I'm installing the upgrade of 23 single sided clutches in the overdrive direct clutch. Do I need a thinner pressure plate? It just seems too thick.



The sun gear should be nested flush with the top of the clutch drum?

 

Anybody? Anybody?

 

Hold on . . . . lemme look at my notes . . . . .

 

BC,

I did find 2 different Transtar part numbers for this. One is .214 thick, the other is .085 thick. I assume this measurement would be from the surface the friction sits against to edge of the shoulder the snap ring nests down into. I need to measure, but I'm guessing mine is the thicker one. Maybe you have the thinner one. Anyway, the snap ring that goes around the end of the sungear holds nothing as it sits now. Everything is held together by the large snap ring on the outer edge against the pressure plate. Maybe this isn't a big deal. I don't know.

 

I got my OD upgrade clutches & steels from PATC. As such, I had to get the companion new Overdrive Direct Clutch Backing Plate so that the new clutch-pac would fit the A518 OD drum. Not sure of it's thickness.

I then . . > REMOVED BS INFO < . . . fit correctly.

One needs to pay close attention to that slack under the waved snap-ring as described in the FSM.

Perhaps Mike (JD730) will chime in shortly, he knows this mess off the top of his head.

 

Are you referring to the Overdrive Direct Clutch or the Overdrive Brake clutch? I got all my parts from PATC also. I got the upgrade for the brake clutch as well, and it DID come with a thinner backing plate. I haven't installed that part yet since I'm trying to get this issue sorted out (and they shipped the wrong frictions for that upgrade power pack). So I think you're talking about the brake clutch. I'm not aware that you have to measure underneath the wave ring on the overdrive direct clutch. It seems like that would be non-productive since you have the gi-normous spring pushing against it.

 

There where 2 different designs on the Direct pressure plate, I don't know when they changed, but hopefully I get time tonight to tear into the extra OD's I have in the shop.
The 1st design measures .215" the way your thinking, from the where the friction sits to the where the snap ring sits and the steel plate for that would have been .085". This one has 8 lined and 7 steels.

The 2nd design is .085" on the pressure plate measurement and .055" on the steel plate. This one would have 10 lined and 9 steel.

Your groove should be .100" from the top of the drum to the top of the groove.

Unfortunately I do not have any notes on the single sided ones nor have I worked with them yet.

Just by looking at your picture it looks like the stack hight on your clutch is too much, the sun gear should be lower in the hub.

 

Foregive me. Strike that line altogether. Clearly I hadn't thought that completly through when I posted it. Yup, different clutch. :duh:

 

Thanks JD and BC,

JD, that helps a ton. I did take 8 friction and 7 steels out of this clutch. I'm inclined to get one of the thinner pressure plates, the .085 ones, and use it. I looked at the photos BC has posted and his is certainly much thinner looking than mine.

The backing plate, at the bottom of the stack, is the same for both situations?

 

The smaller circle snap ring is a back up ring in case of excess clutch wear. The one that fits splines. It should not have pressure against it.
I'm wondering? Since the direct clutches in all honesty only hold in reverse or engine breaking.
What are you hoping to accomplish? The one way clutch holds going forward in direct. The OD clutches take a beating arresting the engine speed during upshift.
The FSM gives a procedure of measuring to assure everything is stacked correct.

 

The overdrive direct clutch pack in the overdrive unit (the one I'm talking about her) is engaged all the time unless O/D is engaged. That's what that gi-normous spring is for. At that point the overdrive piston engages the overdrive break clutch and disengages the overdrive direct clutch. So every gear, 1st, 2nd, 3rd and R go through it whether or not your braking or accelerating. The 23 one-sided clutches give you up to 44% MORE holding area. No likey slip!

 

I took both of my overdrive units apart and checked the plates.
The one out of my old 518 is the 1st design with the .215" thick pressure plate and 8 lined and 7 steels. The total clutch stack height from the bottom of the backer plate to where the snap ring sits in the pressure plate is around 1.410"

The 47RH I have is strange, someone was in there recently, both OD clutches look like new, but the front section shows signs of problems. It has the .085" pressure plate with 9 lined and 8 steels (.085" thick ones, instead of .055" thick ones). The measured clutch height is the same as the other one, right around 1.410"

Hope that helps.

 

Thanks JD, I'll for sure check it out.

 

I called the local Transtar for the .085 thick pressure plate. I found it in there catalog as part# 12567c. They said they couldn't get it. Where do you think I can locate such and animal? Dealer?

 

Got any transmission shops close to you? They might have such an animal laying around on their spare parts shelves.