Fresh Air Inspector
Well-Known Member
Hello All,
I order a set of polyurethane K frame isolators (no, I don't want solid mounts), from ESPO (aka Springs n Things). These are made by Prothane but came without installation instructions. I found the Prothane ones but they are too generic to be useful and although the ones from Energy Suspension are much better, are not applicable.
The challenge (problem?), I have is twofold. One is the fit of the 'insert' section of the isolator that goes through the hole in the K frame. The factory isolator has a metal band around that section so it is a tight fit in the K frame hole. However, the ESPO item has a gap of ~0.5mm between the insert and the hole in the K frame. To me it should be tight to prevent and potential movement. The factory torque specification for the through bolt is 80 lb. ft. which, to me, would not be enough to 'crush' or 'spread' the isolator to prevent any movement. Pictures below; first image shows the lower front polyurethane isolator in place (notice the gap), the second image is original lower front isolator in place.
The second concern is the orientation of the isolators. From the factory the front isolator has the insert piece as part of the lower isolator and the rear has it in the upper isolator. The factory must have done this for a reason??? Pictures below; the third image shows the original front with the upper isolator on the left, the fourth image shows the original rear with the upper isolator on the left.
According to ESPO; 'in 20 years no one has questioned the insert gap or the orientation and no issues have arisen'.
Questions;
1. Has anyone used these isolators?
2. Did you notice the 'gap'?
3. How did you orientate them?
4. Did you have any issues after the install?




Looking forward to the feedback.
I order a set of polyurethane K frame isolators (no, I don't want solid mounts), from ESPO (aka Springs n Things). These are made by Prothane but came without installation instructions. I found the Prothane ones but they are too generic to be useful and although the ones from Energy Suspension are much better, are not applicable.
The challenge (problem?), I have is twofold. One is the fit of the 'insert' section of the isolator that goes through the hole in the K frame. The factory isolator has a metal band around that section so it is a tight fit in the K frame hole. However, the ESPO item has a gap of ~0.5mm between the insert and the hole in the K frame. To me it should be tight to prevent and potential movement. The factory torque specification for the through bolt is 80 lb. ft. which, to me, would not be enough to 'crush' or 'spread' the isolator to prevent any movement. Pictures below; first image shows the lower front polyurethane isolator in place (notice the gap), the second image is original lower front isolator in place.
The second concern is the orientation of the isolators. From the factory the front isolator has the insert piece as part of the lower isolator and the rear has it in the upper isolator. The factory must have done this for a reason??? Pictures below; the third image shows the original front with the upper isolator on the left, the fourth image shows the original rear with the upper isolator on the left.
According to ESPO; 'in 20 years no one has questioned the insert gap or the orientation and no issues have arisen'.
Questions;
1. Has anyone used these isolators?
2. Did you notice the 'gap'?
3. How did you orientate them?
4. Did you have any issues after the install?




Looking forward to the feedback.