Need help diagnosing tranny problem

Santa Gertrudis

Santa Gertrudis

6.4LTTFMF
Ok, Im gonna give yall the scenario, and tell me what you think might be wrong.

So Im stopped at an intersection, and I take off and excelerate at about half throttle. The truck shifts great, just like it should. Then, I stomp it, it down shifts, and keeps gaining RPMs and excelerating fast like it should, but instead of shifting, it hits the rev limiter and doesnt shift. It doesnt do it every time though. Sometimes though, If I dont give it hell for a day or so, then stomp it, sometimes it shifts fine instead of hitting the limiter. What is up with my tranny guys? Thanks.

Also, Ive turned the shift points down on the SCT, and it didnt help at all.
 
Santa Gertrudis said:
Ok, Im gonna give yall the scenario, and tell me what you think might be wrong.

So Im stopped at an intersection, and I take off and excelerate at about half throttle. The truck shifts great, just like it should. Then, I stomp it, it down shifts, and keeps gaining RPMs and excelerating fast like it should, but instead of shifting, it hits the rev limiter and doesnt shift. It doesnt do it every time though. Sometimes though, If I dont give it hell for a day or so, then stomp it, sometimes it shifts fine instead of hitting the limiter. What is up with my tranny guys? Thanks.

Also, Ive turned the shift points down on the SCT, and it didnt help at all.
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I am having similar issues. My tranny was rebuilt at 17k and now at 41k is doing this as well. I forsee a rebuilt soon for me.
 
i think it is from all those times you hammered on it trying to blow your head gaskets to get the updated ones haha.

sorry i do not have any help, colin.
 
im having kind of the same problem i have a fully built suncoast and when i first put it in it shifted real firm now it almost shifts like a stock tranny. anyone else having these problems.
 
also it has less than 3000 miles onit i turned the line pressure up with the sct but i did not do much i also had tadd write me a new tune which also did not help. :doh:
 
I might email DJ tomorrow and see what he says. Im hoping its just a tuning error. Now that I thought about it all day, it did start after I started running a newer version of the Looney. Hmmm....
 
Does it only do it when its cold colin, or any time? My tranny hates shifting until the fluid gets warm.
 
Mine does the same thing as Dalpilots when cold in all gears, then when it warms up I had the problem in the 3-5 shift, holding the shift for an extra long time. I fixed the problem after changing tunes and when running the gears I keep hard on the 3-5 shift all the way through the shift the learning curve it went away. Don't know if it will help you or not but it worked for me as the 3-5 shift is at a bad point where I'm letting off just as it shifts which gives it bad shifts, by keeping on the throttle it keeps the pressures up and shift much better.
 
I don't think it's a tuning issue in my truck. I have been running the same tune for well over a year. I also smell burnt tranny fluid when I run the truck hard.
 
Colin,

I have an 06 also and I tried running the new looney too. Mine did the exact same thing. If i would let up on the pedal it would fall out of gear and hit the limiter. Finally after a few seconds it would go into gear and all is fine. I went back to the regular looney and all was fine. I think its something up with the strategy on the 06's.
 
Thats funny dude, cause I switched back to my old Looney this morning before my drive to school. It was definately a tuning problem. The truck is shifting wonderful now. Me and Vivian have been fighting the "Updated Looney" on my truck and trying to get it to run right for a while now. With the latest attempt (early 08 I think) it was running "ok" for a long time, but still not shifting real great. Its only lately been doing the weird shifting all the time, which is what made me think it was a tranny problem. I think I like how the old one drives better anyhow. Its much smoother. It may have a little less power, but my seat of the pants doenst notice, and its nice for the truck to shift outta 3rd now. LOL

Im begining to thing there is something up with the strategy on the 06s myself. You and myself are not the only 06 owners Ive heard of with tuning glitches. I dont think its any kind of mistake in the tuning, I think the 06s are just a different breed.
 
I know that they "fixed" the solenoid problem in 04' or so, but it sounds like a solenoid is not firing when it is supposed to. I guess that can be tuning if the tune is corrupted, but it could also be that you have a solenoid starting to go.

Ralph
 
Honestly, I don't think its mechanical. I tried the new looney back in jan or so. I ran it for a week and really thought I destroyed my transmission. I loaded the street looney back in and the problem went away. I reloaded the looney wild and the funky shifts or not, came back. I went back to the street looney and have been running it for 4 months without the problem coming back.
 
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