DL650AL5 Clutch Cover

[matt-drummer]

Quote removed

Well, you and me together, your picture of the clutch cover (1) has helped me make sense of it, I can now see that the oil is contained within part number 1 entirely as the only holes in it are the three that hold on the damper.

As my cover, part number 10, has no threads in the lugs or holes for bolts it can only be a push fit onto the damper. It now makes sense as it does not retain any fluids and is mainly a decorative part and a cover for the clutch damper. The clutch damper must only be a part that adds mass to the case to stop resonance, it cannot do anything else as it does not come into contact with the clutch.

[Dark-Strom]

Sounds right Matt, steady as she goes 

(Strange design / thing to do though - I think its more of a heat-sink / cooling mechanism, than noise reduction?)

[matt-drummer]

I have had a tentative pull on the cover (10), it seems pretty firmly and rigidly attached, there is no movement as you might expect if it was mounted on rubber. I am not happy to apply any more force without knowing more. I think I can only damage the damper but I do not want to disable the bike at the moment by breaking something. If the whole clutch cover (1) needs to come off I will wait until an oil change is due in the autumn.

I now have my Haynes manual but good as it is, I can find no help there.

I am wondering whether the cover (10) is held on a bit like a rawl plug where the bolts (12) expand lugs on the damper (11) to hold the cover on but that seems unlikely as the bolts are only 16mm long and they use a 1.2mm washer so there is only around 15mm of thread and some of that has to go through the main clutch cover (1).

I think I have only two ways to find out how it works, take it all apart or find a clutch damper, so I have ordered a clutch damper and I hope that will show me what I want to know. It's not that expensive and I suspect I may well need it anyway if it is constructed how I think it is, a small price to pay to satisfy my curiosity!

[matt-drummer]

Well, my new damper finally arrived and I am really glad I didn't attempt to pull the cover off as it is not fitted how I expected!

The damper is, as you would expect, a big lump of moulded rubber and it fits fairly tightly inside the outer cover (part 10).

There are three holes in the rubber damper and they fit over the three lugs on the inside of the cover (part 10).

There is no way the damper is attached directly to the clutch cover (part 1) as there are no other holes in it for attachment.

That means that the three lugs on the inside of the cover (part 10) mate up with the three holes in the clutch cover (part 1) and must be secured with the three bolts and washers (parts 12 and 13) from inside the clutch cover (part 1).

Now my only issue is how do the bolts hold the cover (part 10) on as there are no threads in the lugs.

I can only see two possibilities, either the part is faulty having missed threads being  tapped in it during manufacture or the bolts are intended to cut their own threads in the aluminium casting.

Is it possible to have screws or bolts cut their own thread into an aluminium casting?

I wouldn't know but it sounds wrong, I wonder if anybody has ever encountered something like this?

I will post some pictures when I get home from work, at the very least there will be some pictures of the damper on the internet now!

[matt-drummer]

After a little research it appears that self tapping screws/bolts into aluminium castings is not as mad as I thought it would be!

There seems to be some issues with tapping threads into aluminium castings with blind holes (as is the case on the cover - part 10).

The problem is that the tap becomes clogged in the blind hole with the material it is cutting and destroys the thread it is trying to cut.

Using a special bolt to basically push the thread into the casting (like rolling a thread into a bar in reverse) works, especially when the parts are not subjected to large torque or constant disassembly.

It would seem that a threaded insert is preferred when parts need to be disassembled on a regular basis.

So, I think the cover (part 10) is attached to the casing (part 1) from inside the casing (part 1) using three self tapping bolts and washers (parts 12 and 13) with the damper (part 11) secured as a press fit inside the cover (part 10). Disassembly requires removal of the clutch cover (part 1).

[mr_diver]

From that diagram it does look as though the screws go through the right hand side case, thought the damper and into the cover.

Does seem it bit overkill but then again try and change a screen on a 17> Fireblade... you start by peeling it from the back end to the front.

Noise reduction was one of the things that Suzuki bragged about with the new Gladius engine and therefore the L2> V-Strom 650.

That cover plate and the different LHS covers deduces the transmitted noise.

It's not for heat dissipation, the contact surface area is far too small and leaving it uncovered like the original engine design was better for heat dissipation.
To dissipate heat efficiently it would need to be part of the casing and look like a massive heat sink. Which it doesn't.

[matt-drummer]

You are correct, it is not for heat, I never thought it was for heat dissipation. It will reduce noise. The cover (part 10) is just a cover for the rubber damper.

The damper is not bolted to the clutch cover (part 1), the cover (part 10) is bolted to the case (part1) and the damper is clamped between the two parts and located over the outside of the lugs inside part 10, the damper is not bolted to anything.

If it is not clear already then it will be when I add some photographs later.

[matt-drummer]

The part that confused me was that I bought part 10, the cover, and did not have a damper to look at, with no threads in part 10 I could not be sure how it was attached, now I have the damper I know that the damper is not secured by bolts and therefore the cover (part 10) must be secured to the case (part 1) by bolts from the inside.

[matt-drummer]

Here is the damper and how it fits in the cover (part 10)