DTSFab.com (Desert, Trail and Sand)
UTV's Off Road ( RZR, YXZ, Mini Buggy, Carts,etc.) => UTV Chassis and Suspension => Topic started by: fabr on January 06, 2013, 05:48:51 PM
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We've had this discussion about the speed oscillations in a u joint that just gets more and more pronounced as the angle increases. We have discussed how there is no such speed oscillations with a constant velocity joint as we all know. Most people that use u joints for rear axles feel the speed oscillations are negligible and not an issue. Maybe they are right but I'll stick with cv's. Sooooooo,what's this have to do with steering uj's ??? Well the Twisted Dart has always handled well in the sand and on dirt roads and such but on asphalt had "squirrelly" steering feel the best I can call it. Had a twitchy feel right at the straight ahead point. Sort of a "you're fine but if you even THINK about nudging the wheel you're going in the ditch " thing. :o I've checked and rechecked the phasing of the uj's. A few times experimented with the clocking also. Nothing worked. The uj's were at approx 40 degrees. Well I spent the day relocating the unisteer power assist unit to get the uj angles to about 20 degrees. VIOLA!!!!! Silky smooth steering at all speeds now on the asphalt. A pleasure to drive. I'm going to look into small cv's to use for my steering shafts from this point on. LMAO LMAO Hmmm, I wonder how small a cv I might actually get? Hmmmmmm..................
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The trophy light that I was doing suspension tuning on this weekend had steering issues. It was all over the place. The rear end was also VERY loose. It swung the rear around more than a 800HP TT. Took some bar out and the rear got happy but it was almost un-drivable in the rough. Finally started looking at the steering column. None of the U-joints were clocked right. The servo was out of phase from the rack and the wheel. Amazing what a few simple changes can do. Truck is better but I still don't like having a U-joint at a 40* angle between the servo and the rack. They never feel right.
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Most folks complain that Charlyn units are twitchy on asphalt. Unisteer is charlyn type so I always wondered how the street rodders could use it with out issue. Makes sense that a front engine with a longer snout would reduce angle. Based on your findings, must be the angle of the dangle?
Mine is squirly on the road. I may have to see if the Charlyn can be salvaged as I assumed I would just have to upgrade to rack at some point. That is a project for another day though.
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Well yours sounds like angle issue more than anything. I will say in my hurry to finish up for fall trip I didn't clock my steering u-joints, forgot. But my angle is low, maybe 25*. And it feels good, but no real experience on asphalt. Sometimes we're good, sometimes just lucky.
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The trophy light that I was doing suspension tuning on this weekend had steering issues. It was all over the place. The rear end was also VERY loose. It swung the rear around more than a 800HP TT. Took some bar out and the rear got happy but it was almost un-drivable in the rough. Finally started looking at the steering column. None of the U-joints were clocked right. The servo was out of phase from the rack and the wheel. Amazing what a few simple changes can do. Truck is better but I still don't like having a U-joint at a 40* anglebetween the servo and the rack. They never feel right.
Right there is the reason.
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Most folks complain that Charlyn units are twitchy on asphalt. Unisteer is charlyn type so I always wondered how the street rodders could use it with out issue. Makes sense that a front engine with a longer snout would reduce angle. Based on your findings, must be the angle of the dangle?
Mine is squirly on the road. I may have to see if the Charlyn can be salvaged as I assumed I would just have to upgrade to rack at some point. That is a project for another day though.
Unisteer is not exactly like Charlyn. The unisteer is torque input sensitive. HOWEVER,it is not sensitive enough. At higher speeds,on asphalt, I just turn it off many times.
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Ya,I never noticed a thing in the sand but on asphalt..........................well,all is good now.
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Right there is the reason.
I agree, after the race this weekend I will se if there is enough room to mount it directly to the input shaft on the rack and redo the rest of the column.
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Reducing the angle drastically improved my setup. Different as a horse and buggy and a Porsche. No joke.
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Ok, stupid question so let the poop fling! I know about clocking a CV but honestly have never heard of clocking a UJ. Can someone post and properly and improperly clocked UJ?
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Clocking CV's is pointless. Clocking U-joints is not. Method is the same as a driveshaft as long as your first and last shaft are parallel. If they are different angles you can offset the joints slightly to compensate.
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ok so this may not be the scientific method but i have built quite a few u joint rear ends and all steering have been u joints as well. to clock the steering u joints i have always started by lining them up like a drive shaft. now when you do this if you look at the shaft that goes through your steering shaft carrier, you'll notice the shaft sort of telescopes in and out of it as you turn the wheel. now i just turn 1 joint 1 spline at a time until the telescoping stops. no problems after that on my end.
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Agree with bdkw. Zero point in clocking cv's regardless of what many believe. It is imperative to clock uj's correctly with MINOR adjustments to improve /lessen the speed oscillations as the shaft turns. A uj shaft out of phase will vibrate like mad if a drive shaft and if a steering column you will definitely feel the speed changes as the car will feel like it is steering unequally as you turn the wheel.
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especially with steering assist!
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I have not clocked my steering joint. Figured it was too slow a speed for any noticeable difference. Maybe it would have been better if I had? Prob just "Carl's Luck" ;D ;D ;D
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You're kidding aren't you? If not, then YES, you once again had Carlluck. LOL!!!!
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You're kidding aren't you? If not, then YES, you once again had Carlluck. LOL!!!!
carl this is the correct spelling for carlluck.... ;D LMAO LMAO rofl rofl rofl :-*
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You know we love ya brotha!!!!!!
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You know we love ya brotha!!!!!!
yes we do!!!!
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Sometime shit happens and it smells good? Usually not though.