Unexplodedcow
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- Joined
- May 23, 2011
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I have own a 2010 GT since 2012. Shortly after getting it, I decided to get J&M polyball rear LCAs. Never had a problem that I knew of.
Around 2017 or so, I lowered the car, changed out the sway bars, and added in LCA relocation brackets. Steeda sport springs, Maximum relocation brackets, and UMI upper, lower, and panhard bars with rotojoints and poly. Here are my thoughts about all that.
The OE LCAs use very large crush sleeves. In the torque box, they have small, .5mm textures to hold it in place at the body, and the OE torque is high (probably from having to torque through the bolt, and not the nut).
The J&M arms say to torque to OE (129 ft. lbs). The UMI arms say to torque to 72 ft. lbs. That's a large difference. So, what could happen with that torque spec?
Well, I've had the arms on my car about 1500 miles tops, mostly cruising, a few medium/hard launches on a slightly modified car (canned tune, 1 piece driveshaft), and even on stock tires sometimes. The J&M arms never had an issue with things, and never loosened up.
The UMI ones, however, have been extremely problematic. Some people say they clunk. Yup, they do...when the crush sleeves are hammering the bolts from sliding back and forth. I have been under the car to torque the bolts about 30 times in a few years, barely driving it.
I finally took the time (about a week) to really shakedown the car and trace the cause. The bolts were not loosening. I noticed problems at both ends. Elongated (wallowed-out) holes at both the chassis torque box, and in the relocation brackets, and hammered bolts/sleeves.
The body side is worse, particularly at the inner hole, where the stock bolt uses threads. The hole is probably 5/8 diameter (16mm). and not overly elongated. Ford used too large of a hole, IMO. Each aftermarket arm has crush sleeves that are much, much smaller, around 19mm outside diameter. This causes the sleeve to torque up fine, but partially extrude itself through the hole, and tear it up, along with the threads. The J&M clamped in just fine. UMI seems to use a stainless steel sleeve that kept getting worse and worse, losing about 3mm of length as it was pushed *through* the chassis hole. Increasing torque only made things worse.
I had some 1" OD, and 9/16" ID crush sleeves sitting around from a spare front control arm bushing (Prothane 6-218). They were a bit long, so I cut them down to 50mm and drilled out the poly front bushings to fit. I went with slightly upsides hardware (9/16" 18 thread) and used large flange washers on the inside (late 90s Humvee lug nuts, actually). The shank end fit well, while about 1/16" slop remained for the 9/16" threaded end. Torqued to OE spec 129 ft. lbs. and the arm does not move. Larger sleeves and hardware solved the issue.
The axle end is another story. UMI specs 72 ft. lbs on the roto joints. They can go slightly above this, to about 90 ft. lbs, but will otherwise collapse if torqued to 100+. The rear LCA bolt holes were also damaged, more on the shank sides. Larger 9/16" hardware and flange nuts again, and that worked, but the roto-joint collapses under higher torque is still a problem. Torquing to UMI spec will, 100% of the time, result in clunks. This is the roto-joint slipping in the LCA bracket, and hammering the bolt (not a good idea).
I even tried without the relocation brackets. Same problem exists, except worse. A shorter lever imparts higher loads on whatever is pushing against it, so the stock axle tabs are a shorter lever than with an LCA relocation bracket. Clunks were worse, and torque beyond 90 also collapsed the roto-joint. Yes, I ordered additional hardware and rebuilt the joints.
How is this fixed? Larger sleeves are needed front and back, so they can take the pressure without collapsing or extruding through/damaging the hole. Despite the massive ends on the OE hardware, those don't have issues with moving around. The downside to them is massive wheelhop.
Future plan is to expand the holes and weld in chromoly stepped washers to prevent the problem from happening again, while still using larger sleeves. I have no fix for the roto-joints, and am going to let UMI know my findings. I'm doubtful one random person will make a difference, but with the problems I've experienced with movement and yielding, I can't recommend the UMI rotojoint arms.
The panhard bar and UCA both use larger joints, by the way, and were able to handle higher torque loads to stop moving. I will say their bracket fit the stock 14mm bolt *tight* that it had to be seated in place with a small hammer. It moved slightly under UMI torque spec, but I increased torque without issue. It's holding well, and has been the entire time. The differential bushing is a BMR multi-piece urethane type. While difficult to get in the car with the axle in place, it's also worked out fine. The panhard bar simply works, and has given zero issues. The roto-joints themselves are built tightly, and I've seen zero wear inside. They do require good greasing, while assembling, and after, through the zerk fitting.
The quality of the UMI part is good. It's not like it's a cheap piece, or sloppily designed, but it comes down to failing to hold torque due to collapse and extrusion.
So, moral of the story: if you're having clunks and think it's a normal part of the joint or suspension design, it certainly is not. Something is loose, and requires tightening. If it fails under tightening, it's not a viable part.
Around 2017 or so, I lowered the car, changed out the sway bars, and added in LCA relocation brackets. Steeda sport springs, Maximum relocation brackets, and UMI upper, lower, and panhard bars with rotojoints and poly. Here are my thoughts about all that.
The OE LCAs use very large crush sleeves. In the torque box, they have small, .5mm textures to hold it in place at the body, and the OE torque is high (probably from having to torque through the bolt, and not the nut).
The J&M arms say to torque to OE (129 ft. lbs). The UMI arms say to torque to 72 ft. lbs. That's a large difference. So, what could happen with that torque spec?
Well, I've had the arms on my car about 1500 miles tops, mostly cruising, a few medium/hard launches on a slightly modified car (canned tune, 1 piece driveshaft), and even on stock tires sometimes. The J&M arms never had an issue with things, and never loosened up.
The UMI ones, however, have been extremely problematic. Some people say they clunk. Yup, they do...when the crush sleeves are hammering the bolts from sliding back and forth. I have been under the car to torque the bolts about 30 times in a few years, barely driving it.
I finally took the time (about a week) to really shakedown the car and trace the cause. The bolts were not loosening. I noticed problems at both ends. Elongated (wallowed-out) holes at both the chassis torque box, and in the relocation brackets, and hammered bolts/sleeves.
The body side is worse, particularly at the inner hole, where the stock bolt uses threads. The hole is probably 5/8 diameter (16mm). and not overly elongated. Ford used too large of a hole, IMO. Each aftermarket arm has crush sleeves that are much, much smaller, around 19mm outside diameter. This causes the sleeve to torque up fine, but partially extrude itself through the hole, and tear it up, along with the threads. The J&M clamped in just fine. UMI seems to use a stainless steel sleeve that kept getting worse and worse, losing about 3mm of length as it was pushed *through* the chassis hole. Increasing torque only made things worse.
I had some 1" OD, and 9/16" ID crush sleeves sitting around from a spare front control arm bushing (Prothane 6-218). They were a bit long, so I cut them down to 50mm and drilled out the poly front bushings to fit. I went with slightly upsides hardware (9/16" 18 thread) and used large flange washers on the inside (late 90s Humvee lug nuts, actually). The shank end fit well, while about 1/16" slop remained for the 9/16" threaded end. Torqued to OE spec 129 ft. lbs. and the arm does not move. Larger sleeves and hardware solved the issue.
The axle end is another story. UMI specs 72 ft. lbs on the roto joints. They can go slightly above this, to about 90 ft. lbs, but will otherwise collapse if torqued to 100+. The rear LCA bolt holes were also damaged, more on the shank sides. Larger 9/16" hardware and flange nuts again, and that worked, but the roto-joint collapses under higher torque is still a problem. Torquing to UMI spec will, 100% of the time, result in clunks. This is the roto-joint slipping in the LCA bracket, and hammering the bolt (not a good idea).
I even tried without the relocation brackets. Same problem exists, except worse. A shorter lever imparts higher loads on whatever is pushing against it, so the stock axle tabs are a shorter lever than with an LCA relocation bracket. Clunks were worse, and torque beyond 90 also collapsed the roto-joint. Yes, I ordered additional hardware and rebuilt the joints.
How is this fixed? Larger sleeves are needed front and back, so they can take the pressure without collapsing or extruding through/damaging the hole. Despite the massive ends on the OE hardware, those don't have issues with moving around. The downside to them is massive wheelhop.
Future plan is to expand the holes and weld in chromoly stepped washers to prevent the problem from happening again, while still using larger sleeves. I have no fix for the roto-joints, and am going to let UMI know my findings. I'm doubtful one random person will make a difference, but with the problems I've experienced with movement and yielding, I can't recommend the UMI rotojoint arms.
The panhard bar and UCA both use larger joints, by the way, and were able to handle higher torque loads to stop moving. I will say their bracket fit the stock 14mm bolt *tight* that it had to be seated in place with a small hammer. It moved slightly under UMI torque spec, but I increased torque without issue. It's holding well, and has been the entire time. The differential bushing is a BMR multi-piece urethane type. While difficult to get in the car with the axle in place, it's also worked out fine. The panhard bar simply works, and has given zero issues. The roto-joints themselves are built tightly, and I've seen zero wear inside. They do require good greasing, while assembling, and after, through the zerk fitting.
The quality of the UMI part is good. It's not like it's a cheap piece, or sloppily designed, but it comes down to failing to hold torque due to collapse and extrusion.
So, moral of the story: if you're having clunks and think it's a normal part of the joint or suspension design, it certainly is not. Something is loose, and requires tightening. If it fails under tightening, it's not a viable part.