Does using 4WD while towing reduce gearbox wear?

[slickshoot]

I have a 2004 2.5 Diesel Kia Sorento that I use for towing my classic mini (on a trailer). I usually just use the Sorento in 2WD but I was recently told that it is recommended to use 4WD while towing to reduce strain/wear & tear on the gearbox. I'm just trying to understand the benefits of this as surely regardless of 2WD or 4WD the power is still transferred through the same gears in the box right?

If there truly is a benefit to the lifespan of the gearbox then I'll hapilly stick it in 4WD but as there'll be economy implications I'd prefer to confirm whether this is a fact.

Any thoughts?

[vtecyo]

Doesn't the power go through the gearbox before being sent back to the rear wheels?

[The Wookie]

The torque going through the gearbox should be broadly similar but you'll be putting twice as much torque through whichever diff is used in 2WD mode (i.e. front or rear), as in AWD mode it will be split between front and rear.

Perhaps with higher loads/torque demands experienced while towing it's enough to cause a durability issue.

[geeks]

Told by whom exactly?

Plenty of 4x4's are in 2WD when in everyday use and while towing they are still in 2WD and have no issues.

Does the Kia have an open centre diff? If not then 4WD on the road is a no-no anyway!

[slickshoot]

I must admit that the recommendation was not specifically for the Kia Sorento. I borrowed my brother's Mitsubishi Shogun recently & in the handbook for that vehicle it recommended using 4WD whilst towing which is why I asked this question about my Sorento. To be honest there is no mention of towing at all in the Sorento handbook even though the manufacturer does list a recommended maximum towing capacity on their spec sheet online.

So it seems like the answer is to stick with 2WD whilst towing (unless of course the road conditions require 4WD for whatever reason). I don't think the Sorento has an open diff but as it has a 4Hi & a 4Lo option I'd only use the 4Hi anyway when on the open road so it's unlikely that option would be open anyway right?

Thanks!

[TooMany2cvs]

slickshoot said:

So it seems like the answer is to stick with 2WD whilst towing (unless of course the road conditions require 4WD for whatever reason). I don't think the Sorento has an open diff but as it has a 4Hi & a 4Lo option I'd only use the 4Hi anyway when on the open road so it's unlikely that option would be open anyway right?

Quick google suggests that it's a viscous centre diff. How closely matched in brand and wear are all your tyres?

How much will you be towing, compared to the maximum allowable?

[Ozzie Osmond]

Have I missed the crisis reports of "2WD towing vehicles in frequent diff failure shocker"??????

[TooMany2cvs]

Ozzie Osmond said:

Have I missed the crisis reports of "2WD towing vehicles in frequent diff failure shocker"??????

No, but have a look at the towing weight limits for typical 2wd vs typical 4wd vehicles.

Sure, 4wd versions of 2wd cars are often fairly similar - but that's because you've got various other limiting factors at play.