Well, I've had my truck for a while now, been working on fixing all the **** the previous owner had managed to screw up in the past, which was a lot of stuff. Its been about 4 months since I bought it, and I've hardly even driven it.

Well, I took it offroading today after getting a bunch of stuff done, and I'm running into a very odd issue with the transmission. First, might be related, might not be, don't know, my speedo cable seems to be binding somewhere now, as my speedometer is bouncing around a bunch.

But the more important issue is the fact that, for the first time as far as I know, the transmission is just shifting up and down repeatedly, and rather rapidly. It didn't do it cold at all, just after it had warmed up. It just shifts up and down, and up and down, pretty much regardless of what speed I'm going, once the thing had been running for maybe 30 minutes. I'm not 100% that it was the transmission, all I know is the RPMs were jumping up and down a bunch.

My first guesses are TV cable (I don't think its that though, doesn't sound right.), fluid level (still seems odd), or possible TPS? Any ideas? I'm supposed to be driving this truck 100 miles from where it is now to where I'm living tomorrow, and I'd like to try to get it drivable before I do.

Thanks for the help,
Ben

 

What gears does it switch between? All of them?

What size tires are you using?

My first guess would be TV cable too, have you messed with it? Have you read the theory on setting the TV cable and it's opperation?

By today you've gone on you 100 mile trip so I hope you come back and tell the story of what happened.

 

It was changing between all the gears, dependent on speed. I checked the transmission fluid level, and it was low. I also fiddled with the TV cable, but I don't think I adjusted it much, and finally, the speedometer has stopped bouncing around. One of these three things, if not all of them, seems to have fixed the problem with the transmission though.

I didn't end up going on the trip. Alternator wound up being dead. I'm very happy with the new battery I got though. I drove that thing around for hours this weekend with a non-functional alternator. Pretty impressive in my book.

 

You shouldn't 'fiddle' with the TV cable.

Could you explain the transmission shifting a little more? does it matter if you're under power or coasting? Is it 'hunting' for gears? Do you have a lift, bigger tires? Do you know your axle gear ratios?

 

Well, as I said, it seems to be functioning perfectly fine now.

But when I was having problems, it was only under power. and Yes, it was exactly like it was hunting for gears. It would shift up, thinking it was ready for that, then shift back down immediately because it decided it needed to do that, and just go back and forth, never settling on one gear for long.

I do have a lift, with 33x12.50s, and my ratio is the stock 3.73.

 

Sounds like symptoms of a misadjusted TV cable.