The Stovebolt Site Forums The Shop Area Driveline how to take pressure off leaf springs

Hello. I’ve decided my next project will be to inspect (and replace where necessary) the bushings on my leaf springs, and replace the rubber parts, such as the grease-retaining washers (original ones are cork; new ones will be rubber). I’ve got the nut off the bolt on the fixed end of one of the rear springs. Now I need to take pressure off the spring and try to get the bolt out of the bushing, then press the bushing out of the spring eye. Here are instructions that one poster shared in 2013 of another poster's clever idea for a homemade tool for pressing a bushing into and out of a spring eye.

The shop manual says to use a chain hoist to take pressure off the spring, but I don’t have a chain hoist (I see they’re not very expensive).
Q1: If I did have a chain hoist, where would I raise the pickup from (where would I attach the chain)?

I do have a small floor jack, but it only has a lift of maybe 12”, and it takes about 8” to get up to the frame. I added some 2x4s last night for a test lift, but that’s inviting disaster. I think I'll build up a base of about three 2x10s to set my jack on.
Q2: Assuming I use a floor jack, where exactly should I jack and how high do I need to go? In my test lift I jacked on a frame side member, but I don’t know how high I need to go. Do you just jack it up until there's some play in the bolt?

Thanks for any tips.

jack the frame enough to take weight of truck but leave weight of axle and springs sitting on the ground, some trial and error, then spring pin/bolt will be approximately free.

It'd be wise to use jack stands under frame to support it while doing your work.

Thanks Grigg. I do have jack stands and will use them . If it were you, would you remove the spring assembly and inspect it, as long as the bolts / pins are out, or would you try to just replace the bushings and call it good? I know it depends on each truck's circumstances, but in my case, from a casual observation, I'm not aware of any signs that I need to do a full removal and inspection. Just wondered if it's perhaps a no-brainer that, yes, if one has gone this far, one should remove and inspect the springs.

Depending on what you have on hand to remove and replace spring bushings may be just easier with springs off the truck.
If you do remove the springs it’s wise to replace U-bolts with new ones, do not reuse.

For the most part if the springs look good, not worn and stepped where the leaves rub, not real rusty, and none broken, then not necessary to disassemble and mess with them unless you just want to.

If the spring leaaves are mildly grooved from heavy use, but spring pack is not flat or broken, I prefer to use them. Weaker springs make for a smoother ride. I just change out all of the pins and bushings.
If you are planning to haul a half a ton of stuff then you should get new springs.
Carl

When I changed the bushings on my one ton I jacked up the side I was working on until the tire was free, then set jack stands to hold it. Then removed the wheel and used my floor jack to raise and lower axle to take pressure off the bushings and pins. Mine were worn enough that there was a ridge in the pin that took careful adjusting to get free.

Good luck.

Tim

Clever approach, Bluesman. Thanks for all the info guys. I hadn't planned on replacing the pins, just the bushings, but it sounds like I should expect that my pins will need to be replaced.

Interestingly, my local Tulsa Auto Spring, which has been in business since 1924 and is very old-school and respected, only sells a shackle kit for the shackle end of the springs (they don't sell just the bushings or bushings and pins; you must buy the entire shackle assembly, $39 for each front, $55 for each rear). One can get just bushings and pins at the online places, so I'll probably go that route, because I don't think I need the entire assembly.

I'm betting if the bushings are so worn that you know it, then the pins will be worn also. I'd be prepared to replace both so the job goes smoother and faster.

If you reuse the old pin make sure you pump/clean all the old grease out before you reinstall it.

Mike B

Mike, I haven't noticed any symptoms. My reason for doing this bit of maintenance is that I can't pump any grease into the fittings. So I want to remove the pins and clean out the passages, at a minimum. I really don't know what to expect, but I was thinking that if I've got the pins out, I may as well replace the bushings. Maybe the only thing that will be necessary is cleaning and lubricating. This truck has been driven so little over the last 30-40 years, but for all I know these are the original bushings and they're 66 years old. I hope to make some progress next week, and I'm sure I'll be back with findings and maybe new questions. Thanks for the suggestions.

Follow-up here. As a reminder, I'm working on a 1951 3100.

I removed a bolt from the fixed end of my left rear leaf spring, cleaned it out reinstalled, and greased through the grease fitting. Not much of an accomplishment, I know, but it's new territory for me, and it's pretty fascinating. Next, I'll tackle the shackle! Then when I fully understand how this is all put together, I'll order some replacement parts.

New question: I see what I'll call a "secondary leaf spring" (Picture #1 below) that's not mentioned in the shop manual nor pictured in the factory assembly manual, at least not in section 4, Rear End Suspension. What is this called and why is it not mentioned in the literature?

My main reason for asking is this spring has an upward-facing bumper (Picture #2 below) that is worn down to the point that metal bumps metal when this spring bottoms out. I'd like to replace the bumper but I don't know what it's called or what the assembly is called (I'm not sure how it's secured in there; it's loose enough to wiggle but won't come out. There's a stud that comes in from the bottom, but it doesn't appear to be a bolt).

Thanks for any info.

DJ,

As you most likely know, there were no optional front springs on 3100 trucks, but there were optional heavy-duty rear springs. 8 leaves were standard and the option had 9 leaves. In both cases, the spring width was 1 3/4"

http://chevy.oldcarmanualproject.com/chevyresto/51128.htm

Someone added helper springs above the axle on your 3100 truck. Non-GM helper springs were readily available (J C Whitney was a well-known mail-order source).

What are the widths of your main (lower) springs, and what are the widths of the auxiliary (upper) springs?

Overload Springs. Quite common back then. Gives you a boost from1/2 ton to 3/4 ton in load capacity. If you don’t plan on hauling heavy loads, just take them off.🛠

No heavy loads for me. This was my Dad's pit truck in the super-modified jalopy circuit (Enid, Wakeeney, Hutchinson, Wichita, etc.), and at his Olds-Cadillac dealership. He probably needed overload springs; I don't.

Tim, both primary and overload springs are 1 3/4" (they're closer to 1 5/8", but I imagine they are nominally 1 3/4", as you say).

Thanks, guys.

Those springs would make for some excellent rear ballast for driving in snow and ice. If you don't carry a load, they will not change the ride one way or the other. You can get these trucks stuck on a flat road if it is slippery.