[grassman09]

I have a 09 LT with 80000 miles. I had the service tech change the fork seals due to leaks under warranty. Now it rides real rough and when I hit a bump in the road I get a real hand stinger. Any ideas

 

[K100Dennis]

Applying historical fault finding principles from my observed trials days, I would be looking at the fork leg seals as it appears as though the fork legs may be sucking in air during extension, thus "jacking' the legs with air pressure. This used to be quite a common problem which could sometimes be rectified by shortening the garter spring on the seals. A caveat though - I am not experienced in the assembly and arrangement of the seals in out K12 fork legs.

 

[deanwoolsey]

Your front tubes are "sliders". Basically they just guide the front wheel up and down. They do not absorb any shock from the wheel and they do not contain springs like the Japanese bikes. This is handled by the single shock assembly behind the tubes. It sounds like something is binding up and transferring too much energy into the bike. I would take it back and have the tech and/or general manager ride it to see what they think. Here's a link to look at the parts involved.

http://www.ascycles.com/Illustrated_catalog2/MicroList.aspx?id=51717&catID=31&catname=Front_axle,_front-wheel_control&bindName=FORK_SLIDER_LOWER_FORK_BRIDGE&bindCat=31_0614

 

[C-A-D]

I haven't done the tubes/sliders yet BUT:

If I understand the "correct way" to change the seals includes opening the bolt from the top of the tube. This requires pretty total dismantling of the steering head? BUT this way you can avoid air being pressurized in the tube which might happen if you just take off the slider by removing the slider tube downwards....So how did the technician change the seals? Through "downstairs" or by dismantling the tubes and opening the top bolt and filling the oil onlly after the tube with slider has been assembled?

 

[JimH]

I have a 09 LT with 80000 miles. I had the service tech change the fork seals due to leaks under warranty. Now it rides real rough and when I hit a bump in the road I get a real hand stinger. Any ideas

Well, the smarty-pants answer would be take it back to the tech, have him ride it over bumps, and ask if the job has been finished properly!

 

[jzeiler]

I haven't done the tubes/sliders yet BUT:

If I understand the "correct way" to change the seals includes opening the bolt from the top of the tube. This requires pretty total dismantling of the steering head? BUT this way you can avoid air being pressurized in the tube which might happen if you just take off the slider by removing the slider tube downwards....So how did the technician change the seals? Through "downstairs" or by dismantling the tubes and opening the top bolt and filling the oil onlly after the tube with slider has been assembled?

Not necessary at all. Just undo the fork bridge at each slider and pull them off. There is a bleed hole that is open at the top all the time so no air gets trapped. At least on the 05 forks (on my bike).

 

[C-A-D]

Not necessary at all. Just undo the fork bridge at each slider and pull them off. There is a bleed hole that is open at the top all the time so no air gets trapped. At least on the 05 forks (on my bike).

Ok. Me thinks Me Trust you As said I haven't done the job (yet) myself. The new seals are still on the shelf waiting for the job. I just remembered having seen a comment on this forum little while ago about changing seals with afterwards problem with additional pressure in the tube during the installation phase when done this way. I must do some digging...

 

[jzeiler]

Ok. Me thinks Me Trust you As said I haven't done the job (yet) myself. The new seals are still on the shelf waiting for the job. I just remembered having seen a comment on this forum little while ago about changing seals with afterwards problem with additional pressure in the tube during the installation phase when done this way. I must do some digging...

Yes I was at the ready with the dental floss and was surprized as I head the Sssss of air as I slid the tube up. The hole may have been just below the lower travel of the slider or up at the top I really don't remember. I just remember I didn't need the dental floss.

 

[C-A-D]

This was the comment I remembered... Quite vague one, but just somehow was stuck on my mind:

May 15th, 2006, 12:21 am

jdiaz

" ......So you probably noticed I didn't remove the top caps to bleed the air when reinstalling the legs. I encountered a bit of resistance when sliding the fork lower up the slider, for maybe the last inch of travel before the lower bottomed on the fork brace. Could this cause a seal problem later? Maybe. I guess I'll find out..."

And the thread was: http://www.bmwlt.com/forums/showthread.php?t=8911&highlight=fork+seal

 

[saddleman]

Yes I was at the ready with the dental floss and was surprized as I head the Sssss of air as I slid the tube up. The hole may have been just below the lower travel of the slider or up at the top I really don't remember. I just remember I didn't need the dental floss.

My 2000 has the bleed hole & the 2008 I just did had it as well. I could only feel a little air the last 1/8 " or so before it stopped against the bridge.

 

[grassman09]

I spoke with the tech and he stated that the shock failed at the time he changed the fork seals. He stated that Ineed a new shock. I agree I need a new set of shocks but I do not understand. The shock failed at the exact second the fork seals were changed ? And that is the reason for the hand stingers. Icall BS on that

http://www.ascycles.com/Illustrated_catalog2/MicroList.aspx?id=51717&catID=31&catname=Front_axle,_front-wheel_control&bindName=FORK_SLIDER_LOWER_FORK_BRIDGE&bindCat=31_0614[/QUOTE]

 

[deanwoolsey]

No reason to touch the shock while changing the seals. I would ask him why he didn't mention this issue before. Besides, every shock I've ever seen fail goes soft. I second your BS and raise you a cover-my-ass.

 

[gary45]

No reason to touch the shock while changing the seals. I would ask him why he didn't mention this issue before. Besides, every shock I've ever seen fail goes soft. I second your BS and raise you a cover-my-ass.

+1 - my springs got weak enough that going over a sharp 1 inch drop (manhole cover) the front end would bottom out with a bang - changed the springs
the strut characteristics are not going to change all of a sudden, they have done something wrong

 

[Centaurious]

My guess (just a guess mind you) would be to check the wheel spacers and the axle. They may have installed things wrong or may have put the sliders in a bind on the legs by pinching them in with the axle. I would loosen the pinch bolts that secure the slider to the axle head and compress the front end by stopping from a low speed with the front brakes. then tighten the pinch bolts and see if it improves things. It may be that the tech missed corrosion between the slider and the axle.

 

[jzeiler]

I spoke with the tech and he stated that the shock failed at the time he changed the fork seals. He stated that Ineed a new shock. I agree I need a new set of shocks but I do not understand. The shock failed at the exact second the fork seals were changed ? And that is the reason for the hand stingers. Icall BS on that

http://www.ascycles.com/Illustrated_catalog2/MicroList.aspx?id=51717&catID=31&catname=Front_axle,_front-wheel_control&bindName=FORK_SLIDER_LOWER_FORK_BRIDGE&bindCat=31_0614

Well 80 K on a set of stock shocks is a bit over the top to expect them to still be working top notch. Mine started to deteriorate at 30 k(front anyway).

 

[Bones1955]

My 2000 has close to 80 k and I think they are the original springs and shocks..though I don't know..just bought it this spring.
Anyways I only bottomed it once in a big hole (just the front)after I added oil to it..it rides great..mind you the wife and I together only weigh in at around 300.