strandwolf

My jeep cherokee sport 1999 auto 4l 6cyl have never gave me issues i could not solve quick. Untill now! First let me explain some facts. I am from Wakvis Bay in Namibia, a fisherman and the jeep do daily fishing trips but i only use 4x4 at certain times as i flat the tyres to 1 bar and can drive without using 4x4. On friday i came back from fishing and as usual when i hit the main or hard road i stop and reverse for 3m just to make sure 4x4 is not engaged. small thing imprinted in my memory to do. Okay going forward about 20m it felt like both rear wheels brake then loose and then brake again. i checked the diff oil and it was correct. i tried again but every 10 m or so the rear wheels lock and then release. PLEASE HELP WHAT IS BROKEN OR WHAT CAUSE THIS?

1. ALL PARTS ON JEEP IS AS FROM FACTORY.
2. I REMOVED REAR BRAKE SYSTEM EVEN HANDBRAKE. (SHOES ETC) thus cannot brake at back.
3. no sound is coming from any bearings, wheels or diff
4. rim, brake drum, sides of diff is cool to the touch but diff hub is hot.
5. the strain was so much on the engine that, whilst i drove less than 15km/h it overheated.
6. i parked the jeep at home as mechanic only avail on monday. since then it havent done anything again. we checked for broken axle, broken gear teeth, bearings but all is fine.
7. gear lube i use is 80w 90

GreaseMonkey17

strandwolf

in front 2x 215/70/15
rear 2x 215/80/15

Rob Jordan

I wouldn't use 4WD with different tire sizes. 2WD will be fine though. Hopefully, you haven't damaged anything. NP231 t-case, correct?

strandwolf

as far as i know np242 and 99% of time when i need 4x4 i use part time 4wd, never used 4low ever and very rarely 4hi. I assume it must be friction in the diff hub caused by the tyres, but then i didnt use 4wd when this happened. Then again this only happened after i put those smaller tyres on front. Tyre place said it will be ok but now i dont know. I hear no sounds at rear and today i drove 20km and nothing happened. I would like the cause so i can prevent this and fix the issue. The diff is dana35 and 30 in front

Suprmn

I would start with the simple things first. Make sure it is in 2wd. it is possible that the linkage for the transfer case is out of adjustment or came loose. You can go under the jeep and manually put into 2wd if necessary. Then I would jack up the rear asle and manually turn the tires to see if you feel the same binding. if your off roading is in high traction areas, the different size tires are not that good of a thing, but otherwise, it is unlikely to break anything. However, if it was stuck in 4x4, the different size tires would be a bad thing and could create the sensation you are feeling. If you can isolate the issue to the rear axle, its time to pull the diff cover and look inside.

strandwolf

Then again this happened only after i fitted the front tyres

00t444e

If you have different size tires the 242 will often bind up and get stuck in 4x4 and not want to shift back into 2wd until you relive the pressure. Jack the front end up and make sure it isn't still in 4x4.

00t444e

Also 4 hi and 4 low are both part time 4x4.

strandwolf

when i drove to the mechanic nothing happened. We checked the 4x4 and it was not engaged. We jacked the jeep putting the jack under the rear diff, then turned the wheel, both turned and vice a verca. He started the jeep and both in forward and reverse both wheels turned. All times no strange sound came. Then we jacked the jeep rear one wheel a time in air and same story except wheel on ground didnt move. Opened the diff cover and could see nothing wrong. The only reason i took the tyres as the sand i drive is always soft but i flat them anyway and never use 4x4 exept emergency but thats rare. Then it was only the rear wheels that did the braking. I really am confused with all my friends and their friends and everybody just dont know what happened. I have 270 000km on the clock and never had any issues with engine gear boxxes diffs etc. Ya changed filters plugs, u joints cv joints new oil but thats it oh ya a fanbelt and tyres.

strandwolf

The lever i pull is to the first mark from 2wd

00t444e

That would be 4 hi part time.

strandwolf

thanks i think the prob was the binding and when at home after the ordeal maybe it came loose to 2wd thats why we just cant seem to get the fault anywhere. My question is then did the front tyres cause this? I presume so as i did use part time 4wd on certain places that day on the beach. But also when i got to road i did check by going forward and reverse that 4wd was disengaged, did i miss somethin g in the hurry.?

00t444e

When I first got my jeep it had different size tires on it, and it would get stuck in 4x4 sometimes. You should put the same size tires on the front and rear.

strandwolf

Thanks for all the help. Will put new tyres asap. A bargain isnt always a bargain frightening lesson learned