Article [13] ST1300 - Pre-load Fluid Replacement

[jbird24]

If you read the bottle of SS8 oil it will say not for use in rear suspension, or something along those lines.
I find hydraulic jack oil works best and lasts the longest.
.02

Thanks Larry. I went with the Hydro, afterall. I didnt have any ss8 left

 

[dduelin]

Regarding SS8 and other fork fluids, it’s “not for use in rear shock applications” because rear shocks are charged with a gas/oil emulsion under pressure and don’t use fork fluids like SS8. The Showa preloader mechanism is external to the shock and is just a hydraulic jack in another application. Jack oil, SS8, or other fork oil used in hydraulically damped forks will interchange and work the same. ATF would work as many older bikes use it.

 

[ST Gui]

Does anyone know if the screw driver provided in the honda tool kit is a JIS or phillips.

While my ST didn't get a tool kit other than the pouch a piece of foam and a 5mm Allen wrench - I'd say the factory screwdriver is in fact JIS. With all my previous bikes -'85 and prior the factory screwdriver worked really well unless the screw was so tight I didn't have the leverage to break it loose. Enter the Vessel impact driver which I didn't know had JIS bits. My only problems with Honda "cheese head screws" occurred when I used a "bigger Phillips". Lesson learned. Now my buddies and I use JIS only on our bikes.

 

[etalors]

Does the pre-load adjuster change the seat height as more load is added or vice versa. or does it change the seat slope from back to front.

 

[dduelin]

Does the pre-load adjuster change the seat height as more load is added or vice versa. or does it change the seat slope from back to front.

Turning the adjuster wheel clockwise adds preload. Adding preload extends the stock rear shock up to 10 mm from zero preload to the max of 36 clicks preload (supposing the adjuster has resistance from 0 to 1 click. It's pretty difficult to get resistance from 1 click.) In theory if you turn 18 clicks you raise the rear ride height 5 mm. This raises the rear of the bike 5 mm, slightly increasing the slope of the seat towards the tank. If you can add fork preload the same amount as shock preload the bike raises by the same amount front and rear. By only adding shock preload only the rear is raised.

 

[etalors]

Turning the adjuster wheel clockwise adds preload. Adding preload extends the stock rear shock up to 10 mm from zero preload to the max of 36 clicks preload (supposing the adjuster has resistance from 0 to 1 click. It's pretty difficult to get resistance from 1 click.) In theory if you turn 18 clicks you raise the rear ride height 5 mm. This raises the rear of the bike 5 mm, slightly increasing the slope of the seat towards the tank. If you can add fork preload the same amount as shock preload the bike raises by the same amount front and rear. By only adding shock preload only the rear is raised.

Great info. 5 mm = 0.2 inches. Therefore, I doubt if this would contribute to the famous forward slide on this bike. Most preloads would be in the range of 10-13 clicks, depending on the each user's weight etc. So theoretically, most bikes have their rear ends up by about 0.1 - 0.2 inches for an average of 0.15 inches.

 

[etalors]

Can you send me your complete instructions for this. Thanks.

 

[etalors]

I have found an even easier short cut! Instead of removing the knob, spring and detent ball, then removing the (2) 10mm bolts, unclipping the line from the fender, loosening the rear master cylinder bolt, and feeling the whole assembly over to the right side etc.....

New improved method:
1. Remove left side cover
2. Observe how the unit is bolted on
3. Instead of removing the 10mm bolts, follow the mounting bar upwards to where it bolts to the frame by the lift handle. You'll see (1) 10mm bolt. simply remove this one bolt, and gently pull the line free from the front of the rear fender. You can then simply turn the entire unit upside down on the left side of the bike without removing anything else. You now have a bar to hang onto while you loosen the banjo fitting. As far as having the line point in the correct position, I simply observe where it was before you loosen it, or mark it with a sharpie. I can now R&R one of these in about 10 minutes! Hope this helps.

In Step 3 where you say, "As far as having the line point in the correct position, I simply observe where it was before you loosen it, or mark it with a sharpie. " Is this critical to observe or can we find the correct position in some other way, in case I did not observe this while loosening it. Which may be the case.

 

[Robfin]

As Dave found out, Showa does not list the banjo bolt (oil bolt), or any components (washers) on their website.
I've got a couple large pickle jars of banjo fittings off of ST1300's.
Honda seems to use just two different banjo bolts, over a broad range of models, from GL1800's to Dual Sports.
These parts are listed as brake parts, not suspension parts (disclaimer).
1. 90145-MS9-612 (10x22)
2. 90145-MR8-014 (10x34)
If I get time later, I'll pull a rear shock apart and measure the Oil Bolt that's in it, and compare it to both of these bolts.
If they are the same, I'd be glad to mail you one if you'd like.

So I recently started on the Pre-load adjustment fluid service and during the process stripped the banjo bolt (bozo move). I ordered both bolts above hoping that one of them would be the correct replacement. Turns out they weren't :-( (see attached photo). So with the measurements and thread size defined at auto supply store (they couldn't locate one either) I did a little digging on internet and found what I hope will be the right piece at www.fittings.store. Sku# gsa29_m8x10m. I'll let you know if it works when I get it next week.

 

[Robfin]

So I recently started on the Pre-load adjustment fluid service and during the process stripped the banjo bolt (bozo move). I ordered both bolts above hoping that one of them would be the correct replacement. Turns out they weren't :-( (see attached photo). So with the measurements and thread size defined at auto supply store (they couldn't locate one either) I did a little digging on internet and found what I hope will be the right piece at www.fitting.store. Sku# gsa29_m8x10m. I'll let you know if it works when I get it next week.

OK, mark that one off as not the correct piece. Onto my NAPA store and perhaps they can find a 3rd party source. My local honda shop was of no help either.

BTW, anyone have a spare pre-load adjuster sitting around that they'd want to sell?

 

[Igofar]

Check out our for sale section, as someone just listed a salvaged/recovered bike that he is either going to part out, or sell cheaply.
He may be willing to remove the preload adjust assembly for you?
'03 parts bike for sale

 

[Ralf_CT]

Adding preload extends the stock rear shock up to 10 mm.

So it should make it easier to get the bike onto the center stand since it will reduce the amount of 'lift' required to roll it onto the center stand?

 

[dduelin]

So it should make it easier to get the bike onto the center stand since it will reduce the amount of 'lift' required to roll it onto the center stand?

That is correct but with no rider weight on the bike the sag is not significant, usually less than 10 mm. Minimal static sag (sag of bike alone, no rider or cargo) with acceptable rider sag (sag measured with rider + passenger) is an indicator the spring is too soft. This combination is unfortunately how a stock shock measures for riders over about 165 lbs riding weight.

 

[Ralf_CT]

Can one not simply use Dexron 2 ATF for the adjuster? It's more or less the same viscosity as 10W fork oil and available in 500ml bottles.

 

[Igofar]

I've found hydraulic jack oil holds up better, and last longer than fork oil, or ATF oil.

 

[dduelin]

Can one not simply use Dexron 2 ATF for the adjuster? It's more or less the same viscosity as 10W fork oil and available in 500ml bottles.

I believe ATF would work just fine. Showa uses this preload mechanism in many OEM applications. I myself have had different 4 motorcycle types in two brands with the same preloader and every bike specific support forum there are threads just like this one regards servicing the preloader and people use a variety of light oils - fork fluids, ATF, jack oil - with good results. Once set to rights there should never be a need to service it again. For me that includes well over 100,000 miles after service on my ST and 36,000 miles on the Goldwing, 20 thousand on my RT. If you anticipate a need for longer service than this something else will probably require service or replacement before the mechanism fluid breaks down.

 

[Ralf_CT]

People use a variety of light oils - fork fluids, ATF, jack oil - with good results.

I managed to get some Ravenol hydraulic lift oil from a friend earlier, probably a little thicker than ATF, but according to the spec it should be okay.

 

[dduelin]

I managed to get some Ravenol hydraulic lift oil from a friend earlier, probably a little thicker than ATF, but according to the spec it should be okay.

That sounds good. I'm sure it will also do just fine.

 

[bairo]

Finally got around to doing this. I just left a job where I was gone for 10-12 weeks at a time, home a week, then out again for
10-12. bought the bike over 2 years ago with 5k and it only has 6700 now.
I opted to leave the bar attached and take off the 2 bolts only on the cylinder. My handle was clicking so I left it on. 15 minutes, I used jack oil, went from 20 clicks resistance to 1.5 clicks. I’d call that a 15 minute win.
p.s. since there was so much milky goop in there (although I flushed it a couple times), I’ll put 500 miles on it and do it again.

 

[wadu]

My way to fix the rear shock absorber.