Can I go Front Wheel Drive?

[kjpilot]

Can I go Front Wheel Drive? I need to have a shop press in new u-joints on my rear drive shaft, but I only have use of the KJ tomorrow. So I'm thinking I could remove the rear drive shaft, & drive in 4WD, which would turn only the front wheels.

I'll be driving less than 50 miles like this, & I can avoid the freeway if need be.

Does anyone foresee a problem with this?

 

[tjkj2002]

Can I go Front Wheel Drive? I need to have a shop press in new u-joints on my rear drive shaft, but I only have use of the KJ tomorrow. So I'm thinking I could remove the rear drive shaft, & drive in 4WD, which would turn only the front wheels.

I'll be driving less than 50 miles like this, & I can avoid the freeway if need be.

Does anyone foresee a problem with this?

With a KJ I wouldn't unless the very last,and I mean very last resort.Remember aluminum front diff.Plus you have a rear slip yoke so when you pull the rear driveshaft the fliud will leak out,and there is no way to plug it unless you keep the rear driveshaft in place.


Oh wait you put in the select trac t-case,you can't do that at all,not unless you want to buy a new t-case(even in part time 4x4).


Sorry your SOL on this one.

 

[kjpilot]

With a KJ I wouldn't unless the very last,and I mean very last resort.Remember aluminum front diff.Plus you have a rear slip yoke so when you pull the rear driveshaft the fliud will leak out,and there is no way to plug it unless you keep the rear driveshaft in place.


Oh wait you put in the select trac t-case,you can't do that at all,not unless you want to buy a new t-case(even in part time 4x4).


Sorry your SOL on this one.

You sure? I can't imagine how anything can leak out. The sleeve of the slip yoke remains completely outside of the t-case& has no gasket or any other way of sealing the rear of the case.

 

[Dave]

Rent/beg/borrow a car for the day. Just a thought.

I don't want to hear about any damage to your KJ. It's not worth it.

Dave

 

[Marlon_JB2]

This would be interesting if it worked...

 

[tjkj2002]

You sure? I can't imagine how anything can leak out. The sleeve of the slip yoke remains completely outside of the t-case& has no gasket or any other way of sealing the rear of the case.

The slip yoke seals the rear output of the t-case and is part of the driveshaft,it does not have anyway of staying on the output shaft without the rest of the driveshaft attached to it,that black rubber boot is just a dust/mud protector(to keep in the grease and keep out the mud and other stuff) since the rear slip yoke slides in/out of the rear of the t-case as you flex and such on the rear output shaft,the rear slip yoke slides on that and the rear output seal.Remove the rear driveshaft and nothing is left to seal the rear output,bye-bye t-case fluid.


Go ahead and try it,I don't care but don't complain when you fry your t-case.

That's why I'm going SYE on my AtlasII.

 

[JeepJeepster]

Why wouldnt the 242 work in part-time tjkj?

 

[tjkj2002]

Why wouldnt the 242 work in part-time tjkj?

It's not strong enough to support FWD only and will mess up the t-case,the center diff though locked will get messed up from the added stress.

I'm a 100% sure you will lose all your t-case fluid if you remove the rear driveshaft and drive it that way.The only way to do that is if you have a non-full time case(or a full time option) and a rear SYE(all the fronts are SYE).

 

[kjpilot]

The slip yoke seals the rear output of the t-case and is part of the driveshaft,it does not have anyway of staying on the output shaft without the rest of the driveshaft attached to it,that black rubber boot is just a dust/mud protector(to keep in the grease and keep out the mud and other stuff) since the rear slip yoke slides in/out of the rear of the t-case as you flex and such on the rear output shaft,the rear slip yoke slides on that and the rear output seal.Remove the rear driveshaft and nothing is left to seal the rear output,bye-bye t-case fluid.


Go ahead and try it,I don't care but don't complain when you fry your t-case.

That's why I'm going SYE on my AtlasII.

I just asked if you were sure. It still makes no sense on how the fluid will leak out. All though the FT system was my biggest concern, & why you've got me thinking that it isn't the best idea... Actually, now I want to try it, but I need this thing running before I leave for Denver next weekend, & I have just enough doubt.

Not being confrontational, just trying to understand the system better. I've spent some quality time with 3 t-cases & my drive shaft in the past, so I know that the boot is a dust cover, & that the output shaft is a solid bar of hardened steel. Also that the yoke slips on the shaft. since all the seals are in the t-case, & the shaft is not free to come out, Leaking fluid still makes no sense to me.

Thanks for you help, It is appreciated.

 

[sevenhelmet]

@ tjkj2002: Are you saying that with a Command Trac (PT) system it IS possible to disconnect the rear driveshaft and drive in 4WD with just the front diff?

 

[tjkj2002]

@ tjkj2002: Are you saying that with a Command Trac (PT) system it IS possible to disconnect the rear driveshaft and drive in 4WD with just the front diff?

Yes but you need to do a SYE so you don't lose all the fluid also.

 

[tjkj2002]

I don't mean to be a smart @ss either but TJKJ: aren't you thinking of another car?

On my KJ the propshaft can be taken off without cousing the T-case to leak. It slides over a splined axle that is fitted into the T-case and which sticks out about 8". Which has its own seal. The propshaft doesn't even come near the seal.

Maybe I'm different being a manual, dunno....I do not have a front U joint either. It's a flex plate.

I think a KJ can drive front only, but I agree with you that it will put a hell of a lot of stress on everything.

KJpilot, why don't you drive to wherever the shop is and take of the propshaft there?

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Sitting still on a flat surface you may not lose any fluid but any incline or driving will shoot it out the rear output.

The shiny outside of the slipyoke rides in a seal on the end of the t-case,I can't say how the exports are done,they may have had to seal it to comply with your laws,but here in the US it is different,I have worked on many t-cases to no how the slip yoke and SYE type t-cases work.

 

[kjpilot]

Well, It became a necessity, and it worked fine. Absolutely zero fluid loss. I only went about 25 miles, top speed of 45, & pulled away from dead stops very delicately. I would not use this as anything other than an emergency maneuver.

TJKJ, I think you are thinking of an older version of the 242, where the output shaft is surrounded by the t-case like this:

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On the KJ, & the 2004 WJ the cases have a totally exposed output shaft (well, except for the slip yoke & dust boot) like this 231:

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This is why we're confused. there is no place for the fluid to leak from.

 

[sevenhelmet]

Wow. I'm impressed. How'd it handle in front wheel only?

 

[JeepJeepster]

^He already ran it without it and said it didnt leak.

Did it handle kinda strange kjpilot? I guess it would be just like a front wheel drive car..

Got a pic of your DS Tony? I would like to see how its set-up..

 

[tommudd]

I would never do it , he just lucked out is all

 

[LibertyOrDeath]

With the exception of the leak I didn't have a doubt it would work. I was only concerned with the durability of the D30A front diff; however, the stress of 4 Low is much higher than the stress of FWD only. 90% of the time we run with only the rear axle going so I don't see a difference front to rear. I have a primarily FWD Ford Escape that works just fine, granted it was made for FWD but I wouldn't hesitate to run in RWD only.

 

[JeepJeepster]

So what covers your slip joint?

 

[kjpilot]

Sorry, Ive been away from the internet this weekend.
What covers my slip joint? A rubber tube/ boot with accordion type bellows just like in this photo:

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2. How did it drive? Fine, all considering. Like I said, I drove it very gently. It was acting pretty normal, & at one point, I was at a light & while waiting for the green, I had forgot about my situation, & stepped on it a little hard. The front bobbed up & down a little, but stopped once I let off the gas.

3. I just got lucky... Well, maybe. Like I said, I did it because I had to. But realistically, This is a Jeep. It is designed to off road. This can include having to put all the power to the front wheels while in a mechanically strenuous situation. I was on road in Minnesota, not quite as flat as Kansas, but we have no interesting topography here. What would you do if you were on the trail & twisted your rear drive shaft in two? Lock it into PT 4X4 & drive out? Apparently, it's an option. Like someone else said, locking it into 4lo & crawling on rocks puts more strain on the system than driving on flat paved roads.

The 242 is not a weak case... period. Is the 231 slightly stronger? Yep it is. If I remember right, 242 can handle about 1500 ft/lbs & the 231 can take about 1800... the KJ 3.7 puts out about 235 ft/lbs. So a 242 can handle a multiplier of about 6.4 & the 231 can take 7.6. It's not a weak case for the KJ at all.

 

[Dave]

The 242 is not a weak case... period. Is the 231 slightly stronger? Yep it is. If I remember right, 242 can handle about 1500 ft/lbs & the 231 can take about 1800... the KJ 3.7 puts out about 235 ft/lbs. So a 242 can handle a multiplier of about 6.4 & the 231 can take 7.6. It's not a weak case for the KJ at all.

That is a lot of torque.......I am not worried with my 242. I use full-time a lot and like it.

Dave