I helped my brother on his 2002 3500 2wd diesel 47RE overdrive. When he got into the overdrive clutch plates they were burned badly and there was about 1/4" gap between clutch pack and snapring. The manual he has shows a heavy plate on each side of clutch pack, one called a reactor plate and the other a pressure plate. His transmission only had one thick plate. He ordered all new clutch plates and 2 heavy plates, when all were installed the distance to the snapring was very little say .020". Truck works great now shifts into overdrive perfectly. Would not shift in to overdrive before replacing parts, also new seal on overdrive piston had a notch out of it so a new seal was installed on piston. Dealer where he got parts from said there should be a lot of clearance between snapring and clutch pack and only one thick steel plate should have been used. Anyone have experience on this?

 

What,, nobody ever rebuilt an automatic transmission? Any ideas would help.

 

Well I read your post and I'm not a trans "expert" by any means, but I have built my fair share of 904, 727, 46rh/re, 47re's, and my service manual confused me even more.....but here goes. From my experience the 47re does not utilize the "pressure plate" that you mentioned. The only "thick" plate on the OD clutch pack is the reaction plate at the bottom. The 46re, (used in the 5.2, 5.9 gas engine trucks) utilized two thick plates as you described. I'm thinking the manual you used may have been printed using that information just as my FACTORY manual is incorrect (pg 21-736, fig 125 for those watching). The 47re should have (from the bottom) reaction plate, clutch, plate, clutch, plate, clutch, plate, clutch, plate, clutch, plate, snap ring. I verified this as I have a complete 47re in my garage and the OD unit is assembled and ready to go. You have basically made your 47re OD to the 46re spec.

 

Is that a good thing or a bad thing? I guess my question is how much clearence between clutch pack and snap ring should there be?

 

there is no spec for that according to the good book. I've always just built them the same way they came apart as far as hard parts go. That or you measure the way it was stock and if you change anything keep it close to the original #'s. You basically eliminated one clutch plate and disc which decreases the surface area of holding capacity for that clutch so in retrospect in my opinion it's not a good thing.

 

all good info!
the round snapring is JUST a ring to hold it togather for assembly so it does NOTHING in oparation. the easyst way to check stackup in the od is to stand it with the clutchs up and the round ring LEFT OUT, put the OD piston with shim and bearing in place on the OD unit. now use drill bits to find out how much clearance you have between the OD piston and OD clutchs. I like to see .090 to .130.