Clutch replacement and input shaft seal replacement

[Julian Sudano]

Hi All,
Pulled the gear box and clutch assembly last night in order to replace the rear main seal and was hoping to do the same with the input shaft seal as well.

I didn't count on the rather large nut on the input shaft! What's the procedure for removing that bad-boy? I'm assuming you need to immobilize the input shaft, via the splines to get the nut moving?

Also, it looked like there was grease in the groove where the big circlip holds the cupped disc in place. When reassembling, should I smear a small amount if grease in that groove so the cup isn't dragging?
Assuming that the clutch friction disc splines, as well as the input shaft splines should get a tad of grease too? I was thinking of using Liqui Moly LM47...

One last question: I have an output shaft seal, and am hoping there is some easy way of replacing that without tearing down the gearbox?!

Thanks for your input!

 

[V700Steve]

If you want to take nut off and are changing clutch plate, trash it by using the center for a tool w/handle. You ought to get a service manual it's all in there except the grease part. I never use any type in a clutch area, not on a Guzzi, it's NOT a bmw.
You can also take out those allen head bolts to gain access to the primary gears.
What you thought was grease was most likely oil mixed w/clutch dust. It all flings around.
You never said what year or model but that looks like a 5 speed in the pic.

 

[Paul Brice]

Workshop manual is critical......If you want to do the small clutch pushrod seal on the back of the clutch shaft, then you'll need to remove the clutch cover. If it's just the input shaft seal then you can leave it on gearbox & save yourself a gasket (and it's easier to hold the gearbox while you undo the nut !)

If you take the clutch cover off, it needs lots of tapping and fiddling (and swearing) as it usually drags the bearing out a bit until it fouls the input shaft gear on top of gearbox .

First use a flat tool to open up the lock nut on the top of clutch shaft.

Next you'll need a suitable spanner (probably cut down to fit inside the starter cover - see pics) for the big nut AND also need to weld a big nut on a cut up clutch plate (your current one OR old one with the right spline size !!).

Then you need to 'hold' the gearbox OR the clutch cover in a very strong workbench, make sure the spanner is locked in place, and turn the nut welded on the clutch plate using a long bar to break the 100nm plus (anti-clockwise cos it's the nut you are actually undoing).
You can change the clutch cover oil seal from there (and I'd change the 'o ring' under the spacer also while you're there).

If you want to do the clutch push rod seal, then pull the clutch cover off & replace that with suitable drift (& check bearings etc while you are there)

 

[Paul Brice]

For the output seal you can do it from outside if you are careful in extracting the seal from around the output spline shaft (the seal sits on the output shaft bearing)....it's just a fiddley job which I use long self-tapping screws to hold the seal and then pull it.

Last time I went the 'long way around' and changed the seal from inside as I had to replace a failed washer on the layshaft; this also let's you replace the 'o' ring on the gear change shaft (which I don't think is possible from outside the box)

but here's a pic of the 'inside view' if it helps..

 

[Julian Sudano]

Hi Paul - thanks for input! I'm still debating whether or not I'll try to pull the input shaft seal, due to a lack of tools, and it doesn't seem to be leaking at this point. I did however just bolt the flywheel and clutch assembly back on this afternoon, and then put the gearbox back in place only to find that it takes a herculean effort now to actuate the clutch arm. I could operate it easily prior to disassembly, but now I'm worried I'll snap my clutch cable, it's that stiff!

I did replace the seal on the plunger at the back of the gearbox, and at one stage pushed the pin on the input shaft back quite far, so am wondering if I've somehow got that whole assembly out of sync. With the gear box off the engine, I can move the pin back and forth freely with little effort. I don't want to put the bike back together just to find out the hard way that I've cocked something up!

I did replace the clutch friction disc, but apart from that haven't made any fundamental changes. Any idea why it is now so stiff?

Cheers.

 

[john zibell]

The arm that acts upon the clutch push rod should be at about 90 degrees to the rod (the block that contacts the rod) when the clutch handle is squeezed in, If less or more could be the reason it is stiff.

 

[Julian Sudano]

The arm that acts upon the clutch push rod should be at about 90 degrees to the rod (the block that contacts the rod) when the clutch handle is squeezed in, If less or more could be the reason it is stiff.

Hi John - thanks for the input. I've attached a few pics as I don't quite follow your explanation.

Could a possible reason for the extreme pressure need to actuate the lever be that the clutch disc is not properly centered and therefore the pin that actuates the cupped disc, is not centered properly? I was pretty careful about getting that aligned before tightening down the clutch housing against the flywheel though, and the gearbox slide into place very easily when attached.

 

[Paul Brice]

Agree with John, adjustment of the clutch arm is critical (and quite a tight range needed to avoid running out of rear lever travel); and often 'stiff clutch' is just stretching the cable if the lever is fully in

Only other things that come to mind are the assembly sequence of the pushrod bits, if you put the clutch plate in the right way around & if you put the round plate the clutch pushrod pushes the right way around....I've spent lots of 'check-recheck' time getting these right in the past

 

[V700Steve]

Sounds correct, looking at that arm & adjuster, it needs to come back for more play, then adjust correctly.
Make sure handlebar adjuster is all the way in.

 

[john zibell]

Hi John - thanks for the input. I've attached a few pics as I don't quite follow your explanation.

Could a possible reason for the extreme pressure need to actuate the lever be that the clutch disc is not properly centered and therefore the pin that actuates the cupped disc, is not centered properly? I was pretty careful about getting that aligned before tightening down the clutch housing against the flywheel though, and the gearbox slide into place very easily when attached.

Without the cable attached and clutch lever in I can't tell you.

 

[Julian Sudano]

Sounds correct, looking at that arm & adjuster, it needs to come back for more play, then adjust correctly.
Make sure handlebar adjuster is all the way in.

So I pulled it all apart again this afternoon to check that everything was out back as I found it, and it was. Still feels really stiff though.

I'm wondering if the there is something up with the parts that make up the pushrod assembly. Can this be removed and reassemble so I can check the parts, without creating further headaches?

 

[Paul Brice]

Yes, easier if the gearbox isn't on the engine but on engine can be doable with some fishing and depending how 'free' the pushrod is in the seal - part 21 inside rear of clutch cover. Good to check by moving in and out the clutch bearing end & rod separately to 'feel' where stiffness may be.

Check for straightness, all the clutch bearing parts for problems (roller cages can wear/break up), 'O'ring size and position (should be 17.2mm x 2.62 mm ish, check parts sequence against relevant diagram (this is V50-3 but probably all the same)

 

[Julian Sudano]

Thanks Paul! Looks exactly the same as the parts diagram I have for my V65. I was just concerned that I might lose some small part into the gearbox if I pulled it all out.

In the meantime, I went ahead and refitted the engine/gearbox back into the frame and reconnected the clutch cable to see if there was a noticeable difference in the force required to move the clutch lever arm, via the handle bars, and while it is definitely firmer, it doesn't seem too bad.

I'm waiting for a few parts to arrive before I can take it for a ride, but I did readjust the grub screw on the clutch arm that pushes on the plunger in order to give the arm a few more degrees of movement, so we'll see how that plays out.