newbie, 1st post with tread wear effect on transfer case question

[Flagman]

Hi all I have a 2001.5 2500 4x4, stock with all the extras, etc. For years I have been a tire salesman but I still don't quit grasp the matching tire thing as it pertains to transfer cases. Now I know it is important to match tires on a full time 4x4. I ask because my new to me truck has all the same size tires and brands but because of a previous owner flat, the right front is almost new while the others are 50%. It seems in we drive in 4 wheel drive only on slippery surfaces, then we do it because the slipping road will take care of the binding by slipping the tires but is there added heat building up that makes it hard on the transfer to run with different tread depths? Im not to worried about around the yard but if Im driving on the hard packed snow for 50 miles at 40mph, am I being hard on the transfere? Does anyone have any experience with this, knowledge of the strength of the transfere? Im more interested in facts and first hand experience verses what we have all heard from others and opionions. Thanks MarkFlagstaff, AZ

[Mopar1973Man]

If you go out to the quarter mile tracks you'll find most Cummins trucks launching off the line in 4WD. The transfer case can typically handle the abuse. Like myself I do a lot of tree skidding and dragging in the summer time in 4WD. But as for drive axles , u-joints, drive shafts, Double Cardan Joints it beats the hell out them... Running 4WD in dry pavement... I've already broke 1 cardan joint, 1 driveshaft, and wore out a set of drive axle u-joint in under 30K miles when I bought my truck and then figure out the the limitations of the 4WD system. If your pulling straight and never turn your fine the stress is reduced. But if your pulling on dry ground and turning sharp... Oh Look Out! Your asking to break something... Even like climbing a mountain road with 4WD and its muddy. I got to go back to 2WD to prevent binding of the driveline on sharp switch backs because there isn't enough wheel slip... Why is the problem so noticable on a Cummins??? Think about is normal gasoline engines are what 500-600 pounds now the Cummins is 1,100 pounds DRY! Now add coolant, oil, etc... so on the scales I'm weighed out at... 7,300# = 4,400# front axle + 2,860# Rear Axle... Hmmm don't you think there is quite a bit of weight pinning those front tires down from slipping??? Now throw in 265/75 R16 or larger tires with agressive tread... This makes it even worse on the driveline... It is one of the few reasons I went back to 235/85R16 tire to allow more slipage of the front axle to allow for stress relief...

[ISX]

I'm not sure about dodges with 4wd but I was able to put my ford in 4hi at any speed, it would practically fall in. If you guys can do this, I don't see why you wouldn't leave it in 2wd until you see something slick coming up. If it is slick, I don't think you would be going over 30mph anyways which is what I think most 2hi-4hi shifts are rated up to. That cardan joint needs to be greased at least once a year. When I helped a guy at a machine shop, the only cardan joints brought in were from 24v's, and he had pretty regular work fixing them. You have to grease them with a needle cert thing since there aren't any grease certs on it, think there are 3 points you have to hit with grease to keep it happy. Obviously anything you grease with a needle greaser is also vulnerable to anything, snow, mud, it all wipes the grease off, thats why you have to stay on top of it. All of the ones people brought in looked like they had been driven in the desert for 50 years. Bearings crushed to powder on most of them, others weren't as bad.

[flagmanruss]

I don't have a definative answer but MY 01.5 with matching OEM rubber will hop like crazy on a turn in 4H... at snail speed on my gravel drive. I think the limited slip diffs have something to do with it. I once used 4H to pull gently off a town commons trying not to tear up the grass following an encampment. When I got on the paved drive the stress was so great & could not disengage. Yikes!Russ

[Flagman]

thanks to all for the responses but what I am really wondering is if I can run tires with different tread depths in four wheel drive without damaging anything. Mark

[ISX]

I don't think same size tires with different tread wear will tear anything up. Seems a little insignificant. On hard pack snow I really doubt it would do anything at all. Probably keep it out on pavement just to be sure but on anything that isn't dry pavement I don't see much of an issue.