Help with rear coilover install (Spherical Bushings)
#1
Drifting
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I recently bought a set of Bilstein Escort rear shocks. The PO of the shocks had the bushings upgraded to solid spherical bushings. I've ordered the bolt upgrade from paragon. The problem that I've run into is that the bushings are all the wrong size. The inner diameter of the ball is 15mm instead of the standard 1/2". I popped one of the bushings out and measured it as follows. The OD of the race is 26mm and the race width is 9mm.
![](http://img.photobucket.com/albums/v624/justinl1979/100_0471.jpg)
So, what are my options? Does anyone know of places where I can find a replacement with an inner diameter of 1/2" with the same race size? Is there a bolt that has a 15mm base with 14mm threads?
What can I do about the upper mount? Do I drill out the mount to accept a 15mm bolt? Is there a spacer or something that I can put on the bolt to increase it's diameter to 15mm?
Worst case scenario is that I have to ship the shocks to bilstein to have the proper bushings welded on.
Thanks for any help you guys can offer.
Justin
![](http://img.photobucket.com/albums/v624/justinl1979/100_0471.jpg)
So, what are my options? Does anyone know of places where I can find a replacement with an inner diameter of 1/2" with the same race size? Is there a bolt that has a 15mm base with 14mm threads?
What can I do about the upper mount? Do I drill out the mount to accept a 15mm bolt? Is there a spacer or something that I can put on the bolt to increase it's diameter to 15mm?
Worst case scenario is that I have to ship the shocks to bilstein to have the proper bushings welded on.
Thanks for any help you guys can offer.
Justin
Last edited by JustinL; 08-13-2007 at 09:02 PM.
#2
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I just had the 1/2" ball mounts welded onto my Bilstein shocks...
You can make do with the 15mm ones though. You will probably need some custom bushings made up by a local machine shop to make it work.
For the top, you'll need a two part something that will go over the 12mm bolt and hold the 15mm bearing properly.
For the bottom, you might be able to make some kind of a spacer sleeve/shim for the 14mm bolt -- or you could install something like the Racer's Edge lower mount and make an adapter for the 1/2" bolt to work with the 15mm ball.
I guess there's no easy answer for you -- you either get 1/2" mounts welded on and buy the readily available stuff, or you keep the 15mm and get some custom stuff made.
You can make do with the 15mm ones though. You will probably need some custom bushings made up by a local machine shop to make it work.
For the top, you'll need a two part something that will go over the 12mm bolt and hold the 15mm bearing properly.
For the bottom, you might be able to make some kind of a spacer sleeve/shim for the 14mm bolt -- or you could install something like the Racer's Edge lower mount and make an adapter for the 1/2" bolt to work with the 15mm ball.
I guess there's no easy answer for you -- you either get 1/2" mounts welded on and buy the readily available stuff, or you keep the 15mm and get some custom stuff made.
#3
Quit Smokin'
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Is the paragon "bolt upgrade" a racer's edge product? If so you should call Racer's edge and explain the issue you have. I had a scimilar problem, and he was able to machine some steel parts and longer bolts that allowed my odd size spherical bearings to work with the standard adapter. If the paragon parts are not racer's edge, I would call them anyway and concider sending your "bolt upgrade" back.
Last edited by Auto_Werks 3.6; 08-02-2007 at 02:38 PM.
#4
Drifting
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Yes the bolt upgrade is the racer's edge adapter. I bought from paragon because I've had such good experience with them in the past. It's starting to look like the cheaper and more effective option is to have the shocks re-welded with the proper sized bushings. If I go this route, what should I get installed?
Would it make sense to have a 1/2" on the bottom for the racer's edge mount and a 12mm for the upper? How does one prevent the upper mount from sliding laterally along the bolt? Would I just spacer the hell out of it?
Would it make sense to have a 1/2" on the bottom for the racer's edge mount and a 12mm for the upper? How does one prevent the upper mount from sliding laterally along the bolt? Would I just spacer the hell out of it?
#5
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by JustinL
Yes the bolt upgrade is the racer's edge adapter. I bought from paragon because I've had such good experience with them in the past. It's starting to look like the cheaper and more effective option is to have the shocks re-welded with the proper sized bushings. If I go this route, what should I get installed?
Would it make sense to have a 1/2" on the bottom for the racer's edge mount and a 12mm for the upper? How does one prevent the upper mount from sliding laterally along the bolt? Would I just spacer the hell out of it?
Would it make sense to have a 1/2" on the bottom for the racer's edge mount and a 12mm for the upper? How does one prevent the upper mount from sliding laterally along the bolt? Would I just spacer the hell out of it?
#6
Drifting
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
With the very generous help of Dan... we made some bushings. They are all 15mm OD with 12mm ID for the upper and 1/2" ID for the lower. We also made some spacers with the left over material that is 12mm ID.
You can see the bronze bushing inside the spherical bushing.
![](http://img.photobucket.com/albums/v624/justinl1979/IMG_0427.jpg)
Installed:
![](http://img.photobucket.com/albums/v624/justinl1979/IMG_0431.jpg)
I got out to stratotech raceway on the weekend to try out the new shocks. They work really well... not optimal, but still very nice. The springs are a touch long, so my car is a 1/2" higher in the rear than the front. Previously it was higher in front and more stiffly sprung with 375lb front springs . I had a bit of sproinging as the springs settled, but that went away pretty quickly. There sure isn't a lot of clearance for the tranny cooler is there! With the bolts torqued up, the bushings are held solidly, so I was pretty happy about that, and I'm glad I didn't drill out the upper mounts as they do look a bit light on material as they are.
Driving: There's way more oversteer than before. I think it's a bit too much as I lose speed correcting the back end frequently, though certainly faster than the previous understeer I had. There is a slight transition when throwing the car back and forth that I can occasionally feel as the torsion bars take up first and then the 550lb springs. The setup isn't optimal, but it is good for having just bolted on a set of shocks. I still have the sway bar to tune with as well as the option of getting softer and/or shorter springs.
I didn't have too much trouble catching up to the instructor driving a c5 z06 but a little more difficulty getting away from the 3rd gen RX-7 that was behind me.
You can see the bronze bushing inside the spherical bushing.
![](http://img.photobucket.com/albums/v624/justinl1979/IMG_0427.jpg)
Installed:
![](http://img.photobucket.com/albums/v624/justinl1979/IMG_0431.jpg)
I got out to stratotech raceway on the weekend to try out the new shocks. They work really well... not optimal, but still very nice. The springs are a touch long, so my car is a 1/2" higher in the rear than the front. Previously it was higher in front and more stiffly sprung with 375lb front springs . I had a bit of sproinging as the springs settled, but that went away pretty quickly. There sure isn't a lot of clearance for the tranny cooler is there! With the bolts torqued up, the bushings are held solidly, so I was pretty happy about that, and I'm glad I didn't drill out the upper mounts as they do look a bit light on material as they are.
Driving: There's way more oversteer than before. I think it's a bit too much as I lose speed correcting the back end frequently, though certainly faster than the previous understeer I had. There is a slight transition when throwing the car back and forth that I can occasionally feel as the torsion bars take up first and then the 550lb springs. The setup isn't optimal, but it is good for having just bolted on a set of shocks. I still have the sway bar to tune with as well as the option of getting softer and/or shorter springs.
I didn't have too much trouble catching up to the instructor driving a c5 z06 but a little more difficulty getting away from the 3rd gen RX-7 that was behind me.
![](http://img.photobucket.com/albums/v624/justinl1979/IMG_0442.jpg)
#7
Burning Brakes
Join Date: Feb 2002
Location: Edmonton
Posts: 1,043
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Great to hear it all worked out Justin. I think you might need some lower rate springs for the back. So you have the 375s in the front and 550s in back? You might want to try swapping front to back.
Trending Topics
#8
Drifting
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Unfortunately the diameter of the springs are different. 2.5" front and 2.25" rear. I'll run it like this until winter and then get another set of springs for the rear. It will be nice to get back to the PCA course and quantify the difference ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I'm calling this the "coilover with helper torsion bar" setup
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I'm calling this the "coilover with helper torsion bar" setup
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
#9
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
what a drama a 15mm bolt is a rare thing don't think there is such a thing . here is the odd thing about spherical bearings they come in 8mm 10 mm 12mm 15mm ID you have the same trpuble doing tower tops the stut shaft is 14mm
i don"t think i will ever go to bearings over rubber bushings on the back .
the rubber bushing with steel inside must have about less than trire tread depth on there . and what does it do ???
it has no effect on suspention geometry . it is the 2 control arm pivots that control the geometry and would flex under high load . are they gone??
i think demon tweeks or rallydesighn UK may have a 14 to 15 bush for tower tops .
i don"t think i will ever go to bearings over rubber bushings on the back .
the rubber bushing with steel inside must have about less than trire tread depth on there . and what does it do ???
it has no effect on suspention geometry . it is the 2 control arm pivots that control the geometry and would flex under high load . are they gone??
i think demon tweeks or rallydesighn UK may have a 14 to 15 bush for tower tops .
#10
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by JustinL
Unfortunately the diameter of the springs are different. 2.5" front and 2.25" rear. I'll run it like this until winter and then get another set of springs for the rear.
http://mall.rennlist.com/scripts/fea...uery=retrieval
#12
Burning Brakes
Join Date: Feb 2002
Location: Edmonton
Posts: 1,043
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by gt37vgt
2.5 is kind of standard could one put 2.25's on the front ???
Dan
#13
Burning Brakes
Join Date: Feb 2002
Location: Edmonton
Posts: 1,043
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by shiners780
There are some brand new spring sets for sale in the classifieds right now for cheap. I picked up a set, and shipping was quick. Just a FYI...
http://mall.rennlist.com/scripts/fea...uery=retrieval
http://mall.rennlist.com/scripts/fea...uery=retrieval
Thanks
#15
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Yep, bilsteins take the 2.25 front and rear. But Im not sure that he has bilstein front struts. Koni front struts have a larger OD barrel/body and require 2.5 ID springs.
Justin, rear of the car will be a little off if you dont reindex the torsion bars (ride height, spring clunking problems, etc...).
Justin, rear of the car will be a little off if you dont reindex the torsion bars (ride height, spring clunking problems, etc...).