Slight Wobble?

[Supermike]

Okay... this may be a stretch, but it's something I've just noticed the past few days. It could be due to bad gas (in the truck...haha) for all I know. I don't really noticed this in drive, but when I'm in park and give it a little gas, I feel like there's a slight "wobble" to the truck. It almost feels like something is "out of round". At first I thought it was the engine, but when I lift the hood and rev it from there, I don't really notice it. I only feel it when I'm sitting in it. And sometimes when it's just idling steady, I hear a slight "thunka-thunka-thunka" coming from underneath.

Any ideas, or should I call Click and Clack?

[ToughOldFord]

Harmonic balancer? Flywheel?

[Supermike]

I wondered about that... though it seems to be coming more from the middle of the truck than under the hood...

[smclaren]

Middle of the truck, eh?

My guess is a Wheel Balance needed ... or Drive Shaft uni's getting sloppy ?

EDIT: Sorry ... just re-read the post ... noise is there when stationary!!! Hmmm ... stationary and from the middle of the vehicle ??? Is the clutch working OK (manual gearbox?).

[basketcase0302]

Had a cracked flywheel make the same noise once...

Basketcase

[Supermike]

No clutch... it's automatic, and the tranny was just rebuilt last year. Has been running and shifting like butter since then.

Could be the drive shaft, maybe... if that were the case, I guess the u-joints would need to be replaced?

[Thunderfoot]

The drive shaft would only be when your moving also...

Check your motor mounts and transmission mount to see if one of them is busted or loose...
Check your cab mounts on the truck as well.
Also, check your exhaust mounts back through the truck, I have seen those come loose and make some noise.

[Supermike]

Ok... thanks.. I'll see if I can get under there sometime in the next few days and see what I see. I could see where if the tranny was recently rebuilt, it could be one of the mounts has loosened.

[Kurt Combs]

My guess is that is one of those things that will run you nuts before you figure-out what it is. Good Luck.

[RedneckTexan]

Sounds like the tourque converter to me

[Supermike]

The torque converter? Given that I'm pretty much a mechanical idiot, is that part of the transmission? I don't notice it when I'm driving, really... just when idling and reving the engine. Should I have my transmission checked before the warranty runs out? As mentioned before, it shifts like new, and doesn't seem to have any other issues...

[ToughOldFord]

The TC and/or the flywheel could be out of balance.

My '79 had that at not moving shake, it would get worse with RPMs then smooth out. I ignored it since I couldn't feel it while driving. Eventually one of the bolts for the oil pump shook itself out and the other one got loose. Blew the damn pump through the bottom of the pan on the freeway.

[Supermike]

Oh... thanks TOF. That makes me feel better...

How the heck does one balance a flywheel? I guess I should call the trans shop about the TC just to see what they say.

[ToughOldFord]

I really don't know how common or likely it is for a TC or a flywheel to be out of balance. If I had to guess I'd say it's more likely to be your harmonic balancer before one of those. You wouldn't be able to tell if it was coming from the front or back as it would be vibrating the crank.
Not trying to scare ya or anything, just pointing out how I learned the hard way not to ignore something that doesn't feel right.

Start with the easy stuff though as mentioned before and pull the dust cover off the tranny and make sure that all four TC to flywheel nuts are present and accounted for. And not loose.

[ToughOldFord]

Probably a good idea to check your engine accessories too, make sure the alternator's tight, the water pump's not losing a bearing, etc.