jeremyearles

I bought a used '99 Grand Cherokee WJ about 2 years ago (my first GC after having owned an amazing '82 CJ7 for years). Anyway, I've always shifted the GC's SelecTrac transmission on the fly at about 35mph without any issues. I recently had the transfer case replaced and a front diff rebuild done by a local garage, and the outcome seemed perfectly fine. UNTIL I tried to shift from 2 to 4-High about a week later (the same way I'd done for the past 2 years). Immediately it stripped the rear diff pinion gears AND bent the front drive shaft (actually the joint connection popped under the rubber boot at the end of the shaft, but will have to now replace the whole thing anyway). So after a tow back to the shop...now they're telling me that this all happened becuase I shifted on the fly, and I shouldn't ever do that, even though the operators manual says I can with that trans. They're telling me that it has nothing to do with the work they completed and the new transfer case could not have caused this. My thought is that nothing else COULD have caused this, but I can't get them to budge. Can anyone please help explain why this would have happened? I feel like I'm getting screwed over, but I'm not knowledgable enough about transmissions to fight them on this. PLEASE HELP!

candymancan

I cant help sorry, but i was always told to never change the car from 2wd to 4wd while driving.. Always do it at a stand still.. as you could dmg your car, which seems to have happend to you.

I could be wrong and that it might be perfectly fine to do that while driving howeever my better judgement says you do it to yourself by changing to 4wd while moving. Again im sorry this doesnt help but i thought id put my 2 cents down on this issue..

4x4Jeep

the manual says you can shift-on-the-fly but not to do it over 55 mph, thats for 2wd-4fulltime. when shifting to 4 parttime, or 4lo do it at 2-3 mph. thats what i no.

sandaddik2

thats what they say but i play it safe and dont change any gears at anything faster than a crawl

trucker

I have select track in my 96 and to get to all time 4x4 you have to go trough "part time" and that what I think mess up your truck. "Part time" is all most as 4low. You should have shift trans in neutral the move shifter to all time 4.
I hope that I am wrong.

candymancan

Yea thats how i do it.. I always go to neutral first then change to 4WD and only when im at a stop.