Vulcan VN1500 - Clutches Slipping After Replacement

rebeltaz · Renault 5 Driver Joined: 02 Jul 2005 Karma :

Sorry for the long winded post, but I am off the opinion that you can never have too much information...

I've got a 2002 Vulcan VN1500 Classic FI that came in leaking oil around the front bevel gear case. After replacing that, I never took the bike out on the road. The customer didn't come get the bike, so it sat for a year before I went and got a title. Once I did and took it out, the clutch was slipping. At first just a little, but after three or four rides, it almost didn't make it back home.

I took it apart and replaced the friction plates [13089]; the steel plates [13088], the limiter springs [92144] (which I found had previous been installed incorrectly prior to coming to me); the clutch spring [92144a]; and the needle bearing [92046a]. I filled it with Kawasaki motorcycle 10w40 oil.

After putting it back together, the clutches worked fine for a couple of months. Then it started slipping again, just like before. Once it starts slipping, it's like it goes from barely slipping to not grabbing at all in the course of a few miles. It almost did not make it back home today.

I have never had this much trouble with a clutch. Since someone had obviously been in this before me, I know it's hard to know what was done, but does anyone have any ideas as to why this is doing this?
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Derek Tombrello
www.ShelbyCycle.com (for profit)
www.RobotsAndComputers.com (just for fun)

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

How's the basket? Notched?

Not familiar with your bike model but my first question would be has it been put together correctly? Some of them have spacers or thrust washers behind the plate stack or basket. Some even need said washer to be the correct way round because there is a chamfer on them. Be worth checking an exploded diagram.

Is it hydraulic? If so, check for corrosion on the pushrod. This is an occasional and known issue on my bike, a VFR750. The rod gets corroded and hangs up on a seal preventing it returning properly. Also check the pushrod is straight by rolling it on a sheet of glass.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

rebeltaz · Renault 5 Driver Joined: 02 Jul 2005 Karma :

Not quite sure what you mean by "notched" but the basket looked ok to me. I didn't see any nicks or obvious wear.

It is back together correctly now. The thrust washers you mentioned... I think those are what I'm calling the "spring washers" and yeah.. when I got the bike, those were turned wrong way around. I replaced those and fixed that when I put it back together as per the service manual.

It is hydraulic, yes. I haven't had the push rod out, but when I take it back apart (again!) I will look at that. I never thought of that.
____________________
Derek Tombrello
www.ShelbyCycle.com (for profit)
www.RobotsAndComputers.com (just for fun)

MCN · Super Spammer Joined: 22 Jul 2015 Karma :

Interesting that the washers were in the wrong way.
Were the correct number of plates and discs fitted previously?

Im not suggesting this is your problem. Im only trying to illustrate that folk can get things wrong. 😀
My old BSA was 'upgraded' by the previous owner to have one more clutch plate. There is historical report of weak clutch in that bike.
The mod left the clutch with almost zero free play when released. Investigation (by me) found that if the clutch is upgraded then a longer pushrod is required as the push rod has to reach the pressure plate which is now a disc and plate further away than original.

I found that the easy fix is to buy one roller from the roller bearing and cut the pushrod in 1/2 and put the roller bearing in the middle of the 1/2s to extend the rod by one plate and one disc. Clutch feel is excellent now.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

rebeltaz · Renault 5 Driver Joined: 02 Jul 2005 Karma :

That sounds like the kind of repair I would do! lol...

Yeah, the bike had the correct number of plates and discs. I know that the manual shows that you can use one plate of slightly thinner or thicker thickness to replace one of the originals, but the way it goes from slightly slipping to full blown slipping in such a short amount of time makes me wonder about that being the issue....
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Derek Tombrello
www.ShelbyCycle.com (for profit)
www.RobotsAndComputers.com (just for fun)

MCN · Super Spammer Joined: 22 Jul 2015 Karma :

rebeltaz · Renault 5 Driver Joined: 02 Jul 2005 Karma :

Grubscrew · Scooby Slapper Joined: 23 Dec 2018 Karma :

Soak them plates overnight in motorcycle oil (car oil has anti friction added). Also , change the hydraulic fluid in the clutch hydraulics.
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FJR1300/CBR1000F