size of lower rear shock bolt?
08-22-2012, 06:46 PM
#16
Charlie,
Do not put washers between the shock and arm. Something looks wrong there. Check that the offset mounts are indexed correctly both top and bottom (bottom does look correct from the pic). Also check the OD of that perch. Even if it is for a 2.25" Spring, is the OD excessively large? That does not look like a Bilstein perch or jam nut.
It gets tight, but I was always able to run the perch and jam nuts down to nearly the bottom of the thread engagement on the bilstein shock bodies. If anything was going to hit the trailing arm, it was actually the springs (which depending on rate, were sometimes slight larger OD than the perch, maybe a 1/16" or so).
As far as the rubber bushings - yes they do deform under load. Over time it will be a permanent deformation/creep. Bilstein rubber bushings are somewhat softer than koni and the steel insert/sleeve is smaller diameter (so more rubber) so the destortion is much more noticeable. I was never a fan of it, but drove them like that for many years w/o problem. And yes, you have to use the washer (or a toe eye plate) on the bottom bolt. Impossible not to, as the shock body will slip right off the bushing if you dont.
Do not put washers between the shock and arm. Something looks wrong there. Check that the offset mounts are indexed correctly both top and bottom (bottom does look correct from the pic). Also check the OD of that perch. Even if it is for a 2.25" Spring, is the OD excessively large? That does not look like a Bilstein perch or jam nut.
It gets tight, but I was always able to run the perch and jam nuts down to nearly the bottom of the thread engagement on the bilstein shock bodies. If anything was going to hit the trailing arm, it was actually the springs (which depending on rate, were sometimes slight larger OD than the perch, maybe a 1/16" or so).
As far as the rubber bushings - yes they do deform under load. Over time it will be a permanent deformation/creep. Bilstein rubber bushings are somewhat softer than koni and the steel insert/sleeve is smaller diameter (so more rubber) so the destortion is much more noticeable. I was never a fan of it, but drove them like that for many years w/o problem. And yes, you have to use the washer (or a toe eye plate) on the bottom bolt. Impossible not to, as the shock body will slip right off the bushing if you dont.
As you say, the springs are about 1/8" greater in outside diameter than the shock collars (for 500lb springs).
Another annoying problem: the collars on both front and rear shocks are at max height, and the car is still a little low (particularly at the rear).
08-23-2012, 12:35 AM
#18
08-23-2012, 02:04 AM
#19
Three Wheelin'
Much appreciated. We did get the offset ends in the right configuration. We put a washer between the shock and arm in order to get everything to fit, but now that it's all back together and the collars are at their highest, it droops without touching, so I think I can pull them out.
As you say, the springs are about 1/8" greater in outside diameter than the shock collars (for 500lb springs).
Another annoying problem: the collars on both front and rear shocks are at max height, and the car is still a little low (particularly at the rear).
As you say, the springs are about 1/8" greater in outside diameter than the shock collars (for 500lb springs).
Another annoying problem: the collars on both front and rear shocks are at max height, and the car is still a little low (particularly at the rear).
It is critical that this bolt is torqued up correctly as well.
Attachment 658329
Cheers,
Mike
Last edited by mikey_audiogeek; 09-19-2012 at 10:54 PM.
08-23-2012, 11:02 AM
#20
My opinion: DEFINITELY pull the washers out. The bolt is in single shear and relies on the clamping force on the shock bush to prevent bending loads being transferred into the bolt, which would cause the bolt to fatigue and fail. A standard washer (between the shock bush and the trailing arm) is not flat enough to assure this. You might get away with it, but do you want to risk it?
It is critical that this bolt is torqued up correctly as well.
It is critical that this bolt is torqued up correctly as well.
It looks as though I'll just order two springs that are an inch longer, as I think they will be cheaper than a helper and perch arrangement. At least they're not hard to get at. I'll pull the extra washers out and put in the grade 10.9 bolts then, too.
As a final coda to this thread hijack, are there any 'kits' available to replace the rubber in the shock's mounts with spherical bearings?
08-23-2012, 11:15 AM
#21
Rennlist Member
Mine were welded on by Bilstein. I was already paying to have the shocks rebuilt, so the extra charge was minimal. Certainly, one wouldn't want to weld on a shock canister while it was fully assembled and under pressure!
08-23-2012, 10:25 PM
#23
Three Wheelin'
Mike and Oddjob, thank you both for the excellent pictures.
It looks as though I'll just order two springs that are an inch longer, as I think they will be cheaper than a helper and perch arrangement. At least they're not hard to get at. I'll pull the extra washers out and put in the grade 10.9 bolts then, too.
As a final coda to this thread hijack, are there any 'kits' available to replace the rubber in the shock's mounts with spherical bearings?
It looks as though I'll just order two springs that are an inch longer, as I think they will be cheaper than a helper and perch arrangement. At least they're not hard to get at. I'll pull the extra washers out and put in the grade 10.9 bolts then, too.
As a final coda to this thread hijack, are there any 'kits' available to replace the rubber in the shock's mounts with spherical bearings?
Not sure how best to retain them in the housing though, might need some lateral thinking. Probably best to get it done by Bilstein, like Oddjob did.
Cheers,
Mike
05-15-2017, 09:58 PM
#24
Addict
Rennlist Member
Rennlist Member
Is there a single washer between the head of the bolt and the lower shock mount, or just the bolt? Thank you.
