Series 2 180 clutch actuating rods lengths? Help please?

Paul LeClair

Paul LeClair

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Location
Calgary, Alberta, Canada
so, 1981 Laverda 1200 Series 2 180 1200.

the existing clutch push rods and bearings are as follows:

ball bearing at clutch slave   8.0   mm
first push rod                   123.72 mm
middle ball bearing              6.0   mm
second push rod               123.72 mm

Total combined length       261.44 mm

first question, I thought one pushrod was supposed to be shorter than the other??

second question, what are the push rod lengths supposed to be for a series 2 180??

using sophisticated measuring tools ( a straightened out coat hangar wire and a ruler), with the clutch assembly out, and the clutch hydraulic slave cover removed, then bolted back on as required:

a) it is 245 mm from the bare face recess of the clutch slave piston to the face of the clutch actuating cross bar in its closest inwards, relaxed, clutch fully engaged position.

b) it is 263 mm from the bare face recess of the clutch slave piston to the face of the clutch actuating cross bar in its furthest extended position, clutch fully disengaged.

c) the calculated "throw" of the clutch actuating bar is 263 - 245 = 17 mm.

d) the actual measured "throw" of the clutch actuating bar in its slot is 17 mm, using a digital caliper

e) I can depress the clutch slave cylinder piston back into its recess 3.5 mm against its internal spring, from its natural resting point where all the other measurements were taken, but the piston won't sit recessed against the spring naturally.

f) I would be really surprised if the actual "throw" of the hydraulic clutch slave piston would reach an actual full 17 mm without popping out past its sealing O ring in the casing, but I haven't taken it apart again to measure, yet.

the point of the post is that the clutch was not working when I trailered the bike home from where it sat not running for 8 + years. After installing the new RedAx kevlar clutch plates, the clutch now sort of works but slips like mad, will not engage enough to allow the bike to be ridden. Maybe that could be why the original clutch pack was really coooked and worn at only 30,000 original kms>

I have stripped everything again to do the above measurements, the inner clutch hub (which I had not removed previously) looks like something has been gnawing at it, it is crumbling, and I just "won" a Malcolm Cox eBay UK auction for a low mileage inner clutch hub and clutch spring cover as it needs to be replaced regardless, but at this point I am thinking the overall length of the clutch actuating rods and ball bearings is wrong, which may be why the bike did not have the 8 mm ball bearing in the face of the clutch slave piston when I first disassembled the bike..... take 8 mm away from the present overall length of 261.44 gives 253.44 in length, which would let the clutch pack be more "engaged" at rest, although it would likely still be slipping as the clutch pack would still not be fully clamped together with spring pressure, the difference between 253.44 and fully relaxed measured at 245 would still be holding the clutch partially disengaged...

anyway, before I start grinding one of the clutch push rods 16.44 mm shorter to make the actual length of the two clutch push rods plus the 2 ball bearings equal 245 mm as my calculations suggest it should probably be, (or 16.44 mm - 3.5 mm to take measurement e) above into account, so 12.94 mm shorter so that total length would be 245 = 3.5 mm = 248.5 mm) could someone confirm to me what actual push rod lengths SHOULD be from a properly operation series 2 180 clutch, thanks!

you can never trust previous owners.........

Paul LeClair
 
I don't have one apart at present so can't confirm lengths. But you've done a very thorough investigation so if I were you I'd just go with cutting down a pushrod to the length you think it should be. Take it in 5mm steps if you're not confident with your arithmetic. What can go wrong?

When I bought my Jota it had a slipping clutch (among a heap of other things that made it awful to ride). I replaced the clutch pack with Redax plates. The plates that came out were worn down thinner than the minimum spec in the manual, so no wonder it was slipping. Anyway, when I put the thicker plates in, the pushrod assembly was a few millimeters too short. I couldn't actually disengage the clutch. When I had a closer look, I found that the end of one pushrod had been ground down, presumably to accommodate the thin, worn-out plates. PO bodge strikes again! It had also been ground off at an angle, so I ended up taking a bit more off it in the lathe to square the end up.

I didn't have anything to make a new pushrod out of and it was a Friday night after work so I couldn't go out and buy a length of shaft steel. I wanted to get the bike going for a weekend trip planned for the following morning, so needed to come up with an alternative fix then and there. I did have a few offcuts of thick aluminium bar and a lathe, so as a temporary solution I turned up an aluminium spacer washer to go between the square toggle bar and the clutch centre. I don't remember the exact thickness of the spacer, but it was enough to take up the slack in the shortened pushrod assembly - about 5 mm or thereabouts. Problem solved - I had clutch operation back again and was able to go on the ride. A couple of years later that temporary spacer is still in there and the clutch is still working fine. (BTW - Red's plates have never slipped or glued themselves together)

The reason for explaining this is that if you cut too much off a pushrod, all is not lost.

Cheers,
Cam
 
Paul: there is a thread about this very topic on the laverdapedia site or even perhaps the MSN sitesince I ran into it when installing new plates in my 180 series 2. The new pushrods sent me by wolfgang did not even allow me to install the gearbox cover without pushing zgainst the clutch springs. Had to grind down on rod to get proper clearance. Do not remember the exact dimensions i ended up with, but Wolfgang was surprised there was a difference.
 
After fitting a new clutch pack years ago and an extended lever one of my rods was to short so I made one out of Silver Steel.It took a couple of goes shortening it till it worked,millimeters count with this.So much so that the Silver Steel which turned out to be to soft ended up failing less than a week later,it had warn to short.Made one out of tool steel and case harden it.They need to be within 2 mm of right to work.Watch out for the 2 ball bearings together between the rods bodge,been there with that one in an emergency.
 
Hi all

thanks for the replies!

after measuring everything as set out in my first post, thinking on the issue some more, and then dry fitting everything together and taking some more measurements, I have come to the conclusion that the previous owner was too cheap to replace worn out clutch fiber plates, removed the 8 mm ball bearing intentionaly, and added a longer than original push rod. When I installed the missing 8 mm ball bearing, coupled with the longer than original push rod already in there, there was no way for the clutch to ever fully engage even with the new fiber clutch plates.

the measurements in my first post in this thread are all accurate, including the 17 mm of "throw" built into the slot in the clutch side for the square actuator bar. However, what that measurement failed to take into account is the width of the actuator bar itself, which is 6 mm. Taking into account a 6 mm bar in a 17 mm slot, there is an actual 11 mm of "throw" in total, and only half of which again, or 5.5 mm, is actually used in the clutch actuation with brand new proper thickness plates.

without boring everyone again with all the calculations, bottom line is that if I am going to use the 8 mm ball bearing (previously missing) and achieve a correct clutch actuation I need to shorten one of the actuation rods, in my case by only 4.44 mm, to get proper clutch actuation and proper clutch engagement without slippage... The bike was unrideable as it was, even with new kevlar fiber clutch plates, should be perfect by just grinding one of the actuator rods shorter by the correct amount.

I hate previous owners, what a horrible bodge to cheap out on not replacing worn out clutch fiber plates, and the clutch wasn't working even after the bodge, may even be why the bike wound up sitting not running for so many years, but it took me about 7 hours to sort this clutch issue, maybe I am just dumb, but it took me quite a while to figure the issue out..........

on the plus side, apparently one of the features of the kevlar clutch plates is that they don't stick together even after sitting for extended periods unused, as confirmed earlier in this thread by Cam's post....!

Paul LeClair
 
I doubt that you'd need anything like 5.5mm of the available throw to fully disengage the clutch. Maybe 1mm would be enough. Once the pressure is taken off the plates, the clutch should be disengaged, although there may be a bit of drag from the oil between the plates.

If you measure the stroke of the master cylinder, you should be able to calculate the stroke of the slave cylinder if you know the bores of each. I'd be surprised if it's as much as 5mm.

The (dry) clutch in my Ducati only moves a fraction of a millimeter between fully engaged to fully disengaged. It's a bit of a pain in the backside because that miniscule movement at the clutch translates to about 1mm of movement at the lever. It's like an on-off switch - very easy to stall when taking off from a a standing start.

Cheers,
Cam
 
Mine are fantastic,way better than The Shoreflex? ones I used before,BUT,you do need to clean the mesh filter after 500ks,they tend to shed a bit early on.The Shoreflex,thats not the right name BTW were graby pains in the arse for the first 500ks.Reds ones work like butter.
 
Dellortoman said:
I doubt that you'd need anything like 5.5mm of the available throw to fully disengage the clutch. Maybe 1mm would be enough. Once the pressure is taken off the plates, the clutch should be disengaged, although there may be a bit of drag from the oil between the plates.

If you measure the stroke of the master cylinder, you should be able to calculate the stroke of the slave cylinder if you know the bores of each. I'd be surprised if it's as much as 5mm.

The (dry) clutch in my Ducati only moves a fraction of a millimeter between fully engaged to fully disengaged. It's a bit of a pain in the backside because that miniscule movement at the clutch translates to about 1mm of movement at the lever. It's like an on-off switch - very easy to stall when taking off from a a standing start.

Cheers,
Cam
Click to expand...

Hi Cam

I agree, the actual movement necessary to disengage the clutch is likely MUCH less than the 5.5 mm movement I measured as available. All that needs to hapen is to lift the spring pressure off the clutch pack, but in my case with the rods being 4.4 mm too long the result was the clutch pack was always disengaged. I feel pretty stupid it took me as long as it did to figure this all out, but I just didn't expect to be dealing with clutch actuating rods that were too long, if anything I would have expected too short as a bodge........ :o  Anyways, all sorted, once the new (used) inner clutch hub arrives from the UK, I can't figure out how the existing inner clutch hub got all chewed up, either, but I will just be happy to have solved the issue!

Paul LeClair
 
Dellortoman said:
I didn't have anything to make a new pushrod out of and it was a Friday night after work so I couldn't go out and buy a length of shaft steel. I wanted to get the bike going for a weekend trip planned for the following morning, so needed to come up with an alternative fix then and there. I did have a few offcuts of thick aluminium bar and a lathe, so as a temporary solution I turned up an aluminium spacer washer to go between the square toggle bar and the clutch centre. The reason for explaining this is that if you cut too much off a pushrod, all is not lost.

Cheers,
Cam
Click to expand...

Cam, an even quicker solution would have been to pop an extra ball bearing in.....
 
I thought of that Bob, but I didn't have one lying around.

Besides, I wasn't sure that two ball bearings in contact with each other would work very well. There's a bit of clearance in the pushrod tube, so the balls would not line up exactly. That would mean they would be trying to pop out sideways and creating friction against the inside of the tube. The squared ends of the pushrods don't create any lateral forces on the balls, so one ball between two rods is OK, but two could be a problem.

Cheers,
Cam
 
Hi Cam,
I once put two in as an expedient measure when I was erm, a bit over enthusiastic with the grinder when trying to shorten a rod. Seemed to work OK, in fact I think they're probably still in there!
 
Will pulled my double ball bolge out during his rebuild and made a new rod,the 2 balls were there for maybe 6 or 7 years and worked ok
 
Ed,
I measured my rods recently and they came in at 123.3 mm & 123.2 mm. They have been missing a ball for many kilometers though. :-[
Rocket
 
Hi,
At the point of assembling the clutch and need to check the lengths of the clutch push rods for my Series 2 Jota.
I've got one pushrod measuring 133mm and another at 112mm (I have two sets of these so assume they're two pairs). I'm sure my measurements aren't 100% but they do add up to 246mm ish. - are these okay for my 180 (this thread has two contributors with measurements of 123mm ish per rod) or are they from an RGS?
If they are okay which order do they go in 133mm to clutch, quarter inch ball, 112mm to slave (piston has final ball in the back)?
Thanks
Nick :-)
 
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