GSX1400 Owners .org

Technically Speaking => Suspension => Topic started by: Michael Whitney on Sunday, 09 July 2017, 07:10 AM

Title: rear left shock pre-load knob not working?
Post by: Michael Whitney on Sunday, 09 July 2017, 07:10 AM
Went to harden the pre-load on the rear shocks and right one turns just fine all the way but then went to adjust the left one and the knob becomes solid once it gets half way between the 3rd and 4th line/mark as if it has run out of adjustment yet the other one continues turning beyond this point. There are no leaks from either of the shocks and both click and move as expected it's just the left one seems to seize between the 3rd and 4th mark.

Is it just an easy fix of spraying it with WD-40 or is a strip down of the shock required?
Title: Re: rear left shock pre-load knob not working?
Post by: Andre on Sunday, 09 July 2017, 03:44 PM
Try pushing the knob in while turning.
Title: Re: rear left shock pre-load knob not working?
Post by: seth on Sunday, 09 July 2017, 04:39 PM
go tead the forum as a whole section on this problem
its a common one and one of the very faults with the gsx1400
Title: Re: rear left shock pre-load knob not working?
Post by: Michael Whitney on Sunday, 09 July 2017, 05:39 PM
I've tried pushing and pulling the knob and it still doesn't turn. It turns anticlockwise still just won't let me harden the shocks anymore.

I've looked at the forum and can only fkmd stuff about leaks which mine aren't leaking
Title: Re: rear left shock pre-load knob not working?
Post by: Michael Whitney on Sunday, 09 July 2017, 05:51 PM
Thought it might have been becsuse I tried ajusting it on it's side stand but I don't see why the right side would still work okay and not the left side. 
Title: Re: rear left shock pre-load knob not working?
Post by: Dusty ST on Sunday, 09 July 2017, 09:03 PM
Winding the knob pushes a piston which pushes oil into a cylinder under the indicator rings. Either you have had an oil leak (there's only a tiny amount even when full) and there's not enough left to push the adjuster any further, or the piston has seized, either in it's bore, or the threads moving it.
Title: Re: rear left shock pre-load knob not working?
Post by: Snapey on Sunday, 09 July 2017, 09:34 PM
FIX FOR GSX1400 LEAKING REAR SHOCKS

1. Remove both shocks.

2. Give them a good clean.

3. On the inner/wheel side of the shock, on the back of the main spring pre-tension chamber, there is a tiny M5x10 mm drain plug with a copper washer - remove it after the black pre tension knob has been completely released (there should be a noticeable slack when released to its end position).

4. Jog the pre tension knob back and forth until the chamber with fluid is completely empty, tilt the shock if necessary to empty remaining fluid, then return knob to its end none-pressurized position.

5. Place the shock horizontal with the M5 drain hole at the highest point.

6. Fill the chamber completely with 15-40 engine oil (CAT is using engine oil in all their hydraulic systems, and it works perfectly. The spring pre-tension reservoir is NOT connected to the main pressurized system, its just a hydraulic isolated substitute for a mechanical device.

7. Replace the drain plug with a new M5x10 mm hex bolt and a new copper washer, tighten the plug and  turn the pre-tension knob in hard direction until the spring starts to compress.

8. Compress as much as possible, then retract and open up the reservoir and refill again. It might take three goes to completely fill the reservoir. You should be able to attain the fifth ring.
9. Leave the shock under pressure overnight preferably tightened to the third or forth ring

10. If there are no leaks and if the shocks are maintaining the same pressure in the morning, attach them to the bike and prepare for a test ride.

11. Go for a decent ride with the preload set on the third or forth ring & if there are no leaks the fix has worked
Title: Re: rear left shock pre-load knob not working?
Post by: Michael Whitney on Sunday, 09 July 2017, 10:07 PM
There's no sign of leaking oil from either shock.
Title: Re: rear left shock pre-load knob not working?
Post by: Andre on Monday, 10 July 2017, 01:17 AM
If you have the unrepaired originals, I bet there is no or too little oil left to adjust the preload.

HOWEVER, it could be that something (don't have the mind right now to explain) is stuck inside. The push against the knob should have freed it, but either it didn't or it just got stuck immediately again.

Doesn't matter, the shock has to be opened and repaired. Either you follow the abundant instructions on this forum or you have someone repair it for you. Or just keep riding with it  :cheers:
Title: Re: rear left shock pre-load knob not working?
Post by: Snapey on Monday, 10 July 2017, 04:27 AM
Quote from: Michael Whitney on Sunday, 09 July  2017, 10:07 PM
There's no sign of leaking oil from either shock.

They hold very little oil so the chances of you seeing a leak is slim. You'll see what I mean when you do the shock fix. What ever you do, don't force the adjusting knob ... it will break internally.
Title: Re: rear left shock pre-load knob not working?
Post by: Michael Whitney on Monday, 10 July 2017, 06:26 AM
So according to the instructions you fill up the resevoir via the drain screw bit?
Title: Re: rear left shock pre-load knob not working?
Post by: Dusty ST on Monday, 10 July 2017, 07:17 AM
Quote from: Michael Whitney on Monday, 10 July  2017, 06:26 AM
So according to the instructions you fill up the resevoir via the drain screw bit?

Yes, it's a bit small, I used a syringe.
Problem is the air needs to come out of the same hole the oil is going in!
Title: Re: rear left shock pre-load knob not working?
Post by: Dave65 on Monday, 23 October 2017, 06:50 AM
Hi All,
I have an 08 model, only had her for a week, so decided to adjust the suspension for my weight, front setup done no hick-ups, came to the rears and just came across the same issue, Left side works fine, Right pre-load dial does nothing. Ive stripped the shock down, the piston was very tight, soaked with some WD40 and after a while it started to move again.
Took out the piston to check for wear or marks and all good.
Would you replace the 2 internal seals in the body??
Of would you just refill the chamber and re-assemble?
Can you even buy the seals?
Cheers

Title: Re: rear left shock pre-load knob not working?
Post by: KiwiCol on Monday, 23 October 2017, 05:48 PM
TBH I've never heard of anyone buying the seals for the shock, but if they're made, ya must be able to get them somewhere in the world.  If I were in your' shoes, I'd re-assemble & re-fill with oil & see how they go. They look ok in the pic's.
The refilling looks to be a fiddly task, involving a syringe n needle to top it up.  There's how to explanation sheets in the downloads section, I'm sure.

Good luck with the rebuild mate.
Title: Re: rear left shock pre-load knob not working?
Post by: Dave65 on Tuesday, 24 October 2017, 02:31 PM
Quote from: KiwiCol on Monday, 23 October  2017, 05:48 PM
TBH I've never heard of anyone buying the seals for the shock, but if they're made, ya must be able to get them somewhere in the world.  If I were in your' shoes, I'd re-assemble & re-fill with oil & see how they go. They look ok in the pic's.
The refilling looks to be a fiddly task, involving a syringe n needle to top it up.  There's how to explanation sheets in the downloads section, I'm sure.

Good luck with the rebuild mate.

The piston has some pitting which is why mine has stopped working, see pic

Asked Suzuki and no go for spares for the shocks....

Looking at options now!!!
Title: Re: rear left shock pre-load knob not working?
Post by: KiwiCol on Tuesday, 24 October 2017, 02:55 PM
I've still got std shocks, but I recall some of the guys fitting Hagon Nitros' (not sure of the spelling) Basically the more money you've got for a new set of shocks the better handling & ride you'll end up with. I know from reading, they're not an inexpensive item for sure.
Title: Re: rear left shock pre-load knob not working?
Post by: KiwiCol on Tuesday, 24 October 2017, 03:02 PM
Have a look at this section, might give you some tips

http://gsx1400owners.org/forum_test/index.php?topic=1031.0