What parts will I need to replace belts and hoses on my 1984 Mercedes 300D?

SOURCE: I need to replace to replace fanbelt on 300D 1984 mercedes.

You must remove the outside belt to get to the inside belt, no way around this problem.

loft404

• 11 Answers
• Posted on Jun 12, 2009

SOURCE: I need to replace to replace fanbelt on 300D 1984 mercedes.

Transit Guru360 is right, It's not so hard and you might remove a few extra nuts...but once you've done it, it's a piece of cake the next time.

I just did this on my 300CD and this is what you do...

I dont have a AC belt since my AC doesn't work I removed it a while ago

1 You'll need:
a. a nice long pry bar (for tightening belts later)
b. a pair of 13m and 17mm wrenchs as well as sockets to do other side of each bolt.
c. a pan for the antifreeze to drip into since you'll remove the top hose to give you more room to
work and it will be full of antifreeze.
d. straight screwdriver
e. Some Gojo...yes working on diesels is a dirty dirty job

First take off top radiator hose, then smaller overflow hose, then upper and lower air intake hoses and unplug that little wire...not sure what it does, but it's in the way.

The power steering and alternator both have 3 bolts that hold them in place...you'll have to remove the power steering belt first. These are all 13mm. If standing at drivers side, there's a bold at bottom of powr steering pump, its an adjustment kind, remove the nut or just loosen it but leave bolt in.

Then remove the other two bolts, they are recessed in the back of pump on lower side. You can see which ones they are by looking for the nuts on front of pump. Loosen them and remove them.

Pump will be totally loose now, take off that belt and carefully finagle it around fan and off if need replaced, if not, just drop and let hang for now.

Then onto Alternator which will be bottom left of engine as you look at front of engine. Theres a through bolt on bottom of alternator, just roll up your sleevesand climb under car and use 17mm wrench...the alternator is threaded so there's not nut down there to loosen. Dont remove this bolt, just loosen it well.

Now loosen the top 2 bolts, dont worry about the adjustment, mine was stripped...and my adjustment was the prybar:) Loosen those but dont remove them...wiggle the alternator until it gives you the slack you need to remove the belt, if you cant get the slack, you can wrap your fingers around the belt upper and lower and squeeze, this will give lots of leverage and force alternator to move in, then pop that belt off and discard.

Now just put the alternator belt back on, use prybar to get proper tension...and tighten. A half inch of play is about the right tension...but tighter is good with a new belt since it will stratch a bit over time.

Make sure all 3 bolts are tight on alternator then move to replace power steering pump belt, but you will have to put at least onee of the top bolts back on to pivot against when using prybar to tighten that belt, then once you have the tension you want, tighten adjustment bolt, then keep the tension and put 3rd bolt in and tighten, make sure all are tight and you have 1/2 inch play on that belt as well. Then put all the other things back together ...check to make sure all tools are out from engine compartment and fire it up, if it squeels, it's too loose, if not, you're good and you can wipe down your tools, put them away and use the GoJo:)

Good Luck!