JKS JSPEC suspension kit

[Fargo]

I have boots over the shocks in the front so they were a little difficult to measure. But it looks like I have about 4.75" of shaft showing. The Rancho 9000xl has a stroke of 8.5". I think I have a little extra bumpstop that will leave about 3/4" of shaft showing. So that leaves 4" uptravel and 3.75" down travel. (4+3.75+.75 unused = 8.5) So currently pretty close to 50/50.

I will gain another 1.7" of down travel when I put the 5160s back on. So then it would be 4 up and 5.45 down. (4.up+5.45down+.75 unused = 10.2" shock) So 40/60 up/down

Note: (Above measurements assumes an additional 1/4" of uptravel if the jounce bumper fully compresses into the cup. I never pulled the bumper out and I think it still had 1/4" to go with full vehicle weight on it.)


In the rear I have about 5" up travel and 3.5." of droop. The 5160 is 8.5" travel shock. So about 60/40 up/down in the rear.

I don't know of thats all right or not. I just measured my bumpstops and found I have room for 4.25" up travel in front and 5.25" up in the rear. So numbers might be off a little. I think I hurt my head a little trying to figure it out. But as strange as it sounds I should have about 40/60 up/down in front and 60/40 up/down in the rear.

I might have to go do a little flexing and see where things fit. I just realized I forgot to check tire clearance in the back. Last time I checked it I had different tires and rims.

 

[jlpierce70]

@Farmergreg and @Fargo

Since you guys both have hard tops and winches in the front I'll ask you guys.

I've got a 1999 TJ that had a RC 2.5 lift and shocks. Replaced the shocks with Rancho RS55239 and RS5524.
Just purchased a set of JKS 3" J Spec coils.

I don't have a winch in the front but I have the mounting hardware for a Western 7'2" LSX plow that I'm too lazy to remove every spring. I don't really off-road much anymore since I bought a RZR so the lost of approach angle isn't that big of a deal to me now.

Before I install them I'd like to order a pair of Air-Lift 1000 air bags on the front to help support the weight of the plow the few times a year I use it. Then I can install everything at once.

Could you measure the distance from the upper spring seat to the bump stop and let me know what bump stop size you have?

 

[Farmergreg]

I'll report back tomorrow.

 

[Fargo]

@Farmergreg and @Fargo

Since you guys both have hard tops and winches in the front I'll ask you guys.

I've got a 1999 TJ that had a RC 2.5 lift and shocks. Replaced the shocks with Rancho RS55239 and RS5524.
Just purchased a set of JKS 3" J Spec coils.

I don't have a winch in the front but I have the mounting hardware for a Western 7'2" LSX plow that I'm too lazy to remove every spring. I don't really off-road much anymore since I bought a RZR so the lost of approach angle isn't that big of a deal to me now.

Before I install them I'd like to order a pair of Air-Lift 1000 air bags on the front to help support the weight of the plow the few times a year I use it. Then I can install everything at once.

Could you measure the distance from the upper spring seat to the bump stop and let me know what bump stop size you have?

I'm not sure what measurement you want. I used 2 hockey pucks bolted down on the axle pad. So my upper spring seat to my bumpstop is the same as factory. Maybe I'm misunderstanding. I'm really tired tonight. Let me know if you want something else. I'm happy to run out and measure things tomorrow.

 

[jlpierce70]

Looking for X

 

[Fargo]

OK, I'll try to get some measurements for you tonight. I'll see if I can get pictures with the tape measure so you can see exactly where I am at.

 

[Farmergreg]

Better late then never!
From the bump stops ( two hockey pucks @.977 bolted to top of axle) to the upper spring perch per your drawing, I’ve got right at 11” edit that to 10 3/4” for the spring diameter.

From the hockey pucks to the joust bumper, 2 3/4”

 

[Fargo]

I just got to measuring mine for you too. Please note I have a Warn winch installed on the factory bumper.

Measuring the X measurement exactly as indicated in the diagram above. From the MIDDLE of the top coil to the factory pad, I have 12". Please note, that Rubicons have an extra 1/4+/- of pad on top of the factory bump stop pad.

Measuring from the MIDDLE of the top coil to the top of my extended bump stop pads (2 hockey pucks), I have 10".

Measuring the compressed coil length at ride height, I have 14 1/2". Stock is 12". I added a 3/8" OME spacer on top of that to get a very level 3" height gain with the hard top.

Measuring from hockey pucks to jounce bumper is 2 3/4"
Measuring from hockey pucks to bump stop housing 4 1/4"

For additional info, the bottom spring seat to the top of the factory pad is 2"

I hope that all make sense for you. Its a lot of measurements and the math may not work out perfect due to having to eyeball things a little. In the end it looks like both Farmer Greg and I have the same 2 3/4" of travel until touching the jounce bumper. I just needed a 3/8' spacer to account for the winch.

Interestingly our x measurements differ with me having 10" and farmergreg has 10 3/4"

How will the jounce bumper in the middle of the spring affect the airbag?

 

[jlpierce70]

Thanks for the measurements guys.

I have front bags on it now for the plow that I ordered to fit the RC 2.5 springs it has now. They are leaking so I'm not sure what caused the leak yet, maybe the jounce bumper punctured it? I wanted the measurements to order bags before I do the new springs but I might be better off just doing the springs first and at that time see what caused the demise of the old bags.

I've been reading up on bump stops and jounce bumpers. I ordered some Daystar extended polyurethane bump stops already that sounds like I'd be better off returning and going with the stock ones and some hockey pucks?


https://www.amazon.com/gp/product/B004IARR9U/?tag=wranglerorg-20

 

[Fargo]

Thanks for the measurements guys.

I have front bags on it now for the plow that I ordered to fit the RC 2.5 springs it has now. They are leaking so I'm not sure what caused the leak yet, maybe the jounce bumper punctured it? I wanted the measurements to order bags before I do the new springs but I might be better off just doing the springs first and at that time see what caused the demise of the old bags.

I've been reading up on bump stops and jounce bumpers. I ordered some Daystar extended polyurethane bump stops already that sounds like I'd be better off returning and going with the stock ones and some hockey pucks?


https://www.amazon.com/gp/product/B004IARR9U/?tag=wranglerorg-20

Yes, I think you are better off to use hockey pucks. The factory jounce bumpers will compress completely into the cup. That is why I mentioned the 4 1/4" number above. That is the actual amount of suspension upward travel. I don't believe the polyurethane bumpstops you purchased will compress at all. So every time you the bump stop they will hit HARD. The factory bump stops compress and almost act like a secondary spring. There are some nice aluminum ones out there too, but the hockey puck work really well and are much cheaper.

To install the hockey puck, just drill a hole in the factory pad. Then thread it. Then just drill a hole in the hockey pucks and run a bolt through the pucks that fits into the threaded hole you just made in the bumpstop pad. On mine I even used a larger boring bit so that I could counter sink the bolt head in the hockey puck so the bolt head sits flush with the top of the puck. I think I used about a 3/4" - 1" bore and then used a washer under my bolt to help distribute the force onto the hockey puck. Its worked great for 10+/- years.

Here I just found this for you.

That is what I did. I like that he just used a shoulder bolt instead of messing with a washer like I did. But you can see how he also has the bolt head counter sunk so its flush with the top of the puck.

Regarding your airbags leaking. It could be the fittings that are leaking and not the bag. I think I have that problem with some airbags I have in my Pathfinder.

 

[jlpierce70]

Reading about the bump stops got me thinking that with the Airlift bags in there I'm loosing a lot of compression distance because the bags are never going allow the spring to compress anywhere near the point that the bump stop touches the lower spring spring seat. So the ride quality has to be worse when using airbags which then got me thinking about air shocks.

I'm thinking for the winter I'll take the front Ranchos off and put on air shocks in their place. I don't drive the Jeep that much with the plow on but when I do it would be nice to have a way to make up for the 500 lbs hanging off the front. Then in the summer I think I'll have a lot better ride quality without the bags limiting the front suspension and the Ranchos back on.

Any thoughts?

 

[Fargo]

If the airbags are deflated in the summer I would think they would completely compress under load. But that also seams like a lot of extra wear on the airbag to be squishing it under the bumpstops. Air shocks might be a reasonable option to account for the weight of the plow in the winter. I've never used them so I don't know how reliable they would be under that kind of a load.

I wonder if you could find a load carrying shock that works upfront. I've seen them from Gabrial and Monroe. Something like this might work. Then swap it out in the spring when the plow is pulled off.
http://www.monroe.com/en-US/product...usting/monroe-load-adjusting-shock-absorbers/

 

[bobthetj03]

Not the cheapest option, but an option none the less.

https://www.amazon.com/dp/B005TTZ7L4/?tag=wranglerorg-20

 

[Fargo]

Thats only a spring spacer with a built in bumpstop. It doesn't really help with the load. It will just make you sit level when your on your bumpstop. There is a such a thing as hydraulic bumpstops that can act like a secondary spring. But they are expensive and I don't think the right solution either.

I think your best options are the airbags, load carrying shocks or air shocks.

You do have one other option, but I hate to mention it since you already purchased your JKS springs. But you could get some custom front springs made specifically to carry the extra load.

http://www.coilsprings.com/

 

[jlpierce70]

You have to run a minimum PSI in the bags or they will be ruined. So now that I realize that the bump stops don't get to do their job, probably stopped 6 inches sooner by the air bags I don't think I want to go with air bags again.

Leaning towards air shocks in the winter. Easy to swap the shocks. The load adjusting spring shocks sound like a hit or miss way of getting what I want. I think air shocks give me more flexibility since I can vary from 20 lbs to 150 lbs as needed.

Emailed Monroe and Gabrial. Monroe answered back they don't have a shock that will fit my application but who knows. I've gotten bad info from emailing customer service online before.

Specs on my front Rancho RS55239

COMPRESSED LENGTH	EXTENDED LENGTH	TRAVEL LENGTH	LOWER MOUNTING CODE	UPPER MOUNTING CODE	PARTS PACK
14.43	23.84	9.41	XP4	S4	P01136

*All measurements are in inches. Boot/Dust Shield end is upper.


Neither of those two companies list all their shocks on a handy graph to see what shock they have would match the specs of my RS55239. Any Suggestions how to find the right air shock?

 

[bobthetj03]

The bar pin on the lower mount will likely be tough to find a comparable shock with the right mounting. You could put bar pin eliminators on the bottom mount and broaden your search criteria to a eye mount for the bottom and stud mount up top.

 

[Fargo]

I was just writing that it might be the stud pin on top that is the problem,. Either way, I think the problem is going to be the mounting pins. Once you figure that out, then find a shock that is the correct compressed length for your needs. I'm not sure proper valving is going to be an option for you.

 

[Fargo]

Look into something like these items. That might free up shock options.

https://www.quadratec.com/products/16301_4460.htm

https://www.quadratec.com/p/rough-c...eliminators-jeep-cherokee-xj-wrangler-tj-1088

DIsclaimer: These were the first I found, they may not be correct and better options might be available. But there adaptors out there to allow you more freedom in shock selection.

 

[jlpierce70]

Thanks @Fargo

That is exactly the direction I need to go. Going to change the top and bottom mounts and then finding an air shock will be easy!

 

[Fargo]

Thanks @Fargo

That is exactly the direction I need to go. Going to change the top and bottom mounts and then finding an air shock will be easy!

Keep us posted on how that works for you.