replace oil dampers

[trev]

Hi all

many years ago, i replaced a front set of oil dampers with KYB shocks... they simply slipped into the front damper housings...

I bought a set of these 9 years ago and have finally gotten to changing them out in my 260z, but can anyone advise how to remove the guts of the damper?

i cant remember what i did last time as it was probably about 25years ago!

i have removed the front damper, taken off the top retainer cap, but not sure what to do next?

thanks in advance for advice

[RestoZ]

Check this post. Might have something you are looking for. There are some photos in here which might be helpful.

https://www.viczcar.com/forums/topic/21227-original-strut-rebuild/?tab=comments#comment-221250

Cheers 

Paul

 

 

[gilltech]

I'm not clear what you are trying to do? Replace original damper assemblies with KYB cartridges? Or replace old KYB cartridges with new ones?

IIRC, although it's been many years, once you unscrew the gland nut the original damper 'guts' or cartridge as applicable just slide up and out. Both will be, or should be, dripping in oil, as even self-contained cartridges are installed in oil to provide heat transfer.

Edited October 9, 2021 by gilltech
grammar

[trev]

Hi guys

thanks for your responses. yes, I am trying to pull out the original oil dampers and replace with KYB inserts. 

if they are just supposed to slip out, perhaps I need to pull a bit harder! they seem to be a bit stuck. i am guessing they have been in there for 40+ years!

will try again and let you know how it goes

 

Edited October 9, 2021 by trev

[C.A.R.]

Trev - dont bin the original wet legs! They are a very good, durable unit with new fluid.

Just remove the old assembly's, wash/scrub everything down in brake cleaner, then refill them with 320ml of ATF.
This will be far better than the KYB's!

Sell the KYB on to someone who needs them.

[trev]

hey guys

success in a way... i managed to extract the old dampers and now have fitted the KYB's...

on your advice, locky i have not discarded the old "wet legs", if they prove to be serviceable i will refill and replace them again...

ended up not being that difficult when i used a bit of slide hammering to get the old dampers out!

in  any case, its ready to drive again!

[trev]

what i will mention is the oil was very black and very stinky!

[RestoZ]

I will be writing up the process of restoring the original struts and dampers that I went through sometime in the future. Mine worked out well but want to be sure they work as they should and can't do that until the car is back on the road.

As a matter of interest, I used fork oil purchased from Honda Motorcycle Shop to refill mine. Not sure of the difference between that and ATF, but the 320ml is the same for both the front and back even though (in my case) they were different lengths. 

[trev]

hey everyone

so I pulled apart the wet legs I removed on the weekend... see what I found inside!

on the DS, seems to be in pretty good condition aside the discoloration on the lower part of the shaft. the PS one seems a little worse for wear with the plastic stopper from the mid part (I guess there purely to keep the shock piston straight in the tube) had completely disintegrated which explains the shattered plastic parts that drained out with the oil! the lower plunger parts has a bit still stuck around it too. but should clean off.

despite all this they both still seemed to "work", but I just thought it was time for an upgrade/rebuild. I gotta say I was surprised that these were in better condition than expected. I dont think they have been looked at from birth!

now I debate shortening the piston rod to accomodate the lowered springs. my idea was to take about 40mm off the threaded top end, so to move the piston back to it original travel area within the inner tube with the lowered ride height? but will this stop bottoming out? or i just get a set of bump stops for the outside.

and yes, i also have the issue that when unloaded, the lowered springs sit shy of the top hat.. about 30-40mm short

all good once the car is the ground... just dont get airborne!

but I figure taking 40mm off the piston rod may help with this issue too?

pics mainly for reference of anyone wanting to see inside these without having to pull them out of your car!

 

but 1 question: does anyone know where I could get the new plastic bit???

[gilltech]

I don't know that Nissan made parts available for the wet legs, apart from the gland nuts, as they offered their own inserts... CAF might know...

Is one 'stopper' still intact, can you have a new pair machined up in a matching plastic or nylon, or maybe better yet in aluminium? Talk to a machine shop. Or some friendly DIY person with a lathe in their home workshop...

There has been talk on this forum previously about spring non-capture when installing short springs to lower the ride height. Some didn't seem concerned, as you say just don't get airborne! - one even suggested wiring the springs in place; but others including myself considered it a safety issue and surely not roadworthy nor insurance compliant. Not to mention a PITA during front end maintenance.

You say 30-40mm, that seems a lot - I once tried King Springs lows on my 260 and they were barely captured at one end and too short by about 12mm at the other so I didn't proceed.

[trev]

hey gilltech...

thanks for that. i think the upper plastic bush may just be an upper "bumper" to stop metal to metal contact when the damper piston extends.

lucky me I have access to a machine shop, so may grab the remaining one and have 2 made from a nylon material. I think ally would be too hard.

then I will have a go at rebuilding on the bench first with oil and see how they feel...

after all this, I am now going to have a look at the rears too!