Lengthening Wheel Base

Badcop

Who Dat? Who Der?
Location
Hyrum UT
I want to move my wheel base on the XJ 2" in both directions. Since I have never done it or read about it being done I tend to think If I adjusted the long arms in the front and redrilled the spring purch in the rear that would do it? If you have a better way than bring it on, I could use the ideas.
 

grinch

inner city redneck
Location
Salt Lake City
The back can be as simple as that.... It will cause your spring rates to change a bit because of where the axle will be located on the springs. We did this to are old K5 blazer we used to compete UROC with a few years ago to stretch the front and back.
The front is not so easy. I havnt tried it on an XJ but things to consider... If you want the pinion angle to stay correct you need to lengthen the top and bottom control arms the same amount. Your steering will move and might cause bump steer or even worse binding so you might have to move steering components. Theirs also track bar issues. It will need to be moved. Then there is always the fact that your coil springs will now be 2 or so inches off center of the axle....
Just some things to think about before you start tearing stuff apart
 
Location
Murray
There's a xj at mepco that's stretched a little. I haven't looked real close at it though so I couldn't tell you what it needs.
You're going to be drilling all day if that's your plan. The springs are made of hardened steel. You'll go through a lot of drill bits and you can't torch through it because you can't heat them up or they'll lose their spring rate.
A better rout that most XJ guys go with is to flip the spring around. The pin is offset towards the front so when you flip the spring around the pin is offset to the rear. You will have to shim or re-mount your spring pads. I can't remember how much this moves the axle back but 2" sounds about right.
In the front you probably don't have enough threads on your arms to strecht two inches unless you have a Clayton long arm kit. You might have to have your arms modified or remade. You'll have to watch the bump stop tower inside the front spring. Two inches will move the spring awefully close to hitting the bumpstop. Also, you may have to have a bend put in your trac bar and drag link to clear the bracketry. Other than that you should have plenty of clearance with the gas tank and such. Plan on lots of fender trimming as well.
 
Location
Murray
If Grinch has done the drilling thing and it wasn't that bad then listen to him. I haven't done it but I have tried to drill through hardened steel and it isn't fun.
 

grinch

inner city redneck
Location
Salt Lake City
Its not fun at all. A drill doctor and Harbor Freight drill bits are your friends on this occasion. So is a drill press. Im not sure on the XJ leaf packs but the chevys I have done all we did was drill the main leaf and slide the shorter leafs back a couple of inches. Still a Major drilling feat. Hardened still is not fun to go through.
 
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RockMonkey

Suddenly Enthusiastic
Do the rear first, and try that. It may be enough to do what you want to do. 4 inches of wheelbase change is a lot, and you may find out you don't really want it that long.
 

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
You can't go back 2" this way, but it's FAR easier to drill a new hole in the spring perch (on the axle) than drilling through the springs. You can probably get 1.5" or slightly less that way.
 

grinch

inner city redneck
Location
Salt Lake City
I Lean said:
You can't go back 2" this way, but it's FAR easier to drill a new hole in the spring perch (on the axle) than drilling through the springs. You can probably get 1.5" or slightly less that way.
I've done this on my scrambler and was able to get another inch and a quarter. It was much easier than drilling the spring. It did however make it start spitting out shims. The fix for that was to cut off the spring perches and re weld them back on at the correct pinion angle.
I am on agreiance with I Lean on this one do the rear first. It changes a lot more than you think. If you go to long you start killing break over angles. Hitting drive lines when you used to not. Getting high centered. ect.
 

Tacoma

Et incurventur ante non
Location
far enough away
wait... so you guys are just moving the pin on the springs, and not moving the spring mounts?? I skimmed, so forgive me if I missed the point lol..

That sure seems a lot easier than rewelding the mounts....
 

Hickey

Burn-barrel enthusiast
Supporting Member
I'm with Ilean. I did this to my CJ5 and it was relatively easy. Some aftermarket spring perches have 3 holes in them, I just used the rear hole, and drilled a new hole in the u-bolt plate to match it.
 

Caleb

Well-Known Member
Location
Riverton
Hickey said:
I'm with Ilean. I did this to my CJ5 and it was relatively easy. Some aftermarket spring perches have 3 holes in them, I just used the rear hole, and drilled a new hole in the u-bolt plate to match it.


rubicon express used to offer some pads that were offset by about 1.5" and had some extra length...I don't know if they still do.
 

Badcop

Who Dat? Who Der?
Location
Hyrum UT
redrilled the spring purch in the rear that would do it?
(just to clear itp, I WILL NOT DRILL OR TORCH THE SPRINGS, lol)

What I was really seeking by moving both axles was to give the X a better stance then what was factory. Right now even with 3" trimmed off the fenders, the front axle movement will collide the tire with the lower/back part of the fender/door mounting.
 

958mtm

Registered User
Location
slc
Why not cut off and re-weld on the mounts to the body. If needed just replace the mounts with new ones.
 

kirk86CJ

Registered User
Location
Riverton, Ut
I did exaclty what Hickey did. I got a pair of stock replacement spring perches from the Dodge dealer on 2100 S State. They only cost about $10.00/pair - if I remember correctly. These perches came with the 3 holes as described. I cut the old ones off and set the new ones for a correct pinion angle. I don't understand why people screw with shims when moving the perches is so easy.
I think I gained between 1 1/4" - 1 1/2".

You may need to get your driveline legnthened - I could see the spline when I moved it back.
 

mbryson

.......a few dollars more
Supporting Member
Badcop said:
(just to clear itp, I WILL NOT DRILL OR TORCH THE SPRINGS, lol)

What I was really seeking by moving both axles was to give the X a better stance then what was factory. Right now even with 3" trimmed off the fenders, the front axle movement will collide the tire with the lower/back part of the fender/door mounting.


It sounds like you're too far back from stock now? When I ran my 35" tires on my XJ I had rub marks on the front and rear of the wheel tub. I'd adjust the length of the suspension links (don't thread things too far out) somehow. I don't know how much I had trimmed off the fenders (a lot) but they were not an issue in uptravel. I LOVED the 101"ish wheelbase. How are your bumpstops?
 

Badcop

Who Dat? Who Der?
Location
Hyrum UT
bumps are fine, I went out and looked after reading all the ideas, I think its just because when I trimmed the front fenders I didnt do it far eanough back and close enough to the doors.
 

RUYellow

Under Construction
Location
Eagle, ID
Remember, in the front as you lift it higher, you are shortening your wheelbase.

most aftermarket adjustable short arms will only get you back to stock wheelbase with a lift.

It is proportional, adjustable arms maxed out and 3" of lift will give you a longer wheel base than the same arms with 6" of lift. This is of course static ride height.
 
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