Wrangler guys - got a new shudder

[GilpinGuy]

99 TJ, 4.0L, 207K miles
I noticed yesterday that I have a shudder when I release the clutch from a stop and when I turn the engine off. It's a deep, "thunking" sound. Otherwise I don't feel or hear anything when going through the gears while driving. Just when starting from a complete stop and when the engine gets turned off. It feels like it's coming from the front half of the Jeep, not the rear end.

I'm thinking maybe a motor mount is bad? It's snowing like hell and the driveway is a mud pit so I'm not diving under there today. Just thought I'd throw it out there to get some ideas on what else to look at when I do.

[newracer]

Definitely start with the motor mounts.

[Great-Kazoo]

Definitely start with the motor mounts.

Then work back, looking at the transmission and drive shaft mounts.

[SideShow Bob]

Also take a look at all the exhaust, cat and, muffler mounting brackets & isolators.

[Walker2970]

easy
Just
Empty
Every
Pocket

Solid advice on the first 3

[Mr Spooky]

you can see the rubber in the motor mounts from the top. No need to crawl under.

[argonstrom]

From your description, I'm guessing the chain slapping around in your np231.

[Mr Spooky]

I also had a shudder from a stop in an old toyota I used to have. The flywheel was starting to glaze. Replaced that and the clutch while in there and it fixed it.

[T. B. Turner]

"Shudder" sound like a clutch issue If its been a long time since the clutch has been replaced that may be the problem. A way to check engine mounts is to open the hood, sit in the drivers seat and find an angle to see the engine. Then push in the clutch, put your heel of the other foot the brake, reach over with your toe and give it some gas, slowly release the clutch, if the engine looks like it is trying to jump out of the engine compartment, the mounts are broke. If there is no abnormal movement they should be good. also with a clutch a new remanufactured clutch can tend to cause "shudder" for that reason I always spend the extra and get a new one.

[Ah Pook]

An easy test for the clutch is to:

Put on the emergency brake.
Put into 1st gear.
Right foot gives gas while the left foot slowly releases the clutch.

If the tach stutters and jumps, there may be a clutch/flywheel issue. If the motor promptly dies, the clutch is probably alright.

There was no rubber left on the driver side motor mount, when I replaced mine. It didn't make any noise though.

Does it make the "clunk" sound if the trans is in neutral when turned off?