wet clutch questions

clutch is slipping on my '72. i plan on replacing the frictions w/ barnett's and add another steel to reduce actuator effort along w/ dynodaves seal.

i'm a little unclear about wet clutchs in general. the clutch is cooled by the lube in the bottom of the chaincase. is this oil intended to migrate between the plates? doesn't that make the clutch slip? the manual says nothing about lubing the plates on reassembly. the clutch rod seal prevents trans oil from finding it's way into the clutch but the clutch is running in a bath of oil anyway so what's the diff? i haven't started dissassembling it yet so maybe a lot of this will be self explanatory.

sorry for the elementary questions. thanx, rick

The Commando clutch is supposed to be a DRY clutch, as in the clutch plates, in theory, are designed to operate in a dry
atmosphere. The oil in the primary is there ONLY to lube the triplex primary chain.
Unfortunately, some of the that oil as it is slopping around does get in on to the clutch plates, that can make them slip.

Many have found that the plates stay drier if the oil level is kept as low as possible in the primary, just enough so some
gets on the bottom rung of the chain as it spins around.

I got sick and tired of my clutch plates getting filthy with oil and occasionally slipping, along with a sometimes leaking
primary. I installed a dry belt drive primary ten years ago. My clutch plates stay clean and dry and the primary cannot
leak because there is no oil in there. The entire drivetrain feels much lighter and smoother with the belt primary.

If you want to keep your chain, then get in there and pull the diaphram spring off and clean the clutch plates, then
fill the primary only to the very bottom of the "drain" plug at middle bottom of the primary.
Many use ATF in the primary as it will lube the chain just fine, but will tend to run off the oil slinging grooves cut in the
clutch plates better than the thick engine oil the manual calls for in the primary.

I have heard of people using mercon atf (type F ) which has a little bit courser fiber in it . As explained to me the courser fiber causes better grip when on the plates. Makes sence but only the experts know for sure. One thing I know..atf is harder to confine than GL-5.

Hello!

The solution to my slipping clutch was.
Asking a friend to give the steelplates a mild sandblast to break the surface.
Combined with the original bronze plates this gave me a nonslip clutch.
At first the clutch was somewhat grabby, but that faded away over time!
40000 miles later.....still no slip! Still running the same plates!
I give the clutch a wash each spring to clear the residues, and then
fill my tranny with 200cc motoroil and I also use no pushrodseal.

Benton

rgrigutis said:

clutch is slipping on my '72. i plan on replacing the frictions w/ barnett's and add another steel to reduce actuator effort along w/ dynodaves seal.

i'm a little unclear about wet clutchs in general. the clutch is cooled by the lube in the bottom of the chaincase. is this oil intended to migrate between the plates? doesn't that make the clutch slip? the manual says nothing about lubing the plates on reassembly. the clutch rod seal prevents trans oil from finding it's way into the clutch but the clutch is running in a bath of oil anyway so what's the diff? i haven't started dissassembling it yet so maybe a lot of this will be self explanatory.

sorry for the elementary questions. thanx, rick

Click to expand...

Rick
I WOULD NOT recommend switching to Barnett plates. the stock surflex clutch is a good clutch if done right. as it is a 72 it should not have the heavier bronze plates. just pull the plates and clean them up well, install the clutch rod seal and DO NOT over fill the primary. As to adding an extra steel be careful as you increase stack up height you decrease apply pressure to keep the clutch from slipping (very critical on a 4 plate clutch) . any light weight motor oil or ATF is fine. if you go the ATF the old hot rod'r trick was to use type F for a firmer engagement. if you want a better clutch I would recommend a belt drive so you can run it dry and use a 5 plate surflex setup, it will take some machining on a couple of steel plates and an 850 top plate to adjust the stack up (you can do this to your wet primary also).

seaguy
as to mercon 5 and type F they are 2 totally different types of ATF (was in the transmission business for 35 years) the mercon has an additive package to stop shudder mostly in the converter clutch and a smother shift while the type F was formulated to be used in the old fords because they used a bronze clutch plate. in the 70's ford followed everybody else and switched to dexron and was using organic friction material on there clutch plates. as to the fiber if you find it in ATF you have a serious problem :shock:

thanx boys
I understand the working of the wet clutch! I know there's some disagreement on the barnett frictions but what is the main negative? Slowed to storm yet again Thursday so I'll do surgery on him then.

rgrigutis said:

thanx boys
I understand the working of the wet clutch! I know there's some disagreement on the barnett frictions but what is the main negative? Slowed to storm yet again Thursday so I'll do surgery on him then.

Click to expand...

IMHO the barnett is to grabby ie hard to get a smooth engagement. it also is an aluminum core with a bonded friction material so is likely to have a wear problem at the spline. the original plates are a solid fiber and is easy on the inner hub (replacement surflex are also bonded). I also don't like the 850 bronze plates as they are WAY to heavy and hard on the center hub.

Not to change the subject but I sure have had good luck with the aluminum center surflex plates in my 880. They have been in my streetbike for over 40,000 miles and that was after serving a season in my racebike. And they have been very easy on the hub that I put in new after removing the bronze plates. Going to buy a new set just like the old ones this winter. Jim

comnoz said:

Not to change the subject but I sure have had good luck with the aluminum center surflex plates in my 880. They have been in my streetbike for over 40,000 miles and that was after serving a season in my racebike. And they have been very easy on the hub that I put in new after removing the bronze plates. Going to buy a new set just like the old ones this winter. Jim

Click to expand...

Jim
I have used both the original solid fiber and bonded surflex with good success.On the bonded ones I have found that the friction has a tendency to flake off at the spline but IMHO it is still way better than barnett and the over weight bronze. Any chance you could convince mat to change his thinking on the barnett kits LOL. I have a 72 that I run a belt and 5 sureflex plates and it has to be the best feeling no slip clutch ive run so far with 25.000 trouble miles.

Nope, I already tried.

Windy, Jim,
I have had similar experience. Barnetts seem to grab suddenly while the aluminum center Surflex plates are much lighter and smoother. I have never had the flaking problem and I have had the same set of plates in my Mk5 750 (5 plate clutch) for at least 15 years. I was given a new set of Barnett plates, so I put them in my Interstate. The grabbiness was horrible so I replaced one plate with a used bronze plate. It made the clutch at least usable. Sometimes free isn't a bargain!

Yeah, I ran a combination of barnett plates and bronze plates in my racebike 20 years ago before I learned about sureflex plates. Getting a racebike off the line with a close ratio trans and all Barnett plates was a tricky proposition. Jim

well i pulled the clutch apart and the plates were soaked and dirty. cleaned them up and rough sanded the steels. frictions were .142, right on the low tolerance. inspected everything and fitted it back together w/ dyno daves seal. put in 200 cc's of type f atf.

well what a difference! no more slip.

one problem remains, w/ the clutch that is , heh heh. bike idles in neutral at 1000 w/ new jrc's, rock steady. when i shift into 1st it dies. dragging clutch. shifting into 1st is a little dicey also. i've read the clutch drag posts, clutch center looked fine. if the frictions were too thin would this contribute to clutch drag?

thanx, rick

rgrigutis said:

well i pulled the clutch apart and the plates were soaked and dirty. cleaned them up and rough sanded the steels. frictions were .142, right on the low tolerance. inspected everything and fitted it back together w/ dyno daves seal. put in 200 cc's of type f atf.

well what a difference! no more slip.

one problem remains, w/ the clutch that is , heh heh. bike idles in neutral at 1000 w/ new jrc's, rock steady. when i shift into 1st it dies. dragging clutch. shifting into 1st is a little dicey also. i've read the clutch drag posts, clutch center looked fine. if the frictions were too thin would this contribute to clutch drag?

thanx, rick

Click to expand...

If the hub was not notched from the friction plates (not normal with fiber plates) and the outer hub was WELL cleaned up so the steel plates will float in the splines you need to look for warped steel plates (probable if slipped a lot)or improper adjustment. If every thing is correct it will not have any drag, neutral will bee easy to find and no slip.

In my experience, the standard clutch/plates hardly ever slip as long as the primary case is not overfilled.

I use bronze plates in my MKIII, and Comma ATF, and keep a good check on the oil level as it only takes a couple minutes to check. Once the bike is warmed up and I crack it open with the throttle initially the clutch will slip, but then will be fine for the rest of the ride. The only thing I can I can think of, like someone else has suggested, is that any oil is flung off the plates when changing gear whilst riding enthusiastically.

Shifting in to first issue MAY be a symptom of an overly tight primary chain. Do you have plenty of slack in the top rung?
Another cause may be that the clutch rod height in the gearbox is not set properly, pulling in the clutch lever may not get full disengagement
if your rod(where clutch cable is secured in the gearbox) is set wrongly. Check these two things, may help.