Clutch plates

After I put The primary back together last year I used Royal Purple ATF in it. The back of the bottle said it was good for type F. When I was out for a ride yesterday, the Clutch started slipping. By the time I got back to the house, the drive plates had blued and had a slight warp to them. I have the bronze driven plates.
So I have a couple of questions.
The plates would gum up every year or so with regular type F ATF. I would clean them on glass with 320 grit wet/dry paper just to remove the gunk from them.
I have the Dyno Dave seal installed.
Is a better type F fluid available that doesn't gum up (why I tried the Royal Purple)?
The second question is That I started out using the 320 grit paper to clean the plates, I quickly moved on to 180 grit. It took just over an hour to clean up a steel plate.
This morning I bought some 80 grit wet/dry paper, and it does move up the time it takes to clean and true a plate.
Is this too course to run or should I finish up with a finer grit paper after I'm done with the 80 grit?
Thank you for your help. Franko

I have never had a to clean up clutch plates on an annual basis like you are describing.
The clutch slipping/blueing sounds like more an adjustment issue than an oil issue.
Regarding the cleaning up of the plates, 80 grit sounds over the top, IMHO.
An hour per plate also sounds over the top. Sounds like you are trying to remove the blueing, which is discolouration deep into the steel plate.
Often when the plates are blue, they are warped. Did you check on a flat surface with feeler gauges?
As long at the plates are flat, all you need to do is leave a scuffed clean surface. 180 grit would be fine. The blueing is irrelevant.

Stephen Hill

I blued my plates the year after I bought it in 88 when the layshaft bearing went and I was stuck in 4th, they are still blue now.

franko said:

The plates would gum up every year or so with regular type F ATF.

Click to expand...

Every year or so? Lucky you! Mine started doing this just about the time the warranty ran out. Take a squint at clutch-slippage-part-enter-your-number-here-t22376.html for one way around this problem. As always, the discussion gets pretty heated (I seem to have that effect on people...)

Nathan

OK, she is back together and we both are happy.....for now.
I didn't check how bad the plates were warped before I started to sand them.
I ended up using the 80 grit to do the work and did not refinish with the 180 grit.
I believe the plates had a slight warp because of when I started to sand them, two sections on one side would start to clean up. When I would start to clean up the other side of the plate the witness marks would be opposite of the cleaned area on the other side.
I used a piece of glass about 16" by 24". The wet/dry paper was just normal hardware store size. When I wetted it down and started sanding, the paper would stay in place. Using a figure 8 rotation or a circular motion and rotating the disk a bit every few moves, I tried to keep the wear from becoming similar to a wedge washer. I sat down while doing this, so as not to be able to put too much downward pressure on them and bend the plate while it was being sanded. Adding water while doing the work, washes away the swarf and keeps the grit cutting.
Each disk was a bit different. Some were resembling a potato chip. Others were only worn where the friction plates contacted them.
I took them all down to clean metal. The bronze plates had scratches in them from manufacture, I believe, but I didn't remove them. I only cleaned up the discoloration.
After Reading the replies, I used the glass and feeler gauge to check where I ended up.
I have two steel plates I can get a .002" gauge under in two spots, one of them I can also get a .003" in one spot.
One of the bronze plates I can get a .002" gauge partially under. This corresponds with the discoloration I didn't finish removing from it. The pressure plate (?) didn't cleanup completely around parts of the outside edge and these areas also let a .002" gauge under it partially.
It was mentioned about the adjustment being out. It wasn't, but looking at everything, I can now see how a problem closing up could happen.
All of the steel plates were assembled with the tapper from stamping toward the inside. Ridges are starting to form on the chain wheel, so this might help them ride out of the ridges while clamping.
The bronze plates have a burr starting where they pound against the splines.
When I assembled the clutch basket, the pressure plate sat a little below the splines of the chain wheel, so I don;t think I removed too much material.
The clutch lever pull is still easy.
We went on a 30 mile ride. She shifts nicely and did not slip.
Thanks again for your replies and I going to look into fiber plates or Barnett plates if this doesn't hold up.
Frank Coleman

You've read the DynoDave clutch stack guides, yes?

The notion of roughing up clutch plates to improve grip is false. Like putting snow tires on a dragster and expecting better acceleration.

Clean with solvent, inspect for flatness, and reassemble.

I run synthetic ATF far above the level plug, for a sure grip, smooth clutch. Type F or Dexron doesn't matter. :idea:

Sorry to challenge the tribal stuff, but those items fail logic, science and standard best practice in the industry. :idea:

Concours: I used the DynoDave information to set up the clutch. When I stated that the clutch lever pull was easy, I meant it to show that I didn't remove too much metal trying to true up the plates.
I was not trying to get more grip by roughening up the surface of the plates, but by trueing them to give more contact area.
The steel plates were blued and slightly warped, at least one had a trough worn into it where it contacts the friction plate.
I used the blueing of the plates as a Prussian Blue would be used when scrapping bearings.
I dropped down to the 80 grit paper to speed up the work, I had intended to finish of with the finer grits, but the surface looked good with just a few scratches from errant pieces of grit that came loose from the edges on the sand paper. I could not catch a fingernail on them so the burr was gone from the sanding.
Stephan Hill suggested that the clutch was out of adjustment. I looked at the parts better with his thought in mind. The chain wheel has started to have grooves worn into it. When I was truing the plates, I could see that one side had a taper to the teeth and the other side had a flat, sharp edge. I thought this sharp edge could catch on the grooves in the chain wheel and stop it from clamping tightly.
I was not trying to get it to grip by giving it a rough surface, just getting the parts to work properly.
Yes I could have bought all new components, and someday probably will have to.
I asked about Royal Purple because it was the last change I made to the clutch and the first time I used a synthetic oil in there. Now, through contribution to the thread from others, I know it is not an issue.
Stephan Hill, I believe pointed me in the right direction with more attention to assembly.
Nator, hobot and others pointed to alternative solutions for when the clutch acts up in the future.
Thanks for the help guys, Frank Coleman

Rubbing a warped clutch flat is probably not a long term solution. Though it might keep you on the road in the short term.
Once the plate has warped, even if you rub it flat, there is a very good chance that the plate will rewarp when hot. Might even go back to flat when cold again! Just to complicate your trouble shooting.

Stephen Hill

:idea: Also, the Barnett aluminum hosted fibre plates work great. Saves your clutch hub too.