Mid to late 1960's Suzuki Shock Rebuild Options The problem is the caps of the shock bodies are crimped. Graham Curtis made a fixture for his lathe so he could machine off the crimp, then he threaded the shock body and made a sleeve nut to hold the innards in after reassembly. The photos and the text that follows is all Graham's, except where I've made a note in italics and highlighted it like this. Crimped - Crimp detail by graham.curtis, on Flickr Crimped - Machining off crimp by graham.curtis, on Flickr
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Mid to late 1960's Suzuki Shock Rebuild Options
The problem is the caps of the shock bodies are crimped. Graham Curtis made a fixture for his lathe so he could machine off the crimp, then he threaded the shock body and made a sleeve nut to hold the innards in after reassembly. The photos and the text that follows is all Graham's, except where I've made a note in italics and highlighted it like this.
Crimped - Crimp detail by graham.curtis, on Flickr
Crimped - Machining off crimp by graham.curtis, on Flickr
CL77 - Threaded Complete disassembly.jpg by graham.curtis, on Flickr
“CL77s 'appear' to have a damper rod of 10mm diameter (there are always exceptions) and a damper body bore of 27.2mm.
CL72 shocks have a damper rod of 9mm diameter and a damper bore of 27.2mm
The CB77 shocks have a rod diameter of 9mm with a damper bore of 26.2mm
CB160s are unusual in that they have a 9mm damper rod and a 27.2mm damper
All of this proves that whatever shock you dismantle you are going to have to measure what you've got in order to proceed.
All seals are of 'double lip' design which means that you need a seal where the part that faces the oil has a lip backed up with a garter spring and the part which faces the outside world is a plain lip to keep dirt and dust out of the damper.
The best I have been able to find so far are double-lip seals in 10 x 22 x 7 and 9 x 22 x 7 sizes. My plan is to machine up aluminium bushes which will convert these seals to work in a 27.2 or 26.2 bore, as required. The bush will have a wall thickness of 2mm or so and I hope will be able to accommodate a thin o-ring to seal it against the damper bore.
My bush will be 10mm thick to match the original oil seals and this will provide a land for the seal to sit against.
CL77 - 10mm Seal Comparison by graham.curtis, on Flickr
CL77 - 10mm Replacement Seal by graham.curtis, on Flickr
CL77 - 10mm New Seal - double Lip.jpg by graham.curtis, on Flickr
Just got the bushing finished and fitted with the new seals. I thought that I had purchased 1mm thick O-rings but they turned out to be 1.5mm. Had to go back and re-work the grooves.....
I'll take a look inside some Dream shocks soon. They should due very similar. Just found out that CB160 damper seals are still available. 9 x 27 x 10. They have a Honda part number too 91254-216-000 - incredible. None of the other bikes have seals listed, as far as I can tell. These will fit the CB160 plus early CL72 / 77 and maybe the Dream...
CL77- 10mm Back side of seal holder by graham.curtis, on Flickr
CL77- 10mm seal holder in damper by graham.curtis, on Flickr
Next job is to reassemble and then sort out some decent covers...
Last post for the time being. Here are the original CL77 damper bodies, rechromed with new sleeve nut and seal holder with new 10 x 22 x 7 seal inserted.
CL77 - 10mm Reassembled Damper by graham.curtis, on Flickr
Just a quick re-cap on the Dream shocks which a couple of people were asking about.
Pretty much the same as the others except for one fortunate detail. As the Dream top mount has to be removed to extract the covers it means that once the damper retaining nut is removed, the seal can be replaced without further dismantling. As the damper rod is 9mm and the shock body 27.2mm internal diameter, the CB160 seal can be used. this is part number 91254-216-000. Physical dimensions 9 x 27.2 x 10 mm.
Compressing the covers to release the top eye and spring.....
The seal just slides off, but if you are going to re-use the seal - don't forget to protect it from the sharp threads with some tape....
Dream - Damper Disasembled by graham.curtis, on Flickr
I think I've covered almost all variations now.......
The slot is, I think, about 3mm wide, so the tool I made is just a piece of 3mm plate with a hole drilled to clear the damper rod. The hole was sawn into a slot, then the ends were heated and bent sharply at right angles.
Retaining Nut tool detail by graham.curtis, on Flickr
The retaining ring a lot easier to remove if you can drill or grind out the center pops that are used to lock the ring in place.
A few more pictures to show progress so far. Here are three pairs of dampers all buttoned up with fresh shock oil, new seal and a new coat of chromium plate.
CB77-CL72-CL77 Dampers Reassembled by graham.curtis, on Flickr
To finish off the CL77 shocks I had to locate some replacement chrome lower covers. All of the original ones I have didn't make it through the chroming process due to pits or other damage.
I found some new lowers made for Girling (or Hagon) shocks on eBay but the hole in the bottom was too large for the Honda damper. Another trip to the lathe was needed to turn up some adapters for the covers but, once mounted, the new covers are a good match for the Honda ones.
CL77 - Old cover - new cover by graham.curtis, on Flickr
The adapter fits inside the chrome cover and just centres it on the preload ring so that the two
pretty pleased. The CB77 dampers shown above have had a similar treatment with a 'seal adapter' but the CL72 shocks were treated to NOS seals which are still available.
My machines are definitely in the hobbyist category. The lathe is almost as old as me and was made just up the road from me by Myford ltd.. Unfortunately they went bust last year. I have a cheap chines milling machine which is OK but a bit flimsy. After only 30 years as an engineer, I am still learning.....
There is only one seal in the Dream shock and yes, it is the 27.2 x 9 x 10 version that is available on eBay. 91254-216-000 from memory.
Yes most Honda shocks have very weak bump damping and stronger rebound damping - that is normal.
You need to be careful when you pull out the damper body. The seal is a tight fit and there is a spring underneath. My 'puller' pulls it out in a controlled way so that you can decant the oil and measure the quantity. I had been using 15wt oil to give a slightly better damping action. The Dream damper rod doesn't need to be dismantled fully as the seal can be pulled off the top of the rod.
Latest (and belated) instalment of my on-going shock restoration project.
Honda CL72 / 77 Scrambler finished shocks by graham.curtis, on Flickr
Left is all NOS CL77 parts with custom color top covers Middle is reworked CL77 with Girling covers and springs as detailed earlier in this thread. Right is early CL72 with genuine (restored) Honda top covers and Girling lowers.
Note: Jim D. On Sundial used Hagon shock bodies as replacements and the shape is similar - could be modified further possibly (see his photo below). I ordered replacement eyelet rubber bushes for my shocks from www.400s3.com in the UK. Reasonable price and fast service.