when put my truck in 4x4 sometimes it makes a jerking motion. like it jerks the hole truck. then sometimes when you drive and the front tires first start to spin it jerks again. then it is fine. anybody have an idea what could cause this. the truck has 130 000 km on it and it hasn't had a trandfer case fluid flush yet. do you think it might just need new fluid.

 

When I engage 4h I get a clunk sound while in motion and when I switch off 4h seems to stay on for a few seconds...new to 4x4's so don't laugh....lol. Also I have switched to 4h while my rears were spinning and again a clunk sound. Sounds violent to me but book says it's normal to hear some noises on certain 4x4's, and the clunking sound is the fronts catching up. Truck is an 06 with 38k km's on it

 

I thought you weren't supposed to switch to 4x4 range with the rears spinning, even if you have ESOTF (elec. shift on the fly)

 

what peter 88 explained is what mine does. except i let the struck stop and go to idle before i switch to 4h. could it also be because the truck is cold. it is winter here and it is like -30. and it usually happens when the tuck is not completely warm. could this be why.

 

x2

 

Red,

Your 04 has a different front axle engagement system. The front axles lock at the hubs. They are prone to vacuum leaks. By default your front axles are always engaged so in case of a vacuum leak they will still be engaged and you are able to use 4x4 and have the front wheels pull. Is the truck lunging or is the steering wheel pulling from side to side?

Peter88,

You should not engage 4x4 any time the rear wheels are spinning. Your slow disengagement of 4x4 is not normal. A small vacuum leak will keep the hubs from quickly unlocking. As per Red's system vacuum has to over come the normally locked hub and if it is leaking it has trouble disengaging. Have it looked at.

JMC

 

ya I know I should not switch when rears are spinning....:o maybe that's why it takes long to switch off...I mean like 10 sec range if that's normal...I've done it a few times in situations like stop lights or you fartin' around. When I switch it on normally it seems all is fine. Anyway truck has to go in for oil change soon so I'll have it looked at then.

Thanks...Peter

 

JMC

the truck lunges. it doesn't do it all the time.

 

I have ESOTF on my 03 and had it on my 2000, I was told that as long as your under 55 MPH, you are good to go. I've done at least a few times under 55 on both vehicles, never had any issues.

Same thing on wifey's 2002 Explorer.

 

Shifting to 4Hi should not cause any clunking at all. If there is wheel spin then it will clunk. When you are on a slippery surface the rear wheels may be slipping and you don't notice it. That will cause a clunk and the truck will jerk forward when it engages. A slow engagement of the front hubs or of the t-case will cause a clunk. On a hard surface there is no slippage of the rear wheels and there fore no clunk. Next time try this. Get up to speed, say 40-45 mph and shift the tranny into Neutral, let off the gas, then engage 4Hi. Wait 1 second then shift the tranny back into Drive then get back on the gas. This should eliminate the clunk and confirm a slow acting hub or t-case.

JMC

 

Well exactly, I can shift like that too, its when the rear wheels are spinning and you engage 4x4 its not supposedly good for the drivetrain, first you've got at least a 5-10 mph speed difference if your spinning your wheels lets assume. Now try to connect 0MPH front wheels and drivetrain with 10mph rear drivetrain and moving parts....not exactly good.

 

ok JMC i have done that before and no jerking. so i think i am just not letting the rear tire finish spinning.