Best way to shave 4th clutch piston?

[CreepinDeth]

It's recommended to shave the OD clutch piston .080" to add a 3rd friction to it in applications over 300hp. (200-4R)
I'm just curious how you guys that have rebuilt your transmissions have gone about doing it.

I was told a lathe was a good way to do it, but I don't own one.
I have a drill press at work, but not exactly sure how I'd go about securing the piston in it.
I thought about a whetstone of aluminum oxide to do it but no idea what I'd use to spin the piston to
get an even surface.

Anyone have any recommendations??
There's a metal working class at the local community college.
I was going to call and ask there as well.

 

[GNeric]

I have always taken mine to work and thrown them on the brake lathe and just take the .080 off with that.

 

[matt69olds]

I have always taken mine to work and thrown them on the brake lathe and just take the .080 off with that.

I have done it that way also. That is how I cut the thick 400 and 350 pistons to fit the extra clutch plates. Works good, my buddy that owns the repair shop save old cutting bits so I don't tear up good ones.

 

[87GN_70GS]

Stationary belt sander/surfacer (the big one for planing manifolds, heads, etc), or stationary table grinder (magnetic holding base with moving grinding wheel).

 

[Steve V]

I have always taken mine to work and thrown them on the brake lathe and just take the .080 off with that.

How are you securing it to the lathe?

 

[GNeric]

I use the flat side of the piston up against the chuck and use a cone to center the piston thru the center lip seal area of the piston. Snug it down and check for straightness with the dial indicator. Only had one that was real bad and didn't want to shave down (would have come out crooked). Works like a charm. Gets it done in about 2 minutes.

How are you securing it to the lathe?