Roto-Joints
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From: Eastern MA
Roto-Joints Anyone else having issues with roto-joints falling apart? There isn't any set/lock screw/nut to keep them from opening up. I find that I have to keep tighten them down often because they loosen up. My Formula is my daily driver (even in winter) and I'd rather not have to be re-tightening these up with each oil change.
Whats worse is that twice now, I've had to re-assemble the roto-joints on the right LCA because they completely disassembled. First time, the front roto-joint fell apart. The second time, the rear roto-joint fell apart. Nothing was missing, all the parts where there. I just had to clean/re-grease/re-assemble (which isn't fun when its raining... funny how it started raining both times I went to repair them).
I did a search, but I couldn't find any threads on this. If there are threads on this, please post links to them.
Whats worse is that twice now, I've had to re-assemble the roto-joints on the right LCA because they completely disassembled. First time, the front roto-joint fell apart. The second time, the rear roto-joint fell apart. Nothing was missing, all the parts where there. I just had to clean/re-grease/re-assemble (which isn't fun when its raining... funny how it started raining both times I went to repair them).
I did a search, but I couldn't find any threads on this. If there are threads on this, please post links to them.
I have heard this one before. They are all forms of johnny joints (Del-sphere, roto-joints, etc). Others use set screws or circlips. I'm not sure why UMI chose not to provide something to keep them together. Maybe UMI will comment.
Hmmm.......so are you thinking the articulation of the suspension movement is causing them to come apart?
I've been considering some of their parts for my setup, but havn't bit the bullet yet; just waiting for someone to have issues. Thanks for posting up.
I've been considering some of their parts for my setup, but havn't bit the bullet yet; just waiting for someone to have issues. Thanks for posting up.
The roto-joints on my panhard bar came apart after only 2 weeks and 200 miles and the LCA ones were starting to back out. I put some thread locker on and they have been fine for about a year now. I'm surprised UMI didn't see the problem while testing since it happens so quickly. A few threads have popped up since the first release and I have even gotten a few PMs concerning the issue.
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The problem is the material they are using as the bearing race. Almost all of the offroad companies are moving away from Delrin as a bearing race since they found it not to be the wonder race of the world. All of the high $$$ offroad companies are switching back to either hard polyurethane or a polymer bearing material depending on what sort of NVH they are looking for. I know this because both my Dodge and Ford aftermarket front track bars had issues with the Delrin front bushings and both companies said they are no longer using Delrin due to problems with wear issues. I guess J&M had it right with the hard poly extreme joint arms they came out with over 5 years ago.
DR Crame
2006 Dodge 2500 (sold)
2009 F350
2001 Camaro
2006 GT Mustang
DR Crame
2006 Dodge 2500 (sold)
2009 F350
2001 Camaro
2006 GT Mustang
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We updated the design awhile back with a set screw that now locks the adjusting ring in place and prevents this.
If you have an older design PM me and I will take care of it.
As for Delrin, we have no issues using Delrin in the Roto-Joint, we are pleased with the performance of Delrin in the applications we are using it. The older style Roto-Joints are a locking issue and not a material choice issue.
Thank you,
Ryan
If you have an older design PM me and I will take care of it.
As for Delrin, we have no issues using Delrin in the Roto-Joint, we are pleased with the performance of Delrin in the applications we are using it. The older style Roto-Joints are a locking issue and not a material choice issue.
Thank you,
Ryan
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From: Eastern MA
Originally Posted by lees02WS6
They are all forms of johnny joints (Del-sphere, roto-joints, etc).
Originally Posted by lees02WS6
Others use set screws or circlips. I'm not sure why UMI chose not to provide something to keep them together. Maybe UMI will comment.
Originally Posted by UMI Performance
We updated the design awhile back with a set screw that now locks the adjusting ring in place and prevents this.
If you have an older design PM me and I will take care of it.
If you have an older design PM me and I will take care of it.
Originally Posted by UMI Performance
As for Delrin, we have no issues using Delrin in the Roto-Joint, we are pleased with the performance of Delrin in the applications we are using it. The older style Roto-Joints are a locking issue and not a material choice issue.
Aside from the coming apart thing (which seems to be solved with the new design) How do you like the roto joints? Ride stiffness and handling? I am seriously considering using those when I get another Camaro.
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From: Eastern MA
Handling is like a rod-end.
Think of it as a less harsh rod-end that you can tighten up as it wears.
I'm just concerned with how this earlier design opens up.
I'll let you know how the new design compares to the old design.
I bought a set of the "Johhny-Joint" equipped LCAs for my Z-28, primarily to correct a slight thrust angle mis-alignment, and also to allow the freer movement of the rear end. While they did this, I found them to be too harsh for the street, and took them out last week. I'm considering selling them....
Thread Starter
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From: Eastern MA
Roto-joints (Johnny Joints) do transmit more noise/harshness into the car, but they aren't as bad as rod-ends (Heim Joints).
My rear was also a bit off with the stock components so I needed adjustables to straighten it out.
My rear was also a bit off with the stock components so I needed adjustables to straighten it out.
In my opinion, there's no question that the roto-joints allow the LCAs to work without binding. However, depending on the general condition of the road where you live, they can be either a "no issue" modification, or a pain in the butt. They have next to no "give", like a rubber bushing, therefore they transmit all the impact from ruts and expansion strips right into the car.
I went with the UMI roto joints and they handle great but because my car is a daily driver and the roads on city streets are not that great where I live, I really found them to be too harsh and noisy for daily driving, so I'm going back to poly.
One thing to consider....Since the 4th gen F-bod uses a panhard bar to control the side-to-side movement of the body, the LCA have to travel in an arc that is defined by the PHB. Therefore the body and LCAs do move back and forth about 1/8-3/16" during normal suspension travel. If the bushings can't/don't flex, something else has to. That "something else" becomes the mounting tabs on the body and rear axle.
As much as I know the poly bushings provide more stability, they also "work" the body of the car quite a bit more than the OE rubber bushings do. Just something to ponder....