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68rfe question

3K views 11 replies 7 participants last post by  SAP2018 
#1 ·
I have a 2018 2500 with a 68rfe.

This truck is completely stock and I will not be deleting.

The only thing I don't care for is the shift points and engagement of the trans.

What are my options for better transmission performance while retaining the
factory emissions?

Any and all input is appreciated.

Thanks in advance.
 
#3 ·
TCM relearn. The correct way is by monitoring pedal input up to 15% if I recall while hitting certain shift points. Then doing a quick learn.

Many companies can get you a non-delete tune with enhanced shift points. Call RGRacing out of Farmington, NM to see what they recommend.

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#4 ·
I have a 2018 2500 with a 68rfe.

This truck is completely stock and I will not be deleting.

The only thing I don't care for is the shift points and engagement of the trans.

What are my options for better transmission performance while retaining the
factory emissions?

Any and all input is appreciated.

Thanks in advance.
I have a new to me18 3500 with 10K on it in the shop right now. I took it in for a check engine light which the service writer said was a preheat code. I asked them to see what they could do with the shift(downshift) points before I start towing with it. Today I tried to check it out some on the way through several known speed traps. It didn't matter if it was in drive or tow haul mode the truck would drop all the way to 1000 rpm at 35 mph without downshifting.(3.42 gears). This would cause a vibration and noise if the truck was in the slightest load like slight uphill climb or if I gently accelerated.
I have had it a week and have been running it in tow haul in town which seems to help until I get down around 40. I have also manually shifted it to keep the rpm up around 1500. My experience with CTD automatics is with 95, 98 and 2006 which all needed manual shifting at times but I thought this one would be much better. In fact a friend's 2007.5 6.7 RFE downshifts much better.
This was the dealership's delivery truck so it hasn't towed anything heavy. Maybe it does just need educating. I will let you know what if anything I or especially the truck "learns" at the dealer. I plan to have the hitch installed and be on a good road test pulling 15K+ Friday.
 
#6 ·
No. I don't like the fact it will drop to 1000 rpm in a gear without downshifting to eliminate the "lugging" of the engine, the noise, the vibration and the possible damage to the transmission. I got 185K out of the OE tranny in my 98 and so far 141K out of the DTT upgrade by keeping rpm above 1600 when towing. I will shift this one manually too if I have to do that, but it sure seems like the computer should do part of the work at least in Tow/Haul mode.
 
#8 ·
I have but not on my trip to the dealer. Usually I have run it on 2 lane country roads where I am running 45 to 60+ mph.
 
#9 ·
The transmission tune you get from Calibrated Power is great. 10x better than stock. They only offer emissions compliant tuning. Don't know if they will sell just a trans tune without some sort of engine tune though.


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#10 ·
I will investigate that. Thanks Trowel.

As long as the emissions compliant tuning is reason and corrects the shift points and firmness of
upshift and down shifts I would be good with that.

Although I do not have emissions testing where I live I don't want to strip. Been their done that enough.
 
#11 ·
We got the 2018 back yesterday afternoon after replacement of the intake air heater. Never got a code out of the SA or any paperwork. The salesman handled everything well for us though. The only thing I noticed different was the voltage display. Every time I watched it before the heater replacement the display was rock solid 14 V. Now it is constantly jumping between 13 & 14 V. I guess I will check it with my meter when it warms up outside.
SA said the tech told her the transmission performed normally for him and he is their tranny guy. Coming back in traffic the truck went to 35 mph and 1000 rpm in both drive and TH with and without EB. I decided to try adding throttle in TH mode a little more aggressively and the truck did downshift and rev to about 1250 rpm pretty smoothly. Several more times after getting off the interstate the truck in TH mode did keep the rpms up at 35 mph in the 1250 rpm range and was smooth and quiet. I hope I can keep it working that way.
I look forward to seeing how it performs with the fiver later this weekend. I am going to attempt to put on a set of wheel to wheel iBoards on the cold concrete first.
 
#12 ·
You need transmission tuning my friend. Nothing will it from shifting into 6th as quickly as possible in stock form. It’s how the factory tune works.

You can get emissions intact tuning (I run CTT) and it will be a different truck shifting wise. Mines shifts into 4th at 35mph not 6th.

On top of it all, YOU can tell the tuner where you want your shift points.
 
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