Hard jerk/slip in 4lo 07 KJ

[jgo23]

I'm a recent lurker and an XJ owner. I've decided after 6 years it's time to let the XJ pass to a family member. I've decided I want a KJ or KK to replace my beloved DD. Ive shopped a lot with lots of disappointments to finally find an 07 KJ with low miles and proof of maintenance. I did a test drive today and really liked it although coming from the 4.0 I was surprised to find the 3.7 lacking in acceleration.

Long story short while testing the 4wd, in 4hi things worked fine, but when I put it in 4lo it ****** hard with ANY acceleration. I understand how 4lo works mostly and yes I was on pavement (it was slightly gravely) but it felt like something was wrong. Is this normal? A 2nd XJ I briefly owned was 4wd and 4lo was rough but nothing like this. Just to be clear, it was loose pavement, no turns, gassed as light as possible but the jerk felt like it was slipping. I tried both dead stop from case neutral and idle roll from neutral. Any KJ owners have similar experience

Any feedback appreciated. I hate to first post something like this, just not able to find something specific enough online.

 

[dude1116]

I've just never done anything on dry pavement. When I use 4LO it's only off road, up hill. I get no jerking. Just glides smoothly up the hill I'm climbing with no gas whatsoever. Sounds to me like it didn't shift in all the way, because you shouldn't have to give it gas to get it to move. It's super torquey.

 

[HoosierJeeper]

Mine doesn't do that for sure.

 

[Leeann]

Never tried it on pavement because you're not supposed to, ever.

On dirt, I had no such trouble. Did you get underneath and verify that the transfer case shift lever was fully in 4 low?

 

[jgo23]

Wow quick answer. There is a river bottom near by I'm going to ask if we can take it to and try. I'm REALLY set on this vehicle but that jerking caught me off guard. I shifted it out and back in more than once and even if I idled and then eased back on the gas it ******. I know it shifts with almost no rpms.

 

[tjkj2002]

Normal when on a high traction surface and the fact the '07 has throttle by wire system so it will always be a little jerky no matter what without a actual throttle cable.

 

[jgo23]

Nope I didn't check, good tip. Ill look at the lever. The 4wd Cherokee I had did have the shifter come loose and wouldn't go into 4lo. I'm going to check it again tomorrow.

Wow you guys have a great community...

Good to know on the jerking, but even being slightly familiar with 4wd this was rough.

 

[HoosierJeeper]

I engage mine once every week or so in the driveway and drive in a straight line in 4LO, doesn't jerk. My LR3 is drive by wire though and it doesn't jerk.

I'd try another KJ- something could be up with this one since I bet you're the first one to put it in 4LO.

 

[tjkj2002]

I engage mine once every week or so in the driveway and drive in a straight line in 4LO, doesn't jerk. My LR3 is drive by wire though and it doesn't jerk.

I'd try another KJ- something could be up with this one since I bet you're the first one to put it in 4LO.

Mine jerks like crazy in 4low,then again having 66:1 crawl ratio before adding in the TC reduction will do that,makes the throttle very sensitive.


Besides there's a huge difference between a a LR3 and a KJ.

 

[Akedos]

My jerks pretty hard when I put it in 4lo on pavement. It's a lot of torque to be putting on an immovable surface.

 

[TheBlueKJ]

^Why would you do that???

 

[Akedos]

^Why would you do that???

The only few times I've done it were recently before and while changing the t-case position sensor. I was making sure the sensor was working correctly and I was in my driveway. I rolled it back and forth a few feet in all positon to watch the light.