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Overload Assist for Rear Pickup

Posted by AndyF (My Page) on
Sun, Jun 5, 05 at 9:23

I haul firewood this time of year in my 86 Comanche. But the springs are tired and after my first load I had a leaf break. I welded this OK, and now I'm back in action. Problem is I'm afraid it will break again on my next load.

My options are shock spring over kits they sold 30 years ago for 10$ that I can't find, and gave you an additional 700 lbs capacity. Air-assist shocks I know nothing about, but however they work, they need to hold the load up, not just give me a stiffer absorption. If anyone can tell me how they work, I'd appreciate it. I can also remove the rubber bumpers and make my own that are larger. This will give me a stiff ride and be harder on the bearings for lack of suspension but at least it will save the springs, besides, it's all highway driving at 40 mph. I was also thinking of using the coil for a strut off a small car that has the same ID has my existing shock. Then I'd cut them to length then use muffler clamps to hold them mid way on the shock. They would be great has the coil is about 1/2in thick. I can install an additional leaf, but it'd be a hassle handling rusted hanger bolts which have to be made, and I need a quick fix and a good shop.

The truck can take the weight (2 cords) and has done for the past 6 years, but because of it's age I can't install a 300$ kit, looking for something cheap, and I can't find any kits on vehicles at the scrap yards, except one pickup which had the air shocks.

Will air charged shocks hold the weight up? How much aditional weight can I add using these?



Follow-Up Postings:

RE: Overload Assist for Rear Pickup

I used to cut and haul lots of wood with a Datsoon P/U. Made a set of bunks and hauled 6 foot logs. Well I made 2 sets of leaf springs. One had 3 leaves for easy riding most the year; tuther had 8-10 leaves for hauling logs. Took 45 minutes to switch spring sets. Hauled 1 ton loads w/o sagging.

I got a couple or 3 extra spring sets from a wrecking yard and fit all the various leaves together plus extra hangers and such. If you do this be sure to squeeze the spring together with a vice or similar device B4 tightening the spring center bolt. Don't pull it together with the bolt alone as it could bust; kill ya. Put grease between the leaves.

I tried coil spring add-ons, more grief than changing leaf springs. Have to get the angle just right etc.

RE: Overload Assist for Rear Pickup

2 Cords??? I'd like to be PC in the way I approach this, but the heck with that. ARE YOU NUTS??? VBG..

2 cord of wood would be an overload in a one ton dump truck. In fact it's almost twice the rated payload of a one ton truck. An '86 Commanche is not designed to carry that kind of weight, in fact it's probably right at the vehicles towing limit, if you didn't include how heavy the trailer would have to be! Maximum load in your truck should be about 1/2 a cord, thats 2ft, by 4ft, by 8ft. of stacked wood. (1 cord is 4x4x8)

You cannot weld spring steel without seriously altering it's performance. You cannot beef up your truck by changing/adding springs to carry the kind of weight you are attempting. Your truck dosen't have the axle capacity, brake capacity, nor cooling system capacity to operate correctly. Frankly, I think one of these days you will have one of your rear axles snap off just outside of the wheel bearing, and you'll be going for the last ride of your life. I just hope you either stop doing this and don't have that happen, or at the least you dont take someone else with you!

RE: Overload Assist for Rear Pickup

My cousin tried to do something like this to "Beef" up a truck. Now it's been about 30 years he's ridning a wheel chair and his friend died in the wreck that happened from the "mods". Don't do this! Put the truck back to factory spec's and use it within it's design limits.

RE: Overload Assist for Rear Pickup

Hmmm! You guys have some good points. I never thunk about that 2 cord weight. But then I don't know a Commanche P/U from an anchor chain.

I found the following in Mark's Mechanical Engineers Handbook, 1952, (1 $/pound new).

A cord =(128 ft cut & stacked) = 90ft solid wood.

White Pine, Green, 3240lbs, 12% moisture, 2250 lbs
Red Oak, Green, 5760lbs, 12% moisture, 3960 lbs

so 2 cords could weigh up to 11,520 lbs. Wow!

Assuming a P/U bed 6' X 8' the load would be 5.3 ft high loaded even along its length which would make it too heavy on the drivers so you'd have to pile it higher toward the front..... Wow Again!
====================================================================== =====

I hauled dry cedar logs never over a ton net which gave me a GVW of about 4500 lbs. Legal! I checked weighed it once to calibrate my eyeballs for loading in the woods. I also divided the gross weight by 4 (=1125 lbs) and my tires were rated for 1500 lbs so the cops wouldn't gitme for an overload. The beefed up springs proved to be extremely stable. The logs were tied down 2 places with truckers rope and since I are a trucker I know how to do a secure tie down. The brakes were more than adequate for this GVW because I tested em out with a simulated panic stop to make sure. At the time I was given to understand that the Datsoon rear axle bearings were sized for way more than the load I put on em. Don't remember anymore how that was determined but it was considered.

I did this in the California mountains with no trouble aytall. I geared down going downhill thereby keeping my brakes cool. etc etc. Did I do it right?

Altho many big trucks use airbag suspensions I don't believe air shocks would be reliable for this application unless they were mounted directly between the axle and the frame. Most are mounted to welded-on struts which can bust off. They can leak or spring a leak. They have no lateral stability. Coil springs have no lateral stability. Leaf springs are better. Thick stiff ones are best.

RE: Overload Assist for Rear Pickup

And I was going to say a cord of wood is 2 x 4 x 8, one ton; but I was smart enough to look it up and read this forum.

Twenty to thirty years ago, many sold wood by a PU truck load and claimed it was one cord..
The reason for regulations...

One should be able to find and install "overload" leaf springs for a Jeep, I had these on my old VW Diesel 1/4 ton truck...

RE: Overload Assist for Rear Pickup

John G says it best. To answer your question about air shocks they provide no movement. Any frame shop will tell you. DON'T. They could snap your frame supports at the shock mounts. Actually they do. Green poplar is about 2300
lbs a cord. If you think your truck can take 2 cords of wood weight, your dreaming. a cord is 4x4x8 ft. and there
can be no place you can put 3 fingers between the wood.
Yes i live in the bush and i know how they do the " cord "
thing and how it is messured. If you can put 2 cords of
wood on your truck the wood will be piled 8x8x8 or 4x4x16 ft high. It ain't going to happen. A " face cord " yes.

cord wood size. miscalculation

Made a type-o on the size for a half ton. the wood would have to be 4 feet wide, 8 feet long, and 16 feet high for 2

RE: Overload Assist for Rear Pickup


1 cord of wood is, 4x4x8.
2 cord of wood would be, 4x8x8.

4x8x16 would be 4 cord and would heat my house for about 1.5yrs...

RE: Overload Assist for Rear Pickup

Sorry about the major type-o. Most trucks have a 6 foot box now and the wood is cut 4 feet long so it dosen't stick
out the end. That is why it will be 16 feet high. I wish i
could heat my house for a year and a half with 4 cords. I Had 7 cords last year and ran out in april. Most of us use
a satellite boiler and on a 24/7 burn. That will take about 10 cords for one winter. That wood is tamarac. You
don't burn that in your house wood stove unless you know
what your doing. That could be your last burn. I use a
house wood stove and still used 8 cords. Our winters are long and a little on the cool side. As a matter of fact i
have the wood stove on now. No, i'm not kidding. It hasn't
stopped raining since last thursday. It is 5 C. here. Hope
your weather is better than ours.

RE: Overload Assist for Rear Pickup

try a company called timbren , timbren overload springs google it they are very easy to install and work great

RE: Overload Assist for Rear Pickup

Thanks much for all the advice. I discovered a problem after posting that's my fault. A cord is just as you say 4 X 4 X 8 ft. Around here everyone here buys a cord as 16inches X 4ft X 8 ft.

Now I realize this is really a face cord and it didn't hit home until I got the surprises expressed by you folks, then too late to stop it, so I extend my apology.

The truck handles the load quite well and the V6 hardly seems to notice the weight. The AX5 Japanese tranny is noisy but that's because on my last rebuild they put in Chinese main bearings instead of American brands. (Weak tranny in a Jeep, almost a sacriledge isn't it. AM should have been shot.). The load bottoms out so I was looking for a leveler (the bumper stop for that broken spring side turns out is missing, so that explains that).

The load I figure is pretty close to 1100 lbs, and it seems the truck can just about handle it. It couldn't for green timber as it would be too heavy. The rated Gross load weight is 2000 lbs for this truck, but I assume that means for towing.

The spring was welded with 200,000 tensile rod (forget the brand), and thats about 50000 over the spring tensile. The weld hasn't broken so far and I never had any problems with my welding jobs.

I bought Monroe airs yesterday and installed them. I'm really happy with them and it seems they do the job. I hauled 6 cords(face) with them with an initial charge of 40lbs. But now I'm at 60lbs, and that seems to give a better ride. It does bottom out slightly, but I won't strain fastenings any more than that. Max pressure for these shocks is 150.

Sorry for the mix up and thanks for the advice.


RE: Overload Assist for Rear Pickup

The main problem with air assisted shocks is with the shock brackets. These were not designed for the additional load and can break, especially after seeing years of salt spray and corrosion.

In regard to assembling a set of leaf springs, don't forget the anti-corrosion feature. Leaf springs for vehicle suspensions should have lead-loaded pads between the leaves. These pads are usually found near the tips of the leaves. The lead provides sacrifical anodic protection to the leaves and helps to stave off fatigue cracking of the spring.

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