Author Topic: Front suspension shock diameter  (Read 799 times)

Offline juz0

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Front suspension shock diameter
« on: May 03, 2012, 07:52:58 AM »
Hello everyone!
I'm in need of some help with shocks for my front end.
I bought some el cheapo pedders shocks to put in the front and rear while im getting it on the road but they are physically smaller in diameter than what was in there It has Bilsteins in the car originally, but the part numbers dont match up to their catalogue (according to the rep i was talking to). The OD on the front Bilsteins appears to me an imperial size but could be paint oversizing it.
So i'm a bit lost as to where its gone wrong / mismatched
The front tubes are 55mm OD
Bilstein shocks are 45-46mm OD
Pedders shocks (front and rear) are 41mm OD
i dont have any inside mic's or telescopic guages at the moment to measure inside the tube.
I've been searching around for what size OD shocks are going into the tubes but i haven't found a hell of a lot.
so can anyone help out with some info on shock tube sizes and shock OD sizes.
also the part number on the bilsteins are P36-065
the bilsteins have hot spots around the chrome thats why i'm replacing them.
which is a shame because the rods are huge compared to the pedders shocks

thanks people
Justin






Offline DAZDA

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Re: Front suspension shock diameter
« Reply #1 on: May 03, 2012, 08:27:01 AM »
Heat marks (hot spots) on the Bilstein shock tubes (silver) doesn't necessarily mean they are stuffed.  The marks show up when the oil inside the shock tube gets hot (normal) and then the grease (from the slide bearings in the yellow tube) & the seal at the top of the yellow tube leave a mark on the outside shock tube. 

If the shock tube (silver) is still straight, AND there is still gas pressure, AND there is no sign of oil leaking from the shock tube, chances are the Bilsteins are fine.   My old rally shocks (Bilsteins) have had these heat marks on them for years and they are still working fine.
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Offline DAZDA

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Re: Front suspension shock diameter
« Reply #2 on: May 03, 2012, 08:48:08 AM »
I should also add, Bilsteins can be rebuilt which means you may not have to pay as much as the cost of replacing them.

http://www.bilstein.com.au/   (Sydney)
http://www.quadrantsuspensions.com.au/   (Melbourne)
We use and recommend;

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Offline juz0

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Re: Front suspension shock diameter
« Reply #3 on: May 03, 2012, 10:53:55 AM »
Oh true?
so once again ive jumped the gun and bought stuff i didnt need...
Hmm i wonder if i can get a refund.
I need different gland nuts and dust boots too....

Online dat2kman

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Re: Front suspension shock diameter
« Reply #4 on: May 03, 2012, 01:15:33 PM »
Take all new stuff back, tell them it is incorrect fitment,request full refund for unused unfitted items in original packaging,,,,  and that you have existing better quality Bilsteins!
Since they are all out of car, contact/send them off for shock dyno testing, if thay are within limits for that model unit, then pay the dyno cost, and refit.

If they need some work, then go ahead.
Badically, if you can, with effort, put a unit between you legs with one end on floor, and other end in your palm of your hand, and push firmly down, and it comes slowly back up, and all feel the same, they will be pretty right.
You cannot get a better quality unit, considering you already have them, your costs from here on will be minimal.

I run them in three of my competition cars, and Koni Reds in a fourth( to comply with rules)
I just race old datsuns:
Group S Historic 280Z ( not a zx but a USA 280z)
Group O/T Historic Datsun Sports 2000
Group G Datsun 120y  with FJ24 fitted( ex G. Fury)
Marque Sports Datsun Fairlady 1966 -SR20DET

Offline DAZDA

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Re: Front suspension shock diameter
« Reply #5 on: May 03, 2012, 01:22:37 PM »
Without seeing and checking your Bilsteins for myself I can't be sure.  The best advice I can give you is, if you aren't confident of diagnosing the shocks yourself then get more than one opinion (from a suspension shop or a couple of the Zed guys up there in sunny QLD by showing them the shocks) before making any more decisions.  Or as Jason said, said them off to be tested on a shock dyno, but I'd only do this if they are for a race car.

Also, you shouldn't need dust boots with the inverted Bilsteins on a road car. 

 8)
We use and recommend;

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Online dat2kman

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Re: Front suspension shock diameter
« Reply #6 on: May 03, 2012, 03:36:14 PM »
Juz0 i should have looked at your location in the sidebar, DOH!
Edgar at Extreme Motorsports in Nudgee has a shock dyno, he is not a Bilstein agent, so he will give you an unbiased opinion.
Once the valving is set on assembly they should stay at that, unless they have had a hard life.
They can be re valved, but you need to know what they are now, what you need them to do, ie dirt, tarmac, circuit etc.
If you are over my way, welcome to call in with all the bits and i can have a look at them, and steer you in right direction re any work needed or items you need.
I just race old datsuns:
Group S Historic 280Z ( not a zx but a USA 280z)
Group O/T Historic Datsun Sports 2000
Group G Datsun 120y  with FJ24 fitted( ex G. Fury)
Marque Sports Datsun Fairlady 1966 -SR20DET

Offline juz0

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Re: Front suspension shock diameter
« Reply #7 on: May 03, 2012, 08:25:39 PM »
thanks for the input guys.
I'll check over the bilsteins again tomorrow and talk with pedders

Auszcar 240z, 260z, 280zx Forums

Re: Front suspension shock diameter
« Reply #7 on: May 03, 2012, 08:25:39 PM »