Author Topic: Loose steering stem top center bolt symptom (Read 8823 times)

roadie · « **on:** September 21, 2011, 01:40:53 PM »

While riding home last night I noticed a single knock when I engaged the front break (stopping at red light slow speed), and another knock when I disengaged the front break. Its almost a two-step knock. All coming from somewhere in the fork area. Is this potentially a loose steering stem top center bolt issue or some other possibilities? thoughts? Haven't had time to check it yet but would value any insight anyone might have. i'm on an '09 ABS.

B.D.F. · « **Reply #1 on:** September 21, 2011, 02:04:11 PM »

Most likely, yes. We have seen quite a lot of that on C-14s, and with very few miles on them- mine started to 'clank' with less than 3K miles on it.

The bearings are adequate but seem to be a little on the weak side. Also, I think a bike this big needs a little more damping on the steering stem than provided by the O.E.M. angular contact ball bearings. I changed mine somewhere around 50K (I think) to tapered roller bearings and they have proven to require a lot less adjusting, provide more damping and I have not noticed any change in the turn- in speed or any other handling degradation. Changing them is a bit painful and requires a small bucket of bad words but it is worth it in the end IMO. By the way, my dealer offered to change the bearings on my bike under warranty but I still chose tapered roller bearings although I had to provide the labor and actually buy the bearings.... and it was still the better way to go.

Brian

Quote from: roadie on September 21, 2011, 01:40:53 PM

While riding home last night I noticed a single knock when I engaged the front break (stopping at red light slow speed), and another knock when I disengaged the front break. Its almost a two-step knock. All coming from somewhere in the fork area. Is this potentially a loose steering stem top center bolt issue or some other possibilities? thoughts? Haven't had time to check it yet but would value any insight anyone might have. i'm on an '09 ABS.

roadie · « **Reply #2 on:** September 21, 2011, 03:04:29 PM »

Thanks Brian...as an initial course, do I just need to check that it is at the correct torque spec?

B.D.F. · « **Reply #3 on:** September 21, 2011, 03:12:45 PM »

Usually, yes. Snugging the bearings always seems to take the knock out of the front end. Eventually it does not work for a slight weave that the bike picks up in the 40 MPH range.

Just to expand on this a little bit: the original bearings are angular contact ball bearings. The two races oppose the ball bearings at an angle and it takes two bearings to make one working bearing (or bearing assembly). Unfortunately the angle is shallow and as the bearings wear (pound out actually) the contact angle gets closer and closer to the axis of the steering stem itself. What eventually happens is that all the force between the bearings is <virtually> in-line with the stem axis and while it is perfectly safe and the bearings still work, they can no longer exert any side pressure and therefore cannot create any damping for the steering stem. Even if tightened far beyond spec. they just do not resist the front end from turning enough to absorb the minor, low- speed wobble. It is not dangerous (a low speed wobble is NOT the same as a high speed wobble) but it can be annoying.

Brian

Quote from: roadie on September 21, 2011, 03:04:29 PM

Thanks Brian...as an initial course, do I just need to check that it is at the correct torque spec?

VirginiaJim · « **Reply #4 on:** September 21, 2011, 03:16:33 PM »

Quote from: B.D.F. on September 21, 2011, 03:12:45 PM

It is not dangerous (a low speed wobble is NOT the same as a high speed wobble) but it can be annoying.

Brian

Unless, of course, you are a Weebl.

lt1 · « **Reply #5 on:** September 21, 2011, 03:42:01 PM »

Quote from: VirginiaJim on September 21, 2011, 03:16:33 PM

Unless, of course, you are a Weebl.

Actually, it is more dangerous if you are not a Weeble. Motorcyclists can fall down.

Weebles

(wait for it)

wobble, but they don't fall down.

VirginiaJim · « **Reply #6 on:** September 21, 2011, 03:43:22 PM »

Ya got me....

Wild_Bill · « **Reply #7 on:** September 22, 2011, 12:51:12 PM »

Check your front brake pads.
Mine started to make a slight clunk when stopping and progressed to a squeal and shudder.
One of the pads material was as thin as a piece of paper.

My bike has only 15,500 mile on it.

Bill

roadie · « **Reply #8 on:** September 22, 2011, 05:17:00 PM »

Yeah still got 3mm of tread. Imma check the torque on the stem on Sunday.

HndaTch627 · « **Reply #9 on:** September 26, 2011, 10:44:00 PM »

I had both, the bearings were loose and the top triple tree nut had backed off as well. Mentioned it when i took my bike in to have the tire pressure sensors replaced and the tech's answer was "yeah, we've seen a good deal of that".

Was not exactly the response i had expected.

roadie · « **Reply #10 on:** September 28, 2011, 12:41:50 PM »

so closed issue (for now)...I torqued it to specs and no more double knock. thanks for all the input.

roadie · « **Reply #11 on:** September 28, 2011, 12:43:30 PM »

PS: I f'ing love this bike!

julianm · « **Reply #12 on:** October 01, 2011, 11:15:27 AM »

Quote from: roadie on September 28, 2011, 12:41:50 PM

so closed issue (for now)...I torqued it to specs and no more double knock. thanks for all the input.

I think I have a similar problem. Could you please advise exactly what you tightened and the torque specs. you used.. A pic would be appreciated . (On the old forum there was a sticky with a lot of torque specs. but couldn't find it on the new one )
Many thanks

roadie · « **Reply #13 on:** October 01, 2011, 11:23:26 AM »

Remove the little black plastic cap on stem right between your handlebars. U'll need an Allen socket, extension, and torque wrench. Tighten to 79.7 foot pound. I might be off by a tenth. Will check my manual tonight an correct.

Gsun · « **Reply #14 on:** October 01, 2011, 12:02:59 PM »

Quote from: julianm on October 01, 2011, 11:15:27 AM

I think I have a similar problem. Could you please advise exactly what you tightened and the torque specs. you used.. A pic would be appreciated . (On the old forum there was a sticky with a lot of torque specs. but couldn't find it on the new one )
Many thanks

Here is the torque specs in the C-14 area.

http://www.zggtr.org/index.php?topic=1652.0

Here is what the manual says:

○Tighten the steering stem nut with 55 N·m (5.6 kgf·m, 41
ft·lb) of torque first, and loosen it a fraction of a turn until
it turns lightly. Afterward tighten it again with specified
torque using a steering stem nut wrench [A].
Special Tool - Steering Stem Nut Wrench: 57001-1100
Torque - Steering Stem Nut: 23 N·m (2.3 kgf·m, 17 ft·lb

VirginiaJim · « **Reply #15 on:** October 01, 2011, 01:44:21 PM »

I think the next time I'm doing mine is that I'll increase it to 19lbs and see how it feels with that. I did the 17lbs and it still had the clunk occasionally.

roadie · « **Reply #16 on:** October 01, 2011, 02:04:21 PM »

The steering stem nut? I'm almost positive it gets tightened to 79 ft pound not 17. I'm on a 2009.

Jeremy Mitchell · « **Reply #17 on:** October 01, 2011, 02:11:24 PM »

Quote from: roadie on October 01, 2011, 02:04:21 PM

The steering stem nut? I'm almost positive it gets tightened to 79 ft pound not 17. I'm on a 2009.

You are both correct are correct. On page 2-11 of the manual it states 79 lb ft for the steering stem head bolt.

The steering stem nut is torqued to 17 lb ft.

roadie · « **Reply #18 on:** October 01, 2011, 02:28:56 PM »

Thx, yeah I only Tightened the head bolt. That's what cured my ish.

VirginiaJim · « **Reply #19 on:** October 01, 2011, 02:41:28 PM »

They all work together...

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Author Topic: Loose steering stem top center bolt symptom (Read 8823 times)