As most of you know, I own an pre-production RX-7 which comes with it's own set of rules if you will.. there are random parts unknown factory equipped onto this vehicle unlike any other RX-7.

So I went to replace my front shocks yesterday and ran into a huge issue. Everything was looking fine and dandy, from the outside 'normal'.. but when I went to remove the "shock cartridge" I found out that the whole unit was actually a strut.

When I took off the top nut after fabricating a tool to remove it, I noticed the entire cylinder was full of oil- my first thought was "man that shock is way busted and is sitting in it's own bath of oil". I couldn't remove the "cartridge" just by pulling on it so I rigged up a slide hammer to it to get it out. Once out, I came to the realization that I just yanked out the actual internal structure of the strut. The Oil was meant to be surrounding the cartridge as the unit is fully sealed. The bottom of the cartridge is fully exposed into the chamber, and the top nut has an actual oil seal pressed into it (which subsequently I destroyed trying to remove it thinking that it was retained into the nut by accident from the "insert" over time- wrong. Even placing the replacement cartridge into the shaft didn't fit correctly- the small little base that's welded onto the shock bottom (about 3/5") makes the shock protrude out of the chamber roughly the same amount. No go.

SO, anyone ever seen this before??? Is this suspension set up on any older Mazdas? What the hell... lol.

 

What you have is normal for stock.

1980 FSM - they don't have the 1979
http://www.foxed.ca/rx7manual/manual...Suspension.pdf

 

Yep,original KYB strut assembly.

 

What year strut inserts did you purchase? SA strut inserts are shorter than FB inserts-as in not interchangeable.

 

Oh... Alright then. I feel stupid, but I had not seen them discussed on any searches I made so I thought it was anomalous.

Certainly the inserts I have do not fit without modification. They are KYB 363003 as listed many places for a 79.

Sidebar: In an effort to retain factory original status, should I attempt to service the existing units instead of retrofitting them?

 

I think you could have success with just servicing them. The procedure is in the FSM I posted. Not sure how hard it is to get the seals.

 

I know you want to keep car as original as possible,concessions can be made in the interest of keeping car streetable,this would be one. The car will ride/handle better with the modern cartridge installed than refurbishing original style strut. Have not done a search but suspect availability of collar/seals for strut top not too good. If you can get strut cartridge in housing,once in place,they will not be able to be seen. The dustboot will cover the modern retaining nut. Unseen upgrade.

Post a pic of replacement cartridge,some have a foot tack welded to strut base which can be trimmed off to lower cartridge in housing. You'll want to put enough light oil in housing to bring level of oil about 3" from top of tube. The oil allows the cartridge to transfer its heat to strut housing.

 

I kind of wish I had kept my original oil filled cartridges when I installed the KYBs many moons ago. I hear they are easily serviced and you play with the oil viscosity to very the dampening behavior.

BTW, give me back my cheap plastic oil pan! LOL I have 2 of those and 2 of the big yellow one with the capped pour spout on them.

 

Honestly I think I'm going to try and keep it factory- or perhaps modify the aftermarket KYB's I bought for now until I can source another original top nut/oil seal.. as the NOK oil seal part number isn't even cross reference-able at all.

I definitely understand the point with taking concessions, but I do feel there's something cool about this serviceable(and adjustable) strut.. and honestly I wonder how few people are still running them. A sizable point of this restoration is the nostalgia the car represents. If it's feasible for me to keep running them then I would definitely like to-
And yes, the shocks I received have the small foot on them, I've already begun (carefully) hacking it off.. they're on there much more than that single tack would lend you to believe.

I'll be looking for anyone who happened to keep any of these original top nuts...
And I need to look into oil weights for these things.