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Flat towing an M37

Posted: Fri Feb 08, 2013 7:12 am
by m37jarhead
When I use my tow bar to flat tow my M37 behind my 3/4 ton pickup, the M does not want to "follow" through the turns.
The front wheels on the M want to turn in the opposite direction of the turn.
Why does it do that and what's the fix?
JB
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Re: Flat towing an M37

Posted: Fri Feb 08, 2013 8:20 am
by W_A_Watson_II
Sounds like a caster alignment issue on the M.

I've never been a fan of tow bars.

Re: Flat towing an M37

Posted: Fri Feb 08, 2013 8:34 am
by Carter
I have flat towed M37 alot and found half a doz. bungee straps attached to the steering wheel and the lip edge of the drivers steel seat box in an X pattern (left to right and right to left) allowed the towed truck to corner then have the front wheels swing back to center when thru. the turn.

Re: Flat towing an M37

Posted: Fri Feb 08, 2013 12:17 pm
by PoW
Ditto Carter's technique.

PoW

Re: Flat towing an M37

Posted: Fri Feb 08, 2013 2:14 pm
by m37jarhead
W_A_Watson_II wrote:Sounds like a caster alignment issue on the M.

I've never been a fan of tow bars.
Will: Probably would be a good idea to take the M to an alignment shop and
have them check the castor, camber and toe-in. Thanks.

I'm not a big fan of tow bars either. They are an accident waiting to happen.
I purposely bought a 3/4 ton pickup to tow the M. Not for the power but
for the big ol' disc. brakes front and rear. But, until I can afford a trailer
with hydraulic or electric brakes and big enough to haul the 6500 lbs. M,
I'm stuck with the tow bar. Hey.... Columbus took a chance.
Thanks,
JB

Re: Flat towing an M37

Posted: Fri Feb 08, 2013 2:19 pm
by m37jarhead
Carter wrote:I have flat towed M37 alot and found half a doz. bungee straps attached to the steering wheel and the lip edge of the drivers steel seat box in an X pattern (left to right and right to left) allowed the towed truck to corner then have the front wheels swing back to center when thru. the turn.
Thanks Carter and PoW:
I'll give the bungee cords a try.
It would also make sense to take the M in for an alignment to check castor, camber and toe-in.
That should help on the tire wear too.

Tks,
JB

Re: Flat towing an M37

Posted: Fri Feb 08, 2013 4:42 pm
by Carter
My tow bar set-up hooked to an M37 fire company rescue that Lee and I brought home in a 125 mile recovery trip. Used the bungee trick for the entire trip and that old yellow M followed us all the way home with out needing someone to steer it around turns/corners and I backed the entire rig into my driveway, the way you see it sitting here.

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Re: Flat towing an M37

Posted: Fri Feb 08, 2013 6:53 pm
by W_A_Watson_II
Just FYI, other than Toe in there isn't any real alignment adjustments. If the caster is out, it might be spring related (axle leaning), and might need spring shims to correct.

Re: Flat towing an M37

Posted: Sat Feb 09, 2013 10:54 am
by m37jarhead
W_A_Watson_II wrote:Just FYI, other than Toe in there isn't any real alignment adjustments. If the caster is out, it might be spring related (axle leaning), and might need spring shims to correct.

W A:
As of today, I know nothing about M37 castor and camber. Will have to check the TM's. There may be NO "adjustment" to
speak of on castor and camber. May have been set by the factory and only wear and tear takes it out of spec. A few
months ago I did adjust the toe-in to TM specs. Don't remember the exact "spec." but it was something ridiculous like 1/64th
or 1/32nd. Well, duh.... who the heck could accurately set toe-in to that tolerance using a tape measure and eye-balling it?
So, I did my best to follow the spec., 1/32nd or some such. Mainly settled on the fact that there WAS toe-in and not neutral
or toe-out. At that time also checked axle alignment, side to side, to avoid "dog tracking." Used the "tight string" method
along one side to make sure both front and rear tires are parallel. Mine came out near perfect.

Thanks to Carter for the tow-bar pic. He's convinced me to use the bungee cord trick. I'm stuck with the tow bar until
the M is street legal. That may be a while.

Thanks,
Jerry

Re: Flat towing an M37

Posted: Tue Feb 26, 2013 5:50 am
by m37jarhead
Carter:
I flat towed the M this weekend using the bungee cord trick. That worked pretty well and kept me
from jumping out of the tow vehicle to straighten out the front wheels on the M.
The front tires on the M still drag a bit through the turn while the front wheels try to go in
the opposite direction. Is this normal or do I need to add more or fewer bungee cords?
Jerry

Re: Flat towing an M37

Posted: Tue Feb 26, 2013 9:11 am
by Carter
m37jarhead wrote:Carter:
I flat towed the M this weekend using the bungee cord trick. That worked pretty well and kept me
from jumping out of the tow vehicle to straighten out the front wheels on the M.
The front tires on the M still drag a bit through the turn while the front wheels try to go in
the opposite direction. Is this normal or do I need to add more or fewer bungee cords?
Jerry
I have had the same thing happen to me while towing an M and found that inflating the front tires to 50-55 lbs resulted in much better steering "return" along with another set of bungees. I have dragged a half a doz. on various trips, sometimes with another M. and always was successful with not one accident.

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Re: Flat towing an M37

Posted: Tue Feb 26, 2013 7:14 pm
by m37jarhead
OK, thanks Carter. I'll try higher tire pressures and a couple more bungees.
JB