Towing in 4 wheel drive vs. 2

[mykytiukr]

Originally Posted by Boxite

A lot of presumptive/incorrect info is being produced in this thread.

Firstly, read your owners manual. Some vehicles tow in 4WD full time just fine.

VERY FEW will “explode” any drivelines….mostly OLD MODELS are injured by full-time, high-speed 4WD use on dry pavement….not modern vehicles.

Many modern vehicles have differentials and transfer cases which accommodate dry pavement just fine…. READ YOUR OWNERS’ MANUAL.

HOwever, your tires will wear at a faster rate if 4WD is used on dry pavement.

Also, the advice to shift OUT of 4WD as soon as you notice it …can cause failure if done improperly.
For the Sequoia models:
Older 4WD systems must be manually shifted between 2WD and 4WD and from 4HI to 4LO while the vehicle is stopped. Newer s 4 wheel drive systems have electronic push button 'on the fly' features that let you shift while driving.

Yep! Agree!

[guskmg]

Use 4x4 when negotiating camp grounds with gravel roads. It will keep the rock dings down.
guskmg

[Waterbeach]

Just a personal experience a few days ago. Highway 4 on Vancouver island is being "improved" which means massive roadworks in a mountain pass - see picture. We have Ford Expedition and FC 23FB. On our return trip we were behind several trucks which chewed up the gravel on a steep grade - halfway up in 2wd we lost traction, rear started bouncing up and down and we bounced sideways towards the edge - I switched to 4 High and all was serene and we got out of there with no problems; at the top switched back to 2 High and on we went. I hardly ever use 4wd but sure am thankful it is there when needed!

[Life is a Highway]

Could have not said it better. You most likely dodged a problem.

Watch KYD's latest Youtube where his friends cell phone dropped off the dash on a his new F-450, hit the 4WD electronic turn button and put it in gear, Destroyed the front axle was months waiting for parts.

I would definitely at your best connivence get the transfer case and front diff gearlube changed, while your at it and the vehicle is on a lift the rear diff also.

Originally Posted by wulfraat

It works fine until your transfer case gears or chain implode. [emoji4]

Front axle rotation rate is different than the rear axle rotation rate when you are not driving in an exact straight line. 4wd transfer case locks the ratio forcing both axles to turn at the same rate.

On wide turns on wet pavement or snow the tires will be forced to loose grip and will slip to accommodate the transfer case forcing the front/rear axles to turn at the same speed.

Under load with tighter turns on dry pavement tires have more friction and it’s your transfer case gears that will pay the price - something needs to give, mechanically - tires will loose grip, you will break a drive shaft or the transfer case gears will fail. The energy needs to go somewhere.

Transfer case gears are about the size of your fist. That’s not much surface area to deal will the tremendous resistance of different axle speeds with high friction coefficient of dry tires on dry pavement.

https://m.youtube.com/watch?time_con...ature=emb_logo

[pteck]

Not great advice in this thread as most is in the context of their own vehicles, which is almost all wrong (except Alumineer) when applied to the Sequoia. It's actually got a really great multi-mode full-time capable 4WD, 2WD, and 4x4 system that doesn't have the same set of limitations as most trucks and SUVs. It's not a passenger car AWD system (Toyota/Lexus uses legitimate transfer cases in all their body on frame vehicles.)

The JF3A transfer case has many talents
- Full time 4WD with center diff
- Center diff is a Torsen limited slip mechanical differential with a 30% front bias until it senses rear a slippage at which time it will apply more torque to the front wheels
- 4x4 with center locking capability for hi or lo
- RWD only mode

The OP can use full-time 4WD if he so chooses. RWD is a gas savings mode. For mountains, hills, or weather, I would highly recommend 4WD. Engine braking is also more stable with all drive wheels engaged in slowing down the rig.