CJ to Wrangler height conversion?

Kane · 03-09-2010, 10:31 PM

A stock wrangler has a flat spring, duh we all know that.
A stock CJ has some curve to it. duh again.

So what does a lift of 2.5 inches equal for a CJ if you were to use a wrangler lift spring? Because that arch would be different for each lift due to the difference in stock arch. Would a 4 inch wrangler spring equal a 2.5-3 inch CJ lift. Inquiring minds want to know.

tdkask · 03-12-2010, 11:18 PM

I'd like to know this too. If a 4" CJ kit clears my 33's fine, would a 4" YJ kit have the same clearance? Or is a 4" YJ like a 2.5" CJ?

LASTCJ786 · 03-14-2010, 04:42 PM

I know you can run YJ rear springs on a CJ. I think a 4" lift is a 4" lift
from stock on any Jeep.

TDHofstetter · 03-14-2010, 06:00 PM

It's gonna' be close - I know. I happen to be in exactly that position right now - a couple days ago I dragged home a set of Wrangler springs for one of my CJs. Didn't notice then that they're lift springs, but it's sure obvious now. I WANTED flat springs... oh, well.

They're lifted about 4", and it takes a lot of weight to flatten 'em at all. They'll wind up being a good solid 4" lift, I'm sure, when I've done the conversion (which I may not DO now, unless I can get hold of a set of real STOCK springs).

73CJ · 03-14-2010, 09:42 PM

2.5" Cj is close to 2.5" YJ but all depends on the spring rate of the pack. Do some Goggling on spring manufactures. They give the spring rate, lengths etc.
My Trail Master 4" had a spring rate of 500#/in. Rode like a tank and cracked the frame by the spring perches. Do not recommend TM. Besides they wouldn't honor their lifetime warranty on shocks.

I've got YJ 2.5" OME now with a rate of 230#/in or so. They are great.

81laredo · 03-18-2010, 09:50 AM

would a set of Warngler Springs on the rear of my '81 CJ7 produce a smoother ride?

TDHofstetter · 03-18-2010, 10:29 AM

It might, but it might also produce a rougher ride. It depends upon the spring rate.

CJs and Wranglers were all produced with three different spring rates each - soft, standard, and heavy-duty. If your CJ currently has soft springs and you switch to YJ heavy springs, your ride will turn into something similar to that of a farm tractor. If your CJ has standard springs and you switch to YJ standard springs, you may not be able to discern the difference; they compress about as much per inch of travel. If you switch to SOFTER YJ springs, or softer CJ springs, your ride will soften.

Old Dog · 03-18-2010, 11:03 AM

Quote:

Originally Posted by 81laredo

would a set of Warngler Springs on the rear of my '81 CJ7 produce a smoother ride?

Quote:

Originally Posted by TDHofstetter

It might, but it might also produce a rougher ride. It depends upon the spring rate.

CJs and Wranglers were all produced with three different spring rates each - soft, standard, and heavy-duty. If your CJ currently has soft springs and you switch to YJ heavy springs, your ride will turn into something similar to that of a farm tractor. If your CJ has standard springs and you switch to YJ standard springs, you may not be able to discern the difference; they compress about as much per inch of travel. If you switch to SOFTER YJ springs, or softer CJ springs, your ride will soften.

81 here's a link that might help you understand what Tim ia talking about
1976 - 1986 Jeep CJ Leaf Springs
Look at the spring rates for both the cj and the yj to see how they differ.

81laredo · 03-18-2010, 04:53 PM

that answers my question.
I have the OEM 6 leafs in the front and 6 leafs in the rear, this looks to be heavy duty springs fore and aft. I did notice the CJ get a bit stiffer with the new polyurethane spring and shackle bushings and shocks (not heavy duty) but some of that was expected since the old parts may have been original. The CJ rides much better with a couple hundred pounds in it (wife and dogs).
I wouldn't mind if the CJ was a bit lower so looks like just shifting to 4 or 5 leaf springs would help, by the way it does ride similar to my Ford 8N Tractor right now.
Could I simply remove one of the spring to get a softer ride or could this create more trouble? If so which one would be the correct one to pull out of the spring pack.

Kane · 03-18-2010, 08:46 PM

81Laredo I have done this before with good results. it is just like when someone puts an add-a-leaf lift and the ride gets stiffer. Generally people will pull out the second or third longest leaf. I saw about a 3/4 inch drop on mine when i had Pro-comp springs. they are stiff springs and this helped allot for ride quality.