Re-filling the rear shock's preload oil

Post by **CycleRob** » Tue Mar 06, 2007 11:02 pm

I had to remove my leaking Ohlins rear shock today and replaced it with the stock shock until the Ohlins factory service center in Hendersonville NC fixes it I spoke to them on the phone and hand delivery is OK. My GPS says it's 159 miles away. I want to strap on the boxed shock and ride it there . . . . because I can. Besides, I did the math:
Shipping+Insurance-Ride <= Gas+FoodMoney+FunRide

Before I put the stock shock back in, I noticed the free spinning, do nothing, 4+ turns at minimum preload. It had no resistance until the knob was turned in to the "Normal" bar.

HAA! This is gonna be fixed and now. I remember reading about how to do it but decided to tackle it until I had to ask my computer to remind me what and how to do it. How hard can it be?

Took the knob off. The shaft is UNscrewed to the limit. Hmmmm. There's no filler plug visible. Then it hit me. Invert it, remove the hydraulic line's banjo bolt and add the oil.

OK.The banjo bolt is out now but the oil's full. The line doesn't leak much at all after removal. Apparently the piston doesn't have a return spring, so I got a small screwdriver, pushed down into the oil until I felt the internal piston. With a harder push, the piston "thunked" against the fully retracted preload shaft. It moved about a quarter inch (5mm). BINGO! Now I have a lotta air space that used to have oil in it. Who knows were the oil went - - - there's no sign of a leak. Using a small squeeze bottle to add new engine oil, I filled it up. Not much. Maybe 3 tablespoons (10ml) of oil until it was full. Reconnect the hose and then I realized I forgot to mark it's proper location before loosening the banjo bolt. No worries. That's adjustable on the bike.

Putting the stock shock back on was easy with the wheel & muffler removed. Top bolt first, then the bottom bolt. After mounting the preload assembly's bracket to the bike the hose position looked OK. Then I put the muffler on and it's clear the nose needed repositioning over a half turn away to miss the hot muffler. Loosen slightly and turn it there. Done.

Worth a note; you do not have to remove the shock to refill the preload oil.

I have not ridden the bike yet, it was supper time and the temp dropped under 60F (15.5C) from the high of 72F (22.2C) today. I love my new home!! I'll ride it tomorrow. The plan is to hand deliver the leaky Ohlins to the service center, about a 3+ hr ride away. Their address in in the GPS and the next nice day I'm gonna go for a nice long ride. Maybe they'll give me a mini tour of the place. Story later . . . .

Sunbeemer · Post by **Sunbeemer** » Wed Mar 07, 2007 12:08 am

Thanks (AGAIN!) Rob for that very timely report on your preload reload. I also have 4+ turns of free-play in my preloader and have been thinking about refilling it, but couldn't quite remember what the procedure was I'd read around here a while ago. So I do appreciate your recap and feel confident I can go forth reloaded...

Greybeard · Post by **Greybeard** » Tue Mar 13, 2007 4:13 pm

I'm thinking mine needs checking but what did you use for oil Rob?

Post by **rdsmith3** » Wed Mar 14, 2007 2:22 pm

Greybeard wrote:I'm thinking mine needs checking but what did you use for oil Rob?

"new engine oil"

or did you mean synthetic vs. regular?

Greybeard · Post by **Greybeard** » Wed Mar 14, 2007 3:25 pm

No, I was actually wondering if they spec'd a hydraulic oil or something along that line.

Engine oil then?

Hi detergent?

Post by **owldaddy** » Wed Mar 14, 2007 7:28 pm

In previous posts on this subject, hydraulic jack oil was the oil used, I doubt that it makes much difference though.
Don

Greybeard · Post by **Greybeard** » Wed Mar 14, 2007 7:49 pm

Talk about irony.

I have an unopened container of hydraulic jack oil that I bought to refill the bottle jack in my H press.

Label on the side of the bottle jack says "Refill with 30 weight engine oil only", I kid you not.

Post by **CycleRob** » Thu Mar 15, 2007 2:18 am

There's not a lot of movement there so any new engine or hydraulic oil will do. I had some Motul 5100 10W-40 synthetic blend engine oil in my plastic squirt bottle and used that. I prolly should have used the power steering oil I later found instead, but that didn't turn up until after I used the engine oil.

One big omission I made involves the twice-per-turn indexing click's ball & spring that will fall out when you loosen the knob's phillips screw IF you decide to take the knob off . . . . . for graphite lubing the threads and general cleaning, like I did. On mine, when I got the knob off, the ball was missing and the spring was bent over and worn away, like it fell out long ago. That explains the curious scraping noises it made every time I boosted the preload setting for my wife and then again when I removed it for solo riding. I should have investigated that long ago.
I replaced the missing ball with a custom made 2 step rod that the fatter diameter fit in the hole and the smaller diameter inside half of the spring. It works better than a ball and cannot fall out with forceful or wobbly knob motions. The junk box part I used was already made and all I had to do was cut it to the proper length and create a polished dome on the fat end so it doesn't destroy the plastic knob's interior. Looking at the (large) space between the knob and the preload assembly, I wonder if there was actually a ball in there, rather than something like the better designed 2 step steel plunger I made, to provide a "click" turns indicator.

Post by **mick Hoff** » Thu Mar 15, 2007 10:50 am

Here is a link to a page, this guy added oil & took pics so you can see how easy it is to perform
http://members.cox.net/slartidbartfast/ ... ck-oil.htm

Hope this helps everyone get a better idea of how easy this is...

Thanks Rob for all of your great advice & instruction on this site

Post by **wncbmw** » Thu Mar 15, 2007 1:15 pm

Rob - you do know the Hendersonville is 25 miles from my house don't you?

Give me some notice next time, I take off work if I can and we can ride some! I am leaving town tonight until next week.

Post by **CycleRob** » Thu Mar 15, 2007 10:36 pm

Vann,

I knew you're near Asheville but not 25 miles close to the Ohlins service center in Hendersonville. I'm waiting for a warm day with no chance of rain and I'll make the trip to drop off my leaky Ohlins. Let me know by E-Mail a few days before you know what good weather day you can take off work and I'll go on that day. I'll call you Fri or Sat evening so we can make plans.

To stay on topic, here's my preload knob's plunger pin modification that I made this week to replace the mysteriously missing steel ball. It works great now, making a loud click every half turn of the knob.

Sunbeemer · Post by **Sunbeemer** » Thu Mar 15, 2007 10:44 pm

Son-Of-A-Gun...I found a ball bearing in a crack in the garage floor next to my bike yesterday...could it be???? I'll check tomorrow! Thanks Rob!

Sunbeemer · Post by **Sunbeemer** » Sun Mar 18, 2007 5:32 pm

Well that ball bearing must have come from something else as my pre-load adjuster felt just fine, so I topped it up with Sta-Lube Hydraulic Jack Oil. It only took about a tablespoon to refill it (it was loose ~5 clicks). I found a geasy dirt stain underneath the adjuster and on the adjuster mounting tab, suggesting that the oil leaked from the banjo-bolt fitting, but only very slowly as it was just 2 clicks loose when I bought the bike 2-1/2 years ago, so no worries! It's easy to refill.