[SuziBlu]

Gday, I was out playing, and was hearing a knocking noise, came home slow, crawled under, and recon as the gear box mount is cactus.

I went to ebay and found one, but cannot see how it works, looks like the gear box just sits on it, two bolts to mount to the car, but as I look, nothing to fasten the box to. ??

I'm not a mechanic.

[v.w.dave]

Ummmm what zook? Mine (92 sierra) has 4 12mm bolts at one end 2 of those also hold the exaust bracket. at the other end there is 2 14 mm and one 12 mm up in the little hole in the middle. It should only take you a few mins to get out and back in.
Are you sure it isnt a transfer case mount? Are you sure you didnt brake a transfercase mount? They are very commen and even easier to replace. one 14 mm on top one 14 mm on the base.
Get under there and have a better look.
A nother way to find out without going under you zook if it is a sierra. Put it in 4x4 low and take off a littlehard and watch your shifters. If the transfer shifter is rocking over and trying to hit the driver seat then you have a T-case mount going bad or broken. If when you take off the gear shifter lifts up you have a trans mount going bad or broken. last thing when you take off the gear shifter moves exesivly left to right you most probably have a motor mount going bad or broken.

[SuziBlu]

Thanks dave, Ill have a look in the morning.

I have replaced the engine mounts about a month ago, she has had a fair thrashing since, so, dunno, but ill have a look.

[v.w.dave]

you will also see where the t-case has hit your floorboard if that mount has let go.

[SuziBlu]

Def the gear box mount, and from your above description, I can see how it works, the part screwed into the box, stays, and its just the piece tween it and the chassis mount that changes, took a light and could see well.

Thanks, $25 on ebay, and looks like a quick and easy job.