Question about an issue with rear shocks and mounts

[djpdiag]

Hi 2002FAQ community.

 

I am new to '02s but not to BMWs. I think I have owned or worked on just about every model that has come after!

 

I bought a 1975 '02 last summer and have been going through it as time allows. Last week I replaced the front struts and mounts, rear shocks and mounts and springs all the way around. I went with KYBs for the struts and shocks and H&R sports for the springs. After the install, the upper shock mounts in the rear have me puzzled. I searched here in the forums for an answer and also to check my work but didnt come across the issue that Im running into.

 

It seems that the upper mount is pushing through the bore in the shock tower and into the trunk almost completely. On the right side, the top of the shock has even contacted the evap reservoir when the suspension was jounced. I verified that the mounts are installed correctly, through the top - at first id assumed I may have put them in backwards. I compared them to images i found here in other posts as well as in manuals that I have. The original mounts were two piece but completely obliterated from years of neglect.

 

I tried to embed the images here directly but for some reason it wouldnt take. The two shock towers should be able to be viewed here:

Album — Postimages

POSTIMG.CC

 

Can someone see what Im doing wrong here? Thanks is advance for any help!

[visionaut]

Only the top donut rubber should be above…

 

 

[djpdiag]

Thanks for the reply.

 

These KYBs came with one piece mounts for each shock, not two. So the mount has effectively been pushed back through into the trunk on both sides, what’s shown in the picture is the bottom half coming back up through the bore once the weight is down on the springs.

[visionaut]

How big is your hole in the top of the shock riser?  BMW rear upper mount IS one-piece.

 

[djpdiag]

I grabbed a digital caliper and it’s a bit under 26mm without removing the mount to take an exact measurement. It didn’t appear that either shock tower bore had been damaged or altered in any way and the mounts did fit snugly when I installed them. I tapped them in with a dead low hammer and had to lube them.

 

The KYB mount looks exactly like what’s pictured above. Im wondering now if the lower ride height of the H&Rs is stressing it out enough to force it back through.

Edited May 15, 2022 by djpdiag

[jimk]

Is the lower ride height causing the shock body to bump the upper donut and bump it our of place?

[djpdiag]

I’m beginning to think that’s the most logical conclusion. Maybe the height of the H&Rs are too short for the KYB shocks? The spring pads, top and bottom are installed too by the way.

 

Out of curiosity, which are the preferred rear shocks for a setup like this? Bilsteins of some sort?  

[bergie33]

Are the large rubber bumpers installed?  #2 in the attached picture.  Also, do you have the cup washer installed on the underside of the rubber mount?

Edited May 15, 2022 by bergie33

[Mike Self]

I've been running H&R progressive springs/Bilstein HDs for many years without that problem.  The springs I'm using lower the car about an inch, but I also am using the thinnest (1 dot) spring pad in the rear, and removed the front aluminum spacer.  

 

It's just possible that the KYB rubber bushing is a little too soft for the application and is pulling through. And you do need to tighten the upper nut firmly so as to compress the rubber.  Otherwise, the shock will make a noise every time you hit a bump.  Learned that the hard way!

 

mike

[visionaut]

I’m having a hard time trying to understand how the rubber shock mount can pull thru if it’s being squashed from top & bottom by the 48mm cup washers…

[Rodolfo Lasparri]

28 minutes ago, visionaut said:

I’m having a hard time trying to understand how the rubber shock mount can pull thru if it’s being squashed from top & bottom by the 48mm cup washers…

+1 - Sure looks like the lower washer isn't in place given the top spacing.

[djpdiag]

Bernie33 - yes, both of those are installed.

 

Mike - thank you for that info. This is bizarre and I’m starting to think that either the shock isn’t compatible with the springs and/or the mount is too soft as well. I have the car on my lift and can watch the inside of the trunk as I lower it and as the tires take on the weight on the car, the mounts begin to progress through. I have cranked on that nut to the point that I could no longer stop the top of the shock from turning with another wrench on it. I’ll give that another go however.

 

visionaut - I’d say it’s about halfway through past the ridge that the sheet metal sits in. The washer is still sitting below that. 

[djpdiag]

Rodolfo - the top and bottom washers are installed. I removed the shock again just to see if there was anything I may have missed. 

[Hans]

I mis-spoke 

Edited May 15, 2022 by Hans

[Son of Marty]

IMO your first and biggest mistake is using KYB shocks they are way to stiff especially the rears, I'm not down on KYB shocks in general I have run them on several different set ups they just missed the boat on the 2002 application.  

 

PS. Isn't the bushing in the picture upside down?

Edited May 15, 2022 by Son of Marty