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does anyone have the exact dimensions of the bolt pattern for the early and late rear shock upper mount?. And also what the exact length differnce is between the early and late rear mounts?
I am trying to get these so I can get a pair of billet adapters made so I can run later year rear shocks on my early '90 C2.
Try this"From model year 1991(1 november build date),The rear strutt upper mounting was modified .As a result of this change the following rear suspension components were modified: Shock absorber outer tube length increased by 38mm/(1.5in)
Rear coil spring length and length of dust cover increased.
From Adrians book
The bolt pattern is the same, you just need a spacer to make up the height of the strut mount. Do you have shocks you're needing to use? seems like a lot of work now a days, most everyone makes a setup for the earlier cars.
Try this"From model year 1991(1 november build date),The rear strutt upper mounting was modified .As a result of this change the following rear suspension components were modified: Shock absorber outer tube length increased by 38mm/(1.5in)
Rear coil spring length and length of dust cover increased.
From Adrians book
I thought the early cars were longer and the strut mount was shortened on the later cars.
also from another thread I was lead to believe the bolt pattern was different as well.
I wanted to use a set of PSS9s or PSS10s and they are only made for the later cars now. wanted to get a set of adapters made like in the pic.
Yes the more I think about the more confussed i am,we must be missing something,because i thought along the same lines as you,anyway my starter motor has to come out so that will keep me curseing for a couple of days
This is a mod that I have done -- and it works well.
I did the mod to allow me to use the adjustable Konis from the later models on my 1990.
The later model shocks plus the late model upper shock mounts are about 2 cm too short -- so I made up spacers out of 1 cm sheet aluminum (2 for each side and replaced the bolts in the late model mount rubbers with longer bolts -- I used bolts from ramset loksons and hardened steel washers so they did not protrude and foul the top coil -- or your could get a machine shop to mod the heads of some longer bolts to suit (look at the heads of the bolts on the late model rubber mount and you will see what the head has to look like -- but you have to use a brass punch and a nut on the bolt end to protect the thread to get the bolt out as it is pressed in) and then use one of the ally spacers as a template -- clamp it up inside the shock tower (with very small G clamps) and then us a hand held electric drill to drill up through the spacer holes to get your new holes -- then bolt it all in -- the shape of the early shock tower must be the same as the shape of the later shock tower because the upper mount rubbers were a neat fit.
If I recall the parts were about $400.00 so it was expensive but is was the only way to get adjustable Konis and I wanted them because I have used Konis before and are happy with them.
I have got some photos but I am not so good on computers and have trouble uploading but will try to do so in the next day for so.
just for future reference the bolt pattern for the early 964 is NOT the same as a late rear shock. I bought some Motons that were in a late 964 and the upper mounts do not have the same bolt pattern. even though there are extra patterns (one for 993 and one for late 964) none of them match up to the early bolt pattern so I will have to get holes drilled and tapped.
Last edited by xcoldricex; 05-24-2015 at 11:16 PM.
I think there is a height difference also not just a change in the bolt pattern. Sorry, looks like this was already talked about a few posts earlier:-(
just for future reference the bolt pattern for the early 964 is NOT the same as a late rear shock. I bought some Motons that were in a late 964 and the upper mounts do not have the same bolt pattern. even though there are extra patterns none of them match up to the early bolt pattern so I will have to get two holes drilled and tapped.
no they are aftermarket monoball strut mounts. they have a 993 pattern and a late 964 pattern. i just drilled and tapped a new set of holes for the early 964 using the oem top hat as a template.
Yes I used a 1" aluminum spacer in the rear I linked in another thread. the spring was tight to the hat but without preload. however, I think I might need a bit more height in the rear.
09-29-2008, 11:56 PM
Rear shock mounts
shock mounts
