slipping clutch

[user 16790]

I recently changed the oil on my 1991 model for some semi synthetic Motul 5000 10w40 but now when I go into v-boost the clutch slips quite badly, I am pretty convinced it is due to the oil but my question is, would the slipping stop by itself if I use a different oil or are the clutch plates likely to be too contaminated and need replacing,
I had this scenario on my TDM900 where I mistakenly put fully synthetic oil in and the clutch slipped badly, changing to a semi synthetic stopped it slipping but the Vmax is a lot heavier and creates a lot more thrust so I'm unsure if it would be ok to keep with the existing plates, thanks

 

[Fire-medic]

If your clutch slips with Motul 5000 10W-40 it's probably gonna slip with whatever you substitute. I use Motul, it's been good to me. Drain the Motul, and save it, try Shell Rotella and see what happens. The amount of residual Motul left-behind in an oil change, including that on the friction plates, probably isn't going to keep the oil change from showing you if it is the oil.

I suspect that your clutch friction discs were about at the point of wear for replacement, and the oil change has coincided with that point. If you do choose to replace your friction discs, rough-up the 'steelies' to break any glaze they may have. Clutch friction discs go-in 'wet,' not dry, when you're re-assembling the clutch. Remember to line-up the alignment points on the clutch components.

Have you replaced the innermost 1/2-width friction plate with a full-width OEM plate, and removed the spring steel band which lies inside the circumference of the 1/2-width OEM friction disc? How about the diaphragm spring, the PCW replacement spring is a good addition. It increases spring pressure significantly, while not changing the hand force required to activate the clutch, like you would have from doing the 'double disc' (DD) use of two stock diaphragm springs stacked one on-top of the other.

PCW Racing
112 Henry St
Schenectady, New York 12304

(518) 346-7203

Their web presence, isn't; don't waste your time. Just call them.

You can also try Larry Fitzgerald who is also in northern NYS, in Rochester. Another-one to-call as he doesn't waste time on the internet, but he answers the phone.

LCR Performance Racing
560 Avis St, Rochester, NY 14615
Hours:
Open ⋅ Closes 5PM
Phone:
(585) 458-8185

https://d23zpyj32c5wn3.cloudfront.net/images/product_descriptions/technical_data_sheets/28/5000_4T_10W-40_(GB).pdf?1579800043

Last, don't forget Sean Morley [email protected] of Morley's Muscle. I'm not a participant in facebook, but he's supposed to have lots of info and pics.

 

[Pighuntingpuppy]

I guess the first question would be, did the bike slip prior to the oil change? Second question I have is, how far did you ride on this oil?

If it didnt slip and it was only a couple miles, I would say change the oil and see what happens. If you still slip, see Fire-Medics response cause he is right on with it as well.

 

[user 16790]

thanks for the replies, as I'm in the UK we get huge import taxes on things from America so it makes it too expensive for me,
I've looked at ordinary replacement oem discs and it comes to around £160 for the friction/material plates, unfortunately I do not know about all the half width disc double spring stuff so will have to stay with standard ones,
I definitely will not use EBC (most available here) ones as they have always given me problems in the past,
the clutch never slipped before the oil change and I estimate that I've done just over 200 miles on the oil that is in there, as I have a bad wrist I can not open the throttle fully anyway so it is possible that the discs got to a worn out state at a similar time as my oil change, thanks again

ps. my bike is on just over 25,000 miles

 

[Fire-medic]

Spend some time in the 'drivetrain' section and the 'how-to' section, to educate yourself about the replacement of the half-width friction disc. There's nothing to it, you're simply exchanging the narrow-width OEM friction disc for another OEM full-width friction disc, and leaving-out a thin flat band which rests inside the circumference of the half-width friction disc. You use the same OEM diaphragm spring. PCW Racing manufactures a replacement diaphragm spring which is about 40% stiffer than the OEM spring. last one I bought it wasn't very-expensive, but you'd have to check with them.

Have you looked at exactrep?

The purpose of the half-width friction disc as the last-one in the stack of friction discs on the clutch ('last one' meaning the friction disc which goes-on first, not the one closest-to the diaphragm spring) was a clever way to provide a function of a slipper clutch to ease downshifts.

 

[Parminio]

How many miles are on the bike?

I'll go ahead and bet good money you've got a good deal of miles on it. I'll guess around 45,000 to 50,000.

 

[Fire-medic]

How many miles are on the bike?

I'll go ahead and bet good money you've got a good deal of miles on it. I'll guess around 45,000 to 50,000.

RRRHHHHH!!!!!
'Thank-you for playing, but no!'

Post #4:
ps. my bike is on just over 25,000 miles

Forward your "good money" to:
Fire-Medic
P.O. box JYA-2WE
Miami FL

 

[Pighuntingpuppy]

RRRHHHHH!!!!!
'Thank-you for playing, but no!'

Post #4:
ps. my bike is on just over 25,000 miles

Forward your "good money" to:
Fire-Medic
P.O. box JYA-2WE
Miami FL

Damn you....LOL.....You beat me to it.

 

[MaxMidnight]

I have used semi-synthetic oil in mine since I have had it without any issues (but see below).

The half plate referred to above are #'s 7 & * which are replaced with full width items.Part of the half plate assembly (# 6) is a Beleville (cupped spring) washer (#6) that cushions the shifts.
Whist you will probably reduce slip by removing the half plate components on the clutch parts fisch) you will also notice that there is a little more noise from the clutch and the shift will be a little more clonkier.

I noticed when my friction plates were getting near the end of their life it would slip during warm-up but be OK when up to operating temperature; this was around the 35K mark.
Mine hadn't reached the minimum but the motor has been breathed on so perhaps that shouldn't surprise me. Replacing the frictions sorted the problem.

'Fraid the only way to check them is to remove them and measure the thickness.

It would be worthwhile changing back to the oil you have previously used so see if that returns things back to the way they were.If you drain the semi synth keep it for another time.

According to the Fowlers web site a set of six frictions would be £108.00 + the gasket @ £16.76. If you decided to replace the half plates with full width (not necessary in a standard motor IMO) add another £28.74

 

[Parminio]

Didn't see that. Sorry.

At any rate, that's a lot of miles gone to start running the bike on synthetic. Typically, manufacturers will run an engine on regular oil for the break in period and then switch to synthetic immediately from there.

Synthetics bond to the parts differently and reduce friction. That's what makes them better for engines and why engines last longer and perform better than conventional oils.

With that many miles on it, your plates had so much wear on them already that the switch makes them slip after it bonds.

That was my point. You're supposed to switch to a synthetic early in a motors life, not later in it. The same thing happens with automotive automatic transmissions as well. If the fluid hasn't been changed and it's got a lot of miles on it, don't change it.

Edit to add: I changed to synthetic (Mobil 1 full synthetic) on my first oil change and have run it ever since as advised by the dealer.

 

[user 16790]

thank you for the replies, being as I'm on low income I have to go for the cheapest option so I will get the 6 full plates and a gasket and replace those,

I'm not running it on fully synthetic, just the semi, the last two oil changes the bike had were also with semi synthetic but the oil brand was Silkolene 10w40, it only slips now I have the Motul semi in it,
I will drain out the Motul to change the plates and then put the same Motul back in as I can't afford more oil again as well right now,

one last question before I buy, could anything else give the symptoms of clutch slip other than the plates, could it be possible for the clutch hydraulic system to not release fully

 

[Fire-medic]

Two things come to-mind, both are rare events.

One, the diaphragm spring hold-down bolts weren't adequately-torqued, and they're backing-out. Use another mechanic next-time! (Do it yourself)

Two, the clutch hose collapses internally, acting like a 1-way valve, and keeping pressure on the diaphragm spring. You probably wouldn't be able to shift the bike.

While either could happen, 'not likely.'

Then-again, as I mentioned for #1, a shade-tree mechanic could have butchered something. I'm finding that out with a recent bike in to be returned to the road where they used brute force to make the connection to the clutch slave cylinder, twisting and kinking the rigid line, instead of routing it properly. I also saw they probably-used the 'spare-change' master cylinder reservoir window repair, placing a dime in-place of the window, and then what appears to be possibly JB Weld over it, and then re-painting the master cylinder black. I just hope that these idiots who owned the bike before me stayed-out of the engine!

If your master cylinder reservoir window is opaque or it leaks, go to a good watch repair shop and they'll have a selection of crystals, match one to the opening, and epoxy it in-place. If you're careful in the removal of the old pieces, you can probably re-use the chrome bezel.

 

[user 16790]

thanks for the info, I have XJR1300 master cylinders and a braided steel line that I fitted last year, I do remember the end of the original rigid line was a bit messed up and I had to smooth it to be able to mate the new line to it, it all bled through ok and has shown no signs of leaks, I was wondering if the slave cylinder could get a bit stuck causing the clutch to not release fully, I have not had that apart yet so I don't know of its condition,
this is my bike

 

[MaxMidnight]

Didn't see that. Sorry.
Typically, manufacturers will run an engine on regular oil for the break in period and then switch to synthetic immediately from there.

Synthetics bond to the parts differently and reduce friction. That's what makes them better for engines and why engines last longer and perform better than conventional oils.

With that many miles on it, your plates had so much wear on them already that the switch makes them slip after it bonds.

That was my point. You're supposed to switch to a synthetic early in a motors life, not later in it. The same thing happens with automotive automatic transmissions as well. If the fluid hasn't been changed and it's got a lot of miles on it, don't change it.

Edit to add: I changed to synthetic (Mobil 1 full synthetic) on my first oil change and have run it ever since as advised by the dealer.

Filling with a 'running in' oil may have been the case many years ago and when vehicles typically had a 1500 mile first service.
That has not been the case for many years now and the first time your motor will get an oil change will be when it reaches the mileage limit or first year.
Vehicles will get the 'in service' oil from the start.

I have never seen anything that warns against changing oil type, i.e mineral, semi synth or full synth beyond a specific mileage.
Given that the Max was designed to run on mineral oils they are more than adequate for the majority of users and whilst I normally use a semi synth, I've also used a strait mineral oil and can't say I have noticed any difference.

That's not to say semi's don't give any benefits; they maintain their properties better and for longer and they produce less sludge over time.
Whether that gives any benefit to the average Max rider is less clear. If you are inclined to miss oil changes or let the level drop perhaps but otherwise....

Julian, if you have used semi synth previously then I doubt that just changing brand would be the issue.
Whist I have never heard of a slave cylinder not returning you should never say never but it would be low down on my list of things to check.
I have read of the return orifice in master cylinders getting blocked and the system holding line pressure but that seems to affect brakes and not clutch.

When you change the plates could you measure the thickness off them and report back? It is useful to get feedback on what you found.
Also note that with the bike on the side stand you don't need to drain the oil as only a little will come out when you remove the side cover. A drip tray is a good idea.

 

[user 16790]

wow that's great to know I don't need to drain the oil , side stand it will be
I can measure the plates but I don't have a micrometer or similar type of measuring tool,
I rode the bike to work today and clutch slip seemed less obvious but the weather is hot if that makes a difference,
I've been pointed in the direction of a kit by EBC and the user said it is good, (maybe they are better than my last experience of them 17 years ago), any body think it is worth a try ?
this is a link to the kit
https://www.ebay.co.uk/itm/Fits-Yam...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

again thank you for the help

 

[Fire-medic]

OEM kit for the friction plates. Use what Yamaha and god intended. Our resident authority Sean Morley will tell you the same thing. There is a recent post by another member who was damning the EBC clutch.

The clutch master cylinder is pretty-much like the front brake master cylinder, though the rebuild kits have different part numbers. The same things can bedevil them. crappy, dirty opaque brake fluid, an obstructed weep-hole in the floor of the reservoir, extended time in-service for the brake fluid resulting in crystallization of the contaminants, and seizure of the brake piston. This can also cause premature failure of the rubber pieces in the master cylinder.

I'm including this to show what some people do to 'repair' their defective parts. While it works, I'd rather be able to monitor the color of and the level of, my brake fluid. See (or rather, you 'don't see') what was the dodge they executed?

A clutch slave cylinder can seize just-like a neglected master cylinder. Look at my clutch slave cylinder thread to see one example of a grungy one. In this case, I elected to replace the slave cylinder, though Yamaha does offer a rebuild kit for not much dosh.

Tell-tale signs of a failing clutch slave cylinder are a clutch not working, or disengaging only when the lever is about to make contact with the handlebar. This causes hard shifting, if shifting happens at all. A descending brake fluid level in the clutch master cylinder and a corresponding drip/puddle of escaping brake fluid in the vicinity below your left footpeg, on your garage floor, are other signs.

Take a close-look at my shot of the open master cylinder. See the two openings in the floor of the master cylinder. The smaller-diameter one, the one closest-to the banjo bolt for the clutch hose, has a geyser of fresh brake fluid shooting upwards out of it. Look closely and you can see the 'tiny little bubbles' (thank-you Don-Ho) which indicate that your reverse-bleed, being performed here, is purging the clutch line of any residual air. Reverse-bleeding is for me the #1 way to quickly obtain a firm clutch lever, and a fully-operational clutch, with the least-amount of fuss. My link tells you how to make your own inexpensive hydraulic system bleeding tool from items available at your friendly well-stocked supermarket (!), and a visit to the auto parts store. I would be surprised to-hear that you spent >$10 or 8 Euros, or whatever you barter-with in these days of Brexit.

https://www.vmaxforum.net/threads/clutch-slave-cylinder-replacement.45011/

 

[Parminio]

Disadvantages of Synthetic Motor Oil

• Many of the synthetic oil blends reduce friction better than conventional motor oil. This was a problem with a new engine break in period. The friction during this period was to smooth out any rough spots in the engine. With the improved manufacturing processes now available, a break in period is not as crucial as it was in the past.

And that's the problem.

You get an older engine with wear on it and switch to a semi or full synthetic that reduces that friction and you get the slipping.

I bet a dollar if he goes back to conventional oil, runs it 500 miles, then changes it again, he'll notice the slipping stops.

 

[user 16790]

it's had semi synthetic since I've owned it, 3000 miles and 15 months with no slipping

 

[Parminio]

it's had semi synthetic since I've owned it, 3000 miles and 15 months with no slipping

I run full synthetic in mine and have since it had 1200 miles on it. It presently has 15,000. Never had a problem. That was never my point.

My point is if you've been running an engine pretty hard for 10's of thousands of miles on regular oil and it's got a good deal of wear on it, when you put a synthetic oil in it that reduces friction a good bit the instant you use it you can run into problems like this.

 

[user 16790]

well unfortunately I don't know how it has been run or what oil has been used in the past before I bought it, I just carried on using a semi synthetic as that's what the dealer put in who sold me the bike