Excessive NDCC tire wear

cabinfever · Post by **cabinfever** » Mon Sep 21, 2015 2:01 pm

I've had my M38A1 for three years now. During this time I've put about 1,500 miles on it. I'd say about two-thirds of those miles were from towing the jeep on all four tires to shows and parades. When I purchased the Willys, the tires were like new. These are the Firestone military NDCC tires.

Yesterday, for the first time, and after towing the jeep for 110 miles round trip, I noticed excessive tire wear on the front two tires. I was surprised to measure that about 1/4" or more rubber has worn off the front tires. The tire wear seems to be even across the face of the tire with no cupping. The rear tires look fine.

Tire pressure is 25psi. The jeep drives just fine down the road. Steering is easy and the vehicle does not pull to one side or the other. If I let go off the steering wheel while driving down a straight section of road, the jeep will track straight ahead. The wheels have never been balanced, but I do not feel any vibration at any speed (I only drive up to 35 mph or so). All of the driving and towing have been on blacktop.

Right now I am assuming the excessive tire wear is for some reason due to towing on all four. I use a V-type tow bar that bolts perfectly into the front two lifting shackle brackets. I do not tie the steering wheel down tight, however I do use a loose rope on the steering wheel so that it cannot swing more than 90 degrees to the left or to the right. Shifter and transfer case are both in neutral when towing. The front lockout hubs are set to 2wd. The towbar attaches to my pickup at a higher elevation than where the other end attaches to the shackle brackets. The jeep tows straight behind when driving down the road with no swerving to the left or right. When towing, I drive no faster than 50 mph.

Is there something inherently wrong with towing on all four related to tire wear? Or should I be focusing on front-end alignment or having the wheels balanced? Is there something else I should be checking? Caster/camber?

Thanks.

4x4M38 · Post by **4x4M38** » Mon Sep 21, 2015 7:30 pm

Steve,
Am sure Wes and others will chine in but my understanding
is flat towing jeeps with Ross steering boxes is discouraged.
The box suffers, as well as the tires.

If and when I will move mine it will be with a trailer or a two
wheel dolly like the ones you can rent at Uhaul.

Just my two cents.

Brian

Post by **wesk** » Mon Sep 21, 2015 9:25 pm

Hunters and hobbyists have been flat towing their jeeps for a half century and no major problems.

The only minor issues are tranny / transfer wear when they towed without a free wheeling setup on either the front or rear pair of axles. Splash oil is suspected of being in short supply when only the driveshafts are turning the transfer. Tire wear on the front is a natural due to skidding in turns and minor hunting in the straight away. You won't even notice it most of the time but it does happen. The skinny center ribbed NDT's and NDCC's will oscilate and skid even more than a stock civvy tread. All of us who flat tow learn the value of speed control both on the straight away and during mild turns. The faster than 50 you go the more meat comes off the tires. The steering linkage was never designed to behave well at 60 and above. The two pins in that Ross box and the screw will suffer as well when pushing her to 60 and higher. Also the lack of weight will increase the penalty.

If you are skeptical of what I say then place yourself in the jeep's driver's seat and have your buddy haul you down the highway at 60 and you just allow one finger to rest on the wheel. It will actually be worse when the jeep is empty.

whydahdvr · Post by **whydahdvr** » Tue Sep 22, 2015 4:12 am

For towing, I never liked the added wear to any of my cars by flat towing behind my truck. If I can't drive there I always tow my jeep and use a rented UHaul 6x12 open utility trailer. A buddy of mine who has a MB and drove these jeeps in the Army back in the day recommended I use a 6x12 utility trailer. The trailer handles the weight just fine, it's cheaper for me than a car trailer (and I don't have the space to store a trailer anyway - Boston city suburbs area). UHaul will do a 24 hour rental which usually works for me to take it anywhere I want and get back in time. But that also depends on your situation.
Just a suggestion that has worked for me to go to parades, Summer beach use, etc.

cabinfever · Post by **cabinfever** » Wed Sep 23, 2015 3:19 pm

Thanks for the advice and suggestions. I guess I'll be looking for another way of getting my jeep around without the use of flat towing. I cannot afford new front tires every few thousand miles.

As far as using the U-Haul 6x12 trailer. I looked it up and it has a maximum load capacity of 2100 lbs. A M38A1 is supposed to weigh about 2650 lbs (+/-).

Thanks again.

whydahdvr · Post by **whydahdvr** » Wed Sep 23, 2015 3:23 pm

I thought the open utility trailer had a higher rating, closer to 2400-2700. It's been about 6 months since I rented one. However, I've never had any issues with it but all depends on the roads, how far you drive, and how you drive.
A dedicated trailer - utility or car - would be ideal if you have the space and $$$.

4x4M38 · Post by **4x4M38** » Wed Sep 23, 2015 3:29 pm

Steve,
Uhaul also rents those two wheel jobbies you drive the front
wheels up on and lock down. It is usually a ball hitch attachment.

Post by **wesk** » Wed Sep 23, 2015 10:34 pm

Using the Cartote is ok if you take certain precautions. Leaving the rear wheels rolling without removing the rear drive shaft will cause unnecessary and unwanted transfer case wear.

4x4M38 · Post by **4x4M38** » Fri Sep 25, 2015 6:08 am

Hep Wes,
So you are saying that you should remove the rear driveshaft
when flat towing as well?

Post by **wesk** » Fri Sep 25, 2015 7:55 am

Don't confuse flat towing with cartote towing.

If you intend to operate at 60+ MPH for long distances then in the interest of reducing wear on the transfer case the drive shaft for the axle that is rolling should be disconnected. If flat towing then disconnect both driveshafts.

By disconnected I do not mean you must remove them. They are disconnected at the axle pinions and tied up to the frame for the trip. You should also bag and tie the end yokes.

4x4M38 · Post by **4x4M38** » Fri Sep 25, 2015 6:06 pm

That, Sir, is excellent information.

Not commonly known, nor practiced.

Thanks,

Post by **wesk** » Fri Sep 25, 2015 8:26 pm

I got my first jeep in 1970. A 42 GPW i used for hunting. Do the arithmatic! This standard towing procedure has been around a lot longer than that! I have 1950/60 Mechanics Illustrated mags with articles on how to do this.