68RFE Build

New guy here! This is my first post but I've been trolling the forums for quite a while now haha. 2017 2500 6.7 68RFE. I have questions about Revmax trans builds and why some of you decided to add specific parts (TC, valve body, flex plate, etc) and not just go with a "crate" 550, 700, 850 trans, other than the price. Are the crate transmission overkill? I drive my truck a couple times a week and pull my 11K lbs fifth wheel a couple times a month. Delete parts are on order (don't tell California) with plans on a compound turbo set up. I don't hot rod it around, will never pull a sled and have zero intentions of boosted launches. Just looking to make it a better tow vehicle without imploding my transmission. I appreciate the help in advance. Tons of knowledge on this board.

Andy

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Originally Posted by andytall23

New guy here! This is my first post but I've been trolling the forums for quite a while now haha. 2017 2500 6.7 68RFE. I have questions about Revmax trans builds and why some of you decided to add specific parts (TC, valve body, flex plate, etc) and not just go with a "crate" 550, 700, 850 trans, other than the price. Are the crate transmission overkill? I drive my truck a couple times a week and pull my 11K lbs fifth wheel a couple times a month. Delete parts are on order (don't tell California) with plans on a compound turbo set up. I don't hot rod it around, will never pull a sled and have zero intentions of boosted launches. Just looking to make it a better tow vehicle without imploding my transmission. I appreciate the help in advance. Tons of knowledge on this board.

Andy

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Crate transmissions aren’t over kill. The reality is they are expensive and not too coveinent unless you are local since they require a core charge/exchange

flex plate up grade is to prevent cracking when converter locks. Billet plate being one piece are far superior and not expensive relatively speaking. This is what connects the engine to the trans on the motor side when converter is locked.

valvebody- handles higher line pressure so there is less slipping between clutches. Any slipping is wasted energy/power. Stock vb with tuning can handle about 175psi max. Aftermarket are 220psi+

Torque converter- what connects trans to motor on trans side. Stock converter is a single disc. Think of a ceiling fan with just 1 blade spinning close to a loose sheet of paper. Over time/revolutions the paper will spin at a faster rate until it matches the fan (converter unlocked).

For higher hp applications triple disc converters are preferred. Using the same scenario but having 3 fan blades you will decrease the amount of time/revolutions of the fan to have The paper speed matched. In theory it would be 3x more efficient.

When a converter locks essentially the fan actually drops/engages the paper. This is the converter latching onto the flex plate. With the flex plate spinning rapidly a single disc/blade is much more prone to slipping/shuddering during lock up. With 3x the grabbing force there is less slipping so it’s more efficient. Triple disc lock ups will feel very firm relative to a single disc!

shafts are the other important things to upgrade. The input shaft is near the engine side of the transmission so if it fails it will take our other parts with it. Intermediate and output won’t do as much damage and don’t take as much abuse since they are further down the line

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Originally Posted by TexNeck

Crate transmissions aren’t over kill. The reality is they are expensive and not too coveinent unless you are local since they require a core charge/exchange

flex plate up grade is to prevent cracking when converter locks. Billet plate being one piece are far superior and not expensive relatively speaking. This is what connects the engine to the trans on the motor side when converter is locked.

valvebody- handles higher line pressure so there is less slipping between clutches. Any slipping is wasted energy/power. Stock vb with tuning can handle about 175psi max. Aftermarket are 220psi+

Torque converter- what connects trans to motor on trans side. Stock converter is a single disc. Think of a ceiling fan with just 1 blade spinning close to a loose sheet of paper. Over time/revolutions the paper will spin at a faster rate until it matches the fan (converter unlocked).

For higher hp applications triple disc converters are preferred. Using the same scenario but having 3 fan blades you will decrease the amount of time/revolutions of the fan to have The paper speed matched. In theory it would be 3x more efficient.

When a converter locks essentially the fan actually drops/engages the paper. This is the converter latching onto the flex plate. With the flex plate spinning rapidly a single disc/blade is much more prone to slipping/shuddering during lock up. With 3x the grabbing force there is less slipping so it’s more efficient. Triple disc lock ups will feel very firm relative to a single disc!

shafts are the other important things to upgrade. The input shaft is near the engine side of the transmission so if it fails it will take our other parts with it. Intermediate and output won’t do as much damage and don’t take as much abuse since they are further down the line

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not sure it can be answered much better than that.

Quote:

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Originally Posted by TexNeck

Crate transmissions aren’t over kill. The reality is they are expensive and not too coveinent unless you are local since they require a core charge/exchange

flex plate up grade is to prevent cracking when converter locks. Billet plate being one piece are far superior and not expensive relatively speaking. This is what connects the engine to the trans on the motor side when converter is locked.

valvebody- handles higher line pressure so there is less slipping between clutches. Any slipping is wasted energy/power. Stock vb with tuning can handle about 175psi max. Aftermarket are 220psi+

Torque converter- what connects trans to motor on trans side. Stock converter is a single disc. Think of a ceiling fan with just 1 blade spinning close to a loose sheet of paper. Over time/revolutions the paper will spin at a faster rate until it matches the fan (converter unlocked).

For higher hp applications triple disc converters are preferred. Using the same scenario but having 3 fan blades you will decrease the amount of time/revolutions of the fan to have The paper speed matched. In theory it would be 3x more efficient.

When a converter locks essentially the fan actually drops/engages the paper. This is the converter latching onto the flex plate. With the flex plate spinning rapidly a single disc/blade is much more prone to slipping/shuddering during lock up. With 3x the grabbing force there is less slipping so it’s more efficient. Triple disc lock ups will feel very firm relative to a single disc!

shafts are the other important things to upgrade. The input shaft is near the engine side of the transmission so if it fails it will take our other parts with it. Intermediate and output won’t do as much damage and don’t take as much abuse since they are further down the line

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Umm... Would you like a job? LOL! Fantastic response! Literally nothing else to say.

Awesome write up. Thanks for the help. The initial investment in a crate trans seems crazy expensive but perhaps worth the piece of mind as opposed to installing parts. Something for me to think about.

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Originally Posted by Dude's Diesel Performance

Umm... Would you like a job? LOL! Fantastic response! Literally nothing else to say.

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What ya got? :rolleyes:

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Originally Posted by andytall23

Awesome write up. Thanks for the help. The initial investment in a crate trans seems crazy expensive but perhaps worth the piece of mind as opposed to installing parts. Something for me to think about.

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Sure thing. The other nice thing is you can budget things out (buy one thing at a time) as opposed to one giant bill. Makes it a bit easier pull to swallow IMO. For most applications being heavy towing and a tune with stock fuel a valvebody and flex plate will hold up relatively well. Any more power you’ll want to do converter and shafts along with other internals. Keep us posted with your build!

I have two 1 ton trucks 07 and 012 both with 68RFE transmissions,, the oldest 07 I changed the transmission out at 328k to be clear the transmission had no problems. I only had the trans tune, deep pan, and aux cooling fan on that transmission.. I changed it because of the mileage only and the fact that I had bought a stage 4 at a good price and had it sitting in the garage.. BYI I tow 80% of the time with both trucks.. avg trailer weight 12k. I have towed 21k lbs with the 07 and 24k lbs with the 012 with NO Problems.

The second truck a 012 has only the trans tune and a Revmax valve body and have grossed over 32k gvwr with it.

I highly recommend the Trans Tune, valve body, converter, flex plate, billet input shaft, deep pan. If your not running high HP you'll get along fine with these add-ons.

The biggest problem with the 68RFE IF not launching/racing is the OD 5th and 6th gears just learn not to lug it at lower RPMS. Transmission builders like RevMax, ATS, Suncoast will say the same.

I also change all fluilds and filters every 30k-40k miles

Sound advice...and way cheaper than purchasing a crate trans although with the labor cost of tearing into a trans...it may be cheaper to buy a crate. We shall see after I ask around for some quotes in my area.