I have been searching with no luck for information on the leaf spring replacement for the Hijet. The leafs are tired and I would like to replace them. Also trying to find any numbers for the rear shock absorber. I ordered new front struts and also these coil springs for the front (https://www.summitracing.com/parts/qa1-10ht300) with the hope to end the bottoming out. Anyone have any information on the rear suspension?
Mc, I took my tired old leaf spring sets,(both), to an old time, spring shop in downtown Cleveland, Ohio, Near me, Cleveland Spring, did the work that I wanted. We collectively added another leaf to the stack, on each side, and I re installed them, and I'm very happy with how they turned out and the plan! If I remember correctly, I paid $250.00 for their work, and had them back a week later! I remember that the new leaf to each side added, an additional 650 lbs. of hauling per leaf,(side), which collectively increased my hauling of almost 3/4 of a ton! A little stiffer ride, but not bad, all considering, and the increased lift in the back, was something that I was also planning on, in conjunction with the lift I did! So I just made my rear shackles accordingly! In some past posts about a year ago I had some pics! Limestone
I added a leaf t each side which came out of an old set of trailer springs that my buddy had. They were just a tad narrower than the stock leaves, and had a inherent arc, so adding them at the bottom effectively re-arched the springs, and gave me a stiffer spring. Also replaced the stock bumper with a pair of Timbren bumpers that I had bought for a different problem.
Yeah, I forgot to mention, like Jigs said, that by adding the leaf, it re arched the Springs! Just the way we planned it! I thought about ordering some springs from Summit Racing, who's not far from me, but I went the other route instead! You have options! Limestone
So after excessive amount of searching I was finally able to find a business near enough to me that is able to get a helper spring. Thanks for the help folks
@Mclorivan , what type of helper springs did you get? I'm looking at some bolt-on type, but I am 3 hours from my truck and don't know the rear leaf spring dimensions (width and length to bolt on)...
I installed sumo springs urethane bump stop on mine. When empty they don't do anything so the rear suspension is not affected. When I load the bed up they come into action and helps the leaf springs.
Thanks for the info. However, in my case, I'm actually trying to raise the back slightly, 1/2" to 1". I put stiffer springs on front, which fixed one problem, but now the back sags some relative to the front. I bought a light weight (500#) bolt-on helper and plan to try installing this weekend. I should know in short order if it works and how it drives. If helper doesn't suffice, I think I'll have to add a block between the axle and leaf springs, or perhaps get a longer rear shackle. I'm trying simple first, because I am perpetually lazy.
Full honesty here, I have not ordered the springs or gotten into that job yet. After doing a complete engine rebuild and other projects on the homestead it was put on the back burner until spring. Sorry I can't help you
I ended up trying these bolt-ons (bought at AZone). They fit nicely, easy to install, but only provided 1/4" lift. So now I plan to try a shackle extension.
I added leaves out of the spring pack for a trailer to mine, They had a higher arc, and effectively re-arced the springs. I used the leaf closest to the one with the eyes, out of a 27-inch spring set. It installed above the heavy leaf next to axle, and the middle on of your spring pack. The ones you tried are helper springs, and not intended to raise the vehicle.
Correct. I see that printed no less than 4 times on the box! After adding the stiffer front springs, which added almost 2" lift to the front, I only needed about 1/2" lift in the back for the truck to sit level enough for my taste. I wasn't sure if there was 27 years of spring sag that these helpers could restore. But, my thinking, even if not, stiffening the back springs with these helpers would be fine by me. I'm hoping to extend the back shackle about 1" this weekend. I think that will get me the vehicle stance I want. Then I have to make decisions on tires/wheels. I'd like a combination of smallest diameter wheel with largest tire sidewall. Unfortunately, seems my current 12" x 3.5" wheels are already maxxed out with 145R12 tires. Oddly, my spare (which I removed permanently) was a 12" x 4" wheel with 155/80R12 tire. If I had four of those wheels/tires, I'd probably call it 'good enough'.
Measure the eye to eye length, that is E. Then the center of axle perch to the rear eye, that is ae. Then determine the amount of lift you want directly above the center of the axle, that is R. Then R*(ae/E)= how much longer than the stock shackle length you need the new shackle to be to get that lift. There is a good video on YouTube which explains how to get the right size of tires and wheels:
...i.e., extend shackle twice the desired lift? Are there applications where the axle is not centered on the leaf spring?
On nearly all leaf springs supporting driven axles the distance from the axle to the front eye is less than the distance from the axle to the rear eye. It helps prevent axle wrap during acceleration and braking.
Cool, learned something! But, now I am confused... These are made up numbers. Let's say front eye to axle is 18", axle to rear eye is 20", and I want a 1" lift. Per your equation, if I understand it correctly, you say 1"*(20"/38")=0.526" longer rear shackle? I feel like the equation should be R*(E/ae)? Help?
@Jigs-n-fixtures , dang you making me do geometry!!! When I work it out 'on paper', I actually get R*(E/(E-ae)), or "desired lift"*"eye-to-eye"/"front eye to axle". And, for others paying close attention: yes, we are debating various equations that won't change the result by more than 1/8"! But, brain exercise is good.
I could easily be wrong. I lost my math for almost a month after I had Covid in August. Kind of scary, and really weird. I could move variables around in known equations, and get things set up, insert the numbers, and then just stare at it not knowing how to do the arithmetic. So, I’m not sure of a lot of things right now. I think you’re right. If I think about it as a lever problem and the front eye is the fulcrum, and you want to move the axle one inch, then the other end has to move more than one inch.. So length eye to eye, divided by the length from the front eye to the axle. And multiply how far you want the axle to move by that.
Jigs, Sorry to hear about your Battle with, Covid! I wasn't aware naturally! Glad that your doing better! You were always one of the Sharper, very informative members! God Bless! Limestone
Take you truck to a local spring shop and tell them what you want and they will rearch your springs to your specs. I have done this on many vehicles and then you can have them painted or powder coated.
