Sonnax Line Pressure Booster for 545rfe and 66rfe

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thedriver21
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Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by thedriver21 » Tue Jun 23, 2020 12:52 am

Hey guys, so I was looking around for 66rfe upgrades and was coming up mostly empty until I ran across the Sonnax RFE-LB1 line pressure booster. It’s basically a fooler that tells the computer to give more line pressure. Apparently a shift kit does not really work on the RFE trans and I haven’t gotten custom tuning done yet. So for $80 I figured why not. Install was easy and took about 5 min. All I had to do was bend back the heat shield around the plug, disconnect the old plug, add the fooler in between, and then reconnect. I also disconnected the battery so the trans could do a re-learn. I wasn’t expecting much after install and driving around town i didn’t notice a difference at first. But as a got progressively more aggressive with the throttle I noticed the delay between shifts was shortened and temps were about 5-10 degrees cooler. I only noticed firmer shifts near full throttle but from about 40% throttle and up the shifts become quicker in normal and tow haul mode. For $80 and 5 min I was impressed. Although be warned, in the kit they also include a spring for the trans pump. Apparently with higher mileage trucks it can cause a CEL to appear from over pressure on the sensor. The only fix is to either drop the trans and install the spring, remove the line pressure booster, or do custom trans tuning. Also, this is not to be used for those with trans tuning already done.
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by PWJouster » Tue Jun 23, 2020 3:31 pm

The quality of the Valve body is our real issue...
low pressure shifts would be ok if the directed pressure didnt divert beyond the proper channels.

i wonder if the higher pressures make the compromised valve body deteriorate further. If it wasnt for that spring, i was also going to do that upgrade.

now ill just have my trans built billet strong once it fully craps out.
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by thedriver21 » Fri Jun 26, 2020 11:51 am

Ya it seems like the softer metal of the valve body can cause some issues later on in the trans life. From what I could find, the only issues I may run into are the accumulator piston, some of the check balls wearing out, and maybe the pressure regulator valve wearing. It seems like these happen on OE chrysler six speeds regardless of mods done, but it brings to question if the booster will expedite this. My 2013 was running quite a few bolt ons with the 66RFE and a trans tune for the last 50k of the total 100k miles it had on it before the truck was assassinated by a corolla blowing a red light. I luckily never had problems with it like I had with my 47re and 48re in my 97 and 04.
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by Colibri » Mon Jun 29, 2020 12:56 am

You can get a billet lower valve body that’s supposed to help with pressure bleeding issues and will tighten up shifts
Central Texas and Houston area
2009 5.7 auto quadcab
Carli 3” coils deaver leafs 3” kings with 4 tube bypass rear and fr/rr hydro bumps
Howe steering pump and gear with hydraulic ram assist
Custom tube bumpers and white knuckle sliders
Creative fab trussed axle. rem polished and cryoed 5.13 gears with arb lockers fr/rr
Sharadon stage 2 545rfe with 3000 stall edge converter
Lots of other stuff lol

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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by PWJouster » Mon Jun 29, 2020 9:30 am

my plan is to build out the entire trans with billet and tune once it finally gives up. It can take power, its just tuned like trash and QC like trash.

im currently experiencing TC lockup issues where it wont lock up from parked into D or R. Takes alot of revs to get moving when cold.

already had valve body replaced and cooling system rebuilt due to prior failure. But at nearly 35k miles, its still under warranty.
2018 Powerwagon-6.4 Hemi
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On-Board air ARB CKMTA12
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by thedriver21 » Tue Jun 30, 2020 5:38 am

I wonder if the 66 and 68 rfe valvebodys are the same. Can’t really fine custom 66 valve body’s but 68 and 545 ones are all over the place
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by PWJouster » Tue Jun 30, 2020 7:47 am

one of the big dogs in trans jobs was slangin billet bodys and beefness for the lump sum of way too much dough but yo, i need it at $6k EASY.
2018 Powerwagon-6.4 Hemi
Nanny kill switch and Locker Bypasses
Thuren Tuned King 3.0 & 2.5 Pintop Stage 3/2
17 Method NV-Toyo RT 37
Evo On-Demand Air Swaybar Disconnect
S&B Intake-Mufflex-Magnaflow/resonator delete
SPOD Bantam
On-Board air ARB CKMTA12
Baja design and Rigid Industries
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by PWJouster » Tue Jun 30, 2020 9:59 am

ordered the Sonnax kit anyways. will report back.
2018 Powerwagon-6.4 Hemi
Nanny kill switch and Locker Bypasses
Thuren Tuned King 3.0 & 2.5 Pintop Stage 3/2
17 Method NV-Toyo RT 37
Evo On-Demand Air Swaybar Disconnect
S&B Intake-Mufflex-Magnaflow/resonator delete
SPOD Bantam
On-Board air ARB CKMTA12
Baja design and Rigid Industries
Purple Cranium Spider dif guards
Pedal Commander

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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by EasyDoesIt » Tue Jun 30, 2020 9:47 pm

Looking forward to more feedback on this!
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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by Colibri » Thu Jul 02, 2020 2:01 am

thedriver21 wrote:
Tue Jun 30, 2020 5:38 am
I wonder if the 66 and 68 rfe valvebodys are the same. Can’t really fine custom 66 valve body’s but 68 and 545 ones are all over the place
Rodeoflyer had his transmission rebuilt with one of these, may want to ask him about it

https://www.dnjcomponents.com/products/d-cf2
Central Texas and Houston area
2009 5.7 auto quadcab
Carli 3” coils deaver leafs 3” kings with 4 tube bypass rear and fr/rr hydro bumps
Howe steering pump and gear with hydraulic ram assist
Custom tube bumpers and white knuckle sliders
Creative fab trussed axle. rem polished and cryoed 5.13 gears with arb lockers fr/rr
Sharadon stage 2 545rfe with 3000 stall edge converter
Lots of other stuff lol

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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by Bigdodge » Mon Jul 06, 2020 6:34 pm

thedriver21 wrote:I wonder if the 66 and 68 rfe valvebodys are the same. Can’t really fine custom 66 valve body’s but 68 and 545 ones are all over the place
They are not the same

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Re: Sonnax Line Pressure Booster for 545rfe and 66rfe

Post by PWJouster » Tue Jul 07, 2020 8:27 am

Holy Crap.

i think my shifts were so "off" that i can immediately tell that the shifts have less hesitation, hang time, and no lurching.

cant promise that it wont grenade the trans eventually...but it does what it says it will do. And it did so for me nearly immediately?!

Its more noticeable when the truck is shifting up or down with a heavier throttle modulation and higher rpms. Almost like it has Tow/Haul mode shift pressure but not the engine breaking high revving nature of it.

Why do we know of only 1 or 2 people who have built up a 66rfe...
2018 Powerwagon-6.4 Hemi
Nanny kill switch and Locker Bypasses
Thuren Tuned King 3.0 & 2.5 Pintop Stage 3/2
17 Method NV-Toyo RT 37
Evo On-Demand Air Swaybar Disconnect
S&B Intake-Mufflex-Magnaflow/resonator delete
SPOD Bantam
On-Board air ARB CKMTA12
Baja design and Rigid Industries
Purple Cranium Spider dif guards
Pedal Commander

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