Rebuilt rear shock leaking

NobodySpecial

NobodySpecial

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Joined
Sep 9, 2018
Messages
194
Location
South Central WI
Bike
2004 ST1300A
As part of a full suspension overhaul about 3.5 years ago, the rear shock on my beloved '04 ST1300 was rebuilt by GMD Computrack as recommended by @Uncle Phil . I believe I ended up with a 1300# spring. A few days ago I noticed some oil drips and - after checking every other piece of equipment that it could be - my son and I finally checked the ST. The swingarm was coated and after tracing it it was clear it's the rear shock. Enough to drip a drip an hour or more. I was (and am!) quite happy with the great work that GMD Computrack did. My question(s) are the following: What would you do in this situation?

1. get it rebuilt again by GMD Computrack?
2. get it rebuilt but by Traxxion Dynamics
3. Replace it (with what?)


Update: it may be worth noting I have gone (double) DarkSide. The rear shock protector I have installed has rubbed in just a few places over the last 1,000 miles but nothing serious. I am a big fan of this accessory. It has kept all manner of nasty things off of the shock and lower gas tank, etc.
 
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Look at the point where the preloader hose connects to the shock. If you have a leak there, the oil will flow downwards and dirt will stick to that. If the shock is leaking, I'd expect oil and dirt all over the place. Your pics were hard for me to interpret, but my best guess is it is the shock. You should also visually follow the preloader hose from the left side preload adjuster over to the shock. This hose dives down in front of the plastic fender and will not be visible for it's entire length.

I'm not sure if you can clean the shock, spring, and area and dust it with talcum powder to see where the leak shows up first. This would be the ideal way to id it but it might not be worth the effort.
 
SMSW said:
Look at the point where the preloader hose connects to the shock. If you have a leak there, the oil will flow downwards and dirt will stick to that. If the shock is leaking, I'd expect oil and dirt all over the place. Your pics were hard for me to interpret, but my best guess is it is the shock. You should also visually follow the preloader hose from the left side preload adjuster over to the shock. This hose dives down in front of the plastic fender and will not be visible for it's entire length.

I'm not sure if you can clean the shock, spring, and area and dust it with talcum powder to see where the leak shows up first. This would be the ideal way to id it but it might not be worth the effort.
Click to expand...

Preloader leak can also happen at the preloader piston itself.

Is the preloader freewheeling? Piston getting less than 9 mm travel?

Clutch slave leaks can also drip oil in this area.
 
If there is no oil/dirt on the shock except where you took pictures of (the lower clevis) the shock body is leaking. The preloader oil is all contained in the collar around the top of the shock and of course in the hose and preload wheel under the right side cover. It is completely separate from the damping oil contained in the shock body. If there is no oil above the area in pic #2 and it is all at the bottom and swing arm as in pics 1, 2, and 4 the shock body is leaking. I wouldn't rebuild an OEM rebuilt once. They aren't that hard to find used if you don't want to spend the money for a good shock from the likes of Penske, Ohlins, Wilburs, or YSS then rebuild another OEM.
 
NobodySpecial said:
As part of a full suspension overhaul about 3.5 years ago, the rear shock on my beloved '04 ST1300 was rebuilt by GMD Computrack as recommended by @Uncle Phil . I believe I ended up with a 1300# spring. A few days ago I noticed some oil drips and - after checking every other piece of equipment that it could be - my son and I finally checked the ST. The swingarm was coated and after tracing it it was clear it's the rear shock. Enough to drip a drip an hour or more. I was (and am!) quite happy with the great work that GMD Computrack did. My question(s) are the following: What would you do in this situation?

1. get it rebuilt again by GMD Computrack?
2. get it rebuilt but by Traxxion Dynamics
3. Replace it (with what?)


Update: it may be worth noting I have gone (double) DarkSide. The rear shock protector I have installed has rubbed in just a few places over the last 1,000 miles but nothing serious. I am a big fan of this accessory. It has kept all manner of nasty things off of the shock and lower gas tank, etc.
Click to expand...
Curious - how many miles on it since the rebuild?
You might give Kent a call at Computrack and see what he has to say.
 
dduelin said:
I wouldn't rebuild an OEM rebuilt once. They aren't that hard to find used if you don't want to spend the money for a good shock from the likes of Penske, Ohlins, Wilburs, or YSS then rebuild another OEM.
Click to expand...

What's the difference between rebuilding an OEM and rebuilding an aftermarket, which is commonly done?
 
Update: a new-to-me (used) rear shock and rear caliper (different issue) are on their way. Thanks @Al Gully ! When the shock arrives, I will inspect it and make a decision as to whether it or my old (rebuilt!) shock will get redone. I spoke with David at GMD Computrack, and he said yes, obviously, the Penske is a better shock all around. But the rebuilt OEM shock with gold valves, etc. and a new spring is actually pretty good. I was happy enough with it's performance for the last 3.5 years and 25,000 miles, so I think that's what I'll do; have the shock refurbished. If it's damaged then I'll either have the spare shock redone or explore a Penske (or maybe a Nitron).

FWIW the 1,300 pound-per-inch spring I have on the shock now (installed at the same time it was rebuilt) is physically larger than the old spring and makes removal and installation a bit more challenging, but it got done.
 
dduelin said:
The OEM isn’t that great to begin with.
Click to expand...

That's why some have them rebuilt (resprung and revalved).

The question is: Why wouldn't you rebuild an OEM a second time? If you were happy with it after a first rebuild, why wouldn't you be happy with it after a second rebuild?
 
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MidLife said:
That's why some have them rebuilt (resprung and revalved).

The question is: Why wouldn't you rebuild an OEM a second time? If you were happy with it after a first rebuild, why wouldn't you be happy with it after a second rebuild?
Click to expand...
That is, in fact, the plan. However, in the event of some more significant issue with the existing shock (such sort of not-easily fixable damage, etc.), I want to have backup plans and my first (of two) backup plans is to have a second OEM shock rebuilt.
 
MidLife said:
That's why some have them rebuilt (resprung and revalved).

The question is: Why wouldn't you rebuild an OEM a second time? If you were happy with it after a first rebuild, why wouldn't you be happy with it after a second rebuild?
Click to expand...
I was very happy with the OEM that Race Tech revalved for my ST1300 but Ohlins and YSS shocks on subsequent bikes were worth to me the not much more money difference over OEM shocks. The best you know is only the best you know.
 
dduelin said:
I was very happy with the OEM that Race Tech revalved for my ST1300 but Ohlins and YSS shocks on subsequent bikes were worth to me the not much more money difference over OEM shocks. The best you know is only the best you know.
Click to expand...

Still doesn't quite explain why a second rebuild is not advisable?
 
NobodySpecial said:
That is, in fact, the plan. However, in the event of some more significant issue with the existing shock (such sort of not-easily fixable damage, etc.), I want to have backup plans and my first (of two) backup plans is to have a second OEM shock rebuilt.
Click to expand...

Re: Back Up plan.

I have a Works shock (1300 # spring as well, with remote preload) that was just rebuilt (serialized and warrantied). that would be available for less than the cost of a new Penske.

Send a PM if it is something you might consider.
 
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