Any ideas on 4runner 4WD problem

[Romer]

Rachels 1999 4runner, limited has developed an issue with the 4wd. Sometimes either from a stop or after just shifting into 4WD the rear PS tire is not spinning and then you feel a big bump and it drives fine.

I verified this in the snow. When it occurred, the truck would move to the right because the tire was stuck.

In the 20 minutes I drove it around, it happened twice with the button (4HI) and I was not able to make it happen when downshifting to 4 lo. Doesn't mean it won't happen, just didn't happen in the 20 minutes I was trying it.

To reproduce it, I would stop the truck and push the button (4 HI) the problem would occur and the status (4WD) lights would blink. When it jumped and unlocked the tire, the lights stopped blinking and showed I was in 4WD.

Rachel said it happened (she thinks) to her when she started up from a stop at a red light.

If the rear output shaft froze while engaging, would one tire spin and the other freeze? Not sure what else could do it.

Any thoughts on stuff to try.

 

[treerootCO]

Was the truck ever involved in an accident? Maybe a chipped ring gear with floaties in the diff. MY S-10 acted like that when a few wheelies led to a broken ring gear.

The problem has to be in the ass end, anything forward of the pinion would affect both I would think. You may on the right track with the shifting though, I don't know how the lockers engage on the Runners.

 

[Romer]

That is the center locking up, we did not engage the real locker during this.

Wouldn't an open rear diff only lock up one tire if the tcase has an issue. But then when she is in 2WD with the rear wheel drive, there are no issues.


Happy Thursday Mike. The damn snow kept my snow chains from being delivered today as promised.

 

[JadeRunner]

Somthin' aint right. Never experienced anyting like that with my 5 speed.

I wonder if could be the e-locker. When I was following her at Chinamans, she had a hard time time getting it to engage. There is somthing that disables the locker (light flashes), when going into high range. Just thoughts.

 

[RockRunner]

That is the center locking up, we did not engage the real locker during this.

Wouldn't an open rear diff only lock up one tire if the tcase has an issue. But then when she is in 2WD with the rear wheel drive, there are no issues.


Happy Thursday Mike. The damn snow kept my snow chains from being delivered today as promised.

It sounds to me like it may be an E locker problem but since it does not happen in 2 wd or 4 low it is sounding less likely. I would check and see if the locker engages in 4 low. If it does then try to disengage again and move up to 4 hi. It may be that your accuator is broken and is leaving the locker in a stalled mode, half locked half unlocked. If you suspect it to be the locker and it is not engaging all the way or releasing, you can take the accuator of in about 3 minutes and move the locking mech. by hand. You do not need to remove the electrical and while you have it of you can check the unit to see if it is working. Just put the 4Runner in 4low and engage the locker using the button on the dash. It will only move the gear for about 1-2 seconds so you have to pay attention. I had mine hanging of the axle by the wires and looked under the truck to see it turn while pushing the button to engage and release.

If the motor only works one way then you may have the same problem I had with both of mine, corroded contacts. I fixed mine with some parts I found around the house, saved me anywhere fro $100 to $700 about.

If you need some help give me a call, I have had mine apart 10 times last week but this week they were tearing up the snow, had to my tires suck.

Call me if you need it 303-829-0703

PS one of the accuators was from a 98 LC and the other from a 2K 4Runner, they were both rusting etc. on the inside so the age of your truck is in the ball park.

 

[RockRunner]

That is the center locking up, we did not engage the real locker during this.

Wouldn't an open rear diff only lock up one tire if the tcase has an issue. But then when she is in 2WD with the rear wheel drive, there are no issues.


Happy Thursday Mike. The damn snow kept my snow chains from being delivered today as promised.

Another question for you, did you do the gray wire "conversion" That may cause the problem when engaging 4WD.

 

[RockRunner]

Somthin' aint right. Never experienced anyting like that with my 5 speed.

I wonder if could be the e-locker. When I was following her at Chinamans, she had a hard time time getting it to engage. There is somthing that disables the locker (light flashes), when going into high range. Just thoughts.

When going into 4WD High the ECU shuts of the locker automaticly, it is only to be used in 4WD low according to Toyota. That is the reason for the blinking, it is still under power but dis-engaged. You can by pass this problem by doing the gray wire mod, about 20 minutes, this allows you to use your locker in 2WD or 4WD high. A must in my opinion.

 

[Romer]

Thanks Tom. I did not do the grey wire mod.

 

[Red_Chili]

I think the various symptoms must be confusing ya. If it is rear axle, it must be the locker, not the tcase. Unless you have traction control instead of a locker?

 

[Romer]

I think the various symptoms must be confusing ya. If it is rear axle, it must be the locker, not the tcase. Unless you have traction control instead of a locker?

Not familiar with the runner. BUT on a Land Cruiser if on an open rear diff (Unlocked) one tire was locked and the other was spinning could be the diff or Tcase (V coupler). Reason is it's only momentary and when engaging part of 4WD system (CDL) that shouldn't have any impact on the rear axle other than tieing the front and rear drive shafts together.

I know the runner doesn't have a V coupler and your probably right.

 

[Romer]

I think the various symptoms must be confusing ya. If it is rear axle, it must be the locker, not the tcase. Unless you have traction control instead of a locker?

Just talked to Oleg and based on my description he thinks it is in the Tcase. When the 4Hi button is pressed it activates an electric motor. His initial thought is that it's a problem with the motor, a sensor, the fork, etc. Shifting into 4 Lo does not work the same as there is no motor it's a mechanical shift and this would explain why it has a problem with the button vs the shifter.

 

[Romer]

Reading the FSM and evaluating the symptoms with the assumption it only happens in 4 Hi. would imply something related to the actuator circuitry for the electronic motor to move the shift fork to lock the center diff. The FSM doesn't say, but is this motor not used when using the shifter to go into 4LO? In other words, I think 4Hi is an electronic shift (Via actuator motor) after pushing the button. 4LO is a mechanical shift based on the movement of the linkage with the shifter arm. Can someone confirm this?

 

[Romer]

Took it for another Test drive and it happened in 2WD. Did some research on Yotatech and sounds like a leaking rear axle seal. I took it over to Toy Car Care and they said that is a common problem and they will let me know by the end of the day.

Didn't want to spend the rest of my holiday working on another truck in the cold garage. Besides, I only like to work on my truck.

 

[Romer]

Yup, it was the rear oil seal. Leaked all over the brake shoes and causes them to bind.

 

[treerootCO]

oil makes things bind?

 

[Romer]

It leaks on the brake shoes making them swell

 

[treerootCO]

oh ok, that makes sense.

 

[RockRunner]

Yup, it was the rear oil seal. Leaked all over the brake shoes and causes them to bind.

Learn something new everyday, nice to see you got it fixed.

 

[JadeRunner]

Good deal, and good call searching on YotaTech. I have heard of the axle seal leaking problem, but havn't had it happen to me yet. All my problems have been directly due to ME.

 

[Red_Chili]

Never heard of the axle seal leak producing the symptoms you described! Goodonya for getting it fixed though. Very easy for unusual symptoms to lead ya down a lonely road, don't ask how I know!!!