Trans line pressure boosters.....

[Michigan BIGHORN]

Anyone have any experience with Sonnax RFE-LB1 New Line Pressure Booster 10-25 PSI Rise 45RFE 545RFE (99696)*? I've just ordered one for $52 on eBay because my trans seems to be confused at times if it wants to be in 4th or 5th gear.

 

[TheEnder]

Anyone have any experience with Sonnax RFE-LB1 New Line Pressure Booster 10-25 PSI Rise 45RFE 545RFE (99696)*? I've just ordered one for $52 on eBay because my trans seems to be confused at times if it wants to be in 4th or 5th gear.

Yes, and i wouldn’t recommend them.

With the RFE series transmissions, they’re fully electronic, and what this means with a pressure booster is that over time they’re gonna learn to shift with the lower pressure, which essentially nulls the use of it in general. More technical explanation below:

Let’s say your trans makes the shift from 4th gear to 5th gear at 120PSI normally. Now, you have that line pressure booster giving the PCM a lower reading than what it is actually, which is lets say 100PSI, when it should be reading at 120PSI.

The PCM over an extended period of time will learn this, and make it to where there will be absolutely 0 difference from how the trans was shifting normally without the pressure booster, therefore nulling its use in general. This is if the increased line pressure doesn’t make the RFEs very crappy valve body fall apart. I don’t think 10-25 PSI will, but there’s always a risk. I recommend at minimum a new enhanced billet VB.

Your issue could be caused from a warped VB. What temps do you normally run?


Sent from iPhone 10S Max

 

[Burla]

Drive on tow haul and let us know if issue is still there. Likely your valve body is leaking.

If your vb is leaking, it would be better to at least put a shift kit gasket on it before increasing pressures. and if you go that far, then look at piston rings.

 

[Michigan BIGHORN]

Yes, and i wouldn’t recommend them.

With the RFE series transmissions, they’re fully electronic, and what this means with a pressure booster is that over time they’re gonna learn to shift with the lower pressure, which essentially nulls the use of it in general. More technical explanation below:

Let’s say your trans makes the shift from 4th gear to 5th gear at 120PSI normally. Now, you have that line pressure booster giving the PCM a lower reading than what it is actually, which is lets say 100PSI, when it should be reading at 120PSI.

The PCM over an extended period of time will learn this, and make it to where there will be absolutely 0 difference from how the trans was shifting normally without the pressure booster, therefore nulling its use in general. This is if the increased line pressure doesn’t make the RFEs very crappy valve body fall apart. I don’t think 10-25 PSI will, but there’s always a risk. I recommend at minimum a new enhanced billet VB.

Your issue could be caused from a warped VB. What temps do you normally run?


Sent from iPhone 10S Max

I don't tow or haul anything. Temps when I check them are in the 160 range. Fluid looks ok with no serious burnt smell but I did buy the truck with 113k miles on it so I don't know the prior history. I have a filter kit and Mopar ATF+4 fluid for a service this coming week. I am thinking about going back to a stock tune/shift points too to see if that makes a difference. Currently I'm running a SuperTuner F5 with a mild 87octane performance tune with the F5's shift points and maybe that is why? It only seems to get confused when I'm easy on the throttle.

 

[TheEnder]

I don't tow or haul anything. Temps when I check them are in the 160 range. Fluid looks ok with no serious burnt smell but I did buy the truck with 113k miles on it so I don't know the prior history. I have a filter kit and Mopar ATF+4 fluid for a service this coming week. I am thinking about going back to a stock tune/shift points too to see if that makes a difference. Currently I'm running a SuperTuner F5 with a mild 87octane performance tune with the F5's shift points and maybe that is why? It only seems to get confused when I'm easy on the throttle.

Maybe..maybe not. Let us know. Any codes?


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[Michigan BIGHORN]

Maybe..maybe not. Let us know. Any codes?


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No codes at all

 

[Burla]

You might want this..



Look for the ones with the hex threads on the inside, they fit tighter. If you are going to do it let me know, I will look it up later. Also, if you are dropping the pan, I'd really consider the VB upgrades, at least the gasket and pistons, fairly cheap and easy to do. Again, if you are going to do it let me know I will look it up for ya later. Anything for a guy from the U P.

 

[Burla]

Again, drive in tow haul and let us know if it changes,

 

[TheEnder]

You might want this..



Look for the ones with the hex threads on the inside, they fit tighter. If you are going to do it let me know, I will look it up later. Also, if you are dropping the pan, I'd really consider the VB upgrades, at least the gasket and pistons, fairly cheap and easy to do. Again, if you are going to do it let me know I will look it up for ya later. Anything for a guy from the U P.

I’m gonna buy one of those, but this is a majorly off topic question i have to ask. The fully rebuilt with all work done to make it as (if not more) reliable than a stock 8 speed 65RFE i bought only weighs 100 pounds? That’s according to UPS, but i was expecting 200+. If it’s anywhere NEAR 100 pounds it’s gonna be a breeze to install..


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[Burla]

no way on the 100 pounds.

Which is more reliable? I really don't know, but I can say I really dislike the serviceability factor on the 8 speed. Even if you pay someone to service it, they can get the level wrong, and you would never know until it takes a dump.

 

[Burla]

Kyle bought a lot, seams like Ender is the rfe man these days, you can buy this lot and get 15 bucks a piece from forum members, maybe 5 bucks for shipping. This one is the top quality ones. I know had to turn people away these are so popular.

 

[TheEnder]

no way on the 100 pounds.

Which is more reliable? I really don't know, but I can say I really dislike the serviceability factor on the 8 speed. Even if you pay someone to service it, they can get the level wrong, and you would never know until it takes a dump.

That’s what happened to my brothers 8 speed on his charger. Slight underfill made it crap itself under WOT, destroyed the trans. It could just be UPS, it’s a perfect 100.00, so that’s why i think it’s over 100LB. It’s also being shipped via freight so who knows.....


Sent from iPhone 10S Max

 

[Burla]

Google say the rfe is 263 pounds, sounds much more likely then 100.

 

[TheEnder]

Kyle bought a lot, seams like Ender is the rfe man these days, you can buy this lot and get 15 bucks a piece from forum members, maybe 5 bucks for shipping. This one is the top quality ones. I know had to turn people away these are so popular.

i like to think of myself as the RFE guy, i mean, i’ve done so much (forced.) research on them *****


Sent from iPhone 10S Max

 

[TheEnder]

Google say the rfe is 263 pounds, sounds much more likely then 100.

MUCH more likely..


Sent from iPhone 10S Max

 

[Burla]

If you buy that lot, you only have to sell 4 and the rest is gravy. 20 bucks shipped to someone's door is a more then fair price for that specific bolt. Kyle sold out in like days, and then he was turning people away. Every single rfe needs those metal threads.

 

[Flryder]

What filter do you use when you put that metal filter adapter on?

 

[TheEnder]

What filter do you use when you put that metal filter adapter on?

You can use any filter. They all have a spin on top.


Sent from iPhone 10S Max

 

[Flryder]

So basically any oil filter?

 

[Killface3]

I bought a heavy duty rebuilt valve body for the 65RFE in my 12' this summer when I put a high lift camshaft in the engine and deleted the mds. The valve body I bought has all the fixes and upgrades for known issues, like overdrive clutch failure, piston scuffing, and cross leaks. It was pretty expensive. Even after the seller accepted an offer but, after adding engine power, the trans became the weak link . comparing the valve body I removed to the central valve bodies one I put in it put my wallet at ease because the differences are obvious. Its built to be tuned with high line pressure and my truck makes solid shifts now. It launches from 1st to 2nd and 2nd to 3rd when flooring it.