I am considering doing an axle under conversion to get some more clearance for bigger tires. I have a 2.5" suspension lift and a 2" shackle (which I am getting rid of) lift. I hear an axle under set up is much better for finding the right angle for your drive shafts and you don't have to lower your transfer case. Has anyone heard of any problems by going this route????
Axle under changeover
- Thread starter 76cj7nola
- Start date
Joopin
Super Moderator
33" baja claws
By "axle under"... do you mean Spring Over Axle? Finding the correct driveline angle depends on what type of shaft you have. A CV shaft helps alot with lowering angles of the driveline but is usually paired with a sye.
My Yj is SOA'd with a sye and CV driveshaft with no T-case drop. even after almost 7 inches of lift. Tell me what shaft you plan on runnin and I'll tell you what angles you need.
By "axle under"... do you mean Spring Over Axle? Finding the correct driveline angle depends on what type of shaft you have. A CV shaft helps alot with lowering angles of the driveline but is usually paired with a sye.
My Yj is SOA'd with a sye and CV driveshaft with no T-case drop. even after almost 7 inches of lift. Tell me what shaft you plan on runnin and I'll tell you what angles you need.
Yes I am talking about a spring over axle set up. I still have my factory drive shaft in place and was planning on keeping it if it is not a problem. When it comes to working on the motor I can talk shop.....But when it comes to suspension I am in grade school. I was taking advice of a friend that did it on his 84 cj7 (all custom w/t chev 350, turbo 400 trans, custom axles, 4" suspension and spring over). His jeep rides much better than mine the way it is set up now (which is the way I bought it). I believe the biggest part of my problem is the 2" shackle lift.
TwistedCU
Active member
Well I can definately tell you that your stock driveshaft, correct angle or not, will simply be too short. SOA nets around 5" lift. Add 2.5" for your existing springs and the 7.5" of lift you will have will require a longer driveshaft. Your buddy with the SOA, if he has 4" lift springs in a SOA config, he must have redone his steering and driveshaft(s) to compensate for 9" of lift.
I think you have it backwards, as a SOA or any large lift will make it more difficult to acheive the proper driveshaft angle. THe pinion would have to be rotated upwards which will increase axle wrap, possibly neccessatating traction bars to correct. The stock driveshaft output should be replace to a fixed output and the driveshaft changed to a CV type which will allow a greater angle. The new driveshaft will telescope to compensate fot the fixed output (Slip Yoke Eliminator).
What size tires do you want to be able to clear?
I think you have it backwards, as a SOA or any large lift will make it more difficult to acheive the proper driveshaft angle. THe pinion would have to be rotated upwards which will increase axle wrap, possibly neccessatating traction bars to correct. The stock driveshaft output should be replace to a fixed output and the driveshaft changed to a CV type which will allow a greater angle. The new driveshaft will telescope to compensate fot the fixed output (Slip Yoke Eliminator).
What size tires do you want to be able to clear?
currupt4130
VT Hokie
ehhh yea, theres no way in hell your getting away with running a slip yoke or the stock drive shaft, the shackles only further increase flex over the stock ones, they allow the spring to travel farther up and down by moving with the spring, 2 inch lift shackles are kind of big and may be swaped for some angled shackles for better flex if you runt he cheapest route, fab everything yourself, look at easily 500 to 600 dollars for the slip yoke and driveshaft if you want decent quality, pitman arms off zj's give you a 3.5" drop and xj pitman arms do 2.5" drop, grab a trackbar bracket, or if you wanna do it right, get a d44 fron axle, flat top knuckles off a chevy and custom high steer it, MORE makes a knuckle for the d30 that has high steer built in
currupt4130
VT Hokie
my fault, its samsoffroad.com that makes the knuckle, more has lots of good stuff for an soa tho, mountainoffroad.com, also look into a shackle reversal
Joopin
Super Moderator
Dual Gas Tank
This will give you a good idea of what you need to do for the driveshaft angles.
www.4xshaft.com
Just click on the tech link on top of the page.
This is the place where I got my CV shaft and SYE too, they sell both to your door for $525. You just need to get some measurements for them to make your driveshaft.
This will give you a good idea of what you need to do for the driveshaft angles.
www.4xshaft.com
Just click on the tech link on top of the page.
This is the place where I got my CV shaft and SYE too, they sell both to your door for $525. You just need to get some measurements for them to make your driveshaft.
I did not realize how much of a lift you get with an "SOA", I am only running 33" tires right now and just want to go to 35". Would it be better to go back to the factory springs get rid of the shackle lift and just do the "SOA"???? If I am understanding all of this correctly, that would give me 5" of lift (big enough for 35" tires?) and a better ride on the highway? Would I still have to change my drive shaft?
I feel suspension challenged!!!!!
I feel suspension challenged!!!!!
Joopin
Super Moderator
If you plan on wheelin' it, I would invest in the sye cv shaft combo. Otherwise you have to guess on the angle of your stock shaft, then worry about it slipping out of the Tcase when you wheel. I have heard of some people getting away with it, but I dont recomend it.
Also I would take a good look at your stock springs if your using them. Are they the originals? Are they almost flat? If they have good arch then they are most likely fine for an SOA. But if they are beat then they wont last long and flatten even more with an SOA. Stinkycheeseman here on jeepz.com has a spring over with flat springs, running 33s. You could replace the springs or install an AAL to add some life to them. Just a heads up.
Also I would take a good look at your stock springs if your using them. Are they the originals? Are they almost flat? If they have good arch then they are most likely fine for an SOA. But if they are beat then they wont last long and flatten even more with an SOA. Stinkycheeseman here on jeepz.com has a spring over with flat springs, running 33s. You could replace the springs or install an AAL to add some life to them. Just a heads up.
TwistedCU
Active member
I would use the stock springs if you still have them. You can recoup some of your money by selling the lift springs.
Alot of guys argue that this lit I'm sending you a link to is a waste of money because all this stuff can be fabricated at home much cheaper, but it is probably the way I am going with my YJ when I get the motoer squared away:
http://full-traction.com/detail.php?MODELID=1&MAKEID=1&TYPEID=1&PRODUCTID=151&NOTES=10
Alot of guys argue that this lit I'm sending you a link to is a waste of money because all this stuff can be fabricated at home much cheaper, but it is probably the way I am going with my YJ when I get the motoer squared away:
http://full-traction.com/detail.php?MODELID=1&MAKEID=1&TYPEID=1&PRODUCTID=151&NOTES=10
Do you have a YJ or a CJ?
CJs don't need a SYE. A 4" suspension and the right offset on the wheels will clear 35s.
Don't use factory CJ springs with that SOA. ANY factory CJ spring is already worn out simply by supporting the weight of the vehicle for all these years, adding the stress that a SOA puts on the springs will make them sag very quickly.
Don't take this the wrong way(especially since I'm not running SOA either).......but SOAs are for the big boys. In order to just clear 35s by doing a SOA is going to require using the factory springs or it's going to sit really high. Factory springs sag very quickly with a SOA. Everybody has their opinions......that's mine. Works great for about five minutes, then you need some new spring packs. Once you get the hunger for something along the lines of a wide 38" tire THEN start thinking about the "axle flip". You'll be happier in the long run with it SUA and using a lift spring.
CJs don't need a SYE. A 4" suspension and the right offset on the wheels will clear 35s.
Don't use factory CJ springs with that SOA. ANY factory CJ spring is already worn out simply by supporting the weight of the vehicle for all these years, adding the stress that a SOA puts on the springs will make them sag very quickly.
Don't take this the wrong way(especially since I'm not running SOA either).......but SOAs are for the big boys. In order to just clear 35s by doing a SOA is going to require using the factory springs or it's going to sit really high. Factory springs sag very quickly with a SOA. Everybody has their opinions......that's mine. Works great for about five minutes, then you need some new spring packs. Once you get the hunger for something along the lines of a wide 38" tire THEN start thinking about the "axle flip". You'll be happier in the long run with it SUA and using a lift spring.
Junkpile said:
I have a 1976 cj7 with a AMC 304 V8, 3 speed T150 transmission, AMC 20 (4:1) rear end, model 30 front end and 33x12.50 super swampers. The only modifications are a 2.5" suspension lift and a 2" shackle lift (both done by previous owner), new 21 gal fuel tank, electric fuel pump, and a one piece axle kit (done by me). A friend of mine still had his factory springs left over after he did his modifications and gave them to me in case I need them. When I dive down the highway I am all over the place, this is the problem I want to get rid of and will take any suggestions on how to get there. I do want to go to 35" tires for more axle clearance but that is secondary. Should I just go with a higher suspension lift and 0" shackles if so how much lift do I need to facilitate 35" tires?
Oh yeah I also have installed a dropped pitman arm to improve my steering but it hasn’t helped much.
Joopin
Super Moderator
Fog Light wiring questions
Sure your lstock springs will sag after a certain period of time with an soa, thats why you buy an AAL (add a leaf) and a FULL leaf AAL. It will acctually give your springs 2.5 inches of lift but after they settle they go down to 1.5... 7 months later my AALs settled down an inch and arn't sagging at all. The only thing that has made them sag is the spare tire carrier i built along with the 36" spare... must wiegh 300 lbs. all together!
I think you should swap your CJ springs for YJs, get rid of the shackle lift and do the SOA if you want to clear those 35s
Rancho makes good AALs... though any AAL will give you a stiffer ride i think.
Sure your lstock springs will sag after a certain period of time with an soa, thats why you buy an AAL (add a leaf) and a FULL leaf AAL. It will acctually give your springs 2.5 inches of lift but after they settle they go down to 1.5... 7 months later my AALs settled down an inch and arn't sagging at all. The only thing that has made them sag is the spare tire carrier i built along with the 36" spare... must wiegh 300 lbs. all together!
I think you should swap your CJ springs for YJs, get rid of the shackle lift and do the SOA if you want to clear those 35s
Rancho makes good AALs... though any AAL will give you a stiffer ride i think.
Similar threads
