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View Full Version : How can I increase the wheelbase? (40)


nakman
08-03-2006, 11:42 PM
And so the mods begin...

Is there a way to slide the rear axle back like 2-3"? Flip the spring around, or get a different spring, or do I have to get a longer spring then have someone weld on a new hanger further back? Just think it looks goofy with the rear tire tucked so far forward, plus with the longer wheel base it would be more stable.

And after seeing this pic I'm putting the hard top on this winter for sure. :cool:

Shark Bait
08-04-2006, 12:28 AM
Aw crap, well now I'm reading ads for 40 stuff. Anyway this seems like a good deal for someone.. 4 speed + tcase http://forum.ih8mud.com/showthread.php?t=104035

You ought to change the title to "Nakman's 40 Build Thread" :lmao:

You need an SM420, too. :lmao: :lmao: :D

treerootCO
08-04-2006, 12:39 AM
The axle is going to move rearwards under compression so don't move it too far back. Flipping the springs would require body mods. You can redrill the lower spring closer to center and I think it would be fine. Keep in mind the pinion angles will change and any addition in length will require drive line modifications and brake lines may need lengthened.

IanB
08-04-2006, 06:15 AM
Reverse the rears or 55 rears or link it. Treeroot is right though, you will need to mod the bod.

I reversed front and rears using the existing mount points and my wheelbase is 98 1/4".

Rzeppa
08-04-2006, 07:03 PM
Flip the rear springs and take a sawzall to the fender wells. You must retain the leaf with the military wrap in it's original orientation and redrill it for the new center pin location. Don't forget that will cost you retubing your driveshafts, I paid $236 at Englewood Driveshaft when I got mine done for my 4 speed conversion a few weeks ago. You can also use pig springs, as has been mentioned. Since they're longer you'll need to cut off, flip around, and reweld the rear shackle perches. As above, you'll still need to get your drivelines changed.

The thing about pig springs is that you've currently got a 4" lift IIRC, so you'll have to figure out how to lift the rear to the same as the front.

nakman
08-05-2006, 10:06 PM
Flip the rear springs and take a sawzall to the fender wells. You must retain the leaf with the military wrap in it's original orientation and redrill it for the new center pin location.

Ok that makes sense, thanks Jeff. I'll probably take a "wait & see" approach to the sawzall though.

bh4rnnr
08-05-2006, 10:28 PM
If you flip the bezel, everything else will look better:hill: :lmao: :beer:

treerootCO
08-06-2006, 12:34 AM
Lookin' for little meats with OE rims???? Why not make a donation to the raffle rig? I am betting the committee would sell them to you.

IanB
08-06-2006, 07:59 AM
Ok that makes sense, thanks Jeff. I'll probably take a "wait & see" approach to the sawzall though.

You will need it, with 33's I had to cut the wheel wells and that was before I reversed the springs.

Don't forget, if you reverse the rears you will need a new driveshaft and your pinion angle will be wrong. You can either cut off and reweld the perches or shim it, shims would most likely suffice.

Rzeppa
08-06-2006, 09:08 AM
I run 33x10.5 with 2-3" lift and the rears stuff nicely inside the rear fender wells without needing to cut. 33x12.5 would need some trimming though. He's currently got 33x9.5 with 4" lift so he's fine right now, but moving the rear back would definitely require cutting some off the back for the wheel opening.

IanB
08-06-2006, 09:40 AM
Ahhh, i was running 12.5s.

MDH33
08-06-2006, 09:58 AM
I just put some 31x10.5's on my 40 with a 3 inch lift and I think they fit great. They don't have that "stuffed-into-the-fender-well" look and they have plenty of clearance without needing to cut anything.

bustanutley
08-07-2006, 09:29 AM
Stretched 12"

http://www.homegrowninc.us/images/whips/nutley/2.jpg

:headbang: :weld:

Hulk
08-07-2006, 02:40 PM
I'm running 33 x 12.50s with a 4" lift, and no trimming was req'd. However, I have an '81 FJ40, and the springs are different (more like FJ60 springs).

Rzeppa
08-07-2006, 03:03 PM
Starting in production month 8/80, 40 series spring eye diameter increased, but the eye to eye length is basically the same for all 40s. A 4" lift never needs trimming for 33s, but a 2.5" lift does for 33x12.50.

nakman
08-07-2006, 04:58 PM
As long as we're digressing...

I've got about a 3' tall pile of 2" granite next to my driveway, left over from my camper parking space project. It's been there about 6 months, occasionally I'd park the 80 or Runner with one wheel up on it to flex it out a little, you know pose one up for the neighbors, etc. It used to be higher, but the trucks had compacted it down quite a bit.

Anyway yesterday I parked the 40 on it, and ended up mashing about a 8" ditch right down the middle of the pile. Physics will always follow the path of least resistance, so in this case it was easier to mash down a ton of rock that had already been compacted by two other trucks, than to flex out a 4" Skyjacker lift under a 40.

Ok, the tires of the 40 are a little narrower too so it's not all about the leafs.. and we already knew coils flexed further, I thought that was funny though, in light of this discussion about flex and the need to trim.. still having a hard time worrying about too much flex! carry on.

PabloCruise
08-08-2006, 11:10 PM
Check my thread here:

http://forum.ih8mud.com/showthread.php?t=45757

I put on a 4" lift and flip the rear spring pack to p/u ~3 inches.

(insert off-color joke here)

PabloCruise
08-08-2006, 11:11 PM
You can aks Kipper how he liked the flex...