My daughters 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.

My daughter 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.

Thanks.

Ken Romer

 

ps rear brake shoes hanging up, possible ear axel seal starting to leak.

 

Thanks for the reply. I was thinking the emergency brake maybe, but it doesn't make sense only when 4WD is engaged since it's rear wheel drive otherwise and it's the rear right wheel I am haveing problems with.

 

Sounds like you may have an issue with the 4WD trac control system. Jack up the rear and just be sure the rear drum isn't sticking, if not then the brakes can pretty well be ruled out as a cause.

 

No trac control system in a 99 Limited.

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 (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?

 

it really sounds like the rear axle seal is leaking there have been a few people that have had this happen although some of them didnt have 4x4...simple check just look at inside of the tire and see if you can see diff fluid on the rim or if the drum looks wet and or smells like gear oil.

 

no leak at the seal.

 

Actually, I just took a quick look. I'll get in there and take a better look.

 

No worries, couldn't remember what year that started (must have been 2000 or 2001). Anyway, I think you may be right, but even if you did have trouble locking the center diff, it still doesn't explain why one wheel was spinning and the other wasn't. A 3rd member diff lock might cause symptoms like that,but I can't imagine how a center diff could manage that since both wheels are connected to the same driveshaft......unless it was just a case where the wheel spinning was unrelated and the shifting difficulty was just from the actuator assembly. I would definately inspect the actuator assembly and verify it is operating per the FSM. I think you are right and the wheel spinning may be totally unrelated (that was throwing me off a bit). First thing to check for sure is the rear drums (jack up both wheels as mentioned and make sure they spin freely after the brake pedal is released).

 

I just got it to happen in 2WD, so the laking axle seal theory is looking real good. Sorry about the piece meal info, but I was trying to diagonse based on what my 18 year old told me was going on.

I'll post up what the solution is so anyone searching in the future will have this to refer to.

Thanks for your inputs

 

You guys are good. It is the rear oil seal.

 

Good stuff, glad you figured it out finally.