Grand Cherokee transfercase questions

[Oil leaks]

Hello people,
I'm new to Jeeps, and wonder if someone can help me, just had a look at a 1996 Grand Cherokee Limited, All looked good with a good price until I tried a low range tight turn in the car park, there was fairly noticeable crabbing, trying again in high range and it was not as bad but still noticeable. The only other one I have driven didn’t do this so I'm assuming it’s not normal.

I assume that the grands have a viscus centre diff and this symptom is a sign that it has locked up and due for replacement (at 130K id expect it to last longer than that?) any advice on this? If it is the Viscus diff can some one give me an idea on the cost of parts to fix it (I assume I can do the work myself)?
I have also read somewhere that the way to go is installing the transfercase from a standard Cherokee with the choice of 2WD and 4WD, any comments?

Thanks for your input!

[Steve F]

Errrm, Low range will lock the centre diff and do exacly what you describe, why would you even try a tight turn on hard ground in low range. Only use low on low traction surfaces as it will lock the centre diff and can cause damage otherwise. My guess is when you put it back in high the centre diff was still partially locked up and it would probably be fine to try the tight turn in high after a say 10m of driving.

Cheers
Steve

[Oil leaks]

thanks for that,
to much playing about with range rovers i guess, Just done some searching and the 1996 grand would have a Viscus Np 249 transfer with lo-range mechanical lock up is that correct? (no lock pre 1995) or is that just for the US built trucks?

[PK]

ZJ's have a viscous coupling and when in high range, locks up when wheel slip is detected - there may be about a half second delay before locking up.

When you put in low range, transfer case locks up so drive is sent front and rear.
DON'T USE LOW RANGE ON A HARD SURFACE! You will get transmission windup, and something will break! Usually something expensive.....

[mightyjimny]

hi all. swapping the jimny for a 97 GC limited in the next week or so. wondering what 4wd system they have? from memory there is Quadra-trac and a factory option of the better Quadra-Drive. could someone explain how these work and how i know which one mine has? if it helps, the transfer lever has 4Lo-N-4Hi but no 4Part-time which i think some jeeps have. have tried search but no luck

[xappas]

Hello,

I have a Grand Cherokee 1994 model. I have read that there is no Lo-range lock in models until 1996. Is there a way to confirm this? The t-case is an NP249 but how can I tell the difference with a one that locks?

[jeepmat]

Quadra-drive only came with the newer grand cherokee (1999 onwards), so yours is a quadra-track.
It'll send power to the end of the vehicle which needs it i.e. if the rears are slipping, it'll send power to the front
What i've found is that on a narrow treacherous rocky track you're best off in low range as it'll lock it in 4wd drive - the mechanical system is just a bit too slow to engage 4wd and you can get the rear end kicking out sideways

[disco-damo]

Does anyone know how it all actually works?

I take it that it takes readings from the wheel speed sensors for the ABS or does quadra trak use its own system?

In our ZG it has a picture that it lights up the driving wheels and most of the time it has all or the rear lit up but I have seen it with just the front 2 lit up but with out putting it on a 2 post you wouldn't really know what is driving what.

I cant work out unless there are actually 2 viscous couplings how you could get front, front and rear, rear drive as I would have thought it would be more like rear unless front needed to be engauged more or less like auto hubs as such.

Give me my trusty old XJ trasfer case any day or my DIsco, at least you know when your in 4wd and you don't have the element of doubt hanging over you.

I like the comfort of the ZG and my wife thinks its great but im more used to tractors and thats how I like my 4wd's so I think this one might not see too much dirt and I'll keep using landy for the fun stuff.

[mightyjimny]

just found this link which might help with some info on the qudratrac system:

http://www.duff.ws/grand_central/tc_swap/249_vs_242.htm

[disco-damo]

Thanks

That has both answered my question as well as worried me about the condition of the TC in the Grand as it drags wheels a bit but I thought it was just a tight as LSD not so much the Viscous copling.

[disco-damo]

Just to Conirm a few answers found on the above site for all to see,

All these have Low Range Centre Diff/ VC lock

NP231 Command-Trac 2Hi, 4Hi (PT), 4Lo mand Trac
NP242 Selec-Trac (93-95) 2Hi, 4Hi (PT), 4Hi (FT), 4Lo
NV242 Selec-Trac (96-01) 2Hi, 4Hi (PT), 4Hi (FT), 4Lo
NV249 Quadratrac (96-98) 4Hi, 4Lo

These Dont

NP249 Quadratrac (93-95) 4Hi, 4Lo
NV247 QuadratracII (WJ) 4Hi, 4Lo

If you want more info I suggest you check the site.