Mechanic help

[Puggy625]

07 Dodge Ram 1500 5.7L

Starts and runs fine at lower speeds. Going about 40 and slightly press down gas to accelerate and you can feel a shudder in the cab. As soon as you let off the gas, it goes away. Press it again to speed up and it comes back, goes away immediately after releasing gas pedal. Without acceleration (just cruising at same speed) no shudder. I've got a feeling the torque converter is going out. Just need to figure it out for sure before spending money on a new one. Any suggestions, tests to try, comments (smartass or otherwise) would be greatly appreciated.
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[Navasot]

Could be u joints or carrier bearing

[Navasot]

Any noise with it?

[kevin nicholls]

Check your fuel pressure. It's probably the fuel pump. It's an easy test with a pressure gauge, I believe it needs to be 65 lbs on the fuel rail.

[jrfan]

I had a 2010 f150 that did that. Took it to ford and they said it was the plugs and wires. I did not believe them because it appears to be a shifting issue/shudder. They said it had a misfire under load. They changed the plugs and wires and it fixed it. Might be something to check.

[TejasNW]

A long shot, but could be an out of balance driveshaft. Like a wheel weight, drive shafts have to be harmonically balanced. When you hit a certain speed it will start to 'wobble'.

[Puggy625]

Could be u joints or carrier bearing

Ujoints were recently changed.

Any noise with it?

No noise with it.

Check your fuel pressure. It's probably the fuel pump. It's an easy test with a pressure gauge, I believe it needs to be 65 lbs on the fuel rail.

Possibility, but I'm thinking it's definitely something in the actual drivetrain.

I had a 2010 f150 that did that. Took it to ford and they said it was the plugs and wires. I did not believe them because it appears to be a shifting issue/shudder. They said it had a misfire under load. They changed the plugs and wires and it fixed it. Might be something to check.

I bought new plugs today as they are due to be changed. No CEL on but I checked the codes and there's none showing on the reader.

[wardog howling]

My company truck does the same thing. Mechanic said overdrive is going out on the tranny.
It's an 2009 tundra with 289,000 miles.

You can also feel it on the highway when coming up to speed, 1st to 2nd is sharp, 2nd to 3rd is sharp, 3rd to 4th is sharp, but when it shifts from 4 to OD running about 70mph, it almost feels like it quickly shifts into a higher gear and then is sluggish under any load. RPM also revs a little then tapers off and builds back slowly.

[kevin nicholls]

I had a shop change the transmission on my Dodge because he said it was going out for the same problem. I drove onto the freeway whith a rebuilt transmission and it did the same thing. Turned out fuel pressure was low. A $40 fuel pump fixed it. Take it to a reputable mechanic and they will diagnose it. We will lead you down the road to insanity with our interweb diagnostic skills.

[ladrones]

My company dodge did that. It was a short in the number 8 cylinder wire. They fixed it six times under warranty. Still does the same.

[Puggy625]

Changed out the spark plugs this morning and the problem is still there. I'll go for the coil packs next. If that doesn't do it, I'll have to get it checked out.

[Navasot]

If just did the joints and still there I bet it's the bearing