Ducati Monster Forum

Moto Board => Tech => Topic started by: otter1 on April 01, 2012, 06:31:11 AM

Title: Clutch push rod length/s
Post by: otter1 on April 01, 2012, 06:31:11 AM
Do clutch push rods come in several various lengths? What models come with the longest ones??

I replaced my leaking clutch slave (old style model with a slave piston and accordian gasket  from OEM 2000 monster 900 i.e.) to a modern style one from a 2004 999.

After complete my clutch would not move when I activated the clutch lever.

I replaced the stock (~33cm long) clutch rod with a longer one (sorry did not measure it before installing but I will guess it is about ~35cm) I had it sitting around the garage (I think it came off a hypermotard 1100).

Now my clutch moves but the clutch lever has to be fully activated before the clutch dis/engages.

I have not tried to adjust the clutch lever piston length yet but will if a longer push rods are not available. Thx for your replies!
Title: Re: Clutch push rod length/s
Post by: Duck-Stew on April 01, 2012, 11:36:30 AM
As far as I know, there are no clutch push-rod length charts.

BUT, I do know this:  When Ducati changed the slave-cylinder design (2001), the slave-cylinder end became spherical and the rods got longer.  Earlier slave-cylinders ( ? - 2000) had a flat end @ the slave-cylinder and were shorter.

If you've got an '04 999 slave cylinder, might be best to get the rod from a 2001-2002 M900 or SS900 for exact fitment.  Or, if you have one too long...  Just start shaving it down little by little.
Title: Re: Clutch push rod length/s
Post by: Speeddog on April 01, 2012, 11:56:05 AM
There's 2 lengths, AFAIK.

I may have one of each at the shop.
Title: Re: Clutch push rod length/s
Post by: koko64 on April 01, 2012, 02:22:05 PM
I've got 33.5cm or 13 1/16" for the later one that suits the post 2001 cylinder (04 marking and 7816  4 numbers on it).
The throw will be shorter and you can't have the lever adjusted too close to the bar.
Title: Re: Clutch push rod length/s
Post by: koko64 on April 01, 2012, 03:37:25 PM
Just to clarify (hopefully). For a given volume of fluid pumped, the bigger the slave bore, the easier the clutch pull, but the shorter the stroke. When I tried out the later slave cylinder, it felt like heaven, but the clutch grabbed earlier.

The later, bigger bore slave cylinder has less stroke for the given capacity of your master cylinder. You may well have to adjust the screw in the lever (not too much) to give you more capacity and if the lever is adjustable increase the span.
If that doesnt work then you might consider a later master cylinder to better match the relative bore of the slave cylinder.

The issue can be exacerbated with aftermarket slave cylinders with even larger bores and therefore even shorter "clutch throw."

The bore of the early oem slave cylinder is 26, the later one must be larger by about a couple of mm (these guys will know). (Edit typo).
Title: Re: Clutch push rod length/s
Post by: otter1 on April 01, 2012, 07:52:07 PM
Appreciate the info - I will try to adjust the clutch lever piston and see how it does later this week. If it is still not working right I will try to get a longer clutch push rod.

Speeddog - can you measure the two rods you have and post?

I may need to order the longer one from you if mine is too short.

Thx!
Title: Re: Clutch push rod length/s
Post by: gatorgrizz27 on April 03, 2012, 08:21:52 PM
You can also use the short rod and make a spacer that is 10mm longer, I found a bit of a bolt that slips inside the slave perfectly.
Title: Re: Clutch push rod length/s
Post by: otter1 on April 05, 2012, 09:56:45 AM
I suppose I could just cut off a piece of my shorter rod instead of using a bolt. Still want to know if I have the longest rod avail -- LOL

PM sent to speeddog.
Title: Re: Clutch push rod length/s
Post by: Speeddog on April 05, 2012, 12:25:15 PM
'02 dry-clutch pushrod
335mm long
Basically flat both ends, necked down ~205mm in the middle

Unknown vintage dry-clutch pushrod
325mm long
Round end on slave cyl end, same necked down ~205mm in the middle

Unknown vintage unknown application pushrod
305mm long
Round both ends short necked down ~37mm toward slave end
(pretty sure these are small-case)
Title: Re: Clutch push rod length/s
Post by: koko64 on April 05, 2012, 03:59:59 PM
The 10mm shorter one matches the oem one in my old 95 model 900. Rounded at the slave end and alittle shorter.
Was it polished and hard chromed?
Did it look better quality than the later, longer one?
Title: Re: Clutch push rod length/s
Post by: Speeddog on April 05, 2012, 06:16:09 PM
Quote from: koko64 on April 05, 2012, 03:59:59 PM
~~~SNIP~~~
Did it look better quality than the later, longer one?

No, it looks a bit more agricultural than the '02 one.  :P
Title: Re: Clutch push rod length/s
Post by: koko64 on April 05, 2012, 07:05:22 PM
I must have a good one. Looks like polished hard chrome. Luigi made it Wednesday.

The later longer pushrod that suits the later oem slave cylinder I have looks like pot metal in comparison.

The shorter one is so much better I have to make a spacer now.
Title: Re: Clutch push rod length/s
Post by: otter1 on April 06, 2012, 06:40:42 AM
Thx speeddog for the measurements.

I think I must have the longer one already  ???

I will measure it to confirm when I pull it to insert a spacer.
Title: Re: Clutch push rod length/s
Post by: WiDuc on April 11, 2012, 11:14:26 AM
Quote from: Speeddog on April 05, 2012, 12:25:15 PM
Unknown vintage unknown application pushrod
305mm long
Round both ends short necked down ~37mm toward slave end
(pretty sure these are small-case)

To add a known application to Speeddog's description above, I measured mine:

2000 M750 wetclutch pushrod
305.8mm