I've been doing quite a bit of research on SOA's and have found different info on the front axle. Some people cut and turn the knuckles, while others adjust the spring perches to get the right pinion angle and steering geometry. Is there a correct way, or is this a matter of preference? I would think that simply adjusting the spring perches is trying to get out of some initial cost, but might not be the best in the long run. Anybody have some good input?

Adusting the spring perches will affect your caster, therefore affect your steering and handling. If you can get away without cutting the knuckles fine (if you don't have too much lift) But if you do have too much lift and a steep front shaft that will bind, then your only choice is to cut and turn the housing. Back in the old days I never used to cut and turn, but now I cut and turn every SOA I do. You just cant beat getting the driveshaft up out of the way from rocks, and saving your yokes from getting destroyed from too much binding.

Bottom line: Cut & Turn...

Jeff

The perches are moved to adjust pinion angle only. Cut and turning allows you to do this (turn the pinion up) and retain decent steering characteristics. The perches get moved to the top of the axle either way. Some don't do either. I would suggest if you drive mostly on road, that you will appreciate the effort of restoring caster specs. I am sure some one will share a different opinion for you to consider.

Since you are doing the aspring over you have to weld on the spring perches, you can set the caster while doing it. You can set up the housing with as much or as little caster as you will like by placement of the perches, but without cutting and rotating the knuckles, this will directly affect the pinion angle... Steep pinion angles lead to driveshaft binding, vibrations and more frequent pinion failure.

Ideally I think you should set up the caster to be a few degrees positive(4-5 or so) and aim the pinion at the front output of the transfercase. this will require cutting and rotating the knuckle balls. steering safety should be number one concern, for you and others...

If you think you might want to rotate the pinion up, do the whole deal at once so you will not have to reweld the perches once you want to...with a longer drivetrain it is not as crucial to rotate up but with a real short drivetrain it is almost imperative.

Pinion angle without rotating the knuckles but retaining correct caster.:emb4:

Pinion angle after keeping correct caster 1 degrees and cutting and turing the housing 16 degrees.:)

I had 8* positive caster built into my front axle and it is SWEET! Tracks and turns so good!

If you are doing a shackle reversal in conjunction with the SOA project, then the cut-turn is a "requirement" to have any chance of the driveshaft not binding and still get decent steering manners.

If you plan to leave the shackles in their stock location, then the cut-turn is "optional" but recommended. The pinion rotates up on droop if you leave the shackles at the front, reducing the severity of pinion bind but you still leave yourself with the handling issues.

Stock caster is +1 degree from the factory. Longer shackles often kick this to +.5 or 0 degrees. With 29" tires, no biggie. With 35-38-bigger (nolen-sized) tires, 0 degrees will suck. Bigger tires like more caster. Easier to steer and handle. Mine is in the +3 range and very workable on and offroad.

Jeff's two simple pictures offer the most convincing argument I have seen or heard for why you really should cut and turn the knuckles in doing a spring over conversion. His pictures are truly worth a thousand words.:D

I have flat stock springs...I did not cut and turn...I run a CV shaft up front to take care of the binding issue...I have no problems with front pinion clearance on the trail...I can let go of the wheel at 75MPH on the freeway and my rig tracks straight as an arrow...I run 35x12.50x15 ProComp Xterrains...I do not have a shackle reversal...my future plans for a front axle include a D60, so I opted to not cut and turn...if I was planning on keeping the stock front axle, I would have cut and turned...if you plan on running a similar setup like mine, don't cut and turn, you will be fine...I have several buddies that also run the same setup and they have described the same positive results without the cut and turn...my 2 cents!

OK, SO POSITIVE CASTER IS IF THE AXIS THE WHEELS ARE TURNING ON IS TILTED FORWARD, INTO THE GROUND, CORRECT? THEN WOULDN'T LONGER SHACKLES INCREASE CASTER IN A STOCK SHACKLE CONFIGURATION? BECAUSE THEYDROP THE FRONT OF THE SPRING, POINTING THE PINION UP AND THE WHEEL AXIS DOWN INTO THE GROUND? :confused:

I think the pictures tell me all I needed to know...(thanks, dog walker)
As far as the shackles helping out with caster, fixxxxah, it makes sense that longer ones would point the pinion upward in a stock configuration, but I think those shackles would have to be hecka long...maybe 6-8 inches or so??? I'm still thinking it over as I post this.:confused:

it makes sense that longer ones would point the pinion upward in a stock configuration,

This is true, but this is not a good thing, it creates positive caster which is what will cause the wandering and the sudden feel of no control when you hit bumps and ruts in the road.

Why do you think in a SUA set up when you go with lift springs and/or longer shackles you need to use shims (slide in backwards) to make up for the caster change. It's becasue your cruiser will handle like crap otherwise.

Jeff

Its quite simple. In order to have 5-8 degree's negative caster, your pinion will simply point down. Therefore, if you want great tracking, easy steering, and safety, then cut and weld. It costs money you say? Then sell the beast, cause the costs are only beginning.

Shaun:D

Positive caster is where the top trunion bearing is rotated BACK of the lower trunion bearing....drawing a line thru them would angle the line back. It's opposite what you would think it should be.

http://www.familycar.com/alignment.htm should answer any questions.

My question. Some say that when going soa you should cut and turn the knuckles. Others say, its fine. The LC is useing stock springs. I already understand caster and pinion angles. I just want to know who is running this setup without cutting and turning without any problems.

Just went through this last week:

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=73609

A) search the Cruiser portion of this site

B) search/browse the forum at ih8mud.com

C) read the tech links at ih8mud.com

D) come back with any questions that haven't been answered.

Happy hunting!

Originally posted by woody
A) search the Cruiser portion of this site

B) search/browse the forum at ih8mud.com

C) read the tech links at ih8mud.com

D) come back with any questions that haven't been answered.

Happy hunting!

I think we should have Jeff change the title of his sticky at the top to

"IF YOU DON'T READ www.ih8mud.com DON'T POST!"

:flipoff2:

Originally posted by GloNDark


I think we should have Jeff change the title of his sticky at the top to

"IF YOU DON'T READ www.ih8mud.com DON'T POST!"

:flipoff2:

Yeah - do not pass "GO" - do not collect $200 - and have to roll a double before you are allowed back on the board:D

hehe


non SOA reply :flipoff2:

Originally posted by Deep South Cruisers
non SOA reply :flipoff2:

REBEL!

...heh heh

AND, speaking of ih8mud.com, I haven't made any updates since July 31...which means you lazy losers need to get off yer behinders and start writing down the junk you change on yer trucks so I can get more links/content!! (subtle, aren't I??)

i just couldnt resist the urge to reply :flipoff2: hehe

Originally posted by Mr McGee
i just couldnt resist the urge to reply :flipoff2: hehe

bahaha, wonder if hell catch on?? :flipoff2:

I am going to actually give a usefull answer since I did not reply to the thread last week:

I have been SOA since about 1995. I did not cut & turn - we bolted everything up, and tacked the perches when the ujoint angles were good on both ends - IOW the perches are not 180 degrees from the stock SUA.

Truck has no driveline binding problems, tracks fine etc. Was not necessary. I know of many others that were done the same way.

BUT - If I were to do it again today (and I might next winter since I want to push my axle forward and flip the front springs) - I would cut & turn.

Jim

Thanks Jim! For the rest of you - :flipoff2: :D :D :D

actually, the longer the front driveshaft, the lesser the need to address binding issues, since the angle is decreased. The issue comes in then with the shackle reversal and how the axle will rotate under compression/extension.

IMO, if you run a longer than stock front shaft, reversed front springs, double t-case, and stock shackle location, you can greatly reduce the need to cut-turn the front axle.

That said, I'd do it anyways to add caster and handling improvements.

BTW - The reason I wanted to reply to the original thread is that I am running a shackle reversal. Stock mounts at the front of the frame - (no extensions the way Danny used to them).

I may do the cut & turn when I push the axle forward anyway. I know I'm going to have to lengthen the DS and probably will do it by using a longer slip joint (if I can find one that will make up the difference.

I didnt do the cut and turn on mine, but there is no shackle reversal, and I flipped the front springs for more approach angle and everything seems fine after a year and a half.
We also kept the stock caster.

My front drive shaft is 42" from flange to flange. I just got this running and have trailed it once. So far no issues.

HTH,

Thanks Jim! For the rest of you -

It would seem as though nobody feels much like posting the exact thing as they just did a few days ago to the same damn topic, so as stated above, atleast try the search button out! Give it a whirl, you just might like it!

Originally posted by dog walker


It would seem as though nobody feels much like posting the exact thing as they just did a few days ago to the same damn topic, so as stated above, atleast try the search button out! Give it a whirl, you just might like it!

thank you moderator.......... can we make that "important" thread red or blue....it seems it is invisible!:D :flipoff2:

Well I tried the "merge" option, and this is what I got! It put everything from 4004ever's post.

I did'nt realize that he is also one that was replying to the first topic as well. Capt. Nemo's topic. Oh well, I'm going to bed now that I messed the threads all up!!

ya...get some rest ya ol mammoth! we feel for ya....:D

Originally posted by dog walker
Well I tried the "merge" option, and this is what I got!

Fretwell is playing with his Moderator toys.....

That's pretty slick!

Originally posted by wngrog


Fretwell is playing with his Moderator toys.....

That's pretty slick!

He's being a Woolly Bully! :flipoff2: