Any opinions?

[CodeXJ]

Ok so I been trying to find any researcj, or maybe I'm just crazy or maybe there is a damn good reason why you don't see this but I have a very peculiar question!!

Slip yoke eliminators: get rid of slip yoke on the transfer case, but you still need a slip yoke in your drive shafts It let's the shaft slide in and out as the suspension moves up and down and makes a more pleasant ride.
Second. Control arms are made with flex joints, they are under extreme stress as the suspension cycels, correct? Say you have a solid piece of metal between two fixed joints that do not flex. this puts even more stress on both mount because as the suspension cycles it can not flex, and the DOM in the middle has little flex. this is why Flex joints are on either both or one end of the control arms, so as the control arms cycle the joiunts absorb a lot of the stress that is put on the joints.
The stock control arms on XJ's ios a very good design to some aftermarket as the U-shaped of the control arms even though fixed ends the U design flexes as the suspension cycles.
Now moving on....
A common long arm set-up are radisu arms. Radius arms however produce more anti-dive from their set up. Anti-dive is pretty much putting more stress on your control arms versus spreading some of that to your springs. So therefor more stress on the arms themselves which is not always great.
Same with a 3 link, can provide up to 6x more stress on the upper arm, and both can cause the axle tubing to bend especially if your running stock axles.

Now!!! This is my theory and I don't mind being proven wrong!!

Let's say the slip yoke in a drive shaft helps dampen the upward and downward motions of the axles cycling. Now Let's take what I said about radius arms with anti-dive and the torque it applies to the axle itself.
Usually Radius arms and a lot of 3link. (Y-arms pretty much) are fixed with flex joints. the flex joints work Well when cycling to prevent SOME stress. But you still get anti-dive

Now let's combine the both of them, and consider possible spots.
(I do know that this creates a weak points, but what would you give up in a weak point to helping preserve your axle?)

Let's say you put a slip yoke in the upper arms on a radius set up. When you have a solid piece of metal with no give it can force the axle to twist, but what if that upper (under-resistance) had a slip yoke on it let the axle cycle without counter pull on the arms which would fight each under in bind? This would reduce wear (In my theory) on the mounts, axle twist, as well as anti-dive because the slip yoke would act as a smoother ride and equally better give in the arms, to say this would transfer anti-dive to the springs would be amazing!?

that's one possible theory: This is my other theory.
What if you used a type of slip yoke farther back by the crossmember plate. This would help in the articulation cycle to the same similar degree which would produce less stress o nthe joint which could equally preserve the unibody frame of an XJ? It could also help with the suspension rising and falling just like a drive shafts slip yoke does the exact same. I understand this creates a weak point, but if it was a very huge concern then the axle dropping could ruin driveshafts which are set-up exactly like that!

Any opinions, or proof that I'm incorrect, or anyone who think this is a unique idea? I havent found anything online through tons of research that incorporate ANY slip inthe control arms themselves. I'm young and learning :thumb:

[Robert B]

i believe you are talking about the arms that hold your axle in place when useing coil springs correct (i know leaf springs not coils lol) ....from what i do know of slip yolks (my truck runs one) they have no limiters in them.....over extend and they fall apart and if its too long then they just crush together when compressed (kinda a limiter?) so there would have to be a way to put a limiter on the arms that could take that much force to not pull apart........ and the main problem i see is it will not hold the axle in place..... there will be a big lag from when the tires (axle) begins to move to when the body follows and it may go all the way until the "limiters" kick in or the 2 ends bottom out when the compress together......this would then be worse when climbing hills regularly and even far worse when offroading and climbing (or decending) hills with rocks and things in them......and since the coils do next to nothing to hold the axle in place they would have an extremely high chance of poppping out of their buckets and the trackbar if one is used would have so much force front to back on its joints it would just bend or snap off .......... so in essence i think it would look like the axles would start to drive off but the body would not move at all since there would be nothing to really hold them together............ now if they were built more like a shock with limiters and pretty heavy resistance they might work for on road use with "sane" driving and would still probably have the lag but it would be less and im sure it would be really odd to drive but they would have to be made of some SUPER heavy duty material and have quite a bit of pressure in the tubes.......and then they moght not hold up to off road use and the huge amounts of torque from rocks ...trees... large tires... gear ratios really low.....and the roughnes of the terrain in general.......

now that should be the simple idea and after rereading your first theory your jeep has 4 arms on it??? 2 oneach side an upper and a lower?? ....and you are thinking of a sollid lower one but a slip yolk upper one pretty much correct? ..from how i know that axle wrap works this would just allow the axle to wrap over instantly when power was applied since it has only 1 solid point holding the axle and that point rotates......wish i had CAD on my comp and i could give great pics to show it but anywhoo........

oh and i just thought of this (duh hehe) but slip yolks have no dampening effect......thats why guys dont like tcase slip yolks cause if it does come out then the flius goes out too and if the driveshaft comes apart and does not take damage they can put it back together no problem..... so they would have to be more like shocks with a gas or an oil or something to dampen the impact... :)

and i do not understand your second theory without a diagram or you showing me on your truck since i dont know exactly how it mounts to the unibody.....

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this may seem like im just shooting you down but this is just what i under stand of the coil set up with the arms and why those arms or bars or rods have sooooo much thought and engineering put into them (hopefully) and in theory (woohoo my theory time :p) they have been designed correctly to allow the suspension to cycle with little to no binds at all....this of course is for stock set ups and when lift is put in it most likely gets very hard to match this even with whole kits since it would have to sit in the exact perfect spot and once the all kinds of different bumpers (weight wise mainly) and other armor things and just stuff are added they affect the height and then the spings that come woth the kit may be too small then and there will be a bind so there would have to be alot of planning involved to get it to ride just right to get the hopefully thought out results that a stock truck would have ...........

i think this is more writing than half my total posts put together lol and half of this stuff i might be wrong on but i am all for learning and next time i am in aurora cody i would love to come and discuss this and compare trucks and the like and see if we can get any farther :thumb:

...and thats more like my $17 but we only have this smiley :2c:


and see now i think of more things as in witing but shocks are made to fit a certain travel range ......so they work so then there would have to be a way to put a "range" into the slip of the arms and that would be really fun to try and do since it has to work both forwards and backwards and if those limits were hit either from wear on the "shock" like arms or they were put under too great a lod and just pushed all the way to the limiters it would be a very hard jerk on the whole truck just like when the springs are compressed ALL the way to the bumpstops in one fast move and the truck bounces hard enough to usually rattle your teeth type of deal..........

oh this topic is too fun for me lol :) hopefully this helps in some way to give you new ideas or to build this one so it would work

[CodeXJ]

This is has helped me out a great deasl, and given me some more thought into the design. And understand wha you are saying on the slip yoke not being able to hold up to the heavy abuse offroad. I think a shock type of set up could be better then slip yoke set-up.

I have no doubt that long arms are designed very well and engineered well, but I do know a lot of aftermarket suspension can and WILL produce a lot of stress on the axle and mounts which a.) Rips the axle mounts off as the suspension cycles, and B.) Can twist the axle tubes when it is cycling. You can find a lot of people who have done this.

So even though they are engineered very well and strong and get the job done for the most part. I think there is a BETTER way to make them function that could reduce stress on the axle itself. To say a shock effect, slip yoke effect, or something unheard of could make long arms cycle better and reduce stress then it would make for happier parts.

This is definietly something to look into further since NO one has any dampened control arms.
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You definitely hit it right on with the stock suspension being already very well designed, but that won't handle heavy abuse offroading. And long arms like Radius arms if you look into the research they are already binding as the suspension flexes. the two upper arms that come off the lowers are fighting each other, and the lower arms flex different so thus you have an upper fighting an upper and attached to a different path lower. If you think about it. The engineers USE flex joints to do that kind of "Dampen" effect because it helps the control arms flex a little before binding or causing more stress then needed, but the design can always be improved.

If you think about the shock valving they do on coilover rigs for high speed racing on rough terrain they put a lot of engineering into those. I mean how i thought is sometimes the shock load to a system can cause stress points. what if you used a dampen effect like you were talking about which under that shock load would let the arms move a little. (Those coilover shosk are valved incredibly well if you ever look into them? they are hard enough to push the tire down, but soft enough to give a little)

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Yes the range would be the most important that your talking about, because if you put way to much ranged for the shock to "give" then it would be just as bad as keeping them solid because your allowing the arms to "Flex" the axle just as bad as the solid arm "torquing" the axle as it cycles. If you or anyone else want to talk about this it would be very interesting. It could, with the right configuration and set-up, very well may be a new way for offroading.

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forgot to answer the on-road situation. for on road, the hard you brake with radius arms the more anti-dive you put on the suspension components primarily the control arms. If we used the "dampen" theory of like a shock then you could make it where the vehicle dips in the front when braking, BUT reduce stress on the suspension components themselves as it brake. Passenger cars are built into to have anti-dive in some situations which help keep the front bumper from hitting the street.

[Brody]

What I would do if I were you, Cody, is to take a look at the suspensions that are being used on both the 2WD and 4WD baja style race trucks. I believe that you will find that pretty much everything that you have discussed or have questions about has been done in the field of off road racing. Maybe wrong, but that is where almost all of the real suspension advances have taken place for off road use.

I would also start "back in the day" to present times, as so much stuff has been done, including double and reversed torsion bar set ups, a 4WD Toronado (with a re machined front end used for the rear) and many other interesting things. Even though I am not a fan of Four Wheeler magazine, I managed to get a free subscription. The newest mag had an article about 15 years of different "Tough Truck Challenge" suspension systems that was an interesting read. CORR race trucks have also been going through a lot of suspension designs and changes, too. You may also want to Google "JeepSpeed" suspensions as there are a lot of Cherokees in that class.

Here is a link to a lot of pictures. If you take the time and run down the articles, I bet that you will get both some answers and ideas:

https://www.google.com/search?q=Off+road+racing+suspensions&start=10&hl=en&client=firefox-a&hs=cqd&sa=N&rls=org.mozilla:en-US:official&prmd=imvns&tbm=isch&tbo=u&source=univ&ei=ujVnT5X6KuL2sQKuvpi3Dw&ved=0CLEBELAEOAo&biw=1366&bih=596

JeepSpeed Suspensions pictures:

https://www.google.com/search?q=JeepSpeed+suspension+systems&hl=en&client=firefox-a&hs=2ey&sa=X&rls=org.mozilla:en-US:official&prmd=imvns&tbm=isch&tbo=u&source=univ&ei=7zdnT_nrEsazsgL408C2Dw&ved=0CIgBELAE&biw=1366&bih=596

[CodeXJ]

I believe that you will find that pretty much everything that you have discussed or have questions about has been done in the field of off road racing. Maybe wrong, but that is where almost all of the real suspension advances have taken place for off road use.

You can't make anything better if you never screw up "fixing" it in the first place, right? I'll definitely look into some of the baja vehicles and other types of suspensions. I do think it would good to induce some technology into some of the "cheap" long arms that small vehicles like jeeps can run which would help in the design feature.

From your link I found this when surfing. http://www.hmracingdesign.com/html/suspension_kit_ranger_aarm_hnm.html That's a pretty awesome engineering right there, I bet you when they first came up with this people looked at them weird. and cost $85k to $225k to build those things :erm:

[Brody]

You can't make anything better if you never screw up "fixing" it in the first place, right?

amen to that1 And these guys bet their junk into oblivion, then make it better. i didn't follow everything you were talking about, mainly because I have different junk on my heap, but was pointing you where I would start looking for ideas and to see if someone hasn't come up with something different. The JeepSpeed stuff came to me last, but those guys bet their junk to a pulp, too, so they have probably figured in a lot of tweaks that work and stand up to real abuse.