OK, a couple things. Tried searching, no luck.

First, I have a 99 250sd w/7.3l auto. It has a DP tuner and BTS valve body along with a 6.8l trans cooler. Here are my questions:


I have had the tuner and valve body for a while now. When I first got the truck 4 years ago, I never noticed any shifting issues. When I installed the VB and tuner I noticed the 2-3 shift and the 3-4 shift seem a little off. If I take off pretty hard, it shifts pretty decent and crisp, but just cruising around it feels kind of jerky. Almost like a small slip, if that makes sense. The 3-4 shift is a little worse than the 2-3 shift.

I contacted Jody at DP Tuner a while back and he had me send the chip back to him to up the line pressure a little. It didnt really change anything.

Now, it doesn't shift horrible, just seems a little jerky on smooth accelaration. Also, I have been meaning to get it in to flush and change the fluid, because when I did the VB, filter, and cooler, I just emptied the pan and added fluid to top it off. After I finished topping it off, I looked at the empty bottles and noticed there was two or three empty quarts of Type F fluid that must have been mixed in with the Mercon at the parts store.

So, do any of you guys have the same shifting as I do with the dp and bts and also, would a few quarts of Type F make the trans shift weird?

Thanks a lot,

 

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How many miles on the truck? What did the fluid look like that you replaced, did it smell burnt?

 

A few quarts of the wrong fluid could make it shift weird, but its not a guarantee. I would get it flushed with the correct fluid ASAP.

 

The truck has about 145,000 now, but it seemed to shift fine before the upgrades. The old fluid didnt look burnt or dark, it looked pretty good. Is it a bad thing that my trans temp never gets above 150 degrees in the summer and now that its cooling down, It doesnt even hit 120. I know the optimal temp is in the 170ish range isnt it?

Thanks for the replies, Im gonna get the trans flushed and report back.

 

OK, so I hooked the truck up to the AE today, and got a P0500 in the Overhead section of the DTCs. In AE, it lists the P0500 as "Vehicle Speed Sensor A". I know the pumpkin has a speed sensor and the trans has an input and output speed sensors. I was gonna swap out the one on the differential and see if that fixes my issues, but the weird thing is, my truck isn't doing anything else that would tell you the speed sensor is bad like flashing OD light or ABS light and/or speedo not working.

I do know the speed sensor is crucial to how the trans will shift and the symptoms sound like a speed sensor, but can that sensor be bad and the speedo still work fine?

Thanks

 

The speed sensors cost about $20. Get one.

 

Well, I picked up a VSS from Napa today. I put in the new sensor in the Napa parking lot. Drove down the street and no change to how the trans shifted. When I got home, I hooked up the AE again and the P0500 was there, along with a P0478 for "exhaust back pressure control valve high".

I cleared the codes and took it for a spin. While I was out, I got on it hard a couple times at WOT. I don't hardly ever hit WOT, so I was supprised that the truck wanted to rev past 3500rpm. I had to let off the throttle to get it to shift.

It is definately shifting late and the shifts are pretty firm, if not hard, especially with the tuner on stock or 60hp tow. At 80e and 100hp, its not as bad, but still not right. When I got back, I pulled the codes again and the P0500 was gone, but the P0478 was back. Not sure if the P0478 is just from getting on it hard, or the tube needs cleaning.

Hopefully I can get Mr Kovalski to chime in on this one. The trans doesn't really feel like its going south, no slipping or anything, it just seems consistently late and hard shifts. No problems or slipping while taking off or going up hill.

Any other suggestions on what else to check?
Thanks a lot guys

 

perhaps your tuner is affecting the trans shift strategy ???

 

how accurate is you speedo? can you maybe check it against a GPS maybe?

I have HEARD that vehicle actual speed versus PCM registered speed can mess with the shift strategy quite a bit.

 

Well, a while back, I called Jody and let him know about the shifting and he had me send the chip back to him so he could up the line pressure a little, but it didnt help much.

My speedo is a little off due to my 33" tires, I do have a GPS and it shows Im actually doing about 57 when the speedo shows 55. Its a little more off the faster I go and a little less off the slower I go, if that makes sense.

 

Im not bashing Jody so please dont flame me.

I was having the same issues with my F-5, My truck had the same issue. There was a Lag then Jerk into the next gear. It would even get my Trans Shifter OD light to flash. I never did much for it because I was already gonna try some different tuning. I switch tuners and I have not had any more shifting issues.

If you are still having issues your gonna have to Call Jody back and have him go over it agian.

 

Thats what I was worried about. Now, when I put the tuner to stock, it still does it. Are the changes that he makes to the trans settings still there when the F5 is on Stock since the chip is still connected? Or does it go back to completely stock?

I saw another post where a guy had my same setup( Dp tuner and BTS vb) and was having the same issues also, but he never said what fixed it. And what you describe is exactly what mine is doing, when it finally shifts, it kind of jerks and lunges forward into gear.

Which tuner did you end up going with? Thanks for the post.

 

PHP (Power Hungry Performance),

I was already planing on changing Tuners. I dont know if that is what you want I would call Jody back and give him a chance to get it settled and fixed. That and it is alot cheaper then getting a whole new Chip.

 

Yea, ill give him a ring, I just hope he can fix it up. Its really annoying how the truck drives right now. That was supposed to be THE setup to get, but he was cool the first time I needed it adjusted, so Im sure he will be the same way, I just hope I dont have to keep sending it back and fourth.

Thanks for the help!