Big Blue24
Comp Diesel Sponsor
- Joined
- Jan 5, 2008
- Messages
- 6,310
Wanted to post a few pictures of some of the clutch pack upgrades that I recently performed on my 47re transmission. The most noticeable gains driving around with upgraded clutch packs are crisp-firm 2-3 shift and 3rd-overdrive shift.
Starting in the overdrive section of the transmission, there are two clutch packs: Overdrive/Direct clutch pack and the Overdrive/Brake clutch pack.
Overdrive/Direct
- Stock 47re clutch count is (10) double sided clutches for a total of (20) friction surfaces.
- This pack is engaged in gears 1, 2, 3, and Reverse. When the tranny shifts to overdrive, it releases this clutch pack.
- This pack is engaged with a large 820# spring, there is a sprag/overrunning clutch behind this clutch pack that prevents it from slipping in forward gears so failure in this pack will result in the loss of reverse and extreme wear and premature failure of the one-way overrunning clutch. In short this clutch pack is probably not that important to upgrade, but it's easy so I did it.
This is the clutch pack and the drums it engages. I built my own compressing tool to compress the heavy spring located under the center splined drum.
I decided to install a stock 48re clutch pack which includes (23) single sided friction/steel combo pieces or (23) total friction surfaces.
Picture of backside of same friction/steel combo piece
After installing the last steel/friction combo piece, you are left with a steel side facing up and the heavy steel reaction plate so common sense tells us this is one more place to add a two sided friction commonly found in a 47re.
Before double sided friction:
Double sided friction:
And after installing it, it looks like this:
That makes a grand total of (25) friction surfaces or a 25% increase in clutch capacity.
Now just compress the clutch pack and install the retaining snap rings and move on to the next clutch pack upgrades.
Starting in the overdrive section of the transmission, there are two clutch packs: Overdrive/Direct clutch pack and the Overdrive/Brake clutch pack.
Overdrive/Direct
- Stock 47re clutch count is (10) double sided clutches for a total of (20) friction surfaces.
- This pack is engaged in gears 1, 2, 3, and Reverse. When the tranny shifts to overdrive, it releases this clutch pack.
- This pack is engaged with a large 820# spring, there is a sprag/overrunning clutch behind this clutch pack that prevents it from slipping in forward gears so failure in this pack will result in the loss of reverse and extreme wear and premature failure of the one-way overrunning clutch. In short this clutch pack is probably not that important to upgrade, but it's easy so I did it.
This is the clutch pack and the drums it engages. I built my own compressing tool to compress the heavy spring located under the center splined drum.
I decided to install a stock 48re clutch pack which includes (23) single sided friction/steel combo pieces or (23) total friction surfaces.
Picture of backside of same friction/steel combo piece
After installing the last steel/friction combo piece, you are left with a steel side facing up and the heavy steel reaction plate so common sense tells us this is one more place to add a two sided friction commonly found in a 47re.
Before double sided friction:
Double sided friction:
And after installing it, it looks like this:
That makes a grand total of (25) friction surfaces or a 25% increase in clutch capacity.
Now just compress the clutch pack and install the retaining snap rings and move on to the next clutch pack upgrades.
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