Question about 4wd?

After driving a few miles in 4wd fulltime, my jeep jerks when making sharp turns? Is this normal? The jerks only occur after driving in 4wd fulltime & I havn't used partime at all! My vehicle is a '98 laredo.

After driving a few miles in 4wd fulltime, my jeep jerks when making sharp turns? Is this normal? The jerks only occur after driving in 4wd fulltime & I havn't used partime at all! My vehicle is a '98 laredo.

WHY WOULD YOU WANT TO DRIVE AROUND IN 4WD FULLTIME ESPECIALLY ON DRY HARD PAVEMENT. THAT IS WHY IT IS JERKY, HARD PAVEMENT IS PUTTING DRIVE LINE IN BIND. USE PART-TIME THARS WHAT ITS FOR DALE :nono:

I sometimes use 4wd FullTime on dry pavement because the manual that came with the car says it's ok! The manual states to only use PartTime when driving on pavement that is either slick, snowy, or otherwise non-dry! It also states that 4wd FullTime can be used on dry pavement all the time if one chooses! There's a mix up somewhere?

full time is supposed to allow for slip in drivetrain so it does not bind. it sounds like you have a problem. don't use it until you have it checked!

I will get it checked! If there is a problem hopefully I can catch it before it gets worse. Thanks

well it sounds like a Viscous Coupling problem, but the 242 doesn't have a VC.

when was the last time u changed the fluid in then Transfer case and Diffs

I had the fluid in both Diffs changed in August & the Transfer Case in April!

did u add Mopar Friction Modifier to the rear diff?

I'm not sure if Mopar Friction Modifer was added when I had the diff fluid changed. Chrysler did the change because they overhauled my rear diff! Isn't true that Mopar Friction Modifier is only required for limited slip differentials? I'm not sure if my '98 GC (laredo) has a limited slip or what?

yes it is required for the Trac Loc (limited slip) rear axle. I'm not sure if yours Axle is limited slip or not, but if Chrysler did it then they most likely added the Friction Mod if needed.

Does anyone know how I could identify if my rear axle is limited slip or not? I plan to change my diff fluid myself next time, & I'm not sure if friction modifier will be needed?

there should be a tab bolted on with the differential cover. but if someone else aren't there frst owner of the jeep and the last owner changed the fluid b4 they might not have put the tab back on. then u would have to check with the dealer.

does the front diff require friction modifier?

I do not believe so (I am notpossitive), I think it is only required on the Trac-Loc rear axles

I'll ask my local Jeep dealer tomorrow but, would friction modifier hurt a diff it its not needed?

The modifier wont hurt anything at all if it is not a posi diff.

The jeep dealer can get you a line sheet (build sheet, option sheet) or what ever they call them if you give them the serial number. It will list all the equipment and trim that it came from the factory with along with the option codes. very handy if you are trying to replace factory mats or interior/exterior trim etc.

JD

Thanks, I'll ask the dealer about a line sheet (or similar) as well, it would be good to have!

The front axle has an open differential so there would be no need for friction modifier.

I had my dealer check my 4wd & they told me they could not find anything wrong, but turning is still a problem in 4wd Full-Time?

I have Selec-Trac, no VC, & I should be able to drive in 4wd Full-Time regardless of the surface w/out experiencing any binding!

Has anyone experienced this w/Selec-Trac?

The binding is driving me crazy & it doesn't sound good!

Just because you have the 242 and that unit does not have the notorious VC, doesn't mean the center differential can't fail. Sounds like it could also be the front differential.
ByronP

I'll take it to a different place to see if they can diagnose the problem. I just hope major work isn't needed to correct this issue!

I suggest that you look at my post" full time, part time 4wd" from about 5 pages ago. i got some good reponses that may be helpful.

Immediate possibilities: 1. Your tires are different sizes or worn differently which causes immediate binding when shifting thru the 4WD PT high-range mode into the FT mode. 2. the transfer case shift linkage may need adjustment to fully allow the shift collar to release the T-case differential. 2. the lubricant level is low and the shift collar is getting stuck. 3. the transfer case is damaged - interfering with the shifting.

Does the 2WD mode work? If it shifts easily back into 2WD but will not fully enter 4WD FT, then the linkage may need to be adjusted - assuming the T-case is OK.

Mine has the 242 selec-trac (which rules - usually) and I find that when I shift between the modes, it often takes a slight throttle bump & release to get the t-case to shift. This is especially true if you've run it in part-time for even a little while - even when driving straight. Hold your hand tight on the T-case shift level while shifting and you should usually feel a slight 'pop' indicating that the shift collar has properly relocated itself. I find that when I shift back into 2WD from 4WD FT, it takes a second or two with my hand pushing on the lever before I feel the 'pop' indicating that it's out of 4WD PT. It also helps if you put the tranny into Neutral while shifting to 'unload' the driveline and more easily allow the shifting to occur. Hope this helps.

Thanks for the input Traktor & yes, my 2wd mode works just fine!

My T-Case & Diff fluids are good but I have not adjusted my T-Case shift linkage, I only lubricated it, & my tires are all the same size & appear to be wearing quite evenly!

I'm starting to think that my linkage may need adjusting because the symptoms I describe sound similar to the results of driving around in 4wd Part-Time.

When shifting from 2wd to 4wd Full-Time, I think my T-Case may only be engaging in the 4wd Part-Time mode, even though my lever will be in Full-Time & my diagram reads "Full-Time"!

I'll try putting my tranny into neutral before shifting into 4wd Full-Time to see if works for me.

Thanks again

Also, when I get into my Jeep after its been sitting, sometimes I put it into 4wd Full-Time before pulling off but when I do pull off, I hear a loud "pop" from turning shaply to exit a parking space.

I'm not sure if this is normal or what?

Yeah, if your 2WD works fine then I would guess that it's your shift linkage. To get mine into 2WD quickly, I sometimes need to hold the lever forward a little bit and give it a little throttle bump. If yours goes into 2WD easier than this, then maybe the linkage is adjusted a bit too far forward which may prevent it from completing the shift into 4WD full-time. The linkage is fairly easy to adjust. The VIC (vehicle information center) will indicate 4WD Full-Time once the lever is in that position unless the linkage is far out of adjustment. It doesn't mean that the differential is actually engaged tho. Good luck with it.

FYI - I wouldn't shift the transfer case and then immediately execute a turn without allowing the T-case to turn a bit so the splines of the differential shaft can engage. Even with a properly shifting case, this can happen - especially if the transfer case isn't broken in yet.

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http://www.automotiveforums.com/vbulletin/images/icons/icon5.gif Question about 4wd? (Post #1 (http://www.automotiveforums.com/vbulletin/showpost.php?p=2428649&postcount=1))
After driving a few miles in 4wd fulltime, my jeep jerks when making sharp turns? Is this normal? The jerks only occur after driving in 4wd fulltime & I havn't used partime at all! My vehicle is a '98 laredo.


Maybe the clutches are chattering inside the differential.