47-59 Lowered truck can't find new shocks

[TX3100Guy]

The truck that I recently acquired was a work in progress for the former (deceased) owner. He has done a magnificent job on getting the truck 80% done, but with it having sat for the past ten or more years untouched there are a few things that need attention before I can start it up and use it.

One of the items that I see has perished are the shocks, Mind you, the previous owner lowered the truck and its riding on a single leaf spring and as a result, the shocks while modified are not the stock length.

Here is a picture of the front shock and a close up of the part number but no manufacturer visible.





The shock is 13 1/8" long when compressed and shows these part nubmers C3054 0126 and at the bottom 739049.

Any assistance in locating replacements will be appreciated.

[dsraven]

most shock manufactures have a chart that has compressed and extended lengths, top fitting style and bottom fitting style. have you tried google, napa, others? if you find one manufacturer part number you can then try to cross reference that number to your preferred shock manufacturer.

[mr48chev]

That shows up as a carquest shock with a stud on both ends. I'm thinking that it is just a Gas replacement shock for a stock shock

Rock auto's listing for a Gabrial 81270 shows a collapsed length of 10.56 and and extended length of 17.67
https://www.rockauto.com/en/moreinfo...t=7556&jsn=865


Here is the Rock auto shock listings for the 53. Not one of them is very interesting for serious driving but with a part number to start with you can find a lot better shock with the same or more friendly extended and compressed measurements.
https://www.rockauto.com/en/catalog/...+absorber,7556

This PFD is well worth studying
https://gabriel.com/wp-content/uploa...DES_2022-1.pdf

This KYB may be too short total but compressed length is 8.74 and the stroke is 5.51 for an extended length of 14.25 https://www.autozone.com/suspension-...137/726885_0_0

The picking for a short shock with S1 stud ends on both ends are pretty slim though

https://www.kyb.com/resources/techni...on/dimensions/

[TX3100Guy]

Originally Posted by mr48chev

That shows up as a carquest shock with a stud on both ends. I'm thinking that it is just a Gas replacement shock for a stock shock

Rock auto's listing for a Gabrial 81270 shows a collapsed length of 10.56 and and extended length of 17.67
https://www.rockauto.com/en/moreinfo...t=7556&jsn=865


Here is the Rock auto shock listings for the 53. Not one of them is very interesting for serious driving but with a part number to start with you can find a lot better shock with the same or more friendly extended and compressed measurements.
https://www.rockauto.com/en/catalog/...+absorber,7556

This PFD is well worth studying
https://gabriel.com/wp-content/uploa...DES_2022-1.pdf

This KYB may be too short total but compressed length is 8.74 and the stroke is 5.51 for an extended length of 14.25 https://www.autozone.com/suspension-...137/726885_0_0

The picking for a short shock with S1 stud ends on both ends are pretty slim though

https://www.kyb.com/resources/techni...on/dimensions/

Thank you for the great input. But here is a better question. Today I put the truck up on a four post lift and removed all four shocks. The truck has been previously modified and lowered, as I mentioned in my original post.

I decided to measure (roughly) the space between the front and rear mounts for shock "at rest" with all four wheels on the lift deck and not suspended or compressed. The front is approximately 12 inches, while the rear is 22.

Yet the shocks that I've removed from the truck measure as follow:

Front - compressed 8 1/4" - extended 13"
Rear - compressed 12 1/2" - extended 21 1/2"

When I measure, I am not measuring the mounting stud or eyelet, just the shock tube from its top to its bottom, so there is an inch or more of additional shock stud or eyelet to add to the shock total length

Should a truck resting at 12 and 22 inches (front and rear) have shocks installed that are nearly at full extension?

[_Ogre]

it doesn't matter what the length of your current shocks are, as they may or may not be right. you'll need to do a little math to figure out what the "on the bump stops" length is. fully compressed as in when you go over that whoopteedo in the road. then download a chart or catalog to find the correct shock length and ends. i used monroe catalog.

58truk is on stock modified springs in back, flipped axle, stock mounts top and bottom. i used a little math to get the on the bump stops length and then found the longest shock extended length. i'd still hit the bump stops hard every now and then, so i used the shock number to convert to air shocks. the air shocks have been great for ten years.

i believe my shocks are good for the extended length. i'd rather have the shock not be long enough extended, than to bottom out with full dynamic weight of the truck. that's when things break

[dsraven]

you need to have a mount to mount dimension at full compressed and at full extended length, then look for shocks at least that short compressed and that long extended. personally I would go a longer for the extended length and a little shorter for the compressed length and that way it wount be the shocks stopping the suspension, it will be the suspension snubbers. for a full length suspension dimension for a leaf spring, like if your truck got airbourne, you could use a limiting strap so the strap stops the full length travel of the suspension rather than the shock. check some 4x4 sites for the idea and possibly supply.

[TX3100Guy]

Thanks for everyones input, here are my final measurements of the truck:

Front static = 12 1/2 inches, compressed = 11 inches, extended = 13 1/2 inches

Rear static = 21 1/2 inches, compressed = 17 inches, extended = 23 inches

I used the measuring method used in this Summit Racing video

Here are what I think are going to be my choices:

Front = Gabriel 81270 (10.5" compressed, 17.7" extended)
Rear = Gabriel 49237 (air shock) (14.4" compressed, 24.1" extended)

In keeping with the advice above, both shocks will compress smaller than the bump stops will allow and extended slightly longer than the suspension allows.

Any comments, suggestions, criticisms, observations about these choice will be appreciated before I hit the Purchase Now button.

[JDarby]

I guess my question to you is:

What ride height do you want the truck to ride at?

Until you take it our for a spin you are only guessing I would think?

If you only have a single leaf on all four corners I would think it is gonna be bottoming out pretty easily?

I drove my 55 1st series with it's stock suspension for 3 years and I can tell you I didn't like it! That straight front axel sucks!!!

Just my .02

[TX3100Guy]

On second thought I'm looking at a set of Monroe MaxAir shocks for both front and rear. Both sets have a smaller compressed length and a taller extended length than the truck without shocks.

[dsraven]

shocks are, in general, made to control spring oscillations. they and their mounts on the vehicle are not made to take the weight of the truck. if you need to control the bottoming out situation that is a spring issue, not a shock issue.

[dsraven]

is your truck riding on a single leaf front and rear? got some pics? there are some overload style leafs that don't interfere with the normal ride of the truck until the suspension gets down far enough to contact the overloads. they only work on something that has an arch to the springs though. otherwise they are being used all the time. if your truck has a single leaf and it is already flat then this is probably not gonna work, maybe a new spring or a fiberglass mono spring from something else, like an astro van maybe.or maybe a coilover hung on mounts made for a coilover style set up, then the leafs are just there to locate the axle mostly
here is a link to what I am talking about. I'm just showing the pics, not promoting the idea they are showing with the additional appliance mounted to the spring. the overload is a flat leaf at the bottom of the stack that has more resistance than the rest of the pack, it is usually quite a bit thcker. it only really works when the pack is compressed enough for the rest of the leaves to flatten out and contact the overload leaf.

https://www.torklift.com/blog/entry/...our-suspension

[mr48chev]

Originally Posted by TX3100Guy

On second thought I'm looking at a set of Monroe MaxAir shocks for both front and rear. Both sets have a smaller compressed length and a taller extended length than the truck without shocks.

I don't suggest air shocks for the front at all. The only real reason to use them on the front is if the truck is so low that you need to lift it up a bit to clear driveway entrances and such. It beats asking your wife to get out of the truck so you can get over the hump going out of the parking lot. Then you would have to have an on board air compressor.

Rear air shocks are used to level the ride height back to static height when you put a load on the rig. Cadillacs had rear air shocks with a control valve that did that for years with a compressor under the hood.

[TX3100Guy]

Originally Posted by dsraven

is your truck riding on a single leaf front and rear? got some pics? there are some overload style leafs that don't interfere with the normal ride of the truck until the suspension gets down far enough to contact the overloads. they only work on something that has an arch to the springs though. otherwise they are being used all the time. if your truck has a single leaf and it is already flat then this is probably not gonna work, maybe a new spring or a fiberglass mono spring from something else, like an astro van maybe.or maybe a coilover hung on mounts made for a coilover style set up, then the leafs are just there to locate the axle mostly
here is a link to what I am talking about. I'm just showing the pics, not promoting the idea they are showing with the additional appliance mounted to the spring. the overload is a flat leaf at the bottom of the stack that has more resistance than the rest of the pack, it is usually quite a bit thcker. it only really works when the pack is compressed enough for the rest of the leaves to flatten out and contact the overload leaf.

https://www.torklift.com/blog/entry/...our-suspension

Here are pictures of my front and rear spring setup. Mind you, I didn't set this up, the deceased prior owner did and I haven't been able to start it and take it for a drive yet to know how it handles.

[mr48chev]

I don't think the rear is going to be an issue unless you don't have all the weight of the truck sitting on the tires. Front has maybe a little more clearance than my worn out springs have on my 48. With good shocks it won't be bad on smoother roads but may bottom out on potholes or some rough spots.

Outside of really rough spots I don't think you will have an issue, The single leaves do ride a bit different than multi leaf springs but that is a getting used to it thing.

They they stuck that square piece of what looks like 3/8 plate or flat bar between the spring and the axle may make things a bit kattywampus unless you have a matching plate on the other side, That isn't good engineering at all as it raises that side that amount if you don't have a spacer on the other side. If the truck looks like it is sitting a bit high on the left front and low on the right rear that is your answer.

[TX3100Guy]

Originally Posted by mr48chev

They they stuck that square piece of what looks like 3/8 plate or flat bar between the spring and the axle may make things a bit kattywampus unless you have a matching plate on the other side, That isn't good engineering at all as it raises that side that amount if you don't have a spacer on the other side. If the truck looks like it is sitting a bit high on the left front and low on the right rear that is your answer.

Fortunately that piece of flat bar that you see is the mounting bracket on both sides for a front sway bar. It appears to affect each side of the truck equally.

Thanks.