RAM clutch slip

[moscowphil]

I talked to the guys at MG Cycle, who said that the current RAM clutches are very durable. The only problem is making one appear in your shop - I've had one on backorder for close to a year now. You might call those guys and explain your issue, they may be able to advise you and supply a part if needed. I think there is a difference in rod length between single and dual plate clutches. If you have a too-short rod, it may be that the clutch slave has to use up most of its range of motion just to engage initially.

 

I don't think that a twin-plate is a big step backwards. I have one of each. If I ride the LeMans (twin plate) for a while, the first time I get on the Scura (single plate) I find the clutch engages very quickly. While I like the idea of keeping a single plate clutch in my Scura, I'm probably going to end up putting a used twin-plate in there. I prefer the twin-plate, but no so much that I'd be willing to do a lot more maintenance on it - worse yet, letting it sit for a year waiting for a part.

 

FWIW - I have a complete, used twin-plate clutch on the shelf awaiting installation (assuming the new RAM doesn't show up before I'm ready). I can take a measurement or photo of any part for you. Also - I'm pretty sure there are some detailed threads on here with photos of all twin and single-plate parts laid out side-by-side.

Many thanks for the offer Scud. If there is a difference in rod length between the single plate and dual plate clutches this might explain things (though I think it's the other way round - too long a rod would explain my symptoms). Trouble is though, it's a big-ish job to get the push-rod out to measure it, and at the moment I'd rather be riding my bike than pulling it to pieces. So I think I'll save that job till next winter, and carry on with my bodge-fix for now. Cheers, Phil

[Scud]

 

Trouble is though, it's a big-ish job to get the push-rod out to measure it, and at the moment I'd rather be riding my bike than pulling it to pieces.

 

Ha - me too. I'm going to try to get 12,000 miles out of my stock Scura clutch (rolling the proverbial dice that it won't grenade before then). At 12,000 I'll do some other maintenance and put in whatever clutch I can get my hands on.

 

Ride on. 

[Paradiso]

 

I talked to the guys at MG Cycle, who said that the current RAM clutches are very durable. The only problem is making one appear in your shop - I've had one on backorder for close to a year now. You might call those guys and explain your issue, they may be able to advise you and supply a part if needed. I think there is a difference in rod length between single and dual plate clutches. If you have a too-short rod, it may be that the clutch slave has to use up most of its range of motion just to engage initially.

 

I don't think that a twin-plate is a big step backwards. I have one of each. If I ride the LeMans (twin plate) for a while, the first time I get on the Scura (single plate) I find the clutch engages very quickly. While I like the idea of keeping a single plate clutch in my Scura, I'm probably going to end up putting a used twin-plate in there. I prefer the twin-plate, but no so much that I'd be willing to do a lot more maintenance on it - worse yet, letting it sit for a year waiting for a part.

 

FWIW - I have a complete, used twin-plate clutch on the shelf awaiting installation (assuming the new RAM doesn't show up before I'm ready). I can take a measurement or photo of any part for you. Also - I'm pretty sure there are some detailed threads on here with photos of all twin and single-plate parts laid out side-by-side.

Many thanks for the offer Scud. If there is a difference in rod length between the single plate and dual plate clutches this might explain things (though I think it's the other way round - too long a rod would explain my symptoms). Trouble is though, it's a big-ish job to get the push-rod out to measure it, and at the moment I'd rather be riding my bike than pulling it to pieces. So I think I'll save that job till next winter, and carry on with my bodge-fix for now. Cheers, Phil

I swapped the original single plate for a dual plate and the pushrod is the same length. Can't remember the length, but I noted it down in an earlier thread.

The diaphragm spring in the original (single plate) clutch is stamped Ram. I know the diameter of the pushrod is narrower on the Ram replacement for a 5 speed. I was supplied a 5 speed Ram in error and I think it would have worked if I'd taken it apart and swapped the diaphragm spring for the one from the original single plate clutch. Is it possible that the pushrod isn't seating as it should?

 

Sent from my GT-I8190N using Tapatalk

[Lucky Phil]

moscowphil, out of interest when you went to the Ram clutch on your bike (new friction plate etc) at what point did the clutch dis-engage/engage when you pulled the lever?

So when you pulled the clutch lever at what point in the lever travel did the clutch release or conversely at what point did it begin to bite? Did it release very early in the lever pull or did you need to get it nearly all the way back to the bar before it would disengage and then the engagement would also be close to the bar of course? Or was this point right near the fully relaxed end of the lever travel?  

Ciao

[moscowphil]

moscowphil, out of interest when you went to the Ram clutch on your bike (new friction plate etc) at what point did the clutch dis-engage/engage when you pulled the lever?

So when you pulled the clutch lever at what point in the lever travel did the clutch release or conversely at what point did it begin to bite? Did it release very early in the lever pull or did you need to get it nearly all the way back to the bar before it would disengage and then the engagement would also be close to the bar of course? Or was this point right near the fully relaxed end of the lever travel?  

Ciao

From memory it was somewhere in the middle, and didn't feel particularly different to the original Scura single-plater (which only had about 3,000 miles on it, and which I only replaced due to paranoia about exploding flywheels). From which I assumed that the swap had been completely straightforward.

[Lucky Phil]

 

moscowphil, out of interest when you went to the Ram clutch on your bike (new friction plate etc) at what point did the clutch dis-engage/engage when you pulled the lever?

So when you pulled the clutch lever at what point in the lever travel did the clutch release or conversely at what point did it begin to bite? Did it release very early in the lever pull or did you need to get it nearly all the way back to the bar before it would disengage and then the engagement would also be close to the bar of course? Or was this point right near the fully relaxed end of the lever travel?  

Ciao

From memory it was somewhere in the middle, and didn't feel particularly different to the original Scura single-plater (which only had about 3,000 miles on it, and which I only replaced due to paranoia about exploding flywheels). From which I assumed that the swap had been completely straightforward.

 

Ok thanks, was just thinking that if the actuating rod was a bit long for the ram unit then you would expect the release point would be closer to the lever fully out(relaxed) position and the slave cylinder piston would be pushed back further towards it end point and therefore not be able to compensate for wear as well.

Looks like you may just have a worn friction plate.

Ciao

[GuzziMoto]

Unless something is seriously wrong, a hydro clutch is self adjusting and will compensate for clutch wear automatically. The same feature should compensate for a slightly shorter or slightly longer push rod the same way. That is one of the advantages of a hydro clutch. It would have to be near the point of not working for the engagement point to change.

[moscowphil]

Unless something is seriously wrong, a hydro clutch is self adjusting and will compensate for clutch wear automatically. The same feature should compensate for a slightly shorter or slightly longer push rod the same way. That is one of the advantages of a hydro clutch. It would have to be near the point of not working for the engagement point to change.

Yes I think you are right about that. Basically the problem seems to be that it stopped being self adjusting because there is is no more "headroom" in the slave cylinder for the piston to adjust into. I discovered this when I loosened the 3 screws that fasten the slave to the back of the gearbox (I was changing the fluid, and following the manual's suggestion that I should remove the slave to purge it of any old fluid - a job that turns out to be impossible without a major dismantle of the back end). Anyway, to get back to the point, upon loosening the 3 screws, the slave cylinder was pushed back off the back of the geararbox by maybe a quarter of a mil or so, and could not be easily pushed back on. From which I concluded that the force to push it off must be being provided by the diaphragm spring pushing on the pushrod, which in turn was pushing on the piston, which in turn was pushing on - well it could only have been the top of the cylinder bore (I'd already drained the fluid at this point). That's how I concluded that there was no adjustment left in the slave cylinder. And of course this meant that when the slave was bolted up tight against the gearbox, it will have been pushing on the diaphragm, so causing the clutch slip I was experiencing. And the fact that putting spacers between the gearbox and the slave provided a cure does seem to confirm this. The ideal solution would seem to be to fit a slave cylinder with a longer throw, which would be better suited to the RAM clutch, but I suspect this might prove difficult to find.

[Kiwi_Roy]

Why not make a spacer out of 1/8" aluminum, it will extend the life of the clutch until you get new parts?

 

 

Sent from my shoe phone!

[emry]

Hey Moscow,

 

Hydraulic systems like our brake and clutch will function until the slave cylinder piston is physically pushed out of the bore. They are self adjusting to a point of failure due to fluid leakage. The piston in the slave is retracted by the seal (assuming the return port in the MC is not obstructed). Some pressure is balanced from the clutch diaphragm and the resistance of the clutch slave seal, this is very small. When removing the clutch slave you should have been able to press the slave piston back into the clutch slave. If you could not this is a failure of the MC or lines not allowing fluid to return to the reservoir.Very often aftermarket levers cause this, they do not allow the MC piston to return enough to allow for fluid to pass through the return port.  

 

But as clutches wear they can slip, that is why they are a replaceable part. The MC and the slave cylinder (barring modification) are not a replaceable part, for a reason.

[GuzziMoto]

Hey Moscow,

 

Hydraulic systems like our brake and clutch will function until the slave cylinder piston is physically pushed out of the bore. They are self adjusting to a point of failure due to fluid leakage. The piston in the slave is retracted by the seal (assuming the return port in the MC is not obstructed). Some pressure is balanced from the clutch diaphragm and the resistance of the clutch slave seal, this is very small. When removing the clutch slave you should have been able to press the slave piston back into the clutch slave. If you could not this is a failure of the MC or lines not allowing fluid to return to the reservoir.Very often aftermarket levers cause this, they do not allow the MC piston to return enough to allow for fluid to pass through the return port.  

 

But as clutches wear they can slip, that is why they are a replaceable part. The MC and the slave cylinder (barring modification) are not a replaceable part, for a reason.

I think you are looking at this wrong. The slave piston was not fully extended out of the bore, it was fully pushed in to where it could not push into the bore any further. As the clutch wears on a Guzzi with a hydro clutch the slave piston retracts to allow the clutch to engage. As the clutch wears the slave piston goes further into the slave cylinder. His sounds like the slave piston had retracted as far as it could but when the clutch wore further and the piston could not retract any further the clutch started slipping. Buy spacing the slave out away from the clutch it allows more travel in the required direction and thus the clutch has stopped slipping (for now).

The only real fear is that if the clutch is allowed to wear down to far it could cause damage to the rest of the parts, but my guess is that the clutch is OK and it is really just an issue with the pushrod being slightly too long.

It could be an issue with fluid not being able to move back up into the master cylinder, but it does not quite sound like it to me. Perhaps I am wrong, 

[emry]

 

Hey Moscow,

 

Hydraulic systems like our brake and clutch will function until the slave cylinder piston is physically pushed out of the bore. They are self adjusting to a point of failure due to fluid leakage. The piston in the slave is retracted by the seal (assuming the return port in the MC is not obstructed). Some pressure is balanced from the clutch diaphragm and the resistance of the clutch slave seal, this is very small. When removing the clutch slave you should have been able to press the slave piston back into the clutch slave. If you could not this is a failure of the MC or lines not allowing fluid to return to the reservoir.Very often aftermarket levers cause this, they do not allow the MC piston to return enough to allow for fluid to pass through the return port.  

 

But as clutches wear they can slip, that is why they are a replaceable part. The MC and the slave cylinder (barring modification) are not a replaceable part, for a reason.

I think you are looking at this wrong. The slave piston was not fully extended out of the bore, it was fully pushed in to where it could not push into the bore any further. As the clutch wears on a Guzzi with a hydro clutch the slave piston retracts to allow the clutch to engage. As the clutch wears the slave piston goes further into the slave cylinder. His sounds like the slave piston had retracted as far as it could but when the clutch wore further and the piston could not retract any further the clutch started slipping. Buy spacing the slave out away from the clutch it allows more travel in the required direction and thus the clutch has stopped slipping (for now).

The only real fear is that if the clutch is allowed to wear down to far it could cause damage to the rest of the parts, but my guess is that the clutch is OK and it is really just an issue with the pushrod being slightly too long.

It could be an issue with fluid not being able to move back up into the master cylinder, but it does not quite sound like it to me. Perhaps I am wrong, 

 

Durrr. I wasn't quite thinking correctly. Sorry and thanks for the correction.   Carry on as usual. Nothing to see here. 

[docc]

I swear there is a post somewhere with a photo of two different length actuating rods.  Others remember this? Where is it?

[Scud]

I swear there is a post somewhere with a photo of two different length actuating rods.  Others remember this? Where is it?

 

I remember some discussion, but if you look at the "best answer" that appears in the link I put in post 7 of this thread, you'll see that Camn described the problem, but concluded that the push rods for both single and twin had the same part number.

 

At some point, I'm going to pull the single out of my Scura and it seems likely that I will replace with the twin-plate from my parts bike. At a minimum, I will be sure to compare the two push rods.

[czakky]

I swear I read that too Docc....