Transmission Re-Learn

[AustinB]

Ok, I have the 8 speed transmission, and according to my vin lookup, 3:21 gear ratio. Prior to swapping out the factory wheels to 35's, I would usually be cruising at around 70-75mph in 8th gear (about 1.8k rpms). Now I'm rarely in 8th gear unless I'm going down hill. So at about 70mph I'm at roughly 2.2k rpms. Seems like my gas mileage is taking a toll as well.

My question is, because I know some tuners have a transmission re-learn feature... Would something like that help me? Would disconnecting the terminals and touching them together trick work? Am I just stuck with this forever?

 

[RLJ10X]

Austin, I am not aware of the Hemi Fever Tune having any such feature. The reason for that is because the Hemi Fever Tune works so well for me, that I've never given it any thought.

I do have one question, tho. You said you are now running 70 mph and your engine is turning 2200 rpm. Is that in 7 the gear? I would have thought with all those gears, even with 35 inch tires, that you would have had no problem getting the optimum gear/rpm/mph.

Those 35s look cool, but they aren't doing you any favors.

 

[AustinB]

Yes, 7th gear... I'm only in 8th now when going down hill (not flat)


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[Jerry1984]

Last I heard there isn't transmission tuning on the 8 speeds. The 35s will greatly hinder mpg especially if mud terrains. I stayed stock height with 33s and lost 3 mpg with my mud terrain tires. The tuner will be able to adjust tire size so your speedometer will be correct and you will also get a truer mpg.

 

[AustinB]

Ok ... But do the transmissions not have a "learn mode", that basically over time adjust to driving habits? Am I crazy to think this exist? I thought for sure this is something modern vehicles do....? Or am I way off?


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[sicmadek]

Reload the tune with adjusted tire height. Right now your speedo is off and thats your rpms are high. When your speedo says 70 youre prolly actually closer to 80. Use smartphone app to see how far you are off. 35s should only make your rpms go down at 70 cuz you are effecting the final gear ratio.

 

[AustinB]

I don't have a tune.. Was only wondering if that was an option in the tuners (hardware). According to my garmin, my mph actually isn't off at all. If it is, maybe 1 or 2 mph.


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[sicmadek]

I don't have a tune.. Was only wondering if that was an option in the tuners (hardware). According to my garmin, my mph actually isn't off at all. If it is, maybe 1 or 2 mph.


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Then disconnecting the battery for about 20 mins should reset the trans learning. You should actually be off by about 5 mph

 

[AustinB]

I will give that a try tonight and let yall know how it goes.


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[Hemi450hp]

A quick learn or resetting your computer is not going to do anything to fix what you are describing...Only fix for this is going back to shorter tires or upping the gear ratio in the truck.

You are turning a higher rpm because you are in 7th instead of 8th, but you are also going faster than what the speedometer says if you have not tuned it and corrected the speedometer for the larger tires.

 

[AustinB]

Well the damage is done lol.. Worse case, I have to reprogram my radio stations. I'm also sure it won't help but its a placebo operation. I'll tell you in about an hour!

 

[Hemi450hp]

Unplugging the battery isn't going to hurt anything at all, so no worries there. I tell people to unplug their battery everyday when they upgrade anything that affects airflow in or out of the motor.

It just wont have any affect on your truck not going into 8th gear or the speedometer being off from the larger tires.

 

[AustinB]

The results are in. They are as figured. Nothing. Is it weird that my radio stations stayed?


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[RLJ10X]

Austin, I learned a $2000 lesson when I bought my truck. Join a forum for a year, then buy a vehicle. I was burdened with those awful 3.55s, because I didn't know any better. Fortunately, Matt was able to help out by getting me into a set of 4.10s. Ive since bought (with cash) a Jeep Wrangler and a V6 Mustang. The Jeep and Mustang have the lowest factory gearing available, and I'm very pleased with both. And btw, the Jeep and Mustang, with factory gears, are still lower than the "unavailable" 4.10s that I now have in the truck. That is how STUPID tall these things Dodge trucks are geared. The only reason, I can figure is, that there are still a bunch of bone heads that think tall gears equal saving money at the pump. I have no problem getting better gas mileage than the mpg listed on the window sticker of all 3 of my "low geared" vehicles. And they're all much more fun to drive that their miserably tall geared counterparts. Sorry for getting so long winded. Tall gears drive me nuts.

Matt is right. With those tires, I'd look real hard at 4.56s, If that is even feasable in your truck.

 

[AustinB]

There's no way I would spend that kind of cash on regearing! Upwards of 4k to save 3-4 mpg just doesn't seem like it would pay off in the time I'd have the truck (probably for 4-5 more years). And to start dumping money on things like that, I may as well just trade it in for the cummins. So far I'm only losing about 1-2 mpg. That's not bad at all! It's just me being picky. Also, even with the 35s and 3.21 gears... The truck has GREAT acceleration! 6" lift is awaiting arrival and that won't make it any better lol. Hope you're enjoying your ford slowstang.


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[AustinB]

What do you guys know about the hypertech speedometer recalibration tool? It was recommended by a member, and I was reading their website, came across this paragraph.....

Speedometer Calibrator

If you’ve installed tires that are larger or smaller than original equipment tires, or if you have installed a ring and pinion gear set with a different rear gear ratio, the Speedometer Calibrator allows you to re-program for correct speedometer and odometer readings, as well as correct part-throttle shifting. The vehicle’s computer calculates your vehicle’s speed based on the diameter of the stock tires. If you’ve installed taller or shorter tires, or changed the rear gear ratio, the vehicle’s computer doesn’t know how fast your vehicle is going. As a result, the automatic transmission may not shift correctly and the speedometer readings will not be accurate (as required by law).



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[cableguy_hd]

Not sure what it costs but if you looking at buying anything to recalibrate just buy a tuner. You will benefit for from it that just getting a recalibration tool.... Just my .02

 

[AustinB]

Little over $200, I know that's high... But was more interested in knowing how true it is that the vehicle determines the gear by what it thinks the speed is, rather than load.


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[Jerry1984]

A tuner will be a grand for your 15 as you have to buy a spare PCM or have yours unlocked. If the speedo being off is that big of a deal the hypertech calibrator may be your best bet. I'd just leave it as is and not worry too much about it. Agree that regearing would not be cost effective. Probably have to learn to be okay with it staying in 7th.

 

[cableguy_hd]

Oops didn't see he had a 15