Serpentine Belt Replacement

[acvr4]

Jules, It's pretty strait forwards. Look on page 104of the 03 service manual pfd (easily found)
The drive tensioner is directly below the oil filter, just left of the power steering pulley and above the A/C compressor- you can't miss it since it's a smaller pulley. Under it is socket sized knob an a Star insert. You can used either one. Then just twist the ratchet towards the left and this relieves the pressure off the belt. Then slide the belt off the water pump pulley first and then it will easily come off the rest. Installation is just as easy Wrap the belt back around the pulleys at it came off, leaving it off the water pump pulley until the end.

[hkpierce]

I replaced my serpentine belt today on my T1N 2002 w/ 612 for a couple of reasons - over 70,000 miles, and the dealer's mechanic spilled brake fluid all over the front of the engine including the belt. So I started following the instructions above, and quickly ran into trouble.


First, the tension nut is not visible. Indeed, it took considerable searching with the mirror to find it. It is buried way down the front of the engine - virtually impossible to get at from the top by hand due to limited space between the fan and the pulleys.
Belt Ten Location.jpg

The instructions copied by Andy C above for 2003s indicates that the tensioner has a square hole to place a ratchet to relieve the tension. However, on my 612, that is not the case. It requires some large size Torx (T-60 - who has that?!) or a 17mm 12-point socket (thankfully I remembered that from an Dr. A YahooSprinterVan posting from 12/2006):
BTension nut.jpg

I mounted the socket from the top location, loosened the belt - and ran straight into trouble. The socket handle was mounted straight up as shown below. However, in this position, the handle is forced against the top radiator hose, which results in the handle blocking the belt's removal as the clearance between the handle and the tension pulley is so close. Further, the tension locks the socket in place - so I was stuck. I had to use a pry bar to release the tension to remove the socket.
P2150026.JPG

It turns out the picture in the manual is correct - but not for the simple socket handle I was using. Without ratchet control, it is not possible from the top to move the tension pulley far enough to remount the belt - the handle hits the fan pulley limiting its motion. The only way is from under the engine. From under the engine, it is possible for one person to both move the handle to the socket and get the last of the belt on the alternator pulley.
Belt Under.jpg


Once I got the belt off, it all seemed OK except for a very strange clear cut straight across the belt:
Belt cut.jpg


Part Numbers for my 612 w/AC [NOTE that 647 belts are about 1/2 inch longer] :

Mercedes Benz 014 997 0492
Continental 6PK2271
Dodge 0513564AA
NAPA PBH6K895 * Source: NAPA web site
Goodyear 4060887 * Source: Goodyear website
Dayco later 2003+ 5060890 2002-2003 need dayco 5060895 * Source: Dayco.com
Gates K060895 * Source: gates.com
TUF TF060883 * Source: TUFautoparts.com [note: TUF's cross chart does not match hits from the other suppliers]

* I have not used these products. Further, note that the last three digits of NAPA on down approximate the "effective" length of the belt in inches.

Here are pictures of the tensioner and idler pulleys. Note that these pulleys are plastic.

[BaywoodBill]

Looks like you caught that just in time.

Is there a way to turn the engine over so a person can inspect the belt? Like in the old days when you could turn a crank?

[talkinghorse43]

1 1/16" socket on the bolt head securing the harmonic balancer. Just be sure to only rotate that bolt head in the clockwise direction (looking from the front of the engine).

[hkpierce]

Originally Posted by BaywoodBill

Is there a way to turn the engine over so a person can inspect the belt? Like in the old days when you could turn a crank?

Originally Posted by talkinghorse43

1 1/16" socket on the bolt head securing the harmonic balancer. Just be sure to only rotate that bolt head in the clockwise direction (looking from the front of the engine).

But, unlike the old days, the serpentine belt is really long. It would take forever turning the crank from underneath then popping up to look at the belt's interior side as it passes over the fan pulley.

[BaywoodBill]

Originally Posted by hkpierce

But, unlike the old days, the serpentine belt is really long. It would take forever turning the crank from underneath then popping up to look at the belt's interior side as it passes over the fan pulley.

It's your wife who is under there turning the crank while you're on top studying the belt..

And, Talking Horse, just so we have this clear for me and all others who look at this thread during the next 30 years, I turn the crank clockwise when I'm facing the engine while standing in front of the vehicle? And this is the procedure for T1Ns and the other kind?

[talkinghorse43]

Originally Posted by BaywoodBill

I turn the crank clockwise when I'm facing the engine while standing in front of the vehicle? And this is the procedure for T1Ns and the other kind?

Don't know about the NCV3s, but that's right for T1Ns. The principle behind the procedure is to keep the timing chain in tension so it won't (possibly) jump a sprocket tooth on startup, so you turn in the direction the crank pulley (harmonic balancer) rotates when it's running.

[BaywoodBill]

Thanks Talkinghorse

[rlent]

Originally Posted by talkinghorse43

Don't know about the NCV3s, but that's right for T1Ns. The principle behind the procedure is to keep the timing chain in tension so it won't (possibly) jump a sprocket tooth on startup, so you turn in the direction the crank pulley (harmonic balancer) rotates when it's running.

Probably easier just to pull the belt off and inspect it .... close up like ..... and then stick 'er back on there ..... give ya some practice on changing it, if case ya ever have to do it ....

Me, I'd rather do my practicing some sunny afternoon at home in the driveway ..... as opposed to a bitter cold night on a lonely stretch of road ...... in the middle of a snowstorm

[jdcaples]

Originally Posted by rlent

Me, I'd rather do my practicing some sunny afternoon at home in the driveway ..... as opposed to a bitter cold night on a lonely stretch of road ...... in the middle of a snowstorm

..... after you had walked up hill both ways, bare foot, in the snow, on gravel, to the nearest dealership to get the proper belt since the dealership at home sold you your "spare" was actually one for a 1/2 ton dodge pickup.