Info needed: Ford CMP 15cwt Hard Riding

[Edwin Wand]

We have a 1943 Cdn Ford CMP 15cwt. With no load it gives an unpleasantly hard ride. We added about 800lb of weight, and got a much smother ride but still no where nearly as comfortable as a similar unloaded Chev 15cwt would be.

We removed the springs, re-arched them and otherwise did the normal spring maintenance tasks.
We freed up the shocks but did no rebuilding. Local companies do not rebuild and recommended a firm in the US but at US $250 per shock we didn't proceed.
There is another F15cwt in this area with a similar problem but not as severe.

Short of driving with a 1000 lb load, the next step seems to be to remove a leaf from each pack.

Is there anyone who cured a similar problem?

Advice, suggestions, comments are all gladly welcomed

Thanks in advance
.
Edwin Wand

[Phil Waterman]

Hi Edwin

What you discription is not uncommon, so let me ask some questions:

What tires are you running?
Are they hard from age?
Tire pressure?
Have you checked the function of your shocks?
With the link disconnected dose the arm move easily or with resistance?

With my HUP tire pressure and age of tires make a very noticeable difference in the ride, more than the shocks, though with good shocks (original untouched) you can definitely tell when one of the shock links let's go. The welds on the links tend to break over the years I've rewelded all four. Some non-directional tires get really hard with age.

With my C60L Cargo with no shocks and no load the book pressure 35/75 f/r it will compress your spine to hit certain bumps at 20MPH. Hit the same bump with my C60S with the radio truck, with shocks, 55/55 pressure you hardly notice the same bump. Both trucks have the same tires all new a few years ago.

When I dial back the pressures on the C60L till I get a little deflection improves the ride greatly when I hit the same bump. I'm in the process of putting the shocks back on the C60L, they work fine clamped down to the bench, will report back on the difference.

Cheers Phil

[Tim Bates]

The springs on my F15 have been greased and wrapped with denso tap or something similar (looks like a grease filled wrapping possibly may even be hessian). Truck runs fine loaded or unloaded on rough ground or on the road.

Only issue would be having to strip them down to do this.

The other option is to oiled springs, I have done this with good results in the past on other vehicles, but you'll need to try and keep them reasonably clean to stop dirt getting in between the leaves.

[Phil Waterman]

Hi Edwin

Well your question about hare ride, promoted me to get the shocks for my Pat 12 C60L off the shelf and actually install them on the truck, only been driving it without them for 10 years.

Yes shocks actually make a difference that in an unquantifiable way does improve the ride. Drove the truck just before and just after connecting the links on the front over the same stretch dirt road and without changing anything else the ride was improved, maybe I was only feeling each bump once instead of twice.

But how hard the tires are is the major part of ride. Some of the tires I've seen on MVs were so hard that with no air they still held their shape particularly the original runflat tires..

Will report back after I get the rears connected. Of course no good effort goes unpunished, in the process of installing the rear shocks, crimped a brake line so had to replace one side and will bleed the brakes in the morning.

Cheers Phil

[Edwin Wand]

We checked the items suggested in earlier emails. The tires are as they should be; new NDT 900x16 From Specialty Tires of America through Wallace Wade. We have used these elsewhere on Chev 15cwt's with no issues but apart from this Ford we have no other Ford experience.

We are going to rebuild the shocks and see where that takes us. They should move more freely than they are doing at present and rebuilding may solve the problem. In any case its an interesting investigation.

Regards Edwin