VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans shocks

I have never seen a torque figure-doubt is there ever was one.When you pull the lever down the tension of the shock spring,which causes it to go up, should not be confused with the resistance of the fluid and piston.In other words it should not be able to be pulled down rapidly as the fluid must pass thru the valve.When testing the shock must be in the up-right operating position.

Chevnuts right about no definate torque figure because each shock is "rated" or set-up for the load of the specific car and comes as a matched set of Shock+Springs. This "rating" was able to be changed to make a cars' ride qualities softer or stiffer, by taking it to a Dealer and changing the shock relief valves or springs{larger valve orifice = softer ride}.

A single action shock only has a "resistance" in one direction; that is after the leaf spring allows the car to "bounce" the leaf spring returns too far, too fast.... they oscillate... the single action shock dampens this effect in only one direction and that's when the leaf spring extends (the rebound). Thus the shock arm moves downward and pushes its cam ... then its piston... then hydraulic resistance is in effect.

SO a quick test is to clean shock off, fill with oil, let oil soak into packing real well, disconnect shock link from axel and pull arm DOWN, you should "feel" steady resistance (no jerking, and no leaking)....and if you have 8 shocks then the best one should be used to get a 'feel'for how good the other 7 are by comparison.
As Chevnut says, its not an initial "spring feel" but the feel like when you let a hydraulic jack down....that smooth "squirty" fluid feel going thru the castings...maybe like a screen door damper going closed....

Today I tested 3 of my shocks, two of the rear one's seem OK... without oil (power steering fluid) they are very smooth and easy to move. With fluid, the rear's have a LOT of resistance going down: I step on the long lever with one foot (I weigh 220 lbs, so I'm putting a lot of force on them), and they both take several seconds to bottom out. I didn't time them, but it's certainly more resistance than a screen door damper! The rear valves are "C 3 G", and the front are "C 4 G". I haven't tried a front yet, so I don't know if it will offer more or less resistance.

I'd like to know how to get the arms off... from looking at them, I think the arm and shaft should come out as a unit, leaving the cam inside. Otherwise, you could never get the cam out because the shaft would be stuck to it, and there's no way to drive the shaft out from the back. Does anyone know how to get them off? It almost looks like you need a special tool to wedge between the arm and the housing. I'd like to put new seals on the shafts.

Also, are the shocks supposed to be painted, and if so is it the same gloss (debatable) black that everything else get's on the chassis?

Steve, from looking at the picture of the '30 - '32 shock kit, I think the parts will work on the shocks on my '37. Maybe this means I have old shocks on my truck (both of my '37's have the same shocks though). I'll post some pictures tomorrow, and maybe just go ahead and order a kit and check it out rather than sending you parts.

Grumpy,
I didn't mean to confuse ya with my comparison to a screen door damper. I just ment that the "smoothness" was like that s/door damper, not the total resistance.

Do you have a Chevy Shop Manual for those shocks? The 1940's Manuals also show what can, and can not, be removed for repair. They show the specific tools and pics of How-To. {I can't seem to locate a pic of "DELCO Hold Down Tool #515", the tool is used to hold the shock guts in position for arbor pressing....maybe Chevnuts got a replacement suggestion}.

Anyway Service Manuals say "the body arm, packing glands, camshaft and cam are NOT serviceable". So maybe its a good idea to do the "serviceable" stuff first and keep an eye on the aformentioned hard-to-work-on parts and hope they are not worn too much? A least you have other shocks to "cannibalize" if-needed!
(side note; One book I have says that Chevy had an oversize piston to use in place of a worn bore. So maybe you wont have a problem trying to "sleeve" any bores?)

Ps... try soaking those packing gland seals with P/steering fluid for a few days, maybe they will swell and you'll get lucky.

Hello lil' johnny.

I have a shop manual for '37 cars and trucks ("Chevrolet's 19 37 Shop Manual For All Passenger Cars and Trucks")... but it spends a lot of time describing how the stupid things work, and not much on how to service them. It mearly states "DO NOT attempt to remove the absorber arm, shaft or cam, as these parts are assembled under 20,000 lbs pressure and are NOT to be removed." I guess this didn't seem very helpful because I thought the seals should be servicible... wouldn't be the first time I disagreed with GM's engineering decisions . Now if I were a businessman, I'd have realized that it's far better to have my customer's buy NEW shocks rather than let them service their old one's!

Separate subject, but: what are the names of the other books I should have, and where can I find them?

One reason I wanted to remove the arms is that the rubber bushings were worn so badly on the front shocks that the eyelet they fit in (at the end of arm) is worn from the pin bearing against it. I'd rather not have to find a way to repair the eyelets (weld and machine?) so I'm hoping my other front shocks are servicable. I need to remove them from my other frame and check them out. If I can replace the arm, I could use one of the rear shocks and change the valve.

Grumpy, If you stand on the shock lever and it takes that much force to get it to move down there is something wrong (with the shock).It should be easy to pull down by hand but will move slowly -like extending a modern tube shock by hand.If your not intrested in being original but want to improve the ride fabricate some mounting brackets and install tube shocks as Chevrolet used on 1950 and later trucks.

Grumpy,
The 1930's were not a time of 'planned obsolesence'and usually IF a part could be easily be rebuilt, then Chevy offered a way. I'm thinkin' that arm is sealed so tight cause thats the only way Chevy could find to keep it 'economically' together without falling apart in rough service. (I SUSPECT that 20K psi is likely the force applied by the factory machine to press it on in assembly and not any spring loading? Most small shops didn't have a jig & arbor press fancy enough to re-assemble the riveting without mashing it crudely).
My Chevy Shop Manual l942-43 Car & 42-46 Truck seems to tell how to rebuild parts of those single actions. The better description is in 1948-51 Chevy Truck Manuals. (Filling Station may have this?)
{If you have a higher speed internet connection I can scan and email ya pages from Manuals.Larger 100k+ file size attachments for easy reading.}
One of the BEST overall manuals for 1930s-40s-early 50's Chevy mechanics is the various WW-2 Military manuals for car and truck mechanics. They are more general for all cars/trucks BUT are filled with great explainations and really give ya 'training' on how-to-repair/rebuild as a mechanic. Manuals written by William H. Crouse are classics! (ebay has them as do swap meets).

Chevnuts right bout that downward pressure, try to remove the valve and spray/soak it clean with alcohol, re-assemble and maybe try a lighter (thinner) shock oil. I think that Chevy wanted a certain thickness of oil cause of the way its viscosity would give a 'metered flow" thru the valve; petroleum oil in the shock may swell the piston like it would in a brake wheel cylinder So maybe thats why the shock-oil was used? (Todays silicon compressor oils may be OK?) The "seals" are really packing glands and soaking them swells them so they may function. Another "trick" to get a "packing" to seal is to wrap a nylon string around the shaft between the packing and the boss. Its not permanent but it may stop a leak a long time.
Weld-and-drill-out the wallowed eyelet is simple cause the new rubber bushing isn't a critical fit. I've had to do it on newer (1989) power steering but watch weld-overheating that arm...make it fast and cool. Maybe a press-fit bushing would do?
Maybe, just maybe, a modern FAST and thus COOLER mig "weld" can be used to re-assemble those arms in lew of that old "riveting", JUST Guessing?
Chevnut hit the 'preservation' factor on the head, if you find you can't get them old singles to work then set up 1950's tube shock mounts....hey at least ya tried....
You are really doing a good "experiment" on those rebuilds ...keep us posted.

grumpy,

the boys & I spent the whole afternoon down under chipping and scraping pounds of grease & oil just to see if we HAD shocks...maybe they were just more gobs of gunk like all the others hanging around!..

we're going to get them clean enough to check the oil level...maybe next weekend...

the more I look at it though, I'm convinced those high pressure ratings and warnings pertain only to the riveting of the lever arm, shaft, & cam, as these would be under lots of load & movement over the life of the shocks...I just can't see any hazard in disassembling the shock to clean, repair, & refill it...

we'll let you know our progress...

epi

Chevrolet-that is correct, the high pressure is what was needed to press on or remove the arm from the shaft.

chevgene,

thanks for the confirmation...

epi

lil johnny and ChevGene: Thanks for the thoughts and ideas. I'll look for the manuals you mentioned, sounds like good reading at any rate!

Chevrolet:

I'm still scraping Idaho clay and grease/oil/tar from my truck, probably will be for several months. I don't know how long it's been there, but it is REALLY stuck... I've been using diesel fuel, rubber gloves, wire brushes and anything I can find to scrape with. It has taken hours to clean only a few parts.

If you do find your shocks, if they match mine you'll be able to disassemble them (somewhat). My shocks say "Delco-Lovejoy, Made in Dayton, USA"; one of the front's say's "R-1S 1053005" on the frame side, the other say's "1053004 R-35".

I took three of them apart yesterday... I bolted one back on the frame, removed the three screws, then began to pry the cover off with an old screw driver. Before I could get the blade in far enough to it to gently pry the cover loose, the blasted thing spit out the piston, spring, intake valve and the power steering fluid I had carefully poured in 10 minutes eariler. No damage or danger, just a surprise.

When the arm is not mounted in the shock link and attached to the axle, the the back of the cam rides against the cover, waiting for someone to remove the screws. The return spring has a fairly low rate (I guess something like 15 pounds per inch), so you'd have to do something even dumber than I did to get hurt. Anyway, the next one I disassembled I held the arm down by resting it against a pair of vise grips like:



There is no packing around the piston, the piston just slides inside of the cast iron bore in the body. There is little wear on two of my shocks, the other one has the piston rusted in and I haven't gotten it out yet. (This might be the one that get's disected further)

On two of the three I've taken apart, only the gasket and oil HAVE to be replaced. I tore up the screws getting them out though, and the rebuild kits contain replacement screws, gaskets, bushings and pins, so I'll have to get rebuild kits.



If my other set of front arms are worn, I'm thinking of just using JB Weld or some other epoxy to fill up the radial gap so the new bushings have a solid seat to bear up against. Epoxy has a pretty high bearing strength, and is often used as a "liquid shim", so I think this should be OK, but hopefully I won't have to find out.



Here's a look at the valve markings. I think the G 4 C one (front shock) is stiffer, but I'll find out another day.



I'm convinced that the resistance I noticed yesterday is because the power steering fluid is too thick. It has a viscosity between 20 and 25 weight oil. I bought some hydraulic jack oil, and some 5 weight motorcycle fork oil to try. I'll let you know how it goes.

Lenn.

grumpy,

wow...great job sharing your findings...

by the time we chisel all the gunk off (and we ARE using hammers & chisels), we'll have a lot more confidence & knowledge to proceed...

thanks, lenn...

epi

The only seals used are where the arm shaft goes thru the housing.The springs return the pistons only . This causes the arm raise to the top.Mount the shock in a vise with the "uncovered" end up.Fill with kerosene or mineral sprits and if the seal is bad the thin liquid will leak around the shaft.

Thanks ChevNut, that's the tip I was looking for! Any thoughts on repair of the worn bushing hole on the front shock arms?

lenn,

if the arms are steel, I'd weld & regrind to the original shape...

epi

Today I tried Chev Nuts leak check suggestion. I used mineral spirits, and found no leaks on my test shock! Then I tried the Hydraulic Jack oil I bought, and found that the resistance offered by the shock arm seems about the same as it did for the power steering fluid (maybe a LITTLE easier, maybe not).

I was about to try the motorcycle fork oil when I decided to just put diesel fuel in it and try that... this offered roughly the same resistance!

Since I can't believe that viscosity makes no difference, I guess I'll have to wait until the truck is on the road to figure out what to use. I'm betting that my test method isn't sensitive enough to pick up the differences.

As bad as the suspension is beat up on this truck, (mainly the shock absorber links and bushings) I'm concerned about having too much damping from these things.

lenn,

yesterday, we finally got down to the single-action shock...after removing ten pounds of clay, grease, & jimmy hoffa...

after removing the fill plug, we filled it with tranny fluid (dexron II, of course... )...

it must have been bone dry, because, each time we worked it, it would suck more into the chamber and empty the reservoir...

once it wouldn't accept any more, we replaced the fill plug and worked it hard...it offered good (like a comfy, semi-worn, impala-like tube shock) resistance, but only every third stroke or so, so the check valve must be sticky...

we've decided to do them all like this, then re-attach the linkages and just drive it to see it we can't get everything moving free again...

I'll keep you posted on our results...

epi

Kepi, make sure the check valve is installed with the numbers "down", and that the little plunger is able to move up and down through the little disk at the top. It's kind of like a little poppet valve, only the "valve stem" rides up and down inside the "retainer". One of mine was rusted and I had to cycle it outside of the shock to free it up.

Actually, I'm not sure you'd notice the difference if they were installed upside down. I've tried both and the shocks "felt" the same.

Did you notice what numbers were on your valves? My front's were G-4-C, and back's were G-3-C.

lenn,

whoa...you us too much credit...unlike you, we just want stuff to work right now...so we didn't disassemble anything, we just added oil to see if it'd work...

after a bit of driving down the bumpiest roads nearby, we'd say it's working...whether or not it's working all the time, we'll have to undo the linkage to tell you...

we'll let you know...

epi