Overdrive shaking the truck

46re, just started at my new job and it's a solid 35 miles one way trip mostly highway.

Well my problems started after I installed my shift kit - TFOD HD2 - but the truck kinda was weird in OD to begin with

At low speeds approaching 40mph, it tries to shift from 1-2 very quickly and goes back and forth 1-2-1-2-1-2 until I press harder into the gas - it shifts into 3rd and then I let off, it backs down and coasts into the last gear.

If I'm going 40-45 mph (which are most roads around here), it will shift to what I assume is OD and shake the truck a bit hard.

I hope what I am explaining is making sense, maybe I'll take a video on the way to work tomorrow and narrate what is happening.

Weird thing is with OD off there are no issues, it just stays around 2k RPM and revs pretty high which is to be expected.

Did I adjust something wrong? I know there is the white clip on the throttle body and the 1-2 shift adjustment on the actual trans.

Re-reading this, I'll for sure take a video tomorrow when I'm driving to work and it'll probably make alot more sense.

Check fluid level and make sure everything is all good there.

40mph before it shifts out of first? I barely hit 20 before i'm in second, I don't even think I can make it to 40 in first before redlining.

Since you recently put in a shift kit, i'm going to guess you gave it a full service as well. New fluid, filter, and linkage check. I'd check out your oil level and throttle level on the transmission to make sure you didn't knock anything loose when working on it. I had some really weird shifting problems a year back after servicing my transmission because I forgot to put the throttle lever spring back on.

dudeman2009 said:

I had some really weird shifting problems a year back after servicing my transmission because I forgot to put the throttle lever spring back on.

Click to expand...

Yes that spring. I actually forgot to put it on for a few days. When I put it on I'm not sure it's in the correct position. Anyone care to take a picture of theirs?

I'm working on uploading the video to youtube, work was canceled so I'll have plenty of time to work on the truck today.

Yes did a full fluid and filter change. Almost wondering if it doesn't have enough fluid. I guess it wouldn't hurt to add a half quart and try it out?

And I guess I wasn't clear. It does shift normally at normal speeds like 20 mph, but around 40mph is when the OD kicks in and it shakes. At slow steady speeds, especially after starting from a stop is when it has the 1-2-1-2 shifting unless I give her a good bit of gas.

I am getting 10mpg or so now which is great with stock gears and 35s

Don't just add fluid. Check it, drive it, check it again lol. All without shutting the truck off. Id tale a pic of my spring but there's so much **** under there right now you can't see it

Okay went out and got some pictures. Damn it's cramped in there since the front driveshaft is in the way

Okay here is a short video I took. Below 1500 RPM is when the "shaking" happens. It also happens when I'm on the highway, but if I press the gas just right I can keep it below 2000 RPM and it doesn't shake very much when in OD

https://youtu.be/O3CAwRoxcMI

Check for misfires

I second dodgedude. My truck used to misfire in OD so bad I'd swear the front wheels were gonna fall off. Leaking plenum ended up being my primary cause.

However, I noticed in your sig that you have an Airgap, which is a one-piece manifold, yes? If so, the ubiquitous plenum leak should be a non-factor...

Yeret said:

I second dodgedude. My truck used to misfire in OD so bad I'd swear the front wheels were gonna fall off. Leaking plenum ended up being my primary cause.

However, I noticed in your sig that you have an Airgap, which is a one-piece manifold, yes? If so, the ubiquitous plenum leak should be a non-factor...

Click to expand...

Right on it is one piece, eliminating the plenum. I'll check for a misfire code, but damn I hate that shaking. It does sound like a misfire, but as soon as I'm out of it the whole engine sounds smooth.

When I had first got the truck it did this a tiny bit I think . But definitly no where near what it does now. It's hard to remember since I drove it so little before and when I did it was in the city. Thing is when I do my city driving it kicks on and it's annoying. I just was out now and hit the OD off, and it was cruising around 1500-1800 RPMs which is okay with me. But that shaking is annoying as hell

Bad balance on drive shaft? Try to find what RPM it does it and see if it does it without OD at all?