J20 Springs and ride heights.

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crimsonride
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Joined: Sat Feb 23, 2019 10:04 am

J20 Springs and ride heights.

Post by crimsonride »

Hey guys.

I'm new here. Just picked up this J20 from Montana. 1977 J20, Cadillac 500, Turbo 400, chevy 14 bolt. 35" BFG all terrains.

Image

It's had a fair amount done do it and I'm trying to identify what all has been done.

First on my list is to address the springs, brakes, steering to get this thing riding gently enough I want to be in it!

Anyway....I've been reading all I can on the springs and what I've learned is all J20's ride like log wagons. I'm toying with the idea of swapping in some wagoneer springs but I need to know if these are lift springs or not.

Can anyone tell me what their stock ride height is? Something like a measurement from the center cap to the fender flare would help me out. I need to know if these are the stock springs or if they're an aftermarket lift spring.

I'm aiming to keep my height the same but get a softer ride.

My rear springs are some crazy thick (2) spring pack with a massive over load spring underneath. I need to look at some different options for the rear as well.

What have people been doing to get a smoother ride out of these tanks?
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Cecil14
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Re: J20 Springs and ride heights.

Post by Cecil14 »

I believe the TSM gives measurements for ride height. Something like ground to rocker, or axle to frame, or something. That should give you a good starting point.

With that much clearance on 35" tires, and what appear to be untrimmed flares, I would say there's likely at least some lift.

I don't know as many people have done anything to J-20s for a better ride, they really aren't that common around here. The ride is pretty representative of any 3/4 ton truck of the day, with the exception of maybe the front shackles. I think GM had the shackles on the rear of the front springs? Maybe others, too.

How good she rides is going to depend largely on how much you want to spend, and how much load capacity you want. If you want the best of the best, start looking at a full air suspension. There have been a few around here that have converted to front coils. Alcan custom springs are another option, those will be the absolute best you'll ever get from leaf springs. A front shackle reversal would also be a big help, RockLaurence here sells a prefabbed kit in the vendor section:

http://www.fsjnetwork.com/forum/viewtop ... =34&t=2771

Shoot us some pics of your suspension and we can give you a better idea of what you have.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Stuka
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Re: J20 Springs and ride heights.

Post by Stuka »

If those are 35's, I doubt they are stock springs. You can squeeze 33's under a J20 with stock springs. If you can get some photos of the springs themselves, we can probably tell you if they are at least not OEM springs.

Beautiful truck BTW!
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

Topic author
crimsonride
Posts: 4
Joined: Sat Feb 23, 2019 10:04 am

Re: J20 Springs and ride heights.

Post by crimsonride »

Yeah, I kind of figured but wasn't totally sure. They're a 4 leaf pack on the front and a 3 leaf on the rear.....and they are stiff!!!

And thanks! It is a good looking truck. It needs some love though.

Here are some picks of the leafs.

Image

Image

Assuming they are lift springs, who makes the softest lift kits out there?

Topic author
crimsonride
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Re: J20 Springs and ride heights.

Post by crimsonride »

Cecil14 wrote:I believe the TSM gives measurements for ride height. Something like ground to rocker, or axle to frame, or something. That should give you a good starting point.

With that much clearance on 35" tires, and what appear to be untrimmed flares, I would say there's likely at least some lift.

I don't know as many people have done anything to J-20s for a better ride, they really aren't that common around here. The ride is pretty representative of any 3/4 ton truck of the day, with the exception of maybe the front shackles. I think GM had the shackles on the rear of the front springs? Maybe others, too.

How good she rides is going to depend largely on how much you want to spend, and how much load capacity you want. If you want the best of the best, start looking at a full air suspension. There have been a few around here that have converted to front coils. Alcan custom springs are another option, those will be the absolute best you'll ever get from leaf springs. A front shackle reversal would also be a big help, RockLaurence here sells a prefabbed kit in the vendor section:

http://www.fsjnetwork.com/forum/viewtop ... =34&t=2771

Shoot us some pics of your suspension and we can give you a better idea of what you have.
Good info! If I can find out what height these springs are I might be able to go shackle reversal and smaller arch springs. I doubt I'll ever really carry any weight in this truck. I have my Silverado for that. I'm just building this truck for fun. :D

79 Chief
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Re: J20 Springs and ride heights.

Post by 79 Chief »

Soft ride is their such a creature in an fsj?
:evil:
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Stuka
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Re: J20 Springs and ride heights.

Post by Stuka »

So, definitely has lift blocks in back, but the springs look stock. The rear already sat pretty high, so would not require as much lift in back to fit a 35.

For the front looks after market. The spring clip used, arch, and the fact that they still have some black on them points to that. But I could not say who made them. They do have spring pads, which many lift springs do not have.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

superdave
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Re: J20 Springs and ride heights.

Post by superdave »

I'd have to recount the leaves, but it looks a lot like whatever kit that's on my J20 parts truck, from the blocks, to the leaf count, and even the front spring pads look very similar. Definitely didn't look stock to me, but I have no idea how it compares to stock. The frame to axle distance was an inch or two higher than my stock wagoneer though.
Dave Knoerzer
1977 Wagoneer 360/400/QT stock as far as I can tell

candymancan
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Re: J20 Springs and ride heights.

Post by candymancan »

Problem with measuring from the wheel cap to fender or quarter panel is the wagoneers have lower panels then a J20. The rear quarter panel for example is 2 inches lower then the front on the wagoneer giving it the illusion its sagging. The J20 is the same all around i believe. So ot might be better to measure from the ground to the bumper im betting.

Grand wagoneers have 7 pack in front and 4/1 or 5 in rear.


I think im thr only one on here who has stock new springs on so ill measure mine ina few
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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Cecil14
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Re: J20 Springs and ride heights.

Post by Cecil14 »

A J-20 and a wag are apples and oranges, don't even bother comparing. A wag never sat at the same height a J-20 did. Get the TSM, pull the specs from that, and use those figures for your measurements.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Stuka
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Re: J20 Springs and ride heights.

Post by Stuka »

J-Trucks definitely sit higher from the factory than a Wagoneer does. Its both visible and the TSM notes it in the specs area.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

rocklaurence
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Re: J20 Springs and ride heights.

Post by rocklaurence »

Im testing a front Long Spring system on the J20. It provides 4" of lift, rides much softer and provides 12" of wheel travel [if you need that much]. It is a system with FSSR, 7" longer springs, new Shock/Bump stop brackets, steering arm, long travel front drive shaft. This wont be the cheapest system on the market but will be the best riding and performing setup.
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derf
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Re: J20 Springs and ride heights.

Post by derf »

I swapped J20 axles under my J10. I did a lift kit at the same time to fit 35" tires.

I went with the Skyjacker Softride 4" full spring lift kit for the Grand Wagoneer. No blocks. It bolted right up with no problems.

It is a 1/2 ton suspension so it certainly doesn't have the load carrying capacity of the J20. It does ride reasonably comfortably on the road. Of course, it's better with a little weight in the back.

Image


My long term plans involve using a "universal" air bag setup for older pickups. I forget the brand and part number off hand but the kits for older trucks do require a little bit of DIY customization. I've done some measuring and those kits will fit inside the frame rails pretty easily with some custom brackets and some boxing of the frame. That should give me the load carrying upgrade I need to handle a heavier tongue weight without squatting badly. Along with a rear swaybar that I pulled off a GM SUV, I should be set up pretty well for towing my JK on a trailer.
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LMJ20
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Re: J20 Springs and ride heights.

Post by LMJ20 »

Here is a screen shot of a post I think I found somewhere on here, or over on IFSJA. It dosnt really help with ride height but it might help you better identify what you have.Image


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Topic author
crimsonride
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Joined: Sat Feb 23, 2019 10:04 am

Re: J20 Springs and ride heights.

Post by crimsonride »

LMJ20 wrote:Here is a screen shot of a post I think I found somewhere on here, or over on IFSJA. It dosnt really help with ride height but it might help you better identify what you have.Image


Sent from my iPhone using Tapatalk
Great info. Thanks for the input guys. I searched the TSM's and didn't find anything....guess I should have looked harder. So I'm pretty certain it's a 4" kit, still not sure who's it is.

Anyway. If I'm actually ever going to drive this thing I'm going to need it to drive softer.....I guess my f150 has me spoiled. Funny story, I bought a 2017 Silverado High Country a year and a half ago... I put about 50K miles on it in a year so I handed it down to my dad (He works with me) and went back to my old F150....I guess I just put in so much seat time I need a soft quiet ride.

So this jeep is just a novelty for me. I enjoy projects so I just bought it for fun. I won't be driving it other than just for fun...Don't need it to haul or tow anything. I swapped in a new S10 gear box and hydroboost brakes so it's steering and braking better now I just need it to ride softer.

I think I've settled on converting it to a coil spring front suspension. I've researched it a little and I'm planning on using most of the Ford early 70's era radius arms and coil springs. It actually should be a fairly easy swap to fab up. I'll keep you guys posted as I go.

As for the rear I think I just need some softer springs, new shocks, and air bags if I ever decide to load it up with some weight....which I probably won't ha!

rocklaurence
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Re: J20 Springs and ride heights.

Post by rocklaurence »

rocklaurence wrote:Im testing a front Long Spring system on the J20. It provides 4" of lift, rides much softer and provides 12" of wheel travel [if you need that much]. It is a system with FSSR, 7" longer springs, new Shock/Bump stop brackets, steering arm, long travel front drive shaft. This wont be the cheapest system on the market but will be the best riding and performing setup.
Im running the new Long Spring front setup. It rides Great and Im testing it for Bugs before marketing it. Also, I need to consider a matching 4" rear lift to match because the front is so smooth but the rear still slaps you in the Ass when going over high speed bumps. I've got an idea for the rear and will post up on The Slab64 youtube channel in a few weeks. :D
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