Author Topic: Rear OEM shocks, how much oil? (Read 5027 times)

70CB750 · « **on:** October 20, 2013, 08:58:47 AM »

I took apart shocks I had in storage for quite a while, the plan is to clean them up and refill the oil, if I get inspired I will even get new progressive springs.

How much oil and what oil should I use? I was thinking to go with my universal Mobil Delvac 15W40, what do you think?

lucky · « **Reply #1 on:** October 20, 2013, 09:25:28 AM »

Quote from: 70CB750 on October 20, 2013, 08:58:47 AM

I took apart shocks I had in storage for quite a while, the plan is to clean them up and refill the oil, if I get inspired I will even get new progressive springs.

How much oil and what oil should I use? I was thinking to go with my universal Mobil Delvac 15W40, what do you think?

Read the manual and it tells you the correct weight ,the amount, and how to fill them.

strynboen · « **Reply #2 on:** October 20, 2013, 09:58:50 AM »

15/40 are to heavy for shocks...shokes.....shocks..

i use atf ,,and thin hydralik oli..and mix it for korrekt damping..atf alone are to thin..on old bikes..i use it both on fork and back dæmpers..have drilled a small hole and make 3 mm threads to close,,vith a schrev after re filling..
on my 500 i have a set of koni"s..they can easy be opend and renoveret

70CB750 · « **Reply #3 on:** October 20, 2013, 09:59:20 AM »

I forgot to mention these are the rear shocks - sorry.

70CB750 · « **Reply #4 on:** October 20, 2013, 04:07:43 PM »

Anybody?

seanbarney41 · « **Reply #5 on:** October 20, 2013, 06:14:16 PM »

are these stockers?...how about some pics and info about how you got them apart and, more importantly, how you intend to get them back together...I was under the impression that 1970's factory Honda shocks are not rebuildable...

bjbuchanan · « **Reply #6 on:** October 20, 2013, 06:26:36 PM »

Quote from: seanbarney41 on October 20, 2013, 06:14:16 PM

are these stockers?...how about some pics and info about how you got them apart and, more importantly, how you intend to get them back together...I was under the impression that 1970's factory Honda shocks are not rebuildable...

They are "not" rebuildable in the sense that they weren't supposed to be but it doesn't mean you can't.

I wish I could help cb750, my best suggestion albeit not brilliant is to drain them in to a measuring cup and add a few ml's to the measurement to account for the leftover in it. You may not have published numbers to use, most people throw them away

seanbarney41 · « **Reply #7 on:** October 20, 2013, 06:33:18 PM »

Quote from: bjbuchanan on October 20, 2013, 06:26:36 PM

Quote from: seanbarney41 on October 20, 2013, 06:14:16 PM
are these stockers?...how about some pics and info about how you got them apart and, more importantly, how you intend to get them back together...I was under the impression that 1970's factory Honda shocks are not rebuildable...

They are "not" rebuildable in the sense that they weren't supposed to be but it doesn't mean you can't.

sounds great, I just want to know how it can be done!

lone*X · « **Reply #8 on:** October 20, 2013, 08:45:50 PM »

Quite some time back there was a thread about refilling the HONDA OEM shocks. It was along the lines of what Strynboen does. After removing the springs and cover and cleaning them up you drilled, drained, threaded, filled, and plugged. Maybe a search will turn up the old thread.

Duke McDukiedook · « **Reply #9 on:** October 20, 2013, 08:53:46 PM »

Isn't this design a mixed gas shock that requires you put about 150psi of nitrogen in it along with the oil?

Jerry Rxman Griffin aka MuthaF'er · « **Reply #10 on:** October 20, 2013, 10:49:17 PM »

Nitrogen in our old shocks?? Not likely.

bryanj · « **Reply #11 on:** October 20, 2013, 11:56:14 PM »

No gas filling untill the single shock (prolink) rear came in, That is except for air on the big cruisers(wing etc)

70CB750 · « **Reply #12 on:** October 21, 2013, 02:54:30 AM »

Thank you. guys, I will take pictures tonight. Yesterday I searched for some brand or anything that would help to identify - nothing.

They were easy to take apart, everything was screwed - no pun haha - together. When I did the second one, I took notice how far the oil was reaching, I have some idea now.

This is crappy picture of them, but these shocks came with the bike when I got it.

seanbarney41 · « **Reply #13 on:** October 21, 2013, 03:09:31 AM »

ok...yours are not Honda oem

bjbuchanan · « **Reply #14 on:** October 21, 2013, 10:09:19 AM »

Quote from: seanbarney41 on October 21, 2013, 03:09:31 AM

ok...yours are not Honda oem

You have to make them rebuildable. Drill and tap a set screw plug, allen key type so it is flush. No nitrogen, too old

70CB750 · « **Reply #15 on:** October 21, 2013, 01:09:23 PM »

Disassembled.

70CB750 · « **Reply #16 on:** October 21, 2013, 01:10:12 PM »

It cleans up well.

Jerilee · « **Reply #17 on:** October 21, 2013, 01:15:56 PM »

Are there any seals or o-rings that could or should be replaced while we're in there?
It looks pretty simple.

70CB750 · « **Reply #18 on:** October 21, 2013, 02:41:19 PM »

There are some square profile seals but all is nice and tight, I will just clean it, fill it up and use it.

edwardmorris · « **Reply #19 on:** October 22, 2013, 09:18:46 AM »

Quote from: 70CB750 on October 21, 2013, 02:41:19 PM

There are some square profile seals but all is nice and tight, I will just clean it, fill it up and use it.

What are you filling them up with?

Geeto67 · « **Reply #20 on:** October 22, 2013, 09:30:03 AM »

based on the design they look like Boge Mullholland shocks. Pretty common 70'2-90's aftermarket upgrade and NOS ones come up all the time on ebay. The seal kits are NLA for them but even those come up from time to time. I heard there was a company making them again in south america but I have yet to see a set.

I have 50K on a pair of Boge Mullhollands and they have never needed anything (but probably could use a refreshing).

The rebuild kits used to come with new piston and piston shafts so I would check the tolerances on yours. I have no idea what the clearance should be but the shocks are iron lined I own a few sets and have rebuilt them in the past - if you have an industrial supply place near you you can match up the rubber seals and replace them (an auto parts store might work in a pinch but I never tried since there was a great industrial supply place in brooklyn).

70CB750 · « **Reply #21 on:** October 22, 2013, 09:31:34 AM »

Thank you!

Geeto67 · « **Reply #22 on:** October 22, 2013, 09:37:51 AM »

I should add, One of the harder things about identifying Boge shocks is their only mark was a decal on the shock body that looked like this:

some of the MX shocks were pretty great looking for back in the day: safety orange bodies with yellow springs. Every street bike set I have had have been black bodies with chrome springs but I have seen orange bodies with black springs.

edwardmorris · « **Reply #23 on:** October 22, 2013, 09:53:21 AM »

Quote from: bjbuchanan on October 21, 2013, 10:09:19 AM

You have to make them rebuildable. Drill and tap a set screw plug, allen key type so it is flush. No nitrogen, too old

I think someone else here did this, found a link via search (link is to a diff forum)

http://www.hondatwins.net/forum/viewtopic.php?f=19&t=4133

70CB750 · « **Reply #24 on:** October 22, 2013, 11:05:47 AM »

These dont need a plug, they come apart easily, everything is threaded.

edwardmorris · « **Reply #25 on:** October 29, 2013, 06:39:00 PM »

I'm still not having any luck taking mine apart. How did you manage to unscrew them without a compression tool. Or did you use one?

Stev-o · « **Reply #26 on:** October 29, 2013, 06:43:02 PM »

You get em back together yet?

70CB750 · « **Reply #27 on:** October 30, 2013, 02:39:08 AM »

They are filled and assembled without the spring, I will get - hopefully - rubber cups from McMaster to use as the "condom" on them.

I set them up in vice, adjust to hardest setting (shortest spring) and used zip ties all around to keep the spring down - not really safe method but it worked. After that I was able to slip out the end big ring that holds the spring on.

To put the spring back on I will have to figure out some spring compressor, maybe just adapter to a big clamp or something, but that's later.

seanbarney41 · « **Reply #28 on:** October 30, 2013, 03:23:15 AM »

I have rigged up my drill press as a spring compressor before...still helped to have some extra hands.

Geeto67 · « **Reply #29 on:** October 30, 2013, 01:16:57 PM »

how heavy are you? I am a big dude so I usually just put to big screw drivers between one coil of the spring and then put all my weight down on the shock while it sits on the ground (sometimes in a vice if I can manage, but it has to be on the floor). Once I get it down far enough I put my foot on one side and slip the retaining ring on. may not work for everybody.

70CB750 · « **Reply #30 on:** October 30, 2013, 01:26:31 PM »

Quote from: Geeto67 on October 30, 2013, 01:16:57 PM

how heavy are you? I am a big dude so I usually just put to big screw drivers between one coil of the spring and then put all my weight down on the shock while it sits on the ground (sometimes in a vice if I can manage, but it has to be on the floor). Once I get it down far enough I put my foot on one side and slip the retaining ring on. may not work for everybody.

Neat idea! I am around 250, I am sure it will work for me

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Author Topic: Rear OEM shocks, how much oil? (Read 5027 times)