Hello everyone I'm new here since the jeep rarely has issues where I can't find the info already prepackaged online, but this one has me confused.
I have a 98 Grand Cherokee Laredo 5.2L (which I think means Quadra-Trac?) About 4 months ago I noticed after driving from Tahoe to Santa Barbara and back that during long drives when I pulled over to get gas and such it seemed as though there was resistance to the wheels rolling and especially to turning. Trying to navigate gas stations resulted in the car bouncing and tires chirping. The problem would continue until the car had a period long enough to cool down. More recently I had the chance to take the same 90 minute drive on back to back days. The first day I did have the problems, but not as severe as the last time. Overnight I had the thought that it could be related to speeds and sure enough, I never took it over 70 (on the speedo, prolly 65) and the problem never showed up. Fast forward two more months to now and it seems like 65 on the speedo is the level I need to keep it under. I'm new at this tranny type stuff but it seems to me that fluid somewhere is getting too hot. So what are your guesses?
Transfer Case needs work (or just fluid changed)?
Bad Transmission Oil Cooler?
Change the tranny fluid?
Something else?
Shoot it and walk away?

PS- I've had the car about 30k (out of 207k) and don't know the prior history related to fluids. The tranny fluid is between brown and red probably more brown, but doesn't smell burnt. No real slippage to speak of. Sometimes on cold mornings here in Tahoe it will take 1-2 seconds to engage reverse to get out of the driveway the first time but that's it.

 

Welcome to CF!

Quadratrac (NP249) is a 4wd system with which you are in 4wd all the time. You t/case shifter should say 4hi-neutral-4lo. This system supplies power to both axles constantly and uses a viscous clutch to allow speed differences between the 2 axles for cornering. This slippage is turned into heat in the transfer case which doesn't have any means of cooling except by circulating lubricant.

The problem is all 4 tires MUST be the same EXACT diameter, including wear, for the viscous clutch to stay cool. At high speed, even the slightest difference in tire diameter can cause heat to build up. Once it gets hot, the VC will bind causing the tires to drag or hop when going around corners, like in the gas station. In severe cases, the clutch plates in the VC will warp to the point where it will bind all the time. The replacement of the viscous clutch is expensive and time consuming and some guys decide to swap the t/case for a 231 or 242 instead. The 249 takes a special fluid.

The transmission could use a fluid&filter change as well. I always start mine and shift to neutral for a minute or 2 to allow the trans to pressurize and expand the 0-rings before expecting it to start moving the jeep. Mine has 210K miles on it and has never been rebuilt.

You can try a new set of tires and that might solve your problem.

 

Thanks so that definitely sounds like its the transfer case but the tires are all the exact same size, in fact the folks at Les Schwab were surprised they didn't need to be rotated. However there was a period prior to this set of tires where the spare was a 235 and the other three were 225's. Is there a computer this could have messed up that took a while to show symptoms? And if so why would it be getting worse?

Other than that just change the Transfer case oil?

 

So I went ahead and rotated the tires and changed the xfer case oil. The old oil was still bright pink so it doesn't seem like it's getting too hot, but I don't know what too hot is in there. I did get it up to 70 yesterday with no issues but it wasn't in the midst of a long drive so I don't know if enough heat built up to cause the problem.
Since I found some bad info on a couple other threads I will share something. I read on one other thread here and I think on jeepforums that the case (#249) takes a little over 2 quarts. It should be just over 2 PINTs, or like 1.2 quarts. If you try to put in 2 quarts (and you rig up a ghetto gravity system with some plastic tubing and you can't see what's happening under the car) this will happen. The good news is there was too much snow in my driveway so I was in the middle of the road. Neighbors were not impressed.

 

Kitty litter time! LMAO!! I hope you cleaned it up! That stuff is SLIPPERYYYY!

 

I did. Cleaned it all up with rags and then poured soapy boiling water on it, and then we got 2" of rain. It'll leave a dark stain for a year or two (I had a subie blow a seal in my driveway once).
I'm back on the road again tomorrow in the jeepdominium so we'll see how she does. Hopefully it won't get any worse and will start to improve as the tires start to get closer to the same. I have had much much bigger differences in wear though both on this jeep and on subarus with no noticeable effect at all so I'm wondering if something happened to make it even more sensitive.

 

Well, the clutches in the VC might be getting worn.

 

Would that cause the symptoms all by itself or make them more sensitive to small differences in tire size?

And thanks for all your help

 

The VC is a self contained clutch pack similar to an LSD differential with it's own fluid in the clutch pack. Any slippage causes heat like a brake does. As the plates wear, the clutch doesn't grab as well as it used to. More slippage=more heat.

 

Alright well it sounds like my next course of action is to cross my fingers

 

Just my opinion, mind you, but if this jeep were mine and I planned on keeping it a long time, I'd start looking for a t/case swap. The NP242 is the most versatile and trouble free one used in jeeps, mostly in 4.0 ZJs.

Check out http://jeepforum.com/forum/f13/trans...-np242-685644/

 

Not sure what did it or to what extent but I put considerable time last night at 70mph with no noticeable effects afterward.
canthe fluid get all tired without losing color?

 

It is good to be reminded that when working on a JEEP, one of the best tools we have is a sense of humor.

 

I think he does, considering his "laying dead in the street" pic!

Here's an idea, go run it thru a slalom course and so how it reacts after that. In other words, purposely heat it up. When it starts to bind and hop, check the case to see how hot it is.

 

I have a 97 Jeep Grand Cherokee that needs a new transmission n transfer case, I have a 94 limited edition Jeep will the 94 work for the 97?