Replacing Drive Belts on 84 300D-tough job? - PeachParts Mercedes-Benz Forum

mattmacklind · #1 05-09-2009, 01:01 PM

Hey all, I'm having new tires put on and the shop rec's new belts. I turned it down at near $260, but want to do it myself. Is this job a real PITA? Any advice, I'm reading in Haynes right now.

lietuviai · #2 05-09-2009, 01:04 PM

Not really a pita. It's just finding all the adjustment bolts and loosening the right mounting bolts that can be a little time consuming. Some of the bolts have nuts on the other end.

tangofox007 · #3 05-09-2009, 01:11 PM

Quote:

Originally Posted by mattmacklind

Any advice...

A lot of the brand name, made in USA belts are not the correct width. Buy some OEM belts, like Continental /Conti-Tech.

toomany MBZ · #4 05-09-2009, 01:45 PM

Yeah, make sure you have the correct size belts, you may want to take the old ones in and measure them.
The biggest problem I had was seriously over tightened bolts, that where I bent the ratchet, alternator mount on the SD.
The A/C unit has, I believe, a 19mm bolt accessed from under the car, I had it up on jack stands, and with all the torque I could muster, the rest of my body was sliding around on the ground, I couldn't budge it. Took it to a shop where they got it up on a lift and used a cheater bar. That was the CD.

funola · #5 05-09-2009, 01:58 PM

That bent ratchet looks like a David Copperfield magic act.

What brand was it?

Quote:

Originally Posted by toomany MBZ

Yeah, make sure you have the correct size belts, you may want to take the old ones in and measure them.
The biggest problem I had was seriously over tightened bolts, that where I bent the ratchet, alternator mount on the SD.
The A/C unit has, I believe, a 19mm bolt accessed from under the car, I had it up on jack stands, and with all the torque I could muster, the rest of my body was sliding around on the ground, I couldn't budge it. Took it to a shop where they got it up on a lift and used a cheater bar. That was the CD.

tangofox007 · #6 05-09-2009, 02:23 PM

Quote:

Originally Posted by funola

What brand was it?

Looks like a Harbor Freight immitation!!!

toomany MBZ · #7 05-09-2009, 03:10 PM

^^It's a no name, which is probably why it bent, yet, still works. Can't remember where I got it either, I wouldn't buy something that doesn't a name, so maybe someone left it at the house.
Thought I pulled something in my chest too, but everything's fine and that did break the bolt loose.

charmalu · #8 05-10-2009, 02:24 AM

Buy the belts from All Parts Express, probably around $40.00. not really that bad of a job.
Then use the money the shop would charge and take your wife or GF out to dinner.

Charlie

pawoSD · #9 05-10-2009, 09:04 AM

If this is just a generic shop recommending belts I'd be running away before they broke something. It is not hard to do yourself, especially knowing how it is done properly, which all of us form people can help with.

The main part is that since they are V-belts, the Alternator, power steering pump, and A/C compressor will all need to have their mounting bolts loosened (all of them on each)....and then the adjustment bolt will need to be used to put slack into the belts for removal. Re-installation is the reverse, then tighten up all the mounting bolts. BEWARE: When tensioning the new belts, err on the side of "too loose" rather than "nice and tight".....if they squeak or slip, then make them a tiny bit tighter. This is for the sole reason of protecting the crank pulley assembly, if too much force is put on it from real tight belts, it could shear its bolts and come off.

tangofox007 · #10 05-10-2009, 11:58 AM

Quote:

Originally Posted by pawoSD

BEWARE: When tensioning the new belts, err on the side of "too loose" rather than "nice and tight".....if

Better yet, NAPA sells a reasonably decent tension gauge for around $12.

bart_dood · #11 05-10-2009, 12:13 PM

Quote:

Originally Posted by toomany MBZ

Yeah, make sure you have the correct size belts, you may want to take the old ones in and measure them.
The biggest problem I had was seriously over tightened bolts, that where I bent the ratchet, alternator mount on the SD.
The A/C unit has, I believe, a 19mm bolt accessed from under the car, I had it up on jack stands, and with all the torque I could muster, the rest of my body was sliding around on the ground, I couldn't budge it. Took it to a shop where they got it up on a lift and used a cheater bar. That was the CD.

I had exactly the same problem, I ended up using a 1/2" ratchet with a long bar to get enough torque to break it free.