Hey everyone, I've got a couple shifting issues I need to get fixed on my truck, you guys are probably more knowledgeable on these trucks than I am.

So firstly, my first gear seems longer than usual, it doesnt shift into 2nd until around 20 mph, just seems a bit of a high speed to stay in 1st to me.

Secondly, it's got that 3rd/4th gear hunt when you're going about 50-60 mph and haven't been able to find a fix yet, I added a ground wire to the ECM ground and it didn't appear to help at all.

and lastly, it seems like the truck is at too high of an rpm at highway speeds, going 70 mph and just sitting at 2000 rpms seems a bit off, im not entirely sure if the torque converter is locking and unlocking properly. I read into the torque converter lockup switch but heard it was a bad idea to install if you didn't have a built transmission or built input shafts, and I don't want to be replacing either one.

One other unrelated thing is, are 2nd gen cummins usually THAT loud?? I've never heard another stock diesel truck be quite as loud as mine, like I can be heard from around 400 feet away but the exhaust doesn't seem modified I don't think. It's just got what appears to be either a muffler or resonator on it.

 

How much of an RPM change are you seeing when it is 'hunting'?

TV cable adjusted properly? Cable move freely?

2K at 70 doesn't seem out of line.... but, I am used to gas motors.

Your muffler may be blown out..... but, I would have to hear it to give you any kind of accurate opinion.

 

Sorry it's been a few days, the rpm change when it hunts gets bigger as i get closer to 60 mph, I've read insulating the alternator wire helps a lot of the time cause of the rfi the voltage regulator puts off, so I think i'll try that soon. I've also occasionally had problems with the torque converter locking and unlocking around 60-70 mph

I haven't adjusted the TV cable yet but I've heard its normal for it to shift around 1800 rpm which is where it usually does, I guess i'm just not used to diesel rpms lol.

Yeah I'm not sure, i've heard it's fine for it to be like that but it just seems off that it's using like half of the tachometer to cruise at 70

For the muffler I can see if I can get a picture of it or a video for you, maybe somebody can tell if its aftermarket or not

 

As you go faster, any change on the tach is going to get wider as speed goes up. I expect that... If you are seeing around 200 rpm at cruising speed, that's TCC dropping in/out. If it's closer to 500 or so, that's O/D. Two distinctly different problems.