01 Ram 4x4

[quigley]

I have a 01 Ram 1/2 ton 4x4. According to the manual I should be able to shift from 2 wheel drive to 4 high up to 55 mph and back again to 2 wheel drive. Right now I`m lucky if I can do it at 15 mph. And when I go from 4 high to 2 wheel drive at 40 to 55 mph I get a loud bang from transfer case. The dealer says its because my tires are not wearing even and are actually a 3/4 of a inch different size from front to back. Does this sound right? Is the transfer case that sensitive? Any help would be greatfull.
Thank You Quigley

[MRDANGERUS]

Originally Posted by quigley

I have a 01 Ram 1/2 ton 4x4. According to the manual I should be able to shift from 2 wheel drive to 4 high up to 55 mph and back again to 2 wheel drive. Right now I`m lucky if I can do it at 15 mph. And when I go from 4 high to 2 wheel drive at 40 to 55 mph I get a loud bang from transfer case. The dealer says its because my tires are not wearing even and are actually a 3/4 of a inch different size from front to back. Does this sound right? Is the transfer case that sensitive? Any help would be greatfull.
Thank You Quigley

Hi,

I read your 2003 post about Transfer Case bang while shifting from 4H to 2H. Have you found the root cause?
I have a similar problem on my 99 Ram. I Bought it in Jan 04, used, 83 K mi, in good shape, 5.9L, auto, 4x4, first 50-60 Kmi was driven in Canada, 3 owners, no plowing, signs of heavy hitch (removed), frt tyres newer, rr tyres showing some wear (1/4 in , maybe little more). So far, I added 5-6 K mi this year. Did have some banging, last winter.
This winter, when temps came down to 30-s, I noticed the problem have escalated.

When I shift from 4H to 2H, the light goes off, but I can still hear thansfer case working. After 1/4 mi, usuallly under acceleration, kaboom!. Sounds like hitting a large pot-hole. Whole truck shakes violently. Lately, I noticed an oil leak. Couple red drops on the floor every night.

So far I have changed TCase oil and added 12 oz. of the Lucas Trans Fix, which supposed to stop leaks. Adjusted a TC shifter rod.
Well, leaks less, shifts w/less shudder, but the problem did not go away.

Could you please share your experiences/expertise with me.

[1thunder]

tire size is a very likely issue binds up in transfer case eventually will cause damage in the t/case if not already damaged

[fredjacksonsan]

Originally Posted by 1thunder

tire size is a very likely issue binds up in transfer case eventually will cause damage in the t/case if not already damaged

Exactly; how often are you guys rotating your tires? Rotation is the key to even wear.

Even if you have the same size tires, but they are different brands/makes, the diameter is NOT the same!


When tires are the same size, the engagement in the transfer case goes easily because the front and rear driveshafts are turning at the same speed.

But when you get a speed differential between front and rear the transfer case is unable to make the adjustment and you get problems. More speed makes the problem worse, as the rotational speeds of the front and rear shafts get further and further apart. Either it won't engage at all or makes a lot of racket, as you've noticed. AND, while you're driving in 4wd with mismatched tires, there is a lot of stress being put on the entire driveline, which is why you get the "bang" when you disengage.

Picture one of those tractors with the tiny front wheels and the huge rear ones. The small wheels in the front will turn 2-3 times or more for each revolution of the rears. While tire sizes in your trucks aren't that different, it's a useful way to think about it.

So before you do more damage to the Tcase or other components, do yourself a huge favor and make sure your tires are the same.

[crazys182003]

I have always been told with a 4x4 you need to have exactly the same tire same time moutned rotated and such BUT when I got one flat and my spare was wrong size I learned to compromise. my tires from front to abck are about 1/16th of an inch different this is not extreme enoguh to have a problem but 3/4 of an inch is just too much. you can severly ruin your t-case.

[neon_rt]

My Jeep has the same T-case, I have to put 2-3 PSI more air in the front to make the shifting from 2-4wd the smoothest. The T-case seems to be very sensitive to any difference in driveline speed Front to Back.

[1thunder]

well said there fred excellent explanation

[fredjacksonsan]

Originally Posted by 1thunder

well said there fred excellent explanation

I thank you, sir!