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Transmission Tuning - 68RFE model

154K views 375 replies 52 participants last post by  massmayhem 
#1 · (Edited)
Let this be the official 68RFE tuning thread


Admittedly I dont know a ton about tuning the 68RFE past shift points and some of the tricks for the convertor lockup... BUT I did confirm how to get 4th gear lock to act like it does in T/H mode:

(from the other thead)
I really like how when in the tow/haul mode, the convertor locks 100% immediately when going into 4th gear. so back months ago I copied over all the 4th gear convertor values from "T/H" to the regular maps. It worked, but the "locking" came after the shift. I wanted it like the t/h mode where it came DURING the shift. (PS - I started with stock trans values to learn with)

Finally got it the way I wanted when I noticed that the trans tuning on T/H mode actually commands 3rd gear lock just slightly before shifting. In other words you gotta mess with 3rd gear to achieve the 4th gear lock like I wanted.

Obvious to pro tuners... but I wanted to post this for newbs that may not have known.

Now It makes me want to revisit 3rd gear lock at WOT.
 
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#2 ·
It won't lock in 3rd or 4th under wot conditions.Been tried by many people something in there goes into don't hurt me mode and it won't lock till 5th.
 
#23 ·
We must be talking about different things... I just went out on the way to the grocery store and got 4th gear lock at full blown wide open throttle. I'll post video when I get back. It was at the end of 3rd the tc lock light lit up, and when I hit 4th it was lit as well.
 
#5 ·
AND WE HAVE ALL TRIED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Promise..

One thing I want to caution in here. There has been files floating around for some time on transmission tuning. You better understand exactly what it is that your changing before putting it in the truck. The transmission is no where near as durable as the engine. One wrong file and the drive around the block could toast your od's... I've seen it happy and more than once...

The trans is something that most if not all should leave alone IMO..
 
#8 ·
AND WE HAVE ALL TRIED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Promise..

One thing I want to caution in here. There has been files floating around for some time on transmission tuning. You better understand exactly what it is that your changing before putting it in the truck. The transmission is no where near as durable as the engine. One wrong file and the drive around the block could toast your od's... I've seen it happy and more than once...

The trans is something that most if not all should leave alone IMO..
This is a biggie!!!! Ive seen it, and done it myself. The biggest issue i see is usually there is no rhyme are reason of why it did what it did. I mean you can simply adjust something that you want to change and end up with something that changed that leaves you scratching your sack.:rof
 
#13 ·
With my revmax 850 and in tow haul when I mash on it from a stop it will lock up in third mid way just before 4th and quickly jump into 4th locked up.


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#14 ·
Hey Dave.. Still want my tcm lol... I think you forgot again.. No biggie I drive around it right now, just don't wanna hurt it

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#29 ·
This I can attest to as well. Now that I have a lockup vb. There's a big difference. Even with a stock truck it makes a huge difference...

That's WOT??? You need to turn the tune up some bud.

Also, the 4th gen's are easier to command than the 3rd gen's. But I'm not 100% sold on the stability of it. I've honestly given up on electronic lockup unless your referring to the switch I flip... Sometimes it just makes sense to use something mechanical.

I mean you have to have a vb in a built trans anyway. So spend an extra 6-700 and put a lockup vb in it instead of a regular one. Done deal. No messing around with it. When you flip the switch it locks the vb... Rig that up to whatever controller or switch you want and your done.. The cool thing is it doesn't care, if your in drive with your foot on the brake. It locks it. Truck dies, but its locked up...
 
#19 ·
Well I'm going by mini max gauge. When it shifts into third under full throttle just before you think it will shift into 4th it feels like it shifts another gear but it says it's locked up and jumps up in rpm. Kind I hard to explain. When I'm back in town I will take a video. It's for a split second just before it locks into 4th gear.


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#26 ·
Flat foot WOT from a dead stop and watch the RPMS. You will know when it locks...

And as a said, it will get worse as the power gets up there.

I ran 11.78 with Zero lockup and shifted into 6th 100' from the traps. talk about make a little heat.:rof
 
#37 ·
I'm sure you've seen it but here is the little button. It comes with the harness and control box.


Also for the ones that haven't seen a real 100% locked shift on the 68, take a look at the 2nd to last video in my photo bucket. Its nothing crazy but you can clearly see the diff upon shifting.
 
#44 · (Edited)
So first attempt making 3rd gear lock a WOT, failed. At as much as about 50% throttle I can get the lock to start at the end of 2nd, and going into 3rd you can really feel the load from the lock. It feels pretty quick.

To be honest even if 3rd did lock, I am not sure I would notice (at WOT). its in and out of 3rd so darn fast. It was neat though just poking around town though, it would lock immediately going into 3rd and then if you punched it - you were GONE.

I might keep it only on T/H mode in case some ford wants to play and we are already rolling.
 
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