4x4 binding

Excellent post! I wanted to get into the math but didn’t have the time. Good on you!!

 

I think you meant that for 96cardboard. I'm the one that doesn't quite know what's going on, LOL.

 

Oops yeah. Got interpreted while I was posting lol

 

Side to side difference will put wear on the center diff as the spider gears will have to turn at different speeds, can be done with open diffs, but should not be done for a long time.

Front to rear difference will put wear on the tcase when in 4wd as the tcase has to turn both drvshfts at the same speed.

In 4wd on hard surfaces you have to account for the difference in tire diameter, the front tires will be smaller than the rear because there is more weight over the front tires. Like 69carboard said the difference is small but over miles becomes a big difference.

 

I've had driveline bind up on an AWD car with different tread amounts and an AWD suv bind up with a tire that was about 5psi low.

 

I'm not sure what could be done about it, but they all just seems like a major design fail at least I anything worth permanent AWD. In real world conditions, shit like that happens. Even with our tpms you could easily have a tire low that doesn't cause the light.

So... How about this. Drive the truck in 4wd for a few miles a month in a straight line on rainy days? That should lube up the pavement enough right? At least with my shitty tires that really do not do well in rain!

 

40399K miles on my truck and I only engage 4x4 in the dirt. Why anyone would do this while driving at 50 to 60 mph on the street is unbelievable to me. I have no problems with my trucks 4x4 system.

 

Put it this way, if you can engage 4x4 on pavement at 50mph straight stretch of road or hell even slight corners and the 4x4 disengages when you put it back in 2wd the driveline isn’t bound up. It won’t disengage 4x4 if the driveline in binding.

 

This is to do with difference in axle averages.

I.e., if the average diameter of the two front wheels is 30" and the average diameter of the two BACK wheels is 30 1/8".

Moderate side to side differences are irrelevant, since you have a differential on both axles.

 

NO NEVER!
Your STOPPING (front) tires should be the ones with the more meat on them!

But remember that ANY variation in the average tread depth from front to back will result in binding while in 4WD. Simple way to mitigate that problem is to never use the 4WD on hard surfaces.

 

Yes it will release under moderate binding, but it will POP or BANG when the tension is released.

 

Not sure who wrote the manual that suggested a monthly use of 4x4 "to lubricate", but it is nonsense and completely unnecessary. Whether the 4WD is engaged or not, the front parts are still going to move a bit, and that is more than enough to keep everything nice and lubricated.

 

The manual states we can engage/diengage 4wd up to 50 MPH. I’ve slowed on the highway to 50-55 (with no one close) to either go into or out of 4wd during and after snow storms. The Tacoma has a light rear that gets squirrely in 2wd in slippery conditions.

 

On a snowy road is not a problem. Take care.

 

Thank you very much for a detail response. I learned something new today!

 

To avoid the bang/clunk when disengaging... while moving in 4H before turning the switch back into 2WD take foot off gas pedal so there's no load/bind on the driveline- then turn switch back to 2WD.