How do you tell if a motor mount is bad?

[SoCalCruiser]

I had a PPI done on a 1991 GW that I bought (along with a few other minor things). The mechanic, who I think is reilable, gave me a list of things I should look into and fix.

On that list was a left motor mount, trans mount and some fluid changes. I can see the trans mount has collapsed, so I'll change that.

The only way that someone told me to find bad motor mounts was to put the car in Drive and give it gas and see if the engine moves up on the left, Reverse and gas for the right side. I did that and it seems to move higher on the right. On my 1989 when I had a bad mount on the left, the motor jumped about an inch.

Is there another way?

Craig

[SoCalCruiser]

Oh. I looked for a place to put a pry bar, but didn't see a safe one.

Floor jack?

Craig

[EJ10]

I put a floor jack and a piece of wood on the oil pan (it has a skid plate). Motor mounts for my 258 were only seven bucks apiece, so just change them both.

[kyjman]

Set the parking brake, open the hood, have someone start the engine and put vehicle in reverse. Next have the other person gently tap the gad pedal. If the mount on the drivers side is broke the engine will rise a little each time the gas is tapped. Thats the side that goes first usually. Put it in drive and repeat the process to check the passenger side. Good Luck. This has worked for me.

[SoCalCruiser]

I guess that's a good point. "Moves a little" Hmmmmm. Both sides moved. Should good motor mounts allow the motor to move very little, almost nothing?

Craig

[SpruceMoose]

very little movement with new mounts. both of mine were ripped in half, with the motor just sitting on them. that explains the imprint of the power steering fluid reservoir on the underside of the hood! got about 4 inches of twist with a healthy push on the gas pedal.

sm.

[jeepcreep]

I had one with bad motor mounts and one day I gas'd it hard it frickin knocked my hood open and yanked my bottom radiator hose off in the middle of a intersection at rush hour. Pretty embaressing! FIX THE MOUNTS TRUST ME!

[SoCalCruiser]

LOL, that's a great one. What the hell were you trying to get away from.

OK, looks like 2 new motor mounts and a new tranny mount.

Craig

[jeepcreep]

I WAS JUST TRYIN TO MAKE LIGHT BEFORE IT TURNED RED AGAIN.

[Serious Johnson]

Well, one way that I know of is to promise your wife that you'll take her down off the mountain for a real meal, then find that the &^%*&^$*$ shifter won't move! A quick hike down to timberline for a 2" x 5' aspen prybar solved that one.

I've yet to get new OEM mounts to survive a trip up my driveway, and really should look into alternatives. Back in ye olde days, we used to bolt a hunk of chain from the left cylinder head to the chassis to limit movement. You could tell when the rubber was stretched when your teeth rattled with the motor at full chat.

:-

[SoCalCruiser]

Ordered 2 mounts from the Zone. Got under the Jeep with a jack and piece of wood and began lifting the motor. The only thing that happened was the whole motor began to lift up. I didn't see a split on either side. Guess they were OK afterall.

Craig

[ChuckWag]

Good way to tell--radiator shrowd broken, then fix the mounts!!!