Hey guys, so I just received my tow tune from Mike and have been driving around for some miles now. Hooked my trailer up and the tune is amazing for towing my trailer. However, I have a weird issue, not sure if its the tune or my tranny.

1-2shift are real firm and always rev up to minimum of 2500rpm no matter what grade/load etc. When it goes into third gear it almost feels like its going into 3rd for a split second and then going right into 4th gear. The truck feels gutless unless I am below 40mph or WOT, then it stays in 3rd. I am only towing a 8x10' steel trailer with a Polaris Ranger on it. Just seems like the V10 should have way more towing power past 40mph. It definitely does if I start out WOT and just stay on it. It will hit 65 fairly easy.

I have tried manually shifting from 1-2-D and it works fine.
I have tried WOT and it shifts and stays in third if I am in OD or out of OD
It seems the only time it does this is when I am maybe 10%-40% throttle. The truck goes from 2500-3500rpm depending on the grade/load etc in 2nd gear until I hit 40mph and then drops all the way down to like 1200-1500rpm. If I push the pedal 3/4 the way to the floor it just slowly tries to get up to speed but doesn't have any ***** like its in the wrong gear. If I lift and then stand on the pedal it will downshift and be around 3k rpm and start to finally move.

It's driving me nuts and I want to make sure I get my truck fixed before the up coming camping season.


Anyone ever have this same issue or have any idea what's going on?

I just had my truck in the shop about a week ago to get the tranny flushed and they put in new fluid and filter. They said there was no metal in the pan or fluid.

The other interesting thing is the tranny when shifting from 1st to 2nd gear at WOT makes like a liquid squishing sound fairly loud. Kind of like a blow off valve without the whistle sound. Compressed air and fluid is the best way I can explain it.

No OD light flashing and no codes stored.

Hopefully my explanation is enough for someone here to assist.

Contacted local tranny shop and the guy said it could be a bad Throttle Position Sensor which will make it so the Torque converter doesn't lockup correctly. Otherwise if fluid is still good and no metal he thinks its something with the valve body.

 

I don't know if its fixed 100%, but Mike made some adjustments to my tune and wow, what a difference. Downshift adjustment made the biggest difference for sure. It now stays in the gear I want until I hit about 65mph. Also Over drive never comes on until after 64mph. Which made a huge difference. I am just under geared with 3.73's for OD to come on earlier.

Thanks Mike!

 

It's the tune. It is either upshifting too soon, or more likely, the torque converter is locking right after the shift, which is causing too large of an RPM drop.

 

Thanks. I agree, it is more than likely the torque converter issue. We made a pretty drastic change to keep 3rd and 4th gear in a lot longer before OD came on and the problem went away.

After that he changed the mph down a few miles from where it was and it seemed to resolve the issue along with keeping the truck driveable. Also changing the downshift to around 55-58 mph and that seemed to be the biggest difference, I no longer was down to 1700-1800rpm when i had to slow down to traffic and try and get up a hill, it is now around 2000rpm or so and I am able to pull up the grades.

Thanks for the feedback Mark!

After watching my datalog... Before I was hitting around 47 mph and then it would shift and immediately drop to 1300 rpm. This was causing me to pretty much floor it to get it back into the power band. More of an FYI.

 

That sentence doesn't make any sense. You kept it in fourth gear longer before it shifter to fourth gear?!?!? Overdrive *IS* fourth gear. It isn't something that comes on after fourth gear. Maybe you mean lockup instead of OD. Then it makes sense.

 

Not exactly sure what he changed.... but basically made it so I was in third gear all the way until 70 mph and then would shift into fourth gear. I also believe he turned off the OD feature completely at lower mph so my truck wouldn't go from say 30 mph and then hit OD. I wanted him to do that because I don't tend to have my foot all the way in the throttle at lower mph and OD would always come on and it's irritating to me because I have no power when towing.

Sorry, hard to explain in writing. I was basically wanting him to turn off OD completely until a certain MPH and just adjust the shift points based off mph as well. This way I knew what his tune was doing with the shift points so I could diagnose if something odd was happening with my tranny, or if it was in fact just following what he tuned for shift points. We found out after he disabled OD and manually set the shift points the tranny was doing exactly how his tune was set up.

From there I knew my tranny was ok and I just needed him to adjust the tune for my driving style.

That was a long winded post, but hopefully that makes more sense.

 

No, not really. It sounds like you think overdrive and fourth gear are two separate things. They are not. Overdrive IS fourth gear. It is impossible to shift to fourth gear and then have overdrive come on. That cannot happen.

Where you are saying overdrive I think you mean torque converter lockup.

 

Best way I can describe what it was doing...

30 mph normally equals 2nd gear, it would then switch to OD "4th gear" and dog during light acceleration. I then had to either stomp on the gas or lift and press 3/4 way down on the throttle to get it out of OD "4th gear" down to 3rd or 2nd gear to get power again.

I don't know how else to describe it.

I understand OD and 4th are the same. Im trying to say it was basically coming into the mix WAY too early. IE: I shouldn't be in 4th gear going 30mph.

Hopefully that makes sense.

 

Mark, I just went back to normal tune. 30mph cruising I am at 1500rpm, 45mph, again 1500rpm. It just seems like I am shifting too soon for my gears is the best way to describe it. Especially trying to pull a trailer at only 1500rpm down the road. 65mph, im at maybe 1800rpm. Good for steady cruising I guess if you never need to get on the throttle to go faster... Im used to a manual truck where I would spin 2500rpm before shifting all the time, so the truck just feels gutless when im at 1500rpm and lightly try to accelerate.

I know I could swap gears to 4.30 and it would help a bunch, but I also know changing the shift points could accomplish the same thing without spending a ton more money.

 

The only way to change when it shifts is with a custom program.

 

with 3.73 gears OD is almost completely worthless when towing.


just lock it out and you'll be much happier. That will bring your RPMs up over 2k at any reasonable highway speed. The v10 just doesn't make enough power below 2000 RPM to pull anything sizeable.


if it is dead flat, no wind, and you have a light foot, you can pull in 4th, but other than that, just lock it out and be done with it. the motor is much happier above 2,000 RPM.


JMO ... that's what we do.

 

Thanks.

Yeah I had Mike adjust my shift points really aggresive so I spin higher rpms and its insane how much HP/TQ the truck seems like it makes now. Feels like a different truck.

60mph in 3rd gear @ 2400rpm
65mph in 3rd gear @ 2600rpm
70mph I shift into fourth and @ 2000 rpm.

The only downside is @ 45mph I am spinning 3000 rpm, so going down the city streets to get to the highway the truck is spun pretty high, but once it gets on the highway it tames down a little but still allows me to be in my power band.

I had Mike change my shift points again and its not as aggressive. I just haven't had time to datalog it yet.

Perfect would be if I could get the following.

60 mph in 3rd gear @ 2000 rpm
65 mph in 3rd gear @ 2200-2300 rpm
68-70mph shift into 4th @ 2000 rpm

Like I said its real close and he did adjust my shift points again, so I need to drive it and datalog. I can tell you the shift points woke the truck up.