ST1100 Clutch Replacement

[electrajoe]

I just could not stand the clutch slipping at 6,000 RPM + under WOT.

My clutch parts are in, 10 frictions, 5 springs 1 plate, gaskets, nut, etc. I was going over the Service Manual before starting.

Page 9-7 at top states "It is not necessary to disconnect the clutch hydraulic system for clutch disassembly/assembly." Hower Requisite Service item 2 states "see page 9-4 for removal of clutch slave cylinder." It seems removal will open the hydraulic system and would have to be blead on reassembly.

Question: Does the slave have to be removed or can it stay intact with the clutch cover?

[Horst]

I think it can stay intact ... bleeding the clutch is very easy, so if you have to don't sweat it ... I bled mine this spring and clutch action is solid ! ;)

[electrajoe]

Bleeding should not be a problem. It looks like the whole slave comes apart when removed, just did not want another assembly to rebuild (gaskets, o-rings, etc.)

[wjbertrand]

I just could not stand the clutch slipping at 6,000 RPM + under WOT.

My clutch parts are in, 10 frictions, 5 springs 1 plate, gaskets, nut, etc. I was going over the Service Manual before starting.

Page 9-7 at top states "It is not necessary to disconnect the clutch hydraulic system for clutch disassembly/assembly." Hower Requisite Service item 2 states "see page 9-4 for removal of clutch slave cylinder." It seems removal will open the hydraulic system and would have to be blead on reassembly.

Question: Does the slave have to be removed or can it stay intact with the clutch cover?

I replaced my ST1100's clutch last year right before WeSTOC in Minden. I left the slave cylinder attached to the clutch cover and the cover hanging (with some string to support it) from the hydraulic line, no problem at all. You should probalby also replace the right side header gaskets too.

[electrajoe]

Progress Report 1

Every thing came apart after jumping from section to section in the Honda Service Manual. The exhaust header connector was a little difficult, probably something to do it being on for 14 years, did not have the PB Blaster, but WD40 helped. I kept the clutch slave attached to the case.

In order to hold the shaft to remove the big 30mm nut, I made a tool. Got a 1 inch X 6 X 24 board, marked the board near one end using the 5 holes on pressure plate and center. Drilled holes for 6X75 mm bolts and washers then a 3/4 inch hole in the center for a short socket and extension. Tightening the bolts draws the board to the clutch center, hold the board to keep the shaft from turning and loosen the big nut with a breaker bar.

Springs were 42mm, 43 when new, 40 limit - will use new springs since I bought them.

Clutch pack (10 frictions & 9 plates) was 55mm, range is 54.72-56.72, limit 54 - will use all 10 frictions and 1 new plate since I have them.

Frictions were about new thickness, but seemed hard and possibly glazed. The plates were slightly glazed, when compared to the new one. Some plates had blue in some areas. Non friction ares looked as if they were copper plated. I cleaned the plates with scotchbright and fine emery paper. The frictions and plates are soaking in GN4 oil overnight.

Progress Report 2

Installed the clutch pack, new nut, cover, case guard, and exhaust system (2 manifold and 1 header gasket) without any problems. I used my $43.00 ACE hardware 5-80 ft/lb torque wrench where applicable. The photocopy of the Honda Manual pages 9-6 & 9-7 got a little oily. The copy really helps keep the Manual looking new.

Did not put on plastic today. Put on the seat and went for 10 mile test ride. Clutch action is good, it seems to go into 1st gear easier, but noticed 2-3 was a little notchy, probably more noticable without all the tupperware on. Without all the plastic the bike really puts a lot of heat (might be a good idea for a heater in the winter - ha, ha) Everything seems OK, will put on plastic in the morning and go for a ride. Will take it easy for a while before doing 6-8K RPM stress tests.

Background:
I bought my 1991 ST1100 last year with 32k miles, the clutch slipped a little at 6K RPM gear changes (had Castrol in it), Honda GN4 helped a little. I tried Mobil 1 Extended Performance 15w50 (sucessor to Red Cap). Almost immediatley, the clutch would skip without gear change at WOT in 4th gear above 5,800 RPM, it would quickly go to 8,000 RPM. M1 stayed in 357 miles, GN4 moved slip to 6,200 RPM.

Moral:
Don't use a moly oil if you have an older bike or suspect a weak clutch.

[wanderlust]

In order to hold the shaft to remove the big 30mm nut, I made a tool. Got a 1 inch X 6 X 24 board, marked the board near one end using the 5 holes on pressure plate and center. Drilled holes for 6X75 mm bolts and washers then a 3/4 inch hole in the center for a short socket and extension. Tightening the bolts draws the board to the clutch center, hold the board to keep the shaft from turning and loosen the big nut with a breaker bar.


Here are pictures of my makeshift clutch holder. It worked like a champ.

http://www.st-owners.com/forums/attachment.php?attachmentid=7025&stc=1&thumb=1&d=1139969094

http://www.st-owners.com/forums/attachment.php?attachmentid=7026&stc=1&thumb=1&d=1139969094

[Mean]

Or you could use an impact wrench. Just my guess. I haven't had to do my clutch yet.

G

[wjbertrand]

An impact wrench works, that's how I did it. Re-tightening was handled by having someone stand on the brake pedal with the bike in gear. You only need to re-torque the new nut to about 40 something ft lb.

[STingray]

Anybody need the clutch parts for an 1100 (Brand Spankin' New - still in their little baggies:) )?

8/2 friction plates (10 total)
5 springs
Special nut
Gasket

$100.00 firm ($150 retail) + S&H

LMK before they go to eBay!

[Shuswaper]

An impact wrench works, that's how I did it. Re-tightening was handled by having someone stand on the brake pedal with the bike in gear. You only need to re-torque the new nut to about 40 something ft lb.

....ahh, hate to break to u there wj., but that nut calls for "80 ft lbs", according to the factory service manual. I would not trust anything less on such a critical part.

[wjbertrand]

....ahh, hate to break to u there wj., but that nut calls for "80 ft lbs", according to the factory service manual. I would not trust anything less on such a critical part.

Hmmm, could be. This was a while ago so perhaps I have forgotten. Never the less, I know I followed the manual specifications and did it as described using my torque wrench and SO standing on the brake pedal, bike in gear.

[George]

I replaced only the springs on STick last summer. Seems to have solved her minor problem.

[electrajoe]

Update:

05/12/05-----47,457 miles, 10 clutch frictions, 1 plate, 5 springs
02/25/07-----77,494 Galfer brake fluid, front, rear brakes & clutch
3/21/08 ---- 97,863 miles, fluids still light and clear

After 50,406 miles the clutch still feels like new.