TJ Shock & Spring Specification Resource Thread

[jjvw]

.... Also does anybody know why auto correct refuses to let me write Tee Jay and corrects to TI?

Auto correct is protecting you from looking dumb. Don't fight it.

You don't have a spring problem unless you can describe this in terms of ride height and measurements. What you are describing is an issue with shocks and movement control. Are both sway bars still installed?

 

[jjvw]

.... I was looking for a shortcut to the info I can't see unless I buy it from Microsoft. ...

There is no reason why, in this day and age, you can't open the spreadsheet for free and without anything from Microsoft.

 

[3jeepsDave]

There is no reason why, in this day and age, you can't open the spreadsheet for free and without anything from Microsoft.

Working thru The coils I've been able to find online I see 3 ranges. The Tera Flex at 170 lbs per inch, A Dobbinson at 200 and the Rubicon at 240 per inch. I do want to change my coils to eliminate the squishy feel (without the plow on). Would anyone care to advise what direction to go? Is A 240lb coil going to be bone jarring up front? Split the difference with a 200? Go with the 170 and let the bags handle the weight so that I get a soft ride? All three are 3" and I seem to have 2" right now. Will that also dictate a softer spring so I end up with the same ride height but I'm not sure 1" more is critical? I suspect the springs started at 3" and now sit at 2" but that is a guess. I will be changing the shocks and upon the advise of others I'm leaning to the Bilsteen 5100's. It would be nice to "Do it once and do it right".

 

[jjvw]

Working thru The coils I've been able to find online I see 3 ranges. The Tera Flex at 170 lbs per inch, A Dobbinson at 200 and the Rubicon at 240 per inch. I do want to change my coils to eliminate the squishy feel (without the plow on). Would anyone care to advise what direction to go? Is A 240lb coil going to be bone jarring up front? Split the difference with a 200? Go with the 170 and let the bags handle the weight so that I get a soft ride? All three are 3" and I seem to have 2" right now. Will that also dictate a softer spring so I end up with the same ride height but I'm not sure 1" more is critical? I suspect the springs started at 3" and now sit at 2" but that is a guess. I will be changing the shocks and upon the advise of others I'm leaning to the Bilsteen 5100's. It would be nice to "Do it once and do it right".

Stop trying to fix ride quality with springs. This is a shock problem. Not a spring problem.

 

[3jeepsDave]

Stop trying to fix ride quality with springs. This is a shock problem. Not a spring problem.

Ok ,I Will save the money and just put new shocks on. I have to admit I was worried about the weight cantilevered far out front. I'm glad that is not a concern. Much easier in the cold to just do shocks.

 

[3jeepsDave]

Ok ,I Will save the money and just put new shocks on. I have to admit I was worried about the weight cantilevered far out front. I'm glad that is not a concern. Much easier in the cold to just do shocks.

Is there a big difference in this scenario between a Bilsteen 4600 and the 5100? Will both handle the cantilevered load?

 

[jjvw]

Ok ,I Will save the money and just put new shocks on. I have to admit I was worried about the weight cantilevered far out front. I'm glad that is not a concern. Much easier in the cold to just do shocks.

Springs set the ride height. Shocks control the movement.

The plow is adding a bunch of weight that will affect the ride height of the springs as well as the shock's ability to control the movement. Treat the two issues separately.

 

[jjvw]

Is there a big difference in this scenario between a Bilsteen 4600 and the 5100? Will both handle the cantilevered load?

If you are asking how well those shocks will control the movement of the added weight of a snow plow, I have no idea. The shocks don't know or care if a load is cantilevered. While the springs will certainly know. The weight of plow will sink the front and raise the rear. And all that weight will shift and change when you drop the plow on the ground to push snow.

 

[3jeepsDave]

Is there a big difference in this scenario between a Bilsteen 4600 and the 5100? Will both handle the cantilevered load?

Sorry I keep adding on...if The shocks are not the panacea should I be forward thinking and get the 0-2" shocks or get the 2.5-3.5".

 

[jjvw]

Sorry I keep adding on...if The shocks are not the panacea should I be forward thinking and get the 0-2" shocks or get the 2.5-3.5".

Set the ride height first. Then figure out the shocks after the ride height has been established by the springs. In that order. The shock travel bias should be roughly 50/50 from ride height. If you change the ride height, the shock's travel bias will change and their performance will be affected.

 

[3jeepsDave]

Set the ride height first. Then figure out the shocks after the ride height has been established by the springs. In that order. If you change the ride height, the shocks will change and their performance will be affected.

Ok, I'm at coils loaded 14" so 2" lift. I'll buy the 0-2 shocks the front end can only go down with the weight of the plow added. Thanks for the feedback.

 

[jjvw]

Ok, I'm at coils loaded 14" so 2" lift. I'll buy the 0-2 shocks the front end can only go down with the weight of the plow added.

I would never select shocks based on lift height.

 

[3jeepsDave]

I would never select shocks based on lift height.

That seems to be how they list them. What are you thinking? I'm at the upper end of the 0-2" range without any plow mount or blade weight. What should I be thinking?

 

[jjvw]

That seems to be how they list them. What are you thinking? I'm at the upper end of the 0-2" range without any plow mount or blade weight. What should I be thinking?

Shock travel bias should be roughly 50/50 from ride height. That means a shock is to be selected for it's size based the compressed and extended lengths, so that the shock will be at half travel at ride height. This was the entire point of my shock spreadsheet.

Your problem is how to accommodate a snow plow. You might figure out your perfect spring and shock combination that supports a snow plow. But the moment you remove the snow plow for the summer, everything about the existing spring and shock combination will change for the worse.

 

[3jeepsDave]

I would never select shocks based on lift heigt

I would never select shocks based on lift height.

I'm sorry I'm not following at all. Disregard the coil measurement which is 2" lift. buy shocks based on ? If the weight of the plow drops the front end another 2" I'll still be in the 0-2" lift range for the 5100's.

 

[3jeepsDave]

Ok now I follow. It will still be the 0-2" as you said don't change springs. Let the Shocks control the motion.

 

[jjvw]

Ok now I follow. It will still be the 0-2" as you said don't change springs. Let the Shocks control the motion.

Do whatever you want to do. 0-2" means nothing and is useless when the goal is to size for 50/50 travel. Too many assumptions on what is meant by 0-2" are being made.

 

[rasband]

Do whatever you want to do. 0-2" means nothing and is useless when the goal is to size for 50/50 travel. Too many assumptions on what is meant by 0-2" are being made.

Ok now I follow. It will still be the 0-2" as you said don't change springs. Let the Shocks control the motion.

What he's saying here is you should buy shocks based on your actual measurements (not the 0-2" or 2-4" claims by a manufacturer). So get the springs you want in there and measure, then find the shocks that measure to fit. Any decent shock should tell you the collapsed length, and extended length (you can figure out the rest).

Fit means the shock is at 50% travel at ride height, ideally being the final stop when stuffed and being the limiter when extended. As mentioned before, compliment your springs with air bags in the front for the plow (air bags are just springs), and you'll have a better TJ overall.

Getting a proper fit though off the shelf will likely be a "get as close as you can". Many of us rebuilt our shock mounts/towers to achieve this as we've found it builds the best balance for the platform until you go really custom.

 

[3jeepsDave]

What he's saying here is you should buy shocks based on your actual measurements (not the 0-2" or 2-4" claims by a manufacturer). So get the springs you want in there and measure, then find the shocks that measure to fit. Any decent shock should tell you the collapsed length, and extended length (you can figure out the rest).

Fit means the shock is at 50% travel at ride height, ideally being the final stop when stuffed and being the limiter when extended. As mentioned before, compliment your springs with air bags in the front for the plow (air bags are just springs), and you'll have a better TJ overall.

Getting a proper fit though off the shelf will likely be a "get as close as you can". Many of us rebuilt our shock mounts/towers to achieve this as we've found it builds the best balance for the platform until you go really custom.

I was going to use Bilsteens guide for fitment. I'm not changing the coils now just using the bags. The existing coils are 14" compressed with the jeeps weight. I will measure the shock distance as it sits then find the info so it's 50/50. Thanks Now I get what you were trying to tell me. I can be a bit Daft at times. my existing shock mount top to bottom is ride height. Got it

 

[dbbd1]

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