1994 E320 Serpentine Belt removal/replace instructions help

[dmorgan]

Hello; I am a newbie in this forum and I need some help here. I have a 1994 Mercedes Benz E320 Station Wagon. The serpentine belt or V belt needs to be replace due to stripping of the belt. This is what I have done so far:
Removed the fan shroud and the cover.
I have enough room to access the belt tensioner using the breaker bar without taking off the fan and the radiator. I found out the the specific size of the bolt is 6mm hex so I use the 6mm hex socket in order to loosen the bolt from the tensioner pulley. unlike others saying 10 mm bolt, 15 mm bolt, etc. If so, what turn should it be, clockwise or counterclockwise facing toward the driver side from the passenger side of the location? How many turns do I need to loosen the bolt? 1 turn, 2 turns? In addition, the information that I researched so far says that I also need to loosen the 13mm adjusting nut 1/2 turn on top of the tension adjuster after loosening the bolt from the tensioner pulley. It's a long bolt with a hollow interior located just to the right of the thermostat housing. Which direction of the tension adjuster turn, is it clockwise or counterclockwise and is it 1/2 turn or more? Will someone out there please help and guide me step by step process/instructions to remove the belt? I appreciated it.

[sptt]

Facing the the car from the front, you should loosen the set bolt in between the pulleys to the left just like a normal "lefty-loosy". Then the brass bolt tension adjustment from the top. To loosen it you will turn it clockwise which should wind it down towards the tensioner and also let the tensioner come towards the top and loosen the belt. DO NOT do the brass adjustment first!!! After belt is installed, adjust the brass nut by turning it counterclockwise. You should see the belt tighten. Once tight enough, clockwise adjustment of the lock down bolt and it should be good to go.

[dmorgan]

Thank you for responding. However, is there a white plastic marker on the brass bolt tension adjustment from the top? From what I read in the forum, the white marker needs to be line up prior to tighten the tensioner pulley. I don't see any white marker if it is there. Some E320 models don't have it. Any comments is greatly appreciated.

[dmorgan]

Hello there: I was abled to loosen the tensioner pulley bolt lefty left as the previous commentator was correct. Then I lefty left the tensioner bolt a few turns. The serpentine belt came loose. Hooray!! Upon inspecting the old belt, I notice there were only four ribs instead of six ribs. The new serpentine belt is 6 ribs and should be stronger and last longer than the 4 ribs belt. I tried to put the belt on in according to the diagram. However, the fan is in the way. I need to remove the fan itself without taking the fan clutch out in order to make room for the serpentine belt to put on. Otherwise, I have to turn the serpentine belt sideways and sliding under crank pulley underneath the engine which could damage the new belt. I reserched the forum and I don't see any fan removal without taking the fan clutch as well. Any ideas would be appreciated.

[BDBENZ]

There are three 5mm hex head bolts that hold the fan to the clutch. Easy enough to get off but unless you have small hands and some patientce, difficult to get threaded again. Just very small. I did this and found that for me, that it was better to take off the whole fan with clutch intact. If this is your first, it can be hard until you go ahead and make or buy a fan tool which reaches in behind the pulley to hold it stationary, while you remove the 8mm center bolt.

Bdbenz

[Ferdman]

sptt, as far as I know a 1994 E320 (like the 1995 E320) has the newer style drive belt tensioner which has no adjustment. It's far simpler than the older style. Simply use a breaker bar with the correct size socket on the bolt head to release tension/remove drive belt. Installation of the new drive belt is the reverse process ... quick and simple. The most difficult part of the job is removing the radiator cowling and the fan, but definitely not an emergency job you want to perform on the side of a highway.

[Rick76]

The new style tensioner did not get used in the E320 until late in the 1995 production year.

[Ferdman]

Rick, thanks for the clarification about the tensioners. I own two 1995 E320's and they both have the newer style tensioner so that's fortunate.

[dmorgan]

Hey Everybody: I want to thank you all for helping me through this forum. I was abled to get the serpentine belt on without taking the fan clutch off. Instead, I used 5 mm allen hex and 5mm socket using the breaker bar wrench for leverage and more room
to pull off the fan from the fan clutch. I was surprised that the 3 bolts were rather easy to come off. Sure enough, I had more room to put in the serpentine belt without any difficulty. I tightened up the belt tensioner and the belt itself was fallen into place on all pulleys. I, then, tightened the tension pulley bolt. I also did a thorough check on the belt, making sure all is good. I started the car without using the fan on the fan clutch, just in case I need to make further adjustments on the belt. At first, there was this high whining pitch sound after I started the car. I checked under the hood and everything seems alright. After running the engine for a few minutes, the high whining pitch sound went away. I wonder what is that whining sound could be? In any event, I want to express my appreciation for all those who wrote back and giving me some advice.

[sptt]

Sorry...I was out of town and just now checking back. The white plastic indicator on top of the tensioner is just an indicator that lets you know if you are tightening (un tightening) in the right direction correctly and helps you to not go too far. Mine popped off the first time I had it out and I didn't get it back on lined up right so I just tightened the tensioner and "felt" it out. It's been fine since. Looks like you got it figured out though! Nice job. I could not get the three bolts off my fan clutch the first time even with it out of the car! Had to replace both.

[timmyr]

hello,


Just a reminder: before u put it back on the car, clean off the fan blade and inspect carefully,i'm pretty sure you will notice "front" stamped on of the sides of the fan blade, make sure that that side of the fan blade is facing out prior to reinstallation.



belt noises:

prior to new belt installation, i inspect pulleys/bearings for excessive play and then clean up the pulleys with a rag and some brake cleaner.

GATES: Diagnosing Belt Noise - The Spray Bottle Test - YouTube

Dayco - Belt Noise Tech Tips - YouTube

funny how in both videos the cars suffering from belt noise are chryslers

good luck

[dmorgan]

Thanks for the tip in the last message. Just in time to inspect the fan prior to bolted on the fan clutch. All seems ok on the fan. Also, will check out the fan belt noise as well.

[dmorgan]

The three 5 mm bolts on the fan to the fan clutch is now secured. I also cleaned up the fan from dirt, debris, etc. In addition, I used a water bottle to squirt on the belt to get rid of the squeaking or whining noise. It seems so far did the trick. So far so good. Also, I recharged the air conditioner. It does not seem to get cold air in the vent after the recharge. I will go ahead and do some research on that. In any event, you guys are awesome for helping me out. Thanks

[240dddd]

Older thread, but I'm trying to tackle the same project. My 1994 E320 wagon has a 6MM bolt holding the tensioning pulley (#7 in the picture):



I am able to loosen the bolt in the middle of the tensioning pulley.

Next my understanding is that I need to loosen the tension with the adjuster shown in this picture:



Which way loosens the tension? I've read both clock-wise and lefty-loosey. It seems like lefty-loosey (counter-clockwise) would be the right way, but how far does it usually need to be loosened? As soon as I turn it counter clockwise it the adjuster fells pretty loose but the belt doesn't seem to be any looser.

[240dddd]

Nevermind, I figured it out. What wasn't clear to me is that I didn't need to loosen the tensioner pulley (#7), rather I needed to loosen the tensioner itself which sits kind of between #7, #8 and #6. In my case it was a 10mm hex bolt that needed to be loosened. Once I loosened that I turned the tensioner adjuster that sticks out by the power steering fluid resevoir counter-clockwise until the belt was loose enough to come off. The new belt went back on pretty easy at that point.

My next question is regarding correct tension after putting the new belt on. My engine is missing the plastic pointer gauge that would be used to visually calibrate the tension as the tension rod is turned clockwise. Is there another way to calibrate tension? How much deflection should the belt have?