Hard Rain/4 Full-Time/I did it Again

[Dave]

I was coming home and cruising at 70 and real dark clouds all over. All of a sudden really Hard Rain...backed off the gas and pulled into full-time....and then realized I was going 65 when I shifted it.....woooops... this is the second time I have done this (shifting into full-time when going over 55). But it shifted right in smoothe as could be.

Thank you jeep engineers for making the 242 fool proof for people like me.

I am not advocating this but wanted to post it just so you know if you happen to do this by mistake like I did, you're not going to litter the street with parts.

Note to self....make sure you're going under 55 before shifting next time.

Dave

 

[Atrus]

I am sure that 55 mph recommendation is well within a far greater acceptable range.

While I believe this to be true, I still do not shift into 4wd at anything above 50 and always take my foot off the gas.

 

[LibertyOrDeath]

I was coming home and cruising at 70 and real dark clouds all over. All of a sudden really Hard Rain...backed off the gas and pulled into full-time....and then realized I was going 65 when I shifted it.....woooops... this is the second time I have done this (shifting into full-time when going over 55). But it shifted right in smoothe as could be.

Dave

I've lived in a very rainy area for quite some time now and 4WD won't help much at all in this circumstance. Your biggest problem is visibility not traction. Good wipers and tires coupled with slowing down are the best way to go. 4WD does help if you need to do an emergent acceleration for some reason; mudslide on your 6 or crazy redneck chasing you.

I've noticed that you can go slightly out of the specs a few times and not do damage; however, your greatest risk is from doing it all the time or going way out of specs.

 

[aksloan]

I was coming home and cruising at 70 and real dark clouds all over. All of a sudden really Hard Rain...backed off the gas and pulled into full-time

I got lots to learn... I thought with either trac shifting into full-time at that speed would be diastrous.

 

[Marlon_JB2]

I've done it a few times, at 65MPH by accident.

Nothing weird happened.

 

[JeepJeepster]

Meh, I wouldnt worry about it but dont make it a habit.

I had to use full time today. My awesome locker was once again not locking which left me 'stuck' at a red-light.

Stupid locker is coming out this summer.

 

[LibertyOrDeath]

Meh, I wouldnt worry about it but dont make it a habit.

I had to use full time today. My awesome locker was once again not locking which left me 'stuck' at a red-light.

Stupid locker is coming out this summer.

Is that the PowerTrax No Slip that's listed in your profile?

 

[hyde]

Manual recommends shifting while accelerating, so taking the foot off the gas is actually makes it more difficult to engage properly? Maybe I am thinking about something else..

 

[JeepJeepster]

Is that the PowerTrax No Slip that's listed in your profile?

indeed it is. Thing works great offroad but the road manners just are not my thing.

 

[offrovering]

Manual recommends shifting while accelerating, so taking the foot off the gas is actually makes it more difficult to engage properly? Maybe I am thinking about something else..

it should all happen very quickly. let off the gas and quickly pull up to engage, then immediately give it gas. you don't let off the gas very long, just a quick second and then throttle again. helps get things set

 

[WireEd]

I believe the Liberty has a "live" front axle?? "Live" means the wheels/hubs/axleshafts/differential/pinion gear and front propellor shaft are spinning all the time, even when you are in 2wd. In this case the transfer case will be easier to shift into 4wd (on the highway) because the aforementioned components are already up to speed. In a front axle disconnect situation, such as a vacuum disconnect system on the older (pre '95) XJ's you would have some of those same components not rotating. A synchronizer in the transfer case would be used to bring those same components up to speed. In this case, a high speed shift can cause more distress to the transfer case because as you increase speed, the workload of the synchronizer increases, potentially causing blocked shift and clash. The more you clash, the more you will likely clash.

The one bad thing about the live axle setup without synchro in the tcase is if you are not moving yet spinning your rear wheels and try to shift (in other words you are stuck) you will clash. Here the recommendation is to stop spinning your wheels, then make the shift.

It gets a bit complex, but I hope this helps to clarify some of the reasoning!!

offrovering describes torque reversing to help make the shift. This does not hurt the system as long as it is not severely overdone. It allows the shift system components to easier align to make the shift. Usually a light tip-in to light tip-out is sufficient.
Ed

 

[tjkj2002]

I believe the Liberty has a "live" front axle?? "Live" means the wheels/hubs/axleshafts/differential/pinion gear and front propellor shaft are spinning all the time, even when you are in 2wd. In this case the transfer case will be easier to shift into 4wd (on the highway) because the aforementioned components are already up to speed. In a front axle disconnect situation, such as a vacuum disconnect system on the older (pre '95) XJ's you would have some of those same components not rotating. A synchronizer in the transfer case would be used to bring those same components up to speed. In this case, a high speed shift can cause more distress to the transfer case because as you increase speed, the workload of the synchronizer increases, potentially causing blocked shift and clash. The more you clash, the more you will likely clash.

The one bad thing about the live axle setup without synchro in the tcase is if you are not moving yet spinning your rear wheels and try to shift (in other words you are stuck) you will clash. Here the recommendation is to stop spinning your wheels, then make the shift.

It gets a bit complex, but I hope this helps to clarify some of the reasoning!!

offrovering describes torque reversing to help make the shift. This does not hurt the system as long as it is not severely overdone. It allows the shift system components to easier align to make the shift. Usually a light tip-in to light tip-out is sufficient.
Ed

The KJ has a "indepentant" front axle set-up,a "live" axle set-up is the same as a straight axle or solid axle like a Wranger has upfront.The term you are looking for is "locked" front end,or without auto or manual locking hubs(or vacumn hubs).

The 231 in the KJ has a syncro for going into 4hi while driving up to speeds of 55mph,even for 4low also but for reasons of the 2.72:1 gear reduction you are limited to shifting into 4low at 2-3mph.

The "torque reversing" you are referring to is needed because the t-case does not have a clutch to release the torque input like a manual ****** has to stop the torque input,not the rpm's of the gears just the torque applied to the gears is stopped.You can shift a manual ****** without using the clutch by using the same technique used to shift the 231 t-case into 4hi.