1983 300SD. I was in the middle of replacing the alternator when end of the bottom bracket broke where the end of the bolt was. Now I cannot get the last bolt out to release the alternator. The bracket looks like it attaches to the side of the block with four - 17mm bolts. I took the bols off but nothing moves. The bracket looks very large for just the alternator. Does anyone know what else this does. How do I get it off. Without replacing this I cannot get the alternator on. Dennis

Is the bottom bolt stuck in the remainder of the bracket........and won't budge?

Get a bit of heat on the outside of the housing where the bolt sits.......use a propane torch..........and then spray the bolt with PB Blaster.

Then get some vice grips on the head of the bolt and drive the bolt rearward with a hammer while rotating the bolt at the same time.

The bolt is toast........you'll need a replacement. They tend to deform themselves in that position over time.

Oh no!

I hate to say it, but your in deep...

There is another bolt, keeping that bracket from coming out... It is another 17mm but it is kind of hidden behind the harmonic balancer (main pully) this bolt is a MAJOR PITA to get out.

I had to remove the fan/clutch assembly, the fan shroud and the water pump pully. Then I had to rotate the engine until the gap of the main pully lined up with the head of this bolt. Then I chopped off the end of an old 3/8" extension and used it with a 17mm socket and a 3/8" wrench to get the bolt out. Then I had to move the turbo drain to finally get it out.

Quoted from http://www.peachparts.com/shopforum/showthread.php?t=160164

"I removed the main bracket from the car. This is a major PITA and should be avoided at all costs. I will explain. You think you can get off easy by removing 4 nuts and pulling it off. It doesnt work that way.. .there is a hidden bolt holding it in place under the lip of the harmonic balancer located just under the water pump. I had to rotate the engine so that the gap of the harmonic balancer was aligned with the bolt. I could fit a socket on the bolt now, but the socket wrench would not fit. I tried using a regular open end wrench but couldnt get it at the right angle to make the bolt budge. A closed end wrench was too thick around the edges and it didnt work either. So, I took an old 3/8" extention and chopped off the end. I ground it down so that there was just enough of it sticking out of the end of the socket that when I put the socket on the bolt, I could turn it with a 3/8" open end stubby wrench. This worked! So, I got the main bracket all un-bolted, but it still would not come off. It would move, but the turbo oil drain was in the way, which means you have to unbolt that also, just to get that bracket out. Finally it came out."

The end of that bracket cracked . I have to come up wit something creative.