Technical Need advice on how to fix a bounce rear end

Gas v hyd shocks. I had a 59 Chevy PU I put the recommended Gas Monroe’s on the front. Great ride on level-ish surfaces, bouncy on up and down. Now, could have been as @Mimilan said and I had the wrong ones recommended to me, but I sent them back and had them change for hydraulic shocks and was happy.
This was maybe 10-12 years ago, so I don’t want to mis name the place I got them from, but both sets were Gabriels

 

That is the area I asked for more pics of in post #50. Looked wrong to me.

 

Yep-- I think I questioned that early on

 

They have been removed now

 

Back that lower shock nut out a bit as the bushing is crying for help....

 

Yep, those silver clamps on the front half of the springs are effectively making that half a solid bar. They are NOT needed. Also as mentioned, the shock nuts look way too tight, isn’t there a metal sleeve in the rubber bushing? If not, tighten the nut just enough that the shock can’t rattle around on the stud then a half turn more. That should free up the suspension. I would cut the bump stops to half of their current height. And you need to take careful measurements to be sure the shocks aren’t bottoming out.
My experience with gas shocks is that they do “feel” like they slightly increase the spring rate. The effect is more pronounced on light weight cars (like my roadster) or the rear of pickup trucks. I have gas shocks on my Corvair and my ‘56 Chevy for a firmer ride and handling and non-gas shocks on my roadster and woody for a more supple ride. Just my experience.


Sent from my iPad using The H.A.M.B. mobile app

 

I would love to take credit for that..........But I've only been a member here for 16 months

Gas shocks have an almost a non-existent spring rate.
All telescopic shocks need a "Gas" or "Air" cavity or the shock will burst when the shaft is compressed into the body.

The standard run of the mill twin tube shocks have a one-way valve on the piston/shaft and a one-way foot valve.
So up down movements continuously circulated the oil in one direction.
This causes aeration of the oil and it loses damping effects.[fade]

A cheap manufacturers fix, is to pressurized it with nitrogen gas ,as nitrogen is less prone to aerating with the oil. A gas shock and a standard hydraulic shock is almost identical [except the seal around the shaft]

When you compress a gas shock, the displacement of the shaft going into the body compresses the nitrogen. when you release the shock the gas expands back to normal pushing the shaft back out.

100 psi of nitrogen inside the shock only exerts 11 lbs force on a 3/8" shaft

Mono-tube shocks have a pressurized floating piston inside.

A steering damper, is just a twin-tube shock but the gas/air cavity is inside a balloon so the shock can lay sideways .[it cannot burst as it is surrounded by oil]

 

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I used CE springs in my 39 and found they flattened out. Stiff ride. I had them re arced .They sit with an arc now but still stiff . I am going to remove the bottom leaf and see if the ride improves.

 

Points if information:
The CE kit uses dodge pickup (64 - 69 ish) FRONT leaf springs and C2 Corvette (63-79) rear shocks.

The shock should not be at 30 degrees. The installation instructions gave a specific measurement from the frame rail to the mount center

See my build thread for a rear spring mount that lowers the axle 1 inch.

 

I think the aftermarket spring/kit suppliers walk a narrow line with their spring choices. They provide a "best guess" as far as spring rates are concerned. Some customers want very low at all cost, some want reasonably low but with a soft ride, still others are going to use their truck as a truck and need load carrying capability. I'm sure they try to find an off-the-shelf spring that is physically adaptable to the application including a spring rate that is workable for the average installation. Ideally, they also chose springs with several leaves so as to provide some tunability. No one spring can provide the optimum answer to all those requirements. Unfortunately it is up to the customer or his mechanic to install the springs correctly and add or subtract leaves as required to get the desired height and ride quality. The installation on the OP's truck is incorrect for what he is seeking, the flat springs and tall lowering blocks are evidence of that. The best he can hope for is "acceptable" ride with everything freed up so the suspension can move and not bottom out.
As to the gas shock discussion, I just took a brand new standard street rod shock, extended it and placed the bottom on my chassis scale. I slowly compressed the shock fully seeing a reading of 15 lbs during compression. I then took a used gas shock (already extended) and compressed it slowly on the same place on the same scale. It took 50 lbs to fully compress it. (discounting a small spike at first motion due to some stick-tion) That's 35 lbs per corner of resistance to motion which translates to a slightly different "feel" in the seat of the pants between the two types. It may be higher in a new shock. Call it what you will, it's there, it adds to the support of the vehicle and it's measurable.

 

So I got everything back together on the old Ford, I put the lower leaf spring back in the spring pack that really helped bring back the arch in the pack, took out the 3 inch lowering block and replaced them with 2 in lowering blocks, cut my Ubolts so they are at the scrub line now. Shocks are now at the correct height. I have to press in new bottom shock bushings in tomorrow and find or make new metal sleeves for the bushings. Hopefully by tomorrow sometime I can take it for a test ride and see how it rides. I have 5.5 inches of travel now from the frame to the top of the axle. I did cut the bump stops down a bit more to.

 

We want pics when you file your report please.

 

Hi all, a couple of people have mentioned that the CE kit uses Corvette rear shocks. That may be what their website or paperwork states but if the OP has Monroe # 33033 shocks they are in fact front shocks for 1973-86 Chev/GMC C Series truck. Hence they are designed to work with the weight of a 350 or 454 engine sitting above them. Although they may have similar end fittings and compressed/extended lengths as the Corvette rears (Monroe # 33121) I would suggest that they are too stiff for the rear of a pickup with an empty bed. Perhaps this is why it rides nicer with the shocks disconnected. Don't mean to be a smart arse but I've been selling Monroe shocks for 30+ years and as soon as I saw the part number quoted I thought they aint gonna work.
Hope you get it sorted. Cheers, Arnold,

 

Someone mentioned they use front springs too for a pickup. Tried that, too rough a ride

 

So I finally got everything back together and took it for a hour drive to see if everything I did and was mentioned helped. I have to say it 75% better. I do think I will have to get different rear shocks, they do seem alittle stiff and need to look for Ones that are softer and the right size. When I put the Monroe shocks I have back on That have, I had to compress it an inch to get the bolts in. Any suggestions on what shocks to get? Also here are some pics of what my suspension looks like now

 

Still seem to be there in latest pics ??????

 

All the leaf spring clamps are off now and the clamps that where on the front part of the pack are off now to

 

Little better angle

 

So I was suggested to go with Monroe 33121 shocks vs the Monroe 33033 shocks that I have now. Seems like I can get them at Pep boys for $17 ea

 

The suspension problem is probably a symptom of multiple causes. Most of the things pointed out in this thread could be contributing factors. A good approach in circumstances like this is to try one thing at a time so as to isolate the problem. I hope you get it sorted. Not nice when your pride and joy is a bitch to drive.

Oh, just saw the new pic in post #109 above. This was put up while I was typing. Can still see the clamp assembly at the front of the spring pack ???

 

It looks like he's left the bottom part of the clamps riveted to the leaf but removed the bolts so I don't think it will effect the spring pack.

Phil

 

Clamp assemblies are still there, they are rivet to the leaf, I didn’t want to remove those so the leaf springs don’t move around side to side, but nothing is in the way for the leafs to move up and down in the spring motion for it to bind

 

Good call Phil.
My apologies to @Lowbow38 .

 

It’s all good @grumpy65 , seems like pep boys is out of stock on those shocks. Might have to give Napa a call Monday. Looks like the shocks are for a 1963 Corvette rear shock

 

On the Corvette rear shock get the most standard, non performance version. They will be softest.

 

Looks like Napa has their own brand of shocks that I will try.

 

Hey Lowbow38, how did the new shocks work out ?

 

So I finally got the shocks from Napa. The rear shocks are made for a 1963 Corvette. Perfect length and the ride now is amazing. I got the Napa brand and had to change out all the eye bushing and put new ones in and new sleeves I made. 100% improvement to what it was. I want to thank everyone for all the help.

 

Glad we could help "save your butt".