4WD/AWD - 88 Camry All-Trac ???

[empersons]

I have an 88 Camry All-trac, MT, with center diff lock. Can anyone explain how the car operates when the diff lock is on vs being off? Is my car 2WD while off, then 4WD when on? My car has the vacuum actuator for the differential. All four wheels spin when its on. Thanks guys!

[TurboATM]

I have an auto, and sort of want to also know...I am told the MT All Tracs are a 100% lock, 100% unlock, while the Autos are Auto Lock depending on traction of front wheels and such...

is this how it works? Also, does the manual center diff work in the auto drivetrain?

['88 All-Trac]

All the transfer cases interchange.

The center differential remains open... What happens is the transfer case locks shut- providing an even 50/50 torque split providing the center diff does not slip.

[empersons]

What does it mean when the center diff is open? That I am in FWD only?

[dem2757]

torque is provided to each left and right wheel differently when open. lock means that the two front and two rear are applying even torque.

[white90dx]

Originally Posted by '88 All-Trac

All the transfer cases interchange.

The center differential remains open... What happens is the transfer case locks shut- providing an even 50/50 torque split providing the center diff does not slip.

The transfer cases for all the manual transmissions swap - I can almost guarantee the Auto center diff/transfer case doesn't swap... where did you hear this info?

-Charlie

[empersons]

Charlie, do you have an explanation for 'how it works'?

[white90dx]

Originally Posted by empersons

I have an 88 Camry All-trac, MT, with center diff lock. Can anyone explain how the car operates when the diff lock is on vs being off? Is my car 2WD while off, then 4WD when on? My car has the vacuum actuator for the differential. All four wheels spin when its on. Thanks guys!

Your car is always driving all 4 wheels.

When all of your diffs are 'open', each wheel is able to apply the same torque to the ground as the wheel with the least traction (lift one wheel off the ground and your car won't move!). With the center diff locked, the average speed of the two front wheels will be kept the same as the average speed of the two back wheels (if one front wheel is off the ground and spinning and the other front is stopped, the rear two wheels will want to spin at half the speed of the front spinning wheel). In this case, 100% of the torque can be sent to the front or the rear, depending on what needs it. The owners manual states that the center diff lock should only be engaged if you are stuck and a wheel is spinning. It can help while moving for traction, but can make turning more difficult (having the front and rear wheels always going the same speed tends to keep the car going straight).

The automatic transmission center diff in 'auto' mode is good in the 'get you out of bad situations' way, but really not for performance. Its good for what the car was originally meant to do.

If you read up on how differentials work, both open and limited slip (and locking), then apply it 3 times, then you have your car.

My Alltrac now has a viscous limited slip center differential, an open front differential and a gear-type (Torsen) limited slip rear. It should be lots of fun in the snow.

-Charlie

PS. When you have the center diff locked and all 4 wheels are spinning, its a byproduct of how snow traction works (you are in snow right?). Your tires spin down through the snow to get grip on the ground, quickly alternating sides of which has more traction (more or less snow under it at any given time).

['88 All-Trac]

Originally Posted by white90dx

The transfer cases for all the manual transmissions swap - I can almost guarantee the Auto center diff/transfer case doesn't swap... where did you hear this info?

-Charlie

I thought I read it somewhere on one of the many Toyota/All-Trac/Celica forums I've joined up on- but maybe I just confused my information.

Coulda sworn I read somewhere they interchange, but I'm probably all messed up somewhere.

[white90dx]

Originally Posted by '88 All-Trac

I thought I read it somewhere on one of the many Toyota/All-Trac/Celica forums I've joined up on- but maybe I just confused my information.

Coulda sworn I read somewhere they interchange, but I'm probably all messed up somewhere.

That makes sense... if you read it on a Celica Alltrac board, then they don't know/care about the Camry Alltrac.

-Charlie

['88 All-Trac]

Originally Posted by white90dx

That makes sense... if you read it on a Celica Alltrac board, then they don't know/care about the Camry Alltrac.

-Charlie

Just wait until I finish mine... Gonna make 'em all blush, tell you what!

I recommend manual trans swap, just 'cause. Auto transmissions belong in rock crawlers and Jeeps.

[empersons]

I appreciate the info Charlie, you have vast knowledge on these cars .

Im still rebuilding the block, then going to do the head. Hope I can get it done before we get snow here in Portland (if we do). I want to drive this beast in the snow again. It did do well going up a snowy mountain road with deep tire trenches.

Charlie, what transmission has the viscous diff? I have the manual, vacuum actuated one, would like to eliminate that actuator all together.

Also, could start a new thread, but is deleting the EGR system possible on the 3SFE?

[white90dx]

Originally Posted by empersons

I appreciate the info Charlie, you have vast knowledge on these cars .

Im still rebuilding the block, then going to do the head. Hope I can get it done before we get snow here in Portland (if we do). I want to drive this beast in the snow again. It did do well going up a snowy mountain road with deep tire trenches.

Charlie, what transmission has the viscous diff? I have the manual, vacuum actuated one, would like to eliminate that actuator all together.

Also, could start a new thread, but is deleting the EGR system possible on the 3SFE?

All the Celica Alltracs got the viscous center diff (except the first year, JDM only ST165 which has the same system as the Camry Alltrac). The drivetrain in my Camry is from a '95 JDM Celica GT4.

You can pretty easily delete the EGR. It may or may not cause rough running in certain operating conditions, along with increased NOx emissions... Keep it unless you have a specific reason to remove it.

-Charlie

[TurboATM]

Im wanting to do a manual swap, and do celica drivetrain...but at the same time make my Talon awd-and the Talon comes 1st in my life, lol.

I had my car in the snow for the 2nd time the other day, and was very disappointed...Or shall i say impressed? it was pretty hard to drift around...i think the dry spots i kept hitting caused a good bit of why it wouldnt slide very well, but it handled great when you look at it from the "driving normal on open roads in a snow storm" point of view.