3 link long arms
- Thread starter Gary E
- Start date
XJoachim said:But i'm sure there is no stock Dana 30
We will find out soon!
http://www.orgsmfg.com/project/mj.htm
Scroll down to the front suspension pics.
mark
orgs mfg
CRASH
NAXJA Forum User
- Location
- Foresthill, CA
Well, Brent is basing his opinion on his poorly designed front suspension that gave up the ghost on BOTW I. It was designed to be an RE style longarm, but after he busted an arm and a mount, it turned into a single arm system.
A well designed single upper arm works like a champ to control axle torque.
CRASH
A well designed single upper arm works like a champ to control axle torque.
CRASH
- Location
- Indiana-Missouri
would you like to QUALIFY that statement with some visual geometry or some testimony based on first hand experience?
or would ya just like to learn a little bit first?
- Location
- Indiana-Missouri
Cresso, this isn't correct. Remember this is a discussion on radius arms, which is a completely different animal than the quad link per stock.
The axle is rigid, it does not matter where you put the upper, as long as it is strong enough to resist.
if some of you guys are having trouble visualizing the geometry and the movement, build a simple model.
the lowers position the axle underneath the vehicle to maintain wheelbase position. The tracbar keeps the axle positioned under the vehicle (left-to-right) as it pivots in an arc centered on the frame mount on a radius relative to the length of the link to its axle mount. the single upper has a simple task of keeping the axle from rotating in relation to the lower arm arc.
The lower radius arms have ONE CENTERPOINT of arc movement. This is different than the stock quad link that has TWO centerpoints of arc. the upper link on a radius set-up does not go to a different point on the 'frame'. It ties into the lower arm.
the axle CANNOT TWIST AS LONG AS ONE UPPER (OR TWO) REMAIN FIXED.
Safari Ary
NAXJA Forum User
- Location
- Virginia Beach, VA
Mark, do you have any shots of the rear of the axle? I'm trying to figure out what you got goin on and I don't quite get it. It almost looks like you're just running 3 short arms, yes no? It also looks like you inboarded the LCAs makin the angles steeper. Thanks
Ary
Ary
- Location
- Indiana-Missouri
I figure I'm safe posting those pictures since one ton got goofey with yellow paint on his.....
JnJ
NAXJA Forum User
- Location
- San Antonio TX
Beezil said:
True, true.....
Beezil said:
The axle itself can't twist from one end to the other, but that's what produces the poor angle that I'm speaking of. The side with the two links dictates the pinion angle. Adjusting the the links such that the pinion always points at the transfer case is pretty logical and makes it a cinch to set up the dshaft with a double cardan joint. Blah blah blah, you already know that.
The effect I'm talking about happens on the other side of the axle when it's articulated. It's gonna be hard to describe without pictures and I probably shouldn't be drawing pictures while at work. =) The axle you have pictured above doesn't appear to point straight at the xfer case, so it'll have the problem even worse. For illustration, let's say the whole fron suspension is compressed. The pinion will be quite a bit higher than it is now and will be pointing a little bit down (because it's level in the first one and radius arms travel in an arc). Now keep the passenger side up there and let the driver's side articulate all the way down. Your pinion will still be pointing a little below centerline because the side the dictates the twist of the axle is still twisted that way. Conversely, keep the driver's side up and articulate the passenger side down and now your pinion will point up quite a bit.
If, however, you have the arm that determines the pinion angle on the pinion side of the axle, the angle of the pinion will follow the arc of the radius arms MUCH more closely. Obviously, there's no way to get rid of of the wrong rotation completely because the diff is between the two arms and will therefore be somewhere between the two angle-wise. It's easy to brush this off as only a marginal difference, but trust me, it's actually quite significant. The design of the arms I use facilitate switching them from side to side fairly easily and the designer of these arms did exactly that. I'll see if I can dig up some pictures because the difference really should be seen. With the upper arm on the pinion side, the axle always tilted to point right at the xfer case. Put the upper arm on the long side of the axle and the pinion angle got REALLY nasty when articulated.
JnJ
NAXJA Forum User
- Location
- San Antonio TX
Cresso, what did you use at the ends of your links?
Ary'01XJ said:
The arms are all stock style for lifted XJs. Lowers Approx 16.5" and upper around 15.5". They all mount in the stock areas, slight movement on the upper for the large JJ clearance. It's just a basic 3 arm or just one arm removed from the stock set up to releave some bind. The Arms are a little steeper than my XJ but the MJ is a little higher. The camera shot is up at an angle also.
mark
orgs mfg
Yup, you're reading right. I'm using them at the axle end of both the upper and lower arms. They work great and allow a lot less slop, more deflection and superior wear over a standard bolt or heim (maybe not more deflection than a heim, but certainly the other two points hold true).
This is the best pic I have, but unfortunately, it's on my old Ranger. Same exact arms, ever so slightly different mount to the axle (it's now using a bolt-on bracket designed for an EB axle).
Sorry about the slow server.
This is the best pic I have, but unfortunately, it's on my old Ranger. Same exact arms, ever so slightly different mount to the axle (it's now using a bolt-on bracket designed for an EB axle).
Sorry about the slow server.
That top link is the wristed portion. Tighten those top two bolts and the top link becomes a static length link. Combine that with the other side which has a top link as well and you end up with a very solid, very roll-resistant setup. Loosen those two bolts and the top link can slide in and out, thereby wristing that side. It's a super slick configuration and I'm extremely happy with the performance. The duct tape is to hold the drive shaft in without u-bolts. Didn't have any when this picture was taken. The lower TRE is off a commercial truck. I believe a Ford E3000 or something like that. The head of the TRE is roughly the size of my palm. Enormous. EDIT: for scale, that's a Dana 60.
I'll see if I can get some pictures of the current setup as it sits on the XJ tonight.
I'll see if I can get some pictures of the current setup as it sits on the XJ tonight.
- Location
- Indiana-Missouri
okay, I see what yer sayin, but what kinda pinion angle are you seeing on your set-up that has you worried? we talkin NASTY NASTY, or just a lil' bitty nasty?
are we talkin' u-joint shatterin' filthy nasty?
or is it driveline vibration nasty?
if its 15-20 degree driveshaft shakin, I myself don't worry about that for two reasons: hubs and trailer......
Man I used to think a 15-20 degree pinion angle was nasty until I saw all those crazy ridge-runnin CJ'ers down in tellico, holy shit! we're talkin 45-degree angles on some of these rigs...aint no thang!
are we talkin' u-joint shatterin' filthy nasty?
or is it driveline vibration nasty?
if its 15-20 degree driveshaft shakin, I myself don't worry about that for two reasons: hubs and trailer......
Man I used to think a 15-20 degree pinion angle was nasty until I saw all those crazy ridge-runnin CJ'ers down in tellico, holy shit! we're talkin 45-degree angles on some of these rigs...aint no thang!
- Location
- Indiana-Missouri
oh, sorry, one more question.....
does this mean you run your single upper on the drivers side then?
does this mean you run your single upper on the drivers side then?
