How do you rebuild a strut?

[pwee4u2c]

So I have a 73 1200, and I know you can refill the front strut. I want know if anybody can tell me the process and what kind of fluid to use?

[Ratwagon1600]

Ive used motorcycle fork oil previously.

 

The factory manuals have some advice on how to rebuild the struts.

 

The following  link gives good advice on how to do the struts.

 

http://datsun1200.com/modules/mediawiki/index.php?title=Strut

 

Good luck, and use a spring compressor!

[datzenmike]

Sometimes the fluid leaks out but even if not the fluid that was in it is very thin. I replaced with 20W motorcycle fork oil. Thicker oil is harder to push through the valves and firms up the action. Fork oil vomes in a variety of weights so if too firm or too light you can just change it.

 

Compress and remove the spring. Now loosen and remove the gland nut.

 

 

 

There is a small small O ring in there. I used a dental pic to lift it out.

 

 

 

Very messy so have a container to catch the oldoil.

 

The insides look like this if they haven't been replaced by a non stock cartridge.

 

 

 

I guess you could clean it, I didn't bother. I half filled the strut tube with the new oil and set the strut valve mechanism into it and filled up any left over space. Put the O ring and gland nut back on. Hold the strut tube and extend the strut fully and then compress to the bottom. Hold upside down and extend and compress. This will remove all air from the valves. Remove the gland nut one and O ring more time and check the fluid level is about 1/4 from top to allow expansion from heat. Assemble.

 

They hold about 300ml so a liter of 20W will do almost three struts. I bought Bellray motorcycle fork oil about $17 a liter mostly because of advertized anti foam and rust inhibitors but any hydraulic jack oil will do if you can find the weight. I rebuilt a stock set for my wife's car but used ATF in them. Havent tried them yet. ATF is somewhere around 7W to 12W no one seems to know. I may dump it out and go with 15W or 20W not sure yet. In bothcases I cut a coil from the front springs to firm that up as well.

[pwee4u2c]

Awesome, thanks the pictures are really gonna help me

[graveltrapp]

8.96 ounces if running TOKICO struts or,

9.47 ounces if AMPCO/ATSUGI factory struts are used

[pwee4u2c]

I have the factory AMPCO struts...what's the best way to measure the fluid?

[pwee4u2c]

I'm having a hard time getting the gland nut off

[graveltrapp]

Heat up the tube, not to hot as you do not want to melt the oring, and or use a bigger pipe wrench. Lefty loosey righty tighty as always. Good luck. What weight oil will you use?

[pwee4u2c]

Cool ill try it. I ended up getting 20W fork oil...

[pwee4u2c]

Gosh darn it!!! So I got in other and there were some made in USA after market strut inserts, that just F'd up my day

[graveltrapp]

Start shopping, bummer I guess.

Look here,

http://datsun1200.com/modules/mediawiki/index.php?title=2-inch_Strut_Inserts

[guyster]

 

The insides look like this if they haven't been replaced by a non stock cartridge.

 

 

 

 

I guess you could clean it, I didn't bother. I half filled the strut tube with the new oil and set the strut valve mechanism into it and filled up any left over space. Put the O ring and gland nut back on. Hold the strut tube and extend the strut fully and then compress to the bottom. Hold upside down and extend and compress. This will remove all air from the valves. Remove the gland nut one and O ring more time and check the fluid level is about 1/4 from top to allow expansion from heat. Assemble.

 

They hold about 300ml so a liter of 20W will do almost three struts. I bought Bellray motorcycle fork oil about $17 a liter mostly because of advertized anti foam and rust inhibitors but any hydraulic jack oil will do if you can find the weight. I rebuilt a stock set for my wife's car but used ATF in them. Havent tried them yet. ATF is somewhere around 7W to 12W no one seems to know. I may dump it out and go with 15W or 20W not sure yet. In bothcases I cut a coil from the front springs to firm that up as well.

Rebuilding my struts is my weekend project, so I'm happy to see this thread.

 

What's with the welded cartridge? Is that a solution for shortening the strut when lowering the car? I would think you'd need to section the tube shaft also for that to work.

 

I read on the Datsun 1200 forum that oil measurement needed to be exact. Mike, you found your "by eyeball" method to be acceptable?

[datzenmike]

Yup. They're called oil bath so as long as the insert is submerged in oil it's fine. There's a valve at the bottom of the tube for compression and one on the end of the strut rod that moves up and down during suspension travel for expansion. The oil conducts any generated heat to the outer strut casing. I've had them for 4-5 years by now and they're just like when I 'built' them.

[LenRobertson]

Is the seal under the gland nut still available new somewhere for 280ZX struts? One of my yet to be installed ZX struts tipped over and leaked oil out leading me to wonder if it is worthwhile trying to replace the seal. I'm concerned about dirt getting into the strut rather than oil leaking out. Or does the rubber boot at the top of the strut prevent any dirt getting in? Are the rubber boots available new? One of mine may be torn. I can't quite remember.

 

Len

[datzenmike]

A suitable O ring should work Len. The stock one is square edged I think but round should work equally well.

[LenRobertson]

A suitable O ring should work Len. The stock one is square edged I think but round should work equally well.

So is there not a regular lip-type seal inside the gland nut? I thought that is what it looked like in your 5th pic (the one of the upside down gland nut)?

 

If I get energetic today (not very likely since it is already getting hot outside this morning) I can attack one of my struts with a pipe wrench and see for myself. But it is sooo much easier to post the seal question than carry heavy pipe wrenches (I never start with a big enough one for the job. I should always just grab the 36" one first but it really takes effort to move that thing around). :D

 

Len

[LenRobertson]

So I cleverly waited until the hottest part of the afternoon (94F, I know lots of places are hotter), drug a ZX strut out in the direct sun, and went after it with 24" pipe wrench and good sized hammer. The gland nut came off fairly easily but inside was what appears to my untrained eye to be a gas insert. Has a warning about gas pressure and "Do Not Heat". No brand name but numbers stamped in the side 83203 and below that CK19KC10. The thing is painted a sort of blue-grey color. I poked around on eBay and Google Images and didn't see any inserts than color. K-Mart Auto department brand?

 

What is the test to see if the insert is any good? Should the rod be really difficult to push into the cartridge?

 

And the oil that leaked out when the strut fell over seems to be a bit of oil in the bottom of the strut tube that wasn't completely cleaned out. When I originally saw the oil leaking onto the the floor I "knew" I had the oil filled strut so bought a quart of fork oil without bothering to disassemble the strut to see what was really inside.

 

Len

[datzenmike]

Insert should be very firm to compress or extend through the full length. If fluid has leaked out the strut rod may move an inch or more with no effort. They are just like shock absorbers. If you have seen a 'blown' shock you know what I mean. Many put in an insert then fill around it with ATF or any handy oil. The oil transfers any generated heat to the outer strut case.

[guyster]

This weekend I put in 15W motorcycle fork oil. It used about 210cc of oil, per strut, which was odd because the Datsun 1200 tech wiki stated that I'd need 280cc. Anyway, it is very firm to compress and extend, so I guess I'm OK. Won't know for a while. 

 

I decided to use 15W instead of 10W because I've also lowered the spring perch by 1 1/8". Combined with my King Springs, which drops about 1 1/8". Thought maybe a stronger damping might help things. I didn't section the strut tube, so I'm hoping it's not going to bottom out.

[G-Duax]

A long time ago, in a place far, far away, I bought a really screwed up 510 wagon to drive when I had went back to school. The front struts were garbage.

Being broke most of the time, I decided to do a red-neck strut repair.

 

Drilled small holes into the bottom of the struts, and bounced the car until it ejected all the oil that was in them.

Tapped the hole, and loctited a screw in.

Did the same at the top, and using one of the old fassion trigger pump oil cans, injected 30wt fork oil.

 

Drove that damn rust bucket for several years after, and never had a problem with them, other than squirting a little more oil in once a year.

The rear spring mounts finally rusted off the chassis, and it was sold, but the front end still felt good.