68 Firebird Motor Mount Bolt Question????
 

Hello friends, one of my 68 Firebirds is missing the right side bolt in the center of the motor mount. I can't see the location real well, but do see it's missing and also see the threads in the block when it should be secured to. My first question is about the bolt. What size is it? And Can I get one from a really well stocked hardware store in my area? They carry many grade eight automotive nuts and bolts as well as all the bumper bolts for commmon cars and trucks. I noticed the engine was moving more than normal a few days ago when I looked at the mount and and seen the empty hole.

Any help anyone may have would be a wonderful thing, as I want to replace this ASAP. Also, any tricks to installing a new one, like maybe having to lift the engine? Good day friends.

Mike

Ok not sure which one you need but here are measurements for the two types of bolts that hold the motor in the car.

First is the one that bolts the motor mount to the block. They measure 7/16-14 x 1 3/4". They also use a lock washer.

Second is the bigger bolt that goes through the frame pad into the mount itself. They measure 1/2-20 x 1 1/8"

Defiately use grade 8. Also with the 1/2" bolt is a heavy thick washer. Make sure you have that also. Most hardware stores may not have the 1 1/8" bolt. But a good nut and bolt store will.

Hope this helps.

ps - these measurements came from the parts manual.

If your talking about the 1/2" bolt that goes from the frame mount to the motor mount, you can still get the correct washer at the dealership. GM part # 1362249. Use this washer along with a lock washer.

Thanks, the one I need goes through the pad into the block. You saved me a lot of searching for the correct size. This was really decent of both of you who responded with the information. Question: will I need to lift one side of the engine to install the bolt? It looks like it may be a tiny bit out of alingment with the block. However, it could also be simply the angle I'm looking at it from. Thanks, and have a great summer. ... Mike

it might make it easier and save a little knuckle skin :D