97 4wd problem

I've got a 97 taco 4wd with electric on the fly 4wd transfer case. The problem i'm having is my left front wheel has quit locking in, only my right front locks in when i'm in 4wd hi or low. The truck has 280k so I really can't complain, i'm just wondering where to start looking for the problem and any help would be appreciated.

 

If the ADD is working then your differential will send power to both tires (if equal traction conditions under both), but most often only one tire per axle will get the power... this is normal because you have normal 'open' differentials... or at least you do in front.

The purpose of open differentials is to allow the tires on each axle to rotate at different speeds (as needed when turning)... The power will go to either the left, the right, or both at the same time... depending if there is less traction under one tire or not.

The tire with less traction gets the power... which isn't good off the road where we drive over ruts and different soil surfaces... When you do get stuck in 4WD, you will see one tire in front and one tire in the rear spin, and the other two do nothing.

Enter traction aids! Now, 4WD is usually enough as it doubles the traction of 2WD... But, sometimes we need to go higher up or further through a difficult area than normal 4WD Low Range can do for us:

1) Rear Locker... The Toyota Off Road TRD (2WD and 4WD) come with an electronic activated locking rear differential. No matter what the surface below your rear tires... BOTH will get equal power and turn toghether at the same speed. Use only to get unstuck or past the problem area... since steering would be difficult when locked.

2) Limited Slip Rear Differential (on '05-'08 SPORT TRDs) or Limited Slip Traction Control (TRAC) on front and rear differentials (on all Tacomas from '09+)... As the name implies, instead of allowing one tire to take all the power and spin useless when it is in the air or on slippery surfaces, the system slows down that tire so a bigger portion of the power can go to the tire with good traction. After market limited slip differentials can be installed as well.

3) A-TRAC... The 4WD Off Road TRDs from 2009+ have Active Traction Control which goes beyond standard TRAC in not just slowing down a loose tire, but actually matching it to the traction tire, like a locking differential would do to keep you moving.

4) Front (and Rear) Lockers... NOT offered by Toyota, but very popular with 'hard core' off roaders for maximum traction... Does not make the noises that A-TRAC makes, but does make steering most difficult. A-TRAC doesn't affect steering one bit.

 

I understand a lot more about it now. Something still doesn't seem right though. When I got stuck the other day my right front only spun. To figure out what was going on after that I put the truck in Low4wd and reverse and eased my reese hitch up against a large tree stump (it had been raining and was super sloppy out). I let out on the clutch and both right side tires started spinning. I then turned the wheel both ways and back and forth and never could get the left front to spin. Thats why I thought I had a problem.

It appears my truck doesnt have positive traction as the left rear never spins. Do some of the first gen tacomas have positive traction? I would like to do that swap or get the TRD rear end.

 

The truck only has open differentials, the only time it didn't was the rear differential on 2005-2008 SPORT TRDs was limited slip. All 2009+ Tacomas have electronic/ brake limited slip systems.

The OFF ROAD TRDs have electronic activated locking rear differentials, since the late 1990's.