The Stovebolt Site Forums The Shop Area Driveline 3600 Springs, liners, front overload spring and rear leveling block

Continuing the work that started with new kingpins, bushings and rebuilding the drag link shared here. Now the focus is front springs, adding an overload spring (9 total each side now), leaf spring liners and rear leveling blocks.

The front springs have a bit of droop, the 3/4 ton sits like a stock 3100 with the top of the front tires hidden by the fenders. Never liked that look. So a bit of searching turned up a overload leaf for early CJ5 Jeeps that's 1 3/4" wide, about 22" long and 1/2 thick in the middle.

Overload springs are from ProComp item 13170 for $34.99.

Based on the good things others shared about pulling the front spring packs, cleaning and installing liners between each leaf I decided to give it a try. My 3600 does OK with 35 psig in the front 30 in the rear on the rough roads I regularly drive on. Air up to 60 psig where it steers easy and can work and it'll literally like riding on a log wagon.

The Poly-Slide Liner used comes in 20' rolls, two required..

A few days ago I put a couple jack stands under the frame under the seat area and tore into things. Pulled the front wheels, spring u-bolts, rear spring eye bolts, front spring shackle bolts and shackles. I'd ordered new u-bolts and failed to notice they were 1/2", my 3600 needed 9/16" u-bolts. Even though they're 71 years old, they have less than 60,000 miles and when cleaned up look fine. So temporarily they're back in service. I know, always use new u-bolts.

First order of business once the spring packs were disassembled was to take the leaves to the bench grinder with its new wire brush wheel and clean away all the rust.

Next was to open the center bolt hole in each leaf up (from 5/16th inch) for the 3/8th bolt that came with the new overload springs. I really expected this to be a choir but with a good 3/8ths bit it was a fast easy job on the hand-me-down drill press.

The Poly-Slide liner is easily cut to length with a pair of scissors while holding it in place on the spring. Punched the bolt holes with a hole punch made from a short piece of 3/8 stainless tube and a small ball peen hammer. One note, someone posted the liners lip should be installed down, keeping water from collecting on the springs. You can see the lip on the edge of the liner if you look close on the installed spring image.

Last step was to clean and grease all spring bolts and reassemble. After a bit of fiddling decided the add-a-leaf fit best as the 4th spring from the bottom. 3 below and 5 above. It's now a 9 spring pack.

The front threaded bolts showed no wear. One rear eyebolt looked good, the other was cammed out a bit, about 20%. New bushings and bolts are on the list now. Some black paint and a couple hours work and it's all back together.

Sitting in the shop, the truck looks high in the front. Measuring from the top of the axle to the frame shows it's now 2" higher.[img]https://www.stovebolt.com/ubbthreads/ubbthreads.php/ubb/download/Number/39446/filename/IMG_9220.JPG[/img][img]https://www.stovebolt.com/ubbthreads/ubbthreads.php/ubb/download/Number/39446/filename/IMG_9220.JPG[/img][img]https://www.stovebolt.com/ubbthreads/ubbthreads.php/ubb/download/Number/39446/filename/IMG_9220.JPG[/img]

Now for rear squat. It's not much, but it's there. A little digging and found a pair of solid motor mounts from about 1975 built for the 340 Duster. Never put the studs in so they are now going to be rear blocks. At 1"x2"x3.5" solid steel they're almost the right size, just an 1" short on each end. Fix was to weld 1" square tube to the ends. This is mainly needed to make the blocks extend past the u-bolts. Drilled a 1/2" hole through each block and tacked a short piece of 1/2" round stock in one side (locating pin for the bottom) the top part of the hole is for the centering bolt head on the spring pack.

If I could have located a set of 1"X2" steel blocks, I'd have bought them, but it seems our trucks with their narrow 2" wide rear springs get no love from the aftermarket folks. With the old solid, unfinished motor mounts on hand it was only a hour or so to build a set so not too bad.

Last task after getting the new blocks in place was a test drive.

Better, much Better. Not only does it not drive and ride like a old, worn out truck you can feel the springs working on wavy road sections. A log truck beat up paved, potholed, deep rutted 15 mph section of road is now a 20 mph road. Not a huge improvement but it's a definite improvement. Yes, I'd do it again.

You've got to look close to see the difference in ride height with the new leaf in place but it's there. The Luckenbach image shows the stock stance.

Al is used frequently for lift/lowering blocks.

Ed

With you raising the front 2" did you find any difference with the steering angle on the draglink? I used the same basic set up as you mentioned with a 88' power Wagon and had to add a block to the radius arm to correct the steering, of course that was a 4x4.

Craig, I was concerned bump steer would be a problem. With 30 miles driving since the changes, no issues. Drives great. Max speed 60 mph on a good 4 lane highway for a few miles and 20 miles on rutted gravel and pavement at 20 mph to 40 mph.

I haven't looked since driving last evening, but sitting in the shop, the rear of the draglink was about 1" higher than the axle end.

If anything crops up I'll update.

RonR

Added in edit; gave the draglink a second look today. Without breaking out the level and tape, I'm going with 2 or 2 1/2 inches off level. Did put another 30ish miles on with a trip to the barber today. No issues again other than losing a hubcap.

Next time you are in Luckenbach give me a yell. I live 20 miles away. I'll drive my '52 GMC 150 flatbed (same color as yours) and buy you a Shiner.

Bill, good plan! We've made the trip twice. It's about a 1,300 mile round trip for us. First time was in '17, last was '18 and we're about due for another. The old tail bone does get tired though. Blue Bonnets, Beer and Bar-B-Que, hard to beat the Hill Country for a great road trip.

RonR

Moparguy thanks for the write-up. From my post you responded to the other day, my 3600 has the same front end sag. I was going to either re-arch or replace the springs but after reading your post I'm going to try this first.

You're Very Welcome! Sharing what does and doesn't work is what makes forums (and The 'Bolt especially) such great places to hang out.

I grin every time I drive since making the changes. One thing I would recommend is have new u-bolts, rear spring eye bolts (possibly bushings), and front spring shackle bolts on hand just in case they're needed. If your truck is like many and has the typical unknown mileage (but it's likely a lot) I suspect you'll need them.

Good Luck, and be sure and report how it works.

RonR

PS, As mentioned in the original writeup, due to the new u-bolts being 1/2" rather than the needed 9/16th" I did reuse the originals. The threads were good and after cleaning all looked good. What I didn't mention is that with the extra spring, the originals are too short to get a full nut with the bump stop in place. It fits under the u-bolts on top of the axle spring plate (bolts needed to be about an inch longer). My solution, I left the bump stops off. So far so good, but if I ever bottom the suspension out it'll be metal on metal. And if I'm ever off road and going fast enough to bottom out, well I needed to SLOW way down. It'll be a lesson to remember for sure.

Good tips for sure Moparguy; and appreciate all the info. I'll update when I get it done. I ordered everything today, takes a while to get anything delivered up here

Not too many rough roads for me, but the local roads aren't exactly fantastic either.

This truck I'm quite sure has many rough miles on it. Has an interesting backstory as it started out up in the Yukon at a gold mine before finding its way into Northern British Columbia. So, she's seen her share of rough roads! I try and take it easy on 'r.