help with my build in the uk

hi guys and happy new year from the uk.

i am sure i will be spending quite a lot of time here absorbing information and asking questions.
i have a 1996 xj auto and am planning to do full axle swaps on both front and rear,after a lot of searching and learning i have finally come up with a plan of action.

i have a long arm kit and crossmember here already,but i am also going to fabricate a setup for the rear utilizing a lot of landrover parts both stock and aftermarket.

After carefull thought and looking at the limited options that we have in the uk for big axles and aftermarket jeep parts i am going to use rangerover p38 axles and a a-frame 3 link setup on the rear.

this is not a vehicle that is intended to be a rockcrawler and i do not forsee running on anything larger than 35 inch tyres.

here is my first question..

a lot of you guys seem to run a 6.5 inch lift or thereabouts....can someone tell me the actual length of the coil springs before installation??

many thanks

mike

can't give you a length, but even if you get a length it may not be what you need.
depending on the spring rate, springs maybe be various lengths yet still yield the same amount of lift.

my old Rusty's 3" springs were more than 1.5" shorter than the 4.5" lift springs (just over 2") yet because the 4.5" springs had a lower spring rate they settled to the 4.5" of lift I wanted.

hope that makes sense.

I would say your best bet is to look at kits that are available for simular size and weight vehicles that you have access to. Compare what spring rates they use with that of aftermarket xj kits. This is where i would start

thanks guys

the spring rates that i want to use are 195lb/ft.I have these already and they are 17 inches long unladen.

i can get other softer springs but just to get things rolling along i am trying to get a good guesstimation before i start grinding and welding.

mike

chuggaman said:

i have a 1996 xj auto and am planning to do full axle swaps on both front and rear,after a lot of searching and learning i have finally come up with a plan of action.

After carefull thought and looking at the limited options that we have in the uk for big axles and aftermarket jeep parts i am going to use rangerover p38 axles and a a-frame 3 link setup on the rear.

Click to expand...

Mike, don't the Range Rover axles have both pumpkins offset to the left? This is okay for the front, but your rear propshaft will run at quite an angle.

hello gorman

the p38 front axle is in the same place as the jeep xj..........opposite to the landrover standard setup..

i have a choice of rear axles and can either have the disco axle with the diff centre 6 inches to the right as you look at the car from the rear or approximatly the same to the left if i use a p38 axle

mike

There is a fellow on the Hesco website that contributes to the bulletin board..he lives in the UK...and is known as "Limey Mark"...and appearently owns an offroad or high performance shop...register there and post up...i bet he can help you out.

"Limey Mark" runs MDG Offroad in Portsmouth - High quality work and lots of knowledge but not cheap.

I can see the draw of Landrover parts because they are so much cheaper and more available in the UK. However it's worth noting that the LR guys serious about offroading have started to use US parts - Dana 44 axles form Full Size Cherokees being popular. LR axles are also notorius for breaking offroad (although cheap to fix).

I also know someone who modified Toyota 80 series Landcruiser axles to fit with a Clayton coil conversion setup and there are other axles available (Nissan / Toyota)

Personally I'm sticking with built Chrysler 8.25 and Dana 30 axles to run 33-35" tyres.

Where in the UK are you? Have you joined JeepClub and other UK clubs?

Although not that common in the UK, there are 10-year old Ford Explorers making their way to the scrap yards. It's worth placing a search enquiry with the online parts companies. You could pick up a 31 spline rear axle with disc brakes for surprisingly very little.

Land Rover axles are cheap in the UK, but do you really want to spend a lot of money converting to an axle that breaks shafts on stock tyres? You would spend less installing Super35 shafts in your D35 and have better reliability, and keep your ABS a drum brakes intact (why?). Depending on locker/gear choice, the Chrysler 8.25" from a non-ABS 2.5L XJ is sensible option for UK XJ's as they are relatively easy to find.

Why keep the ABS intact? The British annual safety inspection (MoT) has recently been computerised nationally. MoT test inspectors are now being told by the system to check the operation of the ABS Failure Lamp for all vehicles that were originally equipped with ABS. My '93 hasn't had ABS for the last five MoT's but failed in November for the ABS lamp - it's still not fixed. My 2001 has a Ford 8.8 and disc brakes all round. It is going to be in a similar situation in March unless I can come up with an electronic circuit that will extinguish the ABS lamp within 20 seconds.

The C8.25 axle is limited to 4.56 gears lowest but locker selection is fairly good. I would have fitted a Ford 8.8 if I had found one at a sensible price, the 8.25 just jumped out at me one day.

Regarding MOT test, my ABS is disabled and the light is also disabled. I do think I'll remove the ABS system altogether this year to make it look like it came from the factory without ABS. So far I've had no problems with MOT on this issue.

Some Shit ive been working on-

Spring Rates-

Factory 6 cyl AT XJ Coil
Wire dia: .5"
Total Coils: 9 Active: ~8
Coil OD: 5.0"
Calc Spring Rate: 120 lb/in
Tested Spring Rate: 125 lb/in
Unloaded Height: 18.0"

Old man EMU
OEM Old man EMU XJ is supposedly 142-147 lb/in rate. 17" length 5.25" diameter
OEM ZJ with 4.0 is supposedly 190 lb/in rate front and rear.
OME 930 coils: 160 lb. spring rate. 1.75" of lift on XJ
OME 934 coils: 180 lb. spring rate.The 934 spring is 35 mm (1.37") longer than the 930 spring.
The 930 is listed as a XJ or ZJ I-6 spring and the 934 is listed as a
ZJ V-8 spring but is also used on the XJ. the 934 should give about 2.5in lift.
OEM is supposedly 147 lb/in rate. OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate

PORC
XJ 6.5" 185 lbs/in (22.5" long)

Pro-Comp
-Front Coils-

TJ 2" 170 lbs/in
TJ 4" 175 lbs/in
XJ 3" 230 lbs/in
XJ 4" 150-155 lb/in (19" Long) O.D. is 5.1" or 5.25"
ZJ 3" 220 lbs/in

RockKrawler
XJ 3"
XJ 4.5"
XJ 6.5" are 165 lbs/in
Rubicon Express

ZJ 4.5in coils are 240 lb/in. (22" tall long)
(RE 5.5XJ coils are 4.5ZJ coils.)
From Rubicon Express customer service email to T.N. (November 2004):
The 3.5" TJ fronts are approximately 240 pounds per inch. Uncompressed free length is 19"
The 4.5" TJ fronts are approximately 219 pounds per inch. Uncompressed free length is 19.75"

Rustys
XJ 3" 150 lb/in rate.
XJ 4.5" 150 lb/in rate, 22" tall unloaded
XJ 6.5" 150 lb/in (22" long), 12 wraps of 5/16" stock
XJ 8.5-9" 180 lb/in
Rusty's says "Most of our spring are built to 180lbs. Our 4.5" leaves are built to
150lbs. as are our 300 coils. The 305 coil is set to 180lbs."

Sky Jacker
ZJ 3" coils 218 lbs/in

Tera Flex
XJ 3" TJ coils have a 170 lb/in rate
XJ 4" TJ coils have a 200 lb/in rate , 20.25" tall unloaded

From TeraFlex customer service email to T.N. (June 2004):
TJ springs
SR3T- Free length= 15" Spring rate= 190
SR4T- Free length= 15.38" Spring rate= 210
SF3T- Free length= 19.5" Spring rate= 170
SF4T- Free length= 20.25" Spring rate= 200

Links-

From http://www.pirate4x4.com/forum/showthread.php?t=111316
From http://www.pirate4x4.com/forum/showthread.php?s=&threadid=87811
http://www.patricksnorton.com/bronco/lifttech.html
http://www.naxja.org/forum/showthread.php?t=14157
http://therangerstation.com/tech_library/coilspringrate.htm
http://www.cswnet.com/~carother/coil_spring_calculator.htm
http://www.proshocks.com/calcs/coilsprate.htm
OTHER USEFUL SHIT-

Tracker Sidekick 2dr Convertable
452.8 PPI Front 156.5 PPI Rear

Tracker Sidekick 4-dr
508.7PPI Front 177.9 PPI Rear

Ford Ranger 4wd front coils (Rangerstation.com) 500 PPI
Here are some facts about coil springs.

What is Spring Rate?
====================
Spring rate refers to the amount of weight needed to compress a spring
an inch (Example:500# per inch) To understand and properly check a
spring for rate you need to know the factors that determine the rate of the
spring. Fortunately, there are only three things that affect spring
rate, so there's not that much to remember!


1. Wire diameter. This affects rate since greater diameter wire is
stronger than lesser diameter wire. So, when wire diameter is increased,
spring rate increases.
2. Mean diameter of spring. Mean diameter is the overall outside
diameter of the spring less one wire diameter. When mean diameter increases,
the spring rate decreases.
3. Active coils. Determination of the number of active coils varies
according to spring design. Count the total coils minus two for springs
with both ends closed (includes all AFCOILS). Count the total coils minus
one for springs with one end closed and one end open. As the number of
active coils increases, the spring rate decreases.
If a spring's rate is linear (most racing springs have linear rates)
its rate is not affected by the load put onto the spring. For example, a
linear rate spring rated at 500#/inch will compress 1" when a 500#
weight is placed onto the spring. If another 500 pound weight is put onto
the spring the spring will compress another inch. At this point the load
on the spring has increased to 1000 pounds. The rate of the spring,
however, remains constant at 500#/inch.
If the load put onto a spring increases the rate of the spring, the
spring is said to have a progressive rate. Progressive rate springs are
sometimes used on torque arms to absorb engine torque. Keep in mind that
the load (or preload) put onto a progressive rate spring can greatly
increase the rate of the spring.
Typically, progressive rate springs are made by varying the spacing
between the springs' active coils. During compression the close coils
bottom out and deaden. This reduces the amount of active coils and spring
rate increases as a result.
Springs that are designed to include coils of different diameter or are
wound using a tapered wire will also produce a progressive rate.
Most coil springs are actually progressive to some degree

The front springs on a IFS Suzki (used in a A-arm aplication) are under
twice the load of those used in a solid axle configuration. In Short
most solid axle type coils will collapse under the leverage weighted
load on the front of a Suzuki IFS vehicle.
Pictured below are Cherokee fronts on a 4-dr Kick...

These springs are fully colapsed / bottomed out. They will not support
the weight of my Kick due to the IFS A-arm leverage.

Here is a formula to find the PPI measurment of Coil springs....

http://therangerstation.com/tech_library/coilspringrate.htm

Coil Spring Rate Formula:

11,250,000 - Torsional Modules For Steel (Constant)

CSPWD - Coil Spring Wire Diameter (How thick is the wire?)

8 - Constant

NOAC - Number Of Active Coils (Coils that are free to move. Not coils
seated. It may be that 1/2 of the top and bottom coil is seated
causing a spring with 8 coils to have the distance of 7 free.)

CMD - Coil Mean Diameter (The diameter from center to center of the
coil. Measure the diameter of the coil from wire center to wire center. If
you know the coil is .5 inches thick and the outside diameter of the
coil spring is 3 inches, then the Coil Mean Diameter would be 2.5
inches)

(11,250,000 x (CSWD x 4)) {Divided by} (8 x NOAC x (CMD x 3))

All Measurements in inches - Enter as decimal
For Inch Fractions To Decimal Chart, Click HERE
http://therangerstation.com/tech_library/fractionstodecimals.htm
Those Ford Ranger Guys at therangerstation.com have certinly done their
home work and have a very nice site.

English XJ said:

Regarding MOT test, my ABS is disabled and the light is also disabled. I do think I'll remove the ABS system altogether this year to make it look like it came from the factory without ABS. So far I've had no problems with MOT on this issue.

Click to expand...

Both of my XJ's have the same treatment. However, if you look at your last MoT test sheet, does it mention that the ABS lamp must be tested? Some MoT testers have been taking a realistic attitude concerning ABS that is clearly missing from the Jeep but the powers that be are getting tougher on them.

As far as I know, there are only four ways of passing the MoT test with a modified Jeep originally equipped with ABS.

1) To have fully functional ABS.
2) Use an additional circuit that prevents the ABS lamp from being lit for more than 20 seconds.
3) Put the Jeep through SVA testing to get a new Single Vehicle Type Approval certificate.
4) Have the Jeep tested by an MoT tester that knows what a safe braking system looks like.

Vince, PM sent to avoid completely hi-jacking this thread.

Just to throw a red herring into the works.

I was talking to a LR guy in my club a few days ago. He was saying that you can use Toyota HiLux third members and Bobby Long shafts to make a pretty robust Disco axle. Still gotta solve the offset diff part of the equation though using the Disco housings.

Vince said:

Avatar

Click to expand...

Damn Jack has gotten big.

thanks for your replys guys...specifically the length information..

i am in south wales...

thanks alo for your advice with sourcing dana axles in the uk...and the mot regs..

i am going along the landrover axle route for two reasons..

mainly because i truly believe that having the halfshafts as the weakest link is good for fireld repairs and keeping other parts of the drivetrain in good health.

and i love a challenge...

i ran a locked disco with 6 inch lift and 36" simex on 24 spline shafts with no problems except for the rear pinion angle.so i am quite confident that i can make this work...

the abs will probably be removed completly and an sva test will be done also......

i was anticipating that 17 inch coils with 190lb rating and the upper mounts that i need to fabricate (probably 3 inches lower than stock) will provide me with the tolerances that i need to fit these axles...

i should be starting this in a week or two so i will do a thread on the build...

once again thanks for all your help

mike