Turbo Action (and probably others) sold plates machined just like that.

If your buddy does it make sure he leaves a nice radius otherwise it will break.

If your rear clutch is apart look at that pressure plate - some guys install that one upside down in the front clutch to achieve the same thing. It’s tricky sometimes to get the snap ring in and out but it works.

You can run the solid style snap ring like the one in the rear clutch. Then the ring will float upward in the groove.
Doug

Pressure plate lathed for more clearance.

john, does the chatter marks on the side of the lathed pressure plate affect anything ? i would do a better finish if i were doing that job just because.

In the alto power pack setup you can buy the pressure plate is .177 or something- dunno if its heat treated or chromoly or tool steel vs the stocker but to make it easy on the machinist doing me a favor I think mine will still be strong enough shaved flat at over .2”? The stocker is just under .280. That avoids measuring snap ring install clearance and chancing a stress riser in the corner from tool marks or whatever.

I have been doing and re-doing my math- with .045 clearance currently I can shave .037 to just barely get in spec at .082” I’m thinking a little extra room for the clutch to slip unapplied isn’t a bad thing since max spec for 4 plates is .151” My guy is coming to pick up the part and my instructions today. I’m planning to tell him I want .070 trimmed off which would give me just under spec until touching the wave snap ring and .115 total gap to flatten the ring. My tom hand book says to measure at the widest gap under the wave so that’d be at .115” which still leaves room to keep the piston seal in its bore as my fibers wear.

Sound like a good plan?

Also while the trans is out I have the slower lever in there- one line on it makes it a 2.9. I have a tf2 kit installed and kevlar bands. Obviously I haven’t yet experienced a 2-3 shift, the 1-2 was noticable but not harsh and didn’t slip. Should I be looking at a higher ratio servo lever and thicker band strut? Is tig welding a reinforcement on the strut worth doing? Again this is a healthy but mild 512 stroker but not a race car and on street tires.

Thanks
Rdr

.012"-.015" per friction is what most of us shoot for. So with 4 friction it should be .048"-.060" clearance. You easily tig weld reinforcement to the band strut .Make sure the ends of the reinforcement don't interfere with the band or band anchor.The ratio levers multiple servo force times ratio. The 3.8 or 4.2 seem to work well. The higher the ratio the longer the servo travels to engage the band.
Doug

My machinist said he took off .050 on the lathe, .009 on the surface grinder, then flipped it and took .002 of curve off the back to true the faces. So the plate lost .061”

Add that to my existing .045 clearance for the front clutches to freewheel and I will have .106” which is right where I want to be inside a specified clearance of between .082” and .151” for four friction plates. Hopefully right where I want to be anyway. I figured I’d shoot for a 30% over minimum clearance to be safe but not sloppy.

The plate was .280” so it will still be .219” and plenty strong for its purpose. Again, hopefully- I have no idea what I’m doing but I’m catching up fast.

I should have her back together late tonight and I’ll do an air check before re-installing the valve body. I will make sure to butter up and center the sealing rings on the reaction shaft with sticky grease so they stay centered and won’t hang catch and break when I bolt up the pump. I’ll also make sure I use pilot studs to keep the pump centered as it goes in.

Got the PP back- looks great and comes in 1/3 of the way from min to max spec at .106” clearance

[/quote]

.012"-.015" per friction is what most of us shoot for. So with 4 friction it should be .048"-.060" clearance. You easily tig weld reinforcement to the band strut .Make sure the ends of the reinforcement don't interfere with the band or band anchor.The ratio levers multiple servo force times ratio. The 3.8 or 4.2 seem to work well. The higher the ratio the longer the servo travels to engage the band.
Doug [/quote]

Dang I feel like I read this before which is why I thought I could get away with it at .045 when I first built it. Then this week going back through my Tom Hand book he lists the spec for 4 fibers at .082-.151 which is a lot more!

The last thing I want to do is pull this trans again real soon because my front clutches are burning up because I spend a lot of time in 2nd gear hotrodding and they are heating up instead of slipping. All the reading I’ve done talked about how the forward clutch has a small unapplied gap because it’s almost always applied where the front clutch needs some room to slip because it actually does a lot of on and off.

This is all book learning though- I come here for real world experience.

So by my book I’m at the bottom 1/3rd of spec and by your suggestion I’m at double the spec. Not sure if the wave snap ring figures into this? I’m guessing if I went straight snap ring it would apply harder with no cushion which would be harsher but easier on clutches wear wise?

It’s too late to un-shave my pressure plate but I could swap the .050 wave washer for a thicker flat one if it is a big deal?

The old saying - “too many chefs.....”.

Is this lou????

It will function at the larger clearance. The tighter number is what has been recomended for blue printed builds. This why I suggested simple snap ring change in an earlier post. Steels are also available in thin .070" and thick .085". to tailor clearance.
Doug

Thanks Doug.

Well she’s all back together and the air check sounds great on the front clutch now. (Forward clutch and both bands still good too!)

Another item of good news- I was a little terrified to pull the stock 1989 dakota trans crossmember in my chassis. I was thinking after shortening the frame 20” and boxing it all in there is no way it wouldn’t spring when I took the xmember off and it wouldn’t line back up to re-install. That plus needing to finish and paint the bottom of the handmade floor & firewall made me pull the body so the trans would come out the top. I pulled it today and the frame didn’t move at all when the bolts loosened and they didn’t even put up a fight! So any more transmission shenenigans can happen from underneath without pulling the cab again. I have fought trans crossmembers tooth and nail (& torch!!) before so this one will go back on with some anti seize!

Anyway, thanks all for the support and insight. I’ll report back after I crank her back up and hopefully get a cruising gear and a reliable smooth reverse gear.

Radar

Congrats on sticking it out.

Hopefully no more issues.

glad you are back together. hoping for the best for ya.

What kind of line pressure are you running. I use the machined down retainer plate like you have in your picture and never broken one. I build a ton of 47/48 RE Cummins transmissions with up to 220 psi and the plates hold up fine. Stock inputs, nope. I always check pressure once they are back in the vehicle, get some good gauges and go through the pressure tests before you drive and you will prove everything is correct.

Well I don’t have gauges and I am a total noob but what I can say is if I remember right the pressure setting is the screw that moves the little plate on the side of the throttle body? I put it a short and curly from touching, not quite flush. I believe I decided that was ok when I installed the tf2 kit. Most of the choices that kit gave I would go aggressive but short of brutal full race setup.

It must be a decent amount of pressure because reverse was trying to work and sometimes worked ok even with 1/4 of a sealing ring missing on the reaction shaft. That was with an initial setting of .045” clearance below the wave ring but after a while the clutches were burning up and one of the steels was warping in a cupped way that took up more slack...

I was just psyched that my front clutch air check now sounds awesome. I still have the wimpy lever running the kevlar front band set at 1.75 turns out from torqued. It’s all just guesses, I have worked on a million harley evo and shovelhead clutches which are similar to the forward and front clutch setups- bellville and coil springs respectively but mechanical releases instead of hydraulic applies.

The trans is all back together but still on the bench. I have time to make changes if they are important.

Line pressure in Reverse increases by a factor of about three so the increased pressure helps weak parts that would fail at the lower pressure in forward gears.

If by "wimpy lever" you mean a low ratio like 2.9, setting it at 1.75 turns out is a bad idea...the lower the ratio the more turns out. For that lever go at least 2 turns or 2.25.