Grinding/Vibration Directly Under Center Console?

[vt_maverick]

At least that's what it feels like to me. Had mechanic grease the driveshaft and U-joints but if anything it was worse afterwards. Definitely worse on suspension flex. Thoughts? I looked for driveshaft on Rock Auto but couldn't find anything with that specific name, and I'm afraid I'm not mechanically inclined enough to know what everything else is.

Help? Thanks!

[JoFotoz]

Do you have the Trooper skid plates?
If so.. the one under drive coupling sometimes gets bent
and the hex bolts rub against it.

Jo

[Mile High VX]

Check that the AR5 is all tight and snug...sounds like a throwout bearing might be the culprit or a worn clutch plate.

[Y33TREKker]

Transmission crossmember bolt(s) loose?

[Triathlete]

Also make sure your trans mounts are tight

[jmayer40]

If you think it has anything to do with driveshaft, Go to a shop, turns out to be cheaper. They can rebuild it.

[Marlin]

It could also be the prop shaft. Do you have a front diff drop? Mine grinds sometimes, especially when steering.

[vt_maverick]

Update... Well I'm sure no one would have guessed this... for whatever reason, the Trooper flex pipe that you have to switch to as part of the AR-5 swap started making contact with the "X" brace on the center Kilby skid plate. I have no idea why it just started two years after the AR-5 swap (and two years after banging around in Moab) but my guess is the clearance was always really close and was somehow eliminated when my mechanic changed the gear oil and reinstalled the plates a few weeks ago. He ground the cross brace down a bit to try and make some additional space, but if anything that just made it worse (I imagine since the plate is no longer in continuous contact that allows for a bit more play on suspension flex).

So nothing serious (whew!) but we still have some thinking to do on how to solve the problem permanently. Any suggestions? We could always cut a hole in the plate there and then weld another piece of metal over the hole (thus creating another 1/8-1/4" clearance) but I think I'd rather not go that route if possible.

For reference here's what I mean by the X brace:

[Marlin]

Good to hear it is nothing serious. FWIW, my exhaust vibrates on the SFIFS, I wrapped it in some of that heat wrap, looks like fiberglass. No more vibration/rattle.

[vt_maverick]

That's a good idea, we actually talked about doing that but I didn't have any handy (just insulating wrap, which is kind of the opposite of what we want). I'll take a look at the parts store tonight.

[bartmanS4]

I had my exhaust customer rerouted over the top of the prop shaft by a muffler shop. I don't have the Kirby's but this eliminated the exhaust tubing as being the lowest point under the VX.

[vt_maverick]

Hmmm, that's a thought too. We already have to replace the flex pipe because the skid plate sliced into it, so it might be a good idea to look at rerouting now. Thanks for the input!

[eternal21]

I had my exhaust customer rerouted over the top of the prop shaft by a muffler shop. I don't have the Kirby's but this eliminated the exhaust tubing as being the lowest point under the VX.

+1

Did the same on your recommendation

[bartmanS4]

I can't take credit for it though. BigMeat did this on his ride which is now Etfren's (LittleMeat) VX

Cheers,
Scott

[vt_maverick]

Okay so got it fixed last week, my mechanic took a look at the rerouting option and decided that although he could do it the job was way too complex (read expensive) so he came up with a much simpler solution: heating and then slightly flattening the bottom of the exhaust pipe, then using spacers to drop the plate down just a few millimeters. Boom, vibration gone!

I do have a bit of a concern here though, which is why would the vibration start 2 1/2 years after swapping to the manual and installing (on my new VX) the Kilby plates? I'm a little worried that the motor mounts might be going out and letting the engine lean backwards a bit; is that possible or even likely?