C223 Timing Belt Replacement

[JoeIsuzu]

C223 Timing Belt Replacement
From a post by Jerry LeMond (JLEMOND)
with edits and additions from others...
(This is a work in progress -- if you have comments or photos, please submit them in this thread.)

To change the belt is pretty straight forward, and will take about 3-4 hrs if you haven’t done one before. Get everything off of the front but the belt. The cover plate bolts are different lengths, so be careful to keep track of where each one came from.

The manual recommends removing the fan shroud, fan, fan pulley, and radiator. So, of course the belts come off, too. The radiator may not have to come out, but it definitely gives you more room to work.

This is also an excellent time to replace the bypass hose, since you ordinarily can't even see it. It's the small U-shaped hose that connects to the water pump. If your water pump is iffy, it's also a great time to do that job.

The bypass hose is on the right.

Next turn the crank until the number one piston is at TDC (the timing mark will be at 12 o'clock straight up and down with the cam and pump sprockets looking straight at each other with the 2 little arrows). Now, before taking anything loose, there is a small bolt hole in the top of the pump pulley that you stick a 6mm bolt through. It has to be at least 2/1/2 inch long (the one pictured is 4 inches). Thread it in the plate behind the pump and tighten it down enough to hold the pulley from turning. Note, in the photo below, the belt is off. Be sure to align the marks BEFORE removing the belt.

Now loosen the tensioner nut, slide the tension roller bearing off, and replace the belt. Reinstall the roller and the spring, and let the spring only tension the belt. Tighten up the nut, and then remove the 6 mm bolt. Turn the engine over about twice and bring the TDC marks back up to TDC again and double check your cam and pump marks. If the arrows are straight across from each other, put the retaining guide ring on, and put it back together. If you don’t have the proper timing dial indicator, to check the pump timing , you are probably best to leave it alone, or it is a hit and miss method to do accurately. However, if you can see the line marks on the outside of the pump mounting flange, line up the line on the pump with the line of the mounting plate, dead on across from each other, and you will be so close you would never know the difference in the timing.

[arrowmntdiesel]

One more picture....

[jdemaris]

I had trouble getting the crankshaft pulley off of mine. It was rusted stuck and there is no good way to get an outside-jaw puller on it - it would probably break the pulley.

After the four bolts are out, I found that a 3/8" X 16 tap is just the right size to tap some threads into two of the pulley holes. You can then stick a T-bar puller into with via two 3/8" x 16 X 3 1/2" long bolts. Worked great.

I also found that the timing-belt tensioner bearing is commonly available overseas - but not here.
My original bearing is an NSK 2830-6A Another list shows it as 2B30-6ASA
Isuzu part # 5-12539-013-2 Also SKF VKM79003
Also HYE IB-18015 or BE-906 at Japan Parts. It is 62 mm diameter, 38 mm high, and 38 mm deep. Cost overseas is 55 Euros.

And - about the V-belt idler bearing. My original was bad and is a Nachi 6303NK. Local NAPA wanted $32 for one and did stock it. I bought one from VX bearings for $2.50. http://www.vxb.com
For that price, I bought three of them just to have around.

[NeDieselLUV]

So what are we to do about a tensioner? Just check our old one and re use it? That seems foolish on an interference engine.

Or do I just use a bearing of similar style and the correct size instead.

I just got a new belt and want to do this right.

[puttputtinpup]

So what are we to do about a tensioner? Just check our old one and re use it? That seems foolish on an interference engine.

Or do I just use a bearing of similar style and the correct size instead.

I just got a new belt and want to do this right.

I got both my belt and tensioner spring at NAPA. The tensioner bearing is available from Jerry Lemond. Some of us have taken the seal off the bearing, cleaned it, and repacked w/ good grease. This is up to you.
Andy

[barnhart.isuzu]

Ok. I'm in middle of timing belt replacement. Do i have to take of the fan pully before the plastic timing belt face plate will come off? If so, are the timing marks on the fan pully? I've got the left (passenger) side of the face plate off and I'm a little suprised as to how good of condition the belt is in. I've considered just reassembling everything, but since I've gone this far I'm pressing forward.

BTW - thanks JLemmond for the parts!

[JoeIsuzu]

Ok. I'm in middle of timing belt replacement. Do i have to take of the fan pully before the plastic timing belt face plate will come off? If so, are the timing marks on the fan pully? I've got the left (passenger) side of the face plate off and I'm a little suprised as to how good of condition the belt is in. I've considered just reassembling everything, but since I've gone this far I'm pressing forward.

BTW - thanks JLemmond for the parts!

If you're referring to the pulley that the fan clutch is mounted on, yes--you do have to take off the fan pulley first.

As for timing marks, no. Not on the fan pulley. There is a mark on the pulley on the crankshaft, but that pulley has to come off too. But why do you need timing marks? Just make sure NOTHING MOVES while the belt is off. Don't roll the truck in gear, don't turn the engine over. Use a bolt to lock the Injection Pump pulley per the instructions.

Jack

[puttputtinpup]

If you look at the picture showing the timing marks lined up on the IP and cam, you'll see the crank shaft pulley hub w/ a dowel pin sticking out for aligning the pulley back onto the hub. When it's at 12:00 position, it's at TDC[img]timing_gears_aligned.jpg[/img]
Andy
that didn't work....the picture transfer