2002 Grand Cherokee 4.7 TCM Ordered!
Record Breaker
Joined: Jun 2011
Posts: 2,387
Likes: 41
From: Bismarck, ND
This thread is interesting......
I like the idea of using planetary gears. They work very well in heavy equipment and agriculture applications, they are tough and it isn't as hard to add more ratios. That 45rfe has the potential for 6spd, not just five. Looking at the diagram for that new 8spd is pretty much the same except it is a dual clutch with 4 sets of planetary instead of 3. But both have 2 ratios per planetary.
I like the idea of using planetary gears. They work very well in heavy equipment and agriculture applications, they are tough and it isn't as hard to add more ratios. That 45rfe has the potential for 6spd, not just five. Looking at the diagram for that new 8spd is pretty much the same except it is a dual clutch with 4 sets of planetary instead of 3. But both have 2 ratios per planetary.
The 45RFE was introduced in the Jeep Grand Cherokee in 1999, it is notable for including 3 planetary gear sets rather than the two normally used in a 4-speed automatic. It also features 3 multiple disc input clutches, 3 multiple disc holding clutches, and a dual internal filter system (one primary filter for transmission sump, one for the fluid cooler return system). In the 45RFE applications four gears are utilized, with a different (1.50:1 rather than 1.67:1) second gear to increase versatility when downshifting. In 545RFE usage, an extra taller overdrive ratio is also used. Chrysler decided to refer to it as a "multi-speed automatic".
The 45RFE was produced at the Indiana Transmission plant in Kokomo, Indiana. It was normally paired with the 4.7 L PowerTech V8.
The 45RFE later became the 5-speed 545RFE.
The 45RFE was produced at the Indiana Transmission plant in Kokomo, Indiana. It was normally paired with the 4.7 L PowerTech V8.
The 45RFE later became the 5-speed 545RFE.
Veteran
Joined: Sep 2011
Posts: 351
Likes: 0
From: Gloucester, Mass
Ahhh,So it's completely equipped for this and it isn't going to wear out prematurely....I read earlier in the thread that there was a clutch difference.
You mentioned a changed from the 3.55 to 3.92
I'm eager to see what it all turns out like after you've run it for a while with the 3.92's....I have a lot of hills but it still may be a good thing for me.....
My trans was serviced before I got it a few weeks ago.I bet they didn't didn't check the cooler return,Where is this and is it serviceable?
You mentioned a changed from the 3.55 to 3.92
I'm eager to see what it all turns out like after you've run it for a while with the 3.92's....I have a lot of hills but it still may be a good thing for me.....
(one primary filter for transmission sump, one for the fluid cooler return system).
Last edited by laz45; Sep 29, 2011 at 09:45 PM.