Using part-time 4WD on dry pavement (TE - SR5)

[MLA]

Not to beat a dead horse, but I am curious how folks approach driving over mountain passes in mixed conditions with a part time system. Sure, if the road is dry, I don't engage 4wd, and if the roads are snowy or partially plowed, I leave it in 4hi. However, 90% of the time I'm driving over Berthoud Pass or Loveland Pass, there are a set of tracks on the road and the pavement is exposed and appears to be wet (or could have black ice given the winter temps). These passes also have hairpin turns where CDOT tends to dump a lot of sand, so you find the same "wet" pavement. I've personally noticed that if I shift to 2wd before the tight turns, the back end starts to slide out a bit then traction control kicks in. On the other hand, if I leave it in 4hi, I can feel the difference in the steering both during and after the turn (a feeling of "tightness"). I generally leave it in 4hi and err on the safe side going up. On the descent, I'm less confident that leaving my TE in 4hi is the right approach. 4hi has no bearing on the ability to stop, and as already mentioned, impacts the turning radius. I downshift and go slow, but worry about sliding out into oncoming traffic during some of the really tight turns. For those of you with a lot of experience in these conditions, do you leave your SR5/TE in 4wd both going up and down mountain passes in mixed driving conditions? This is different than driving on I70 or other highways with broad turns.

 

[Blitzkrieg]

Not to beat a dead horse, but I am curious how folks approach driving over mountain passes in mixed conditions with a part time system. .....

Brother, I have been driving Colorado's roads my whole life. I consider myself somewhat experienced on it.

Throw that baby into 4 HI and rock on. Unless you are trying to negotiate a strip mall parking lot on dry pavement there is absolutely nothing wrong or harmful with running a part time 4WD in 4 HI on straight and/or snow packed roads.

Just shift her into 2WD if you are on dry pavement and you will be fine. Key point is: Don't over-analyze it. If there is snow on the road, 4WD.

 

[Jetboy]

Not to beat a dead horse, but I am curious how folks approach driving over mountain passes in mixed conditions with a part time system. Sure, if the road is dry, I don't engage 4wd, and if the roads are snowy or partially plowed, I leave it in 4hi. However, 90% of the time I'm driving over Berthoud Pass or Loveland Pass, there are a set of tracks on the road and the pavement is exposed and appears to be wet (or could have black ice given the winter temps). These passes also have hairpin turns where CDOT tends to dump a lot of sand, so you find the same "wet" pavement. I've personally noticed that if I shift to 2wd before the tight turns, the back end starts to slide out a bit then traction control kicks in. On the other hand, if I leave it in 4hi, I can feel the difference in the steering both during and after the turn (a feeling of "tightness"). I generally leave it in 4hi and err on the safe side going up. On the descent, I'm less confident that leaving my TE in 4hi is the right approach. 4hi has no bearing on the ability to stop, and as already mentioned, impacts the turning radius. I downshift and go slow, but worry about sliding out into oncoming traffic during some of the really tight turns. For those of you with a lot of experience in these conditions, do you leave your SR5/TE in 4wd both going up and down mountain passes in mixed driving conditions? This is different than driving on I70 or other highways with broad turns.

Put it in 4wd when it gets slippery. Take it out when you get to consistent dry roads. Contrary to what you may hear, you can actually stop faster in 4x4 than 2x4 on slippery roads. <- It has to do with how mechanically coupled tires approach the threshold of motion as a group rather than individually, but that might be a bit much to explain in this thread. If you really want to see a mathematical proof of this, I'll write one up when I have more time.

Just stick it in 4hi. You won't ever notice a difference except very tight turns at low speed. You might forget to take it out if they didn't put the light on the dash. If you want, toss it in 4x4 when you leave home. Take it out when you get back.

 

[Jetboy]

I like this article, it gives a good explanations why part time 4WD should never be used in dry pavement.

Driveline bind, binding hubs, axle wind up, axle bind, drive line wind up - all terms for one thing: stress due to part time 4 wheel drive

I know it's old, but I would say with almost 100% certainty that driving in 4hi had nothing to do with this failure other than it happened to occur at the same time. Cherokee transfer cases were pretty well known to split in half due to weak casting - typical Chrysler crap product.

 

[LandCruiser]

I use 4HI on roads covered in snow and ice.

I still wish we had a proper center diff that can be run open, which kinda makes me want a LE.

 

[DesertCanyons]

4WD Hi on dry pavement

First of all, some of you guys need to read the manual.

Second, many of you are way over-thinking this or have no clue as to what you are driving.

If you have a 2010-2013 Trail Edition or SR5 4X4 then put it in 4HI every now and then during the spring and summer for some miles of fairly straight roads. This will assure proper lubrication of the transfer case and movement of the actuator. NO HARD TURNS! NO PARKING LOT TURNS!

If you have a 2010-2013 Limited Edition don't worry about it. This does not apply to you.

Thanks Greg. Good explanation. Yes, I read the manual and I always overthink things. :usa2:

I have a 2015 Trail Edition. The manual says to engage 4WD once a month. I never knew why, even if it's written in the manual. Thanks to this thread, I do now.

No hard turns is right. I've made that mistake after coming off of muddy roads onto pavement in 4WD Hi.

You can't engage 4WD Hi at 60 mph. The limit is 55 mph but try slowing to 50 mph before shifting if you can. Then drive any speed needed. If you're in 4WD Hi because of road conditions you probably shouldn't be going much over 60 mph, IMHO.

 

[Stewart]

Glad to have found this thread. I currently own a 2010 SR5 and initially thought that something was wrong. I had previously owned a 2004 Limited and had not experienced this issue.