MoparFins

Techical Discussions => Tech- - STEERING WHEELS AND SUSPENSION => Topic started by: Guests on September 24, 2008, 11:08:58 AM

Title: Leaf Spring Rate
Post by: Guests on September 24, 2008, 11:08:58 AM
I am going to be putting in a Dana 44 front axle in place of my stock Dana 30 - a few reasons but mostly because of the wider track width for stability to go taller and the larger ring\\pinion for my front locker.
 
What I am having trouble deciding is what springs I should run.  The stock CJ springs are only 2" wide and my current suspension setup is amazing up front...it has rate of 290lbs/in for the rate.  It flexes, rides and handles great...even with the 7" lift, 35s and highway driving.
 
Something I am having some trouble finding online is the free arch in relation to spring rate so I know what my compression\\drop will be.  So...for example a 4" vs 2" lift spring and how much compression\\droop I would get if they had the same spring rate. (http://www.moparfins.com/forum/smileys/smiley5.gif)
 
Any help is VERY much appreciated.  Thanks in advance.
Title: Leaf Spring Rate
Post by: Snotty on September 24, 2008, 02:37:34 PM
Great question, but I would suggest you ask this of a Jeep Forum.  They might/should have better expertise on 4WD than most people on this site.
 
That is not meant to put anyone down here.
 
You can find some Jeep Forums through the links provided on GremlinX.com.
 
Just a suggestion.  Good luck with your Jeep!
Title: Leaf Spring Rate
Post by: Leaburn Patey on September 24, 2008, 03:20:56 PM
Hi! Anthony!! (http://www.moparfins.com/forum/smileys/smiley4.gif)

Title: Leaf Spring Rate
Post by: Steve on September 24, 2008, 03:55:41 PM
Quote from: Snotty
Great question, but I would suggest you ask this of a Jeep Forum.  They might/should have better expertise on 4WD than most people on this site.
 
That is not meant to put anyone down here.
 
You can find some Jeep Forums through the links provided on GremlinX.com.
 
 
Ahhh  Hey Snots. . .
 
He works for me  AND!  He gets better answers here than with those "damned Kids" on the Yeep Forum
Title: Leaf Spring Rate
Post by: Bill Mounteer on September 24, 2008, 06:22:23 PM

Does this link help? (http://www.therangerstation.com/tech_library/leafspringrate.htm)

Note the page works with IE but for some reason not in FireFox

Fury4402008-09-24 23:31:16
Title: Leaf Spring Rate
Post by: Bill Mounteer on September 24, 2008, 06:53:26 PM
Or if you like to play with the math, try this ..
uploads/25/Spring_Rate_Excel.jpg (http://uploads/25/Spring_Rate_Excel.jpg)


Title: Leaf Spring Rate
Post by: Matt Aker on September 25, 2008, 05:00:59 AM
So you want a low center of gravity with lots of spring travel...  Here's your answer (http://www.moparfins.com/forum/smileys/smiley2.gif)
 
 
(http://www.moparfins.com/forum/attachments/61/land_rover_defender.jpg)
(The steering wheel being on the wrong side does not make it defective, just different (http://www.moparfins.com/forum/smileys/smiley4.gif))
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 08:40:22 AM
Quote from: MoparMatt
So you want a low center of gravity with lots of spring travel...  Here's your answer (http://www.moparfins.com/forum/smileys/smiley2.gif) 
 
...
 
The steering wheel being on the wrong side does not make it defective, just different (http://www.moparfins.com/forum/smileys/smiley4.gif))
 
Matt you and I both know they don't have a whole lo of spring travel...then again, they don't need it as much with lockers front\\rear. (http://www.moparfins.com/forum/smileys/smiley17.gif)
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 08:42:32 AM
Quote from: Snotty
Great question, but I would suggest you ask this of a Jeep Forum.  They might/should have better expertise on 4WD than most people on this site.
 
That is not meant to put anyone down here.
 
You can find some Jeep Forums through the links provided on GremlinX.com.
 
 
Oh I know...and I am members of many of those forums.  The biggest problem with them is that unless you post regularly (I don't) your topic gets burried quickly...
 
EvulutioN2008-09-25 13:43:05
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 08:43:27 AM
[/QUOTE]
 
GREAT! PAGE....
 
THANK YOU THANK YOU THANK YOU!
Title: Leaf Spring Rate
Post by: Matt Aker on September 25, 2008, 08:54:28 AM
Quote from: EvulutioN
Quote from: MoparMatt
So you want a low center of gravity with lots of spring travel...  Here's your answer (http://www.moparfins.com/forum/smileys/smiley2.gif) 
 
...
 
The steering wheel being on the wrong side does not make it defective, just different (http://www.moparfins.com/forum/smileys/smiley4.gif))
 
 
Those baby's got coils in the late '80s...  same axles though (http://www.moparfins.com/forum/smileys/smiley1.gif)
Title: Leaf Spring Rate
Post by: Steve on September 25, 2008, 08:55:17 AM
Call Alcan
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 09:20:59 AM
[/QUOTE]
 
[/QUOTE]
 
Yes...they did but it doesnt mean they flex really well.  My CJ stock outflexed my buddy's rover :-p
Title: Leaf Spring Rate
Post by: Matt Aker on September 25, 2008, 10:30:34 AM
weaker frame (http://www.moparfins.com/forum/smileys/smiley17.gif)
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 10:37:20 AM
Quote from: MoparMatt
weaker frame (http://www.moparfins.com/forum/smileys/smiley17.gif)
 
which rover vs  Jeep frame? (http://www.moparfins.com/forum/smileys/smiley3.gif)
Title: Leaf Spring Rate
Post by: Matt Aker on September 25, 2008, 02:54:44 PM
(http://www.moparfins.com/forum/smileys/smiley2.gif)  The Wilkes brothers helped thier fellow engineers at Rover pefect that frame for maximum flexibility and strength.  It's design has remained virtually the same since 1948.
 
Alas...  the last time I went rock crawling was in a stock YJ.  So I'll give you that much (http://www.moparfins.com/forum/smileys/smiley2.gif)  nothing broke.
Title: Leaf Spring Rate
Post by: Guests on September 25, 2008, 02:58:12 PM
Quote from: MoparMatt
(http://www.moparfins.com/forum/smileys/smiley2.gif)  The Wilkes brothers helped thier fellow engineers at Rover pefect that frame for maximum flexibility and strength.  It's design has remained virtually the same since 1948.
 
 
I can name countless times a Rover could not follow me.  Christ when I had the RTI ramp setup in town for a fundraiser (when I had my offroad club) I had my CJ sitting on it for awhile and some people came over with a Rover that was well used but still very nice - well...he didnt even want to go up the RTI ramp.  I asked him why "Because I dont want to break anything!"  LOL  and he knew how to wheel.
Title: Leaf Spring Rate
Post by: Matt Aker on September 25, 2008, 03:02:26 PM
Hence, and example of why a Land Rover's life expectancy is sooo long.  A careful owner! (http://www.moparfins.com/forum/smileys/smiley36.gif)
Title: Leaf Spring Rate
Post by: Bill Mounteer on September 25, 2008, 05:28:08 PM
Well I don't know, back in the days before Mopar bought Jeep, I did a lot of heavy duty bush crawling with an IHC Scout and I winched many Jeeps and Range Rovers out of mud holes. Most of the Jeeps were stuck because they were too light for the huge tires they used and they simply couldn't get tracton to dig themselves out of heavy mud and deep snow. The Range Rover's on the other hand usually had nice narrow tires and had good traction, their problem was they kept breaking things like u-joints and axles.

My Scout was 6,000 lbs, leaf springs all around, posi front and rear and a 345 V8 which made it virtually unstopable. I did however manage to bury it a few times and it usually took at least 3 trucks with winches and snatch blocks to get it out again.(http://www.moparfins.com/forum/smileys/smiley4.gif)


Title: Leaf Spring Rate
Post by: Guests on September 26, 2008, 04:38:36 AM
[/QUOTE]
 
(http://www.moparfins.com/forum/smileys/smiley32.gif)Well...if I could actually find a Scout in decent shape where the person didn't want a FORTUNE for one I would buy one in a heartbeat.  The Scouts were\\are amazing trucks.  I completely agree with the Jeeps being too light [the old ones ayways] - this is why I am adding plenty of weight without worry.
 
My truck at last weigh in was 3400lbs - by the time I add front axle, winch, front\\rear bumpers, tire carrier\\spare, onboard Air, spare parts (drive shafts\\hub assy\\etc), recovery gear and camping gear I will be looking at probably close to 4000lbs which will be just right for my stump puller ACM360 and proper gearing...couple that with a front locker and I am SET.
 
Like you said though when you weigh 6000 it take a lot to get you out when you get stuck.  I was wheeling with my buddy and his 89 Full Size Bronco (Weighs in at 6200lbs) and he got stuck in 3.5ft mud.  That was fun to get him out...there is video of me doing it with my worked 4.2L I6, 3.31 Gears, 35s...I had to PULL HARD to get him out a few times and if his truck would have stalled...I think we would have had to call in re-enforcements.
 
Other issue, like you said, they were running the wrong tires for teh job most likely.  For what I prefer (rocks) lighter the better, really.  But my Jeep went thru 3ft of virgin snow when the I6 was in it...its all about traction\\flotation...you want just the right ratio.
Title: Leaf Spring Rate
Post by: Bill Mounteer on September 26, 2008, 08:07:53 AM
Yes, traction\\flotation are most important factors in mud and in some cases deep snow.  In mud the tire must compress the soup to get any traction so you want a very narrow tire that maximizes the lbs/sq in. In fresh snow the same applies, however in deep snow with a crust you want the reverse, a wide tire to minimize lbs/sq in so you stay on top of the crust. Scouts were great in mud and fresh snow, but they were just too heavy to float over most snow crust so we simply chained up all four wheels and kept the speed up.

About the only time a Scout would get stuck was getting it high centered or if it got into muskeg and ended up with the body sitting flat on the ground and all four wheels hanging in the soup. (http://www.moparfins.com/forum/smileys/smiley4.gif) 

The latter was the case when I required 3 trucks each with 8,000 Ramsey winches and snatch blocks to get free.  I had driven down a fairly steep line cut and out onto a nice grassy flat. Turned out the flat was surrounded by a beaver dam and the flat was really about 2' below the surrounding beaver pond.  All four wheels dropped through the top layer and the body of the truck ended up sitting flat on the ground. To get out, we had to spin the truck around 180 degrees so that I could use my winch along with the other three to literally drag the Scout about 50 feet before the wheels got traction. That adventure took about 5 hours and completely exhausted our beer supply. The only damage, one of the units twisted off a front axle u-joint and another mangled one of his locking hubs.  I had spares with me so all ended well. (http://www.moparfins.com/forum/smileys/smiley17.gif)

I miss my Scout!  (http://www.moparfins.com/forum/smileys/smiley19.gif)

My '06 Jeep has basically the same weight and if anything better traction since it has posi on both axles and front to rear, however the ground clearance sucks. All the computers and electronic controls are the biggest problem, break anything in the bush and you're walking out. I did a limited bush run last spring, no winch but with T-bar chains all round. In 4Low the hemi engine is totaly awesome, I think it would darn near climb a tree if the bark would stay on! (http://www.moparfins.com/forum/smileys/smiley36.gif)

Title: Leaf Spring Rate
Post by: Guests on September 26, 2008, 08:16:56 AM
[/QUOTE]
 
Oh I hear you...what do you have a Grand or a Rubicon?
 
My buddy has a 94 Grand Cherokee with 7" lift, 3" WB extension, plenty of fender trimming that sits on 35s.  He has done a nice job with it and it works REALLY nice.  The damn Grand's weigh appx 6,000lbs which is a lot more than i ever thought they would weigh.  But they flex like mad with the proper springs.  Pic of his below - at the time he was running 33s with 1" wheelbase extension:
 
(http://a677.ac-images.myspacecdn.com/images01/106/l_4ed908c379ab8afa8d7f195758e527dc.jpg)
Title: Leaf Spring Rate
Post by: Bill Mounteer on September 26, 2008, 09:10:46 AM

Grand Cherokee Limited  - 5.7 Hemi

I'm getting too long in the tooth for the deep bush so my unit is dressed up with every option known to man and definitely not a bush truck. In this country you simply can't do much without a winch and a truck easily repaired in the bush.

This is our country .. gives dragging home the bacon a whole new meaning! (http://www.moparfins.com/forum/smileys/smiley36.gif)

(http://www.moparfins.com/forum/attachments/25/Moose_1.jpg)

Fury4402008-09-26 14:12:20
Title: Leaf Spring Rate
Post by: Guests on September 26, 2008, 09:20:36 AM
[/QUOTE]
 
I absolutely LOVE it! (http://www.moparfins.com/forum/smileys/smiley36.gif)
 
I bust on all my buddies chops who have fuel injection (except on hill climbs LOL) because when they do break it takes quite some time to get them going again and usually its something stupid like a CPS or equivelant - I definitely hear you there.
 
I have a TBI kit that I made from junkyard parts and a custom harness I made - only cost me $65 between harness, most sensors (were good from the donor), ECU, and rebuild kit.  I am only $150 from bolting it on (need adapter plate for the manifold and fuel pump).  Other than I could just throw it on there, really.  Only problem I have is it still uses a computer and computers don't like moisture much...only plus is the system I am talking about it is easy to unbolt the TB, adapter plate, install a mech fuel pump and bypass the electric if I needed to get back home...just gotta keep the parts with me which I would!
 
Here i
Title: Leaf Spring Rate
Post by: Guests on September 26, 2008, 09:20:36 AM
[/QUOTE]
 
I absolutely LOVE it! (http://www.moparfins.com/forum/smileys/smiley36.gif)
 
I bust on all my buddies chops who have fuel injection (except on hill climbs LOL) because when they do break it takes quite some time to get them going again and usually its something stupid like a CPS or equivelant - I definitely hear you there.
 
I have a TBI kit that I made from junkyard parts and a custom harness I made - only cost me $65 between harness, most sensors (were good from the donor), ECU, and rebuild kit.  I am only $150 from bolting it on (need adapter plate for the manifold and fuel pump).  Other than I could just throw it on there, really.  Only problem I have is it still uses a computer and computers don't like moisture much...only plus is the system I am talking about it is easy to unbolt the TB, adapter plate, install a mech fuel pump and bypass the electric if I needed to get back home...just gotta keep the parts with me which I would!
 
Here is my beast - don't know if I have actually posted any pics up on here of her...
 
EvulutioN2008-09-26 14:22:03