Crawl mode question

I've had my new 16 Taco TRDOR for a couple weeks now. I had a chance to use the Crawl feature today. Got the book out for the setup and put it to work. It was jerky and the sound was that it wasn't fully engaged as if jumping cogs. I turned it off and went thru the sequence again with the same result. Does anyone no if I'm doing something wrong or missing something?

 

I doubt that it was "jumping cogs". The grinding noise was probably your brakes pulsating to distribute power more evenly.
As far as the jerkyness, typical side-effect of operating at a low gear range.

 

Crawl Control is basically low-speed cruise control with A-Trac, nothing to engage mechanically. If you are already stuck, the system will be jerky and give similar sounds as if ABS or traction control is active.

Make sure 4Lo is firmly engaged before activating Crawl, however.

 

I think that is probably the key.

 

Except on hard surfaces....

 

So you like to constantly lock and unlock, when you can just let it do its thing?
Sounds like a whole hell of a lot of fun....

 

Wonder what's the real reason no automaker currently offers front lockers with an independent front suspension. Durability of the CV shafts?

 

The simplest answer is... to prevent people from becoming DEAD. Even at relatively low speeds, on a high traction surface, an attempt to turn could cause the vehicle to jump and possibly roll over.

 

I don't think they are the devil.
But for the majority of uses, they aren't helpful, and can actually be a hindrance.
Limited slip is far superior from a handling and stability point of view, and in most cases, at LEAST as effective.
In MANY cases, more effective, since any attempt to turn with a locked differential necessarily requires traction on one side to be broken.

It is far more effective to be able to apply the same force everywhere, without taking away the "give" that is needed to steer.

 

Even easier: do absolutely nothing.
Result: the thing actually drives correctly.

Just what the hell is your point?

 

Thanks guys. I really really trust Toyota to build a good product. I retired from road building industry where any number of heavy equipment machines utilize a creep or "crawl" mode to accomplish whatever they do. They r O so smooth and probably use a different technology altogether. I called the dealership and they as well as u guys have assured me this is what it is. Hurts my feelings to hear all the clicking and clanking that sounds like gears jumping. Hope I don't have to use it much. Thanks for the help.

 

^It sounds bad but that's all it is, sound. In reality, the system is probably less stressful on the front diff and CV axles than a front locker.

That's the wrong answer. Three production vehicles are currently offered with a front locker: Rubicon, Power Wagon, and Mercedes G-Class. The Land Cruiser / LX had a front locker until the design change from solid axle to IFS.

 

Doesn't make it a good idea.

 

^A front locker is a useful feature off-road as it operates smoother in constantly changing traction conditions, whereas A-Trac is jerky. With existing electronic interlocks (i.e. 4Lo only), if Mercedes can offer this feature in a vehicle driven mostly by lawyers and rich housewives without liability concerns, who are you to say otherwise?

 

Physics always wins.

 

No IFS in any of these...

 

Yes, and there are situations (e.g. off-camber turns where the vehicle is already at a high bank angle or pitch angle) the jerkiness of A-Trac can cause the vehicle to tip over.

 

Try to keep up. I was asking why no production model with IFS is offered with a front locker. tgear.shead thinks it’s due to liability. I say he’s wrong because there are several solid axle models offered with front lockers, and liability doesn’t change whether the vehicle is IFS or solid axle.

 

Caught me!

 

HDC makes the same sounds.