Originally Posted by burla
The rfe's can be upgraded to be near bullet proof, but it aint cheap, first valve body springs, pistons, solonoid, plate, couple small things, then you will need a tune for line pressure, and then you look at the transmision upgraded. Then you get to easy stuff like drain pan and metal thread upgrade to accept synthetic filtration.
Couple great video's...
rfe trans upgrades
rfe valve body
The issue with the 8 speed, they are known as disposable tranny's, $4500 to replace the entire thing. Not easily servicable, over 1200 to get a fluid flush, and you cant even check the fluid level w/o a part one and two dyi video process. Sean's evo diesel Chabbel has a decent flush procedure, but it is nothing like the rfe's. Here's the difference, rfe's are very prone to problems but can easily be upgraded and improved. The 8 speeds are more reliable out of the gate but not very buildable, certainly nothing like the rfe's. Plus I don't like the entire mechanically heated fluid thing personally, there are a decent percent of these tranny's that simply operate over 225f. Something very very rare with the rfe. It is a mixed bag, maybe the edge going to the 8 speed because they really do get better mileage, no joke. To much bogging in the rfe's if you don't tune out the shift points. Rams got mileage upgrade from 545rfe to 68rfe, and then again with the zf8, it's no joke well over 5 real world mpg's. Maybe they will be easily buildable in the future.
There is already people building and upgrading the ZF 8 speeds. My friend was one of the first people to supercharged his 8 speed Durango R/T... first tuner fried the transmission with poor tuning. he now has a built 8 hp70 pushing ~500hp to the wheels with good tuning. Stock they put about 250 to the wheels.
The 68RFE was never used in place of the 545RFE... the 68RFE is for Cummins powered Ram trucks. Unless you mean the 65RFE, which other than an improved torque converter and slightly different software, is identical to the 545RFE. Same shift patterns, same gear ratios, just the 65RFE lets you use all 6 gears when using range select instead of 5.
The rfe's can be upgraded to be near bullet proof, but it aint cheap, first valve body springs, pistons, solonoid, plate, couple small things, then you will need a tune for line pressure, and then you look at the transmision upgraded. Then you get to easy stuff like drain pan and metal thread upgrade to accept synthetic filtration.
Couple great video's...
rfe trans upgrades
rfe valve body
The issue with the 8 speed, they are known as disposable tranny's, $4500 to replace the entire thing. Not easily servicable, over 1200 to get a fluid flush, and you cant even check the fluid level w/o a part one and two dyi video process. Sean's evo diesel Chabbel has a decent flush procedure, but it is nothing like the rfe's. Here's the difference, rfe's are very prone to problems but can easily be upgraded and improved. The 8 speeds are more reliable out of the gate but not very buildable, certainly nothing like the rfe's. Plus I don't like the entire mechanically heated fluid thing personally, there are a decent percent of these tranny's that simply operate over 225f. Something very very rare with the rfe. It is a mixed bag, maybe the edge going to the 8 speed because they really do get better mileage, no joke. To much bogging in the rfe's if you don't tune out the shift points. Rams got mileage upgrade from 545rfe to 68rfe, and then again with the zf8, it's no joke well over 5 real world mpg's. Maybe they will be easily buildable in the future.
There is already people building and upgrading the ZF 8 speeds. My friend was one of the first people to supercharged his 8 speed Durango R/T... first tuner fried the transmission with poor tuning. he now has a built 8 hp70 pushing ~500hp to the wheels with good tuning. Stock they put about 250 to the wheels.
The 68RFE was never used in place of the 545RFE... the 68RFE is for Cummins powered Ram trucks. Unless you mean the 65RFE, which other than an improved torque converter and slightly different software, is identical to the 545RFE. Same shift patterns, same gear ratios, just the 65RFE lets you use all 6 gears when using range select instead of 5.
