

First and foremost, change the diff oil. The Grand Cherokee uses a different transfer system from my XJ so i'm not sure if your rear diff is LSD or not.
The normal test is to jack the rear up and spin one of the rear wheels. If both wheels turn in different directions then you don't have an LSD. If that doesn't happen then you do.

Normal diff oil is easy to come by (non LSD) but if you need LSD stuff you can buy the oil with the additive already included, from the likes of opieoils etc.

Changing the diff oil will require either removing the cover (which may require a new gasket etc) or buying an automotive syringe (like I have) for a tenner or so and sucking the oil out of the filler hole.

It's a messy job but an easy one. Do that first, and quickly. If the oil level is low, you could risk more and lasting damage by keep driving the jeep that way.

[big black thing]

Well folks!! Cheers for the feedback.. I'm gonna go down the changing oil root and I think I'll take the cover off so I can nosy and see if there is any damage obvious in there.. I hope I haven't damaged the thing by driving it but I'll find out no doubt.. Oh and there"s a haynes manual on it's way as we speak so here's hoping.
Again ta folks as no doubt this is not the last of it!!!!!!!!!!

Oh yes and for the gent who's loosing drive. I really don't know anything about automatic trans other tahn it's good when it works.. Sorry!!!!!! Good luck!

[pugwash4x4]

Sounds suspiciously like the centre diff is binding

Can't remember what jeep axles the cherokee has- will either have CVs/Birfields or have yoke joints- you may find that these are heavily worn.

The former can be indentified by warming the vehicle up then jacking up both wheels on one side of the car. Rotating one wheel should cause the other to rotate freely. If it doesn't then you have a cente diff problem. Can also be checked by driving the car in tight circles on a gravel road and seeing if you get chirruping or spinning from an inside wheel.

more difficult to diagnose CVs- also dependant on turning the wheel, but you should hear it just frmo oe side.

[challanger]

i had the same problem its the pinon gear its more than likely lost some teeth there very easy to do but when you strip it down watch for lsd shims make sure when you strip it they go back in the same order, if theres no teeth missing then the lsd shims want changing, when you turn right or left hard the back wheel skips or drags this is a common fault with a jeep, take the diff out and check for teeth missing its mainly the pinon teeth that go,cheap metal, the shafts are held in by a cerclip, remove them the shafts pull out take out the diff when you strip the diff you have lsd shims on either side make sure they go back in order you might find that a shim may be broke,when putting the diff back together use new oil in between each shim this will combat drag when you put the diff back put back together and drive it normaly but use dextron 2 oil in the diffs that will keep it cool

[normalbloke]

challanger said:

i had the same problem its the pinon gear its more than likely lost some teeth there very easy to do but when you strip it down watch for lsd shims make sure when you strip it they go back in the same order, if theres no teeth missing then the lsd shims want changing, when you turn right or left hard the back wheel skips or drags this is a common fault with a jeep, take the diff out and check for teeth missing its mainly the pinon teeth that go,cheap metal, the shafts are held in by a cerclip, remove them the shafts pull out take out the diff when you strip the diff you have lsd shims on either side make sure they go back in order you might find that a shim may be broke,when putting the diff back together use new oil in between each shim this will combat drag when you put the diff back put back together and drive it normaly but use dextron 2 oil in the diffs that will keep it cool

If you replace a pinion, you HAVE to put in a pinion and crownwheel as a numbered matched set. If you do this, it is a whole heap of work to do it properly and acheive the correct gear mesh pattern and pinion preload and backlash. To do it properly involves a fair chunk of time,patience,attention to detail and specialist tools. To replace the pinion on it's own and just "put the old shims back in", is frankly gash work best left to those with champagne tastes and lemonade pockets.

[challanger]

its not gash work. anybody with half a brain can do a diff nothing hard about it, jeeps are prone for diffs some times its pinon some times its shims and some times it takes the teeth of the internal gears, the internal gears are normaly the problem as they strip the teeth of. what causes the shims to snap is when the wheel drags when going around the corner. the early landcruiser internal gears are the same as the jeep cherokee ltd 4ltr 1997 which are stronger i fitted these and it was mint worked a treat you be surprised what what fits what it just takes time and alot of tea lol i love the jeeps its just a pitty they didnt make a good one. since i rebuilt mine ive done 2000 miles and not a sound
most people just pay £400 or £500 for a diff and then pay for fitting i did it for £60 massive savings theres plenty of breakers out there for parts i got a scrap diff and made a good one out of the two mines still working fine even offroad nothing hard in repairing or rebuilding a diff ive done loads even arb,s plenty of info on the web and from jeep them selfs

[normalbloke]

I'm very pleased for you.
To each their own.

[900ssduke]

If I could put a slightly different and uneducated and possibly useless angle on it. My Grand Cherokee used to give a few cracks and shudders, and I thought the diff was going. Usually did it when cold, but intermittent. I ended up putting into the dealer and it was either a dodgy potentiometer on the accelerator pedal or a duff analyser on the exhaust, I cant remember which cause I think they fleeced me for both. Bottom line is, something was causing the car to momentarily cut out causing a bit of a crack from somewhere. Changing out some of the electric wizards sorted it.

[challanger]

weird that my dads got one that kept on trying to go on safety mode when running every time he went forward fast it shook it self as if it was starved of fuel and then stalled we took it to someone with a code reader and it came up with faults on the ignition box it was damp on the inside its a common fault the brain got condencation inside it which caused it to short which then went on saftey mode it could of been that its hard to say not many people want to touch a jeep and when they do theyll charge you the earth theres plenty of ripoff merchants out there

[normalbloke]

I can't read this anymore, I'm going to drown....

[Trooper2]

normalbloke said:

I can't read this anymore, I'm going to drown....

Don't forget your snorkel and fins..