Is my 4WD binding?

[GnarlyMarlysTj]

I bought a 06 that had no front ds. I put one in and when I go into 4hi/low the jeep will roll a few feet but then it's like the brakes are being applied. I can throttle through it and it does the same thing, idle rolls a few feet then stops. I'm new to 4x4's and have checked the forums and think this sounds like a different gear ratio front and back. But everyone says if that's the case, just going into 4wd will grenade the tc. Would diff gear ratios grenade the tc immediately or would I have to be gassing it hard? Any ideas what this could be? Thanks.

 

[89grand]

I bet you have different gearing in the front differential compared to the rear, and that is probably the reason why the driveshaft was removed. That sure seems dumb to have only re-geared the rear, but I bet that's the case.

Definitely do not force it into 4wd and try to drive it.

 

[PatMc]

I bought a 06 that had no front ds. I put one in and when I go into 4hi/low the jeep will roll a few feet but then it's like the brakes are being applied. I can throttle through it and it does the same thing, idle rolls a few feet then stops. I'm new to 4x4's and have checked the forums and think this sounds like a different gear ratio front and back. But everyone says if that's the case, just going into 4wd will grenade the tc. Would diff gear ratios grenade the tc immediately or would I have to be gassing it hard? Any ideas what this could be? Thanks.

If you're going in a straight line and experiencing the binding, then you likely have different gear ratios. You can prove or disprove this by jacking up all 4 wheels, putting the T-case in neutral, spin both driveshafts until the U-joints are straight up and down (for repeatability) then put a piece of tape of on a front and rear tire sidewall at 6:00. Crawl under it and rotate each driveshaft 4 turns (or pick a number) to make both front and rear wheels turn forwards. Your tape marks should be clocked the same on the front and rear wheels...if they're not, then you have different gear ratios.

 

[JEEPCJTJ]

I'm guessing ds is driveshaft. I'm not sure what your TJ's problem is but when my old CJ had different axle ratios 4WD was like being in park if it had an automatic transmission. It didn't want to roll a few millimeters on dry pavement. On dirt was better, mud the best. I got that CJ back, supposedly it has the same axle ratios now but it has different sized tires front and back due to being raced and 4WD is still like park.

Whether or not my ratios are the same, I never worried about the TC. Of course I wasn't driving in 4WD on the road.

 

[GnarlyMarlysTj]

Yep different ratios. Thanks guys.

 

[billiebob]

I'd guess they dropped the drive shaft to hide the incorrect ratios. No it will not grenade. It will bind till it hops. Not good but hardly explosive.

 

[billiebob]

Yep different ratios. Thanks guys.

So what are the 2 ratios ?

 

[GnarlyMarlysTj]

So what are the 2 ratios ?

I havent checked em yet, was able to get ahold of the guy I bought it from and he said he re geared the rear. Didnt do the front to save money cuz he "never used 4wd".

 

[707kevin]

I havent checked em yet, was able to get ahold of the guy I bought it from and he said he re geared the rear. Didnt do the front to save money cuz he "never used 4wd".

What else is he not telling you about this purchase....

 

[89grand]

I'd guess they dropped the drive shaft to hide the incorrect ratios. No it will not grenade. It will bind till it hops. Not good but hardly explosive.

I disagree. Driving a 4wd with two completely different gear ratios WILL grenade something, most likely the t-case. The only way it wouldn't would be if you drove it on an oil slick, so that the rear tires could spin easily since they want to spin much faster than the front tires, but the drivetrain expects them to go at the same speed.

 

[GnarlyMarlysTj]

Yeah its looks like I'll be in 2hi for a while. Thanks again for all the replies everybody.

 

[89grand]

Yeah its looks like I'll be in 2hi for a while. Thanks again for all the replies everybody.

Defintely don't listen to the advice earlier that it won't really be much of a problem. It will, and a t-case is more costly than the front re-gear, and then you'd need both in the aftermath.

 

[GnarlyMarlysTj]

What else is he not telling you about this purchase....

Right, it was pretty well gutted when I got but the frame and tub were solid with really low mileage for the price. Slowly piecing it back together. Just a big blow to find out that I have to put a grand into it since i dont have the expertise to do the re-gear myself.

 

[JEEPCJTJ]

I disagree. Driving a 4wd with two completely different gear ratios WILL grenade something, most likely the t-case. The only way it wouldn't would be if you drove it on an oil slick, so that the rear tires could spin easily since they want to spin much faster than the front tires, but the drivetrain expects them to go at the same speed.

Maybe we should also avoid lockers when in 4WD because lockers will not only add stress to the differential but also to the transfer case because the axles are traveling different distances whenever we turn the steering wheel.

I'd also bet that whoever changed the rear ratio made it lower which would make it slower than the front axle.

Defintely don't listen to the advice earlier that it won't really be much of a problem. It will, and a t-case is more costly than the front re-gear, and then you'd need both in the aftermath.

I drove the CJ for eight years with different ratios. Then it was raced for 18 years. Today it's either the different ratios and/or the front/rear tire sizes that are keeping it from rolling away while parked in 4wd with the transmission in neutral. The same transfer case is still there. I guess it could explode sometime in the future but I bet it won't.

 

[GnarlyMarlysTj]

I was on loose gravel when I tried the 4wd. Deff got a hop/skid from the rears in 4low. Didnt notice it in 4hi. I'll have to check the ratios when i get a chance and see how far off they are. It only had 33s on it so i dont know how much they changed it or why.

 

[89grand]

Maybe we should also avoid lockers when in 4WD because lockers will not only add stress to the differential but also to the transfer case because the axles are traveling different distances whenever we turn the steering wheel.

I'd also bet that whoever changed the rear ratio made it lower which would make it slower than the front axle.

Wait, what? Lockers are not spools, they can allow for different wheels speeds, but even with a spool, the issue is only while turning, and the tire chirps when doing so. The front and rear axles are locked together in 4wd, there is nothing to allow large front the rear axle speed differences.

I drove the CJ for eight years with different ratios. Then it was raced for 18 years. Today it's either the different ratios and/or the front/rear tire sizes that are keeping it from rolling away while parked in 4wd with the transmission in neutral. The same transfer case is still there. I guess it could explode sometime in the future but I bet it won't.

I got ripped off, I regeared both of my differentials. I guess I would have been fine with 3.07 fronts and 4.10 rears. Well, you live and learn.

 

[GnarlyMarlysTj]

Okay, so my original question has been answered- I've got different gear ratios front/back. There seems to be a debate on whether this will break something when using 4wd. I'm not talking about on pavement or even dirt, but on snow or mud. I assume that its gotta be hard on some component based on the hopping/not wanting to roll by itself at idle.

 

[89grand]

There seems to be a debate on whether this will break something when using 4wd.

There shouldn't be one. It's only common sense that no one should want the front and rear axles turning at drastically different speeds.

 

[PatMc]

Okay, so my original question has been answered- I've got different gear ratios front/back. There seems to be a debate on whether this will break something when using 4wd. I'm not talking about on pavement or even dirt, but on snow or mud. I assume that its gotta be hard on some component based on the hopping/not wanting to roll by itself at idle.

If it hopped around on gravel, then the ratios are too far apart to be usable. Keep in mind, the objective is to have traction. If we have different ratios, regardless of whatever mechanical carnage might occur...in order for the vehicle to move, either the front tires or the rear tires will have to loose traction. This will not end well...you have to regear the front.

 

[billiebob]

Driving a 4wd with two completely different gear ratios WILL grenade something

well yeah sure if you can ignore and control the binding hop and jump for 20 miles.
but ever wonder why the slick rock is covered in black rubber???