1st gear issues with 5.015

[Ap67et10]

Ok, I don't think I had this issue with 4.039 when I had it loaded. But over the last 2 days when I loaded 5.015 I've found that 1st gear is not operation like it should. It does not shift according to the shift tables (you can see in the datalog on any acceleration from a stop that it will not shift out of 1st until between 15-18 mph on very light accel, which it should not be doing) and it will command a downshift into first when it shouldn't, however it actually feels like its in neutral when it does this. I can give it a rev up and itll then shift into 2nd or 3rd and start moving again. It felt similar to how I had the issue before when the manual selector was screwing up, except now I can get it to engage again by revving it some.

This typically happens if I am cruising and let off the gas to coast for a second. When I do this it shows commanding 1st, but you do not feel any downshift and when you press the gas again it just feels like neutral. You can see it in the log I attached at 735 sec. I let off the gas and am coasting at that point and it shows downshifting to 1st at 26mph. You can see it does not actually engage first because it stays at that speed for a while until I started hitting the brakes a little. I let off the brake and lightly start back on the throttle at 749 sec, but it does almost nothing for acceleration. The main bump in speed is when it jump to 2nd gear for just a split second, once this happens it feels like the transmission is back in gear and itll engage 1st for real as I revved way up, then shift to 2nd and 3rd as I let off and feel normal again. It feels a lot like when and automatic transmission is very low on fluid and you rev it up until it all of the sudden engages. That is what it actually feels like in the truck when it does this. (fluid level is fine)

It seems to be doing it all the time, but it definitely wasn't doing it when I had the other code in it. Here is a log and the current tune that is in it right now. Extra eyes would be great to see if I screwed something up in it, but I feel like I have gone through the tune changing all kinds of things trying to fix the way 1st is shifting, with nothing changing at all.

[Ap67et10]

here is the datalog

[Bernard Fife]

but you do not feel any downshift and when you press the gas again it just feels like neutral

Ap67,

I will have a look. However, what sort of transmission is this? Is neutral selected electronically using solenoids, or hydraulically using the lever? Is the line pressure too low when this happens allowing internal slippage in the trans?

Lance.

[Ap67et10]

Lance,

This is the 4r75w ford trans behind the 2v 4.6. I was having the speed sensor problems originally, but got those fixed.

I know that P, R, N and 1st all have sol A on and B off, which tells me its mostly mechanical between them.



Andrew

[Ap67et10]

So the problems were getting worse and worse with this thing yesterday. I was trying to log it again last night on my drive home and I kept loosing coms and all kinds a weird crap. kept randomly not shifting and 1st gear wasn't ever doing what it should and neither were the other gears. I figured that it had to be some sort of corruption that occurred somehow when I switched to 5.015. I did have 5.015 in the truck when I was having the speed sensor issues also, and do not remember any weird shifting, so I was pretty sure it was a corruption problem. I knew that 4.139 worked well, and the TPS/MAP blend didn't seem to work like I had anticipated (this could be because of the corruption issues also, so I'll try it again at some point) so instead I decided to reload 4.139 and retest everything again.

I loaded 4.139 put in a tune that I knew functioned well, and everything has been perfect.....well that was on a 10 mile drive through town. I'll keep tweaking and logging to see if anything weird happens, but it was doing what it should so far. I found that the manual lever seems to work correctly now too. If I pull the manual lever down to 2nd or 1st it'll downshift, and it'll hold that gear until I shift it.



Andrew

[ashford]

on a ford 4r7X there is no engine braking in 1st and 2nd when in drive or no engine braking in 1st when in d2, so yes it feels like neutral. 4142 worked quite well for me, it manual upshifted fine but d2 still got 1st and 2nd not just 2nd.

unfortunately i blew my trans sky high this time and replaced it with a tko600, i guess a turboed 4.6dohc with a 4r70w just wasnt meant to be, it has been out 5 times and don't think i had more that 3000 miles on it. oh well i can still use the gpio in a friend car its just a measly 5.3 he wants to put a 4l60 in .

[Ap67et10]

It wasn't about not having engine braking in D, it was about not feeling it downshift and when getting back into the gas it did nothing. The truck just felt like I had tossed it in neutral until I would rev up a bunch and it would all the sudden clunk into gear and shift up to 2nd or 3rd. However I believe it was mainly some sort of corruption that happened. I reloaded firmware, this time 4.139 and it shifted great.

I have started to notice something weird again though. Today I was getting on the freeway and had put the shifter into 1st, then shifted to 2nd as I accelerated onto the freeway (it did what I wanted and expected at this point), however traffic kind of backed up real bad on the on ramp, so I let off the gas while the shifter was still in 2nd and it held the gear great. Then as people merged and I was about to merge I layed into the throttle a little and then went to shift into drive and it didn't do anything. It just stayed in 2nd. I then shifted to neutral and back to drive and when I did that it felt just like it would when it had all the issues with 5.015. It felt like it was just shifted into neutral and if I hit the gas it just free revved with no forward motion of the truck, even though I was back in drive. I had to pull over, put the truck into park and then back to drive and at that point it was fine again.

I also noticed it does something similar if I pull the gear shifter to 1st and shift through the gears manually (into 2nd and then to drive) it functions as expected however after maybe 10-15 seconds if I try to shift it down again with the shifter, it does absolutely nothing. I did have this happen one time when the computer was hooked up and I saw that the manual gear never changed with the shifter change when it did this. It wasn't until I shifted back to neutral that it would function again. I can't figure out why it would do that. It never displayed -99 like it would when I first got it running and was having issues with the PRNDL switch, but that has been replaced and the signal is super clean. I'll see if I have a datalog of this happening. I didn't have the computer hooked up when it felt like it went to neutral getting on the freeway though.



Andrew

[Ap67et10]

unfortunately i blew my trans sky high this time and replaced it with a tko600, i guess a turboed 4.6dohc with a 4r70w just wasnt meant to be, it has been out 5 times and don't think i had more that 3000 miles on it. oh well i can still use the gpio in a friend car its just a measly 5.3 he wants to put a 4l60 in .

I used your write up to get my setup going. It was very useful! I was glad you did the write up, but I remember thinking there was no way you were going to be able to keep a transmission in that thing! If you have any traction at all I doubt you'll keep that TKO operational for long either......unless you set it up so the clutch is the weak link.


Andrew

[ashford]

glad that helped. something else i noticed if you are using my msq(don't remember how old or rough it is) it is tps based shift tables and when the code is updated and the ini changes the shift table load axis is somehow not carried over and reverst to default.

and yes i did put a clutch in that is below the rating of the trans, it is rated at 545ft/lbs, the trans is rated at 600ft/lbs but that rating is for a reasonable service life, not its breaking point.

[Ap67et10]

I originally did use your msq, but now I have a bunch of different reload msq's that I had built from scratch because it seemed better since I had a few issues I was trying to sort out. I wanted to make sure nothing was getting corrupted as Lance had suggested.

What ended up letting go on the transmission? How long did it last? Did you get it pretty dialed in before it let go?

So far I am liking this setup, I have had a couple things to sort out, but its been nice because the engine has been flawless. I had absolutely zero issues with the engine setup (probably the first time I've had no issues at all that needed to be sorted out on an engine I've swapped to MS, and I've probably done 10 or so now) but its worked out since I've had to deal with the trans a bunch.


Andrew