2003 GL1800A Service Manual; Valve clearence check / adjust

[namgniwdlog]

In my Service Manual the Valve Clearance check says to release the Cam Chain tension or your measurements will not reflect correct clearance. I found this step rather puzzling as I believe you want to know the clearances while the valve train is in a normal running environment.

I checked my valve clearances WITHOUT releasing the Cam Chain tension and the clearances were within tolerance. Can anyone comment if the tension relief is a technical error in the manual.

[MikeB]

The manual is correct. They do specify to release the tension on the cam chain.
Personally, I have not found that it makes any significant difference on the three that I have done.

[Road Ranger]

I found on mine that chain tension doesn't seem to matter on checking the clearance,but if adjustment is necessary then I would slack off on chain, I think Honda put this in so the mechanics did not miss a step and try to adjust with the chain tight. I found in the automotive business the manuals are written for the lowest common denominator. That is why release the chain check the valves adjust as necessary, rather than check valves if adjustment is necessary go to page 12-36.

[MikeB]

I found on mine that chain tension doesn't seem to matter on checking the clearance,but if adjustment is necessary then I would slack off on chain, I think Honda put this in so the mechanics did not miss a step and try to adjust with the chain tight. I found in the automotive business the manuals are written for the lowest common denominator. That is why release the chain check the valves adjust as necessary, rather than check valves if adjustment is necessary go to page 12-36.

If the chain tension is not released, the valve lash can be checked but no valve lash adjustment can be made.
The cam has to be removed to replace shims. The chains have to be removed from the cam to do that.

[Road Ranger]

I am sorry that I did not pull the manual and recited all the steps as I was just trying to answer a member's question. I know I am new to this wrenching thing as I only have over 50 years doing it. Sorry if I offended you.

[MikeB]

No offense taken. Sorry if it seemed that way.
Just trying to make sure that when we pass information that it is correct information.
Too often in our haste to help we unknowingly give incorrect info which can only confuse the reader.
I've been guilty of that too many times and will no doubt continue to do so. I can only hope that the frequency of that is less in the future than it was in the past.

[Road Ranger]

The question asked was it necessary to loosen the chain to check valve clearance not to replace shims.