Timing Belt Parts

[SoTxVx]

Bart,

If you want to make sure you got it right ...

Turn over the engine by hand. Make sure the mark line up after turning it over. If that is good. Put your harmonic balancer on and just snug it up and start the engine. Make sure it sounds and revs okay. Don't go overboard and make sure you dont get any loose clothing or hair caught up in the moving parts. This will not hurt your engine and can save you a lot of headache if you didn't get it just right. You know how hard it was to get to where you are now. It would be a pain to have to do it all over again.

John

[nfpgasmask]

Turn over the engine by hand. Make sure the mark line up after turning it over.

Yes, I rotated the engine by hand 3 times and the hash marks lined up correctly every time so I think I am good.

Put your harmonic balancer on and just snug it up and start the engine.

What is a harmonic balancer? No idea what you are talking about??

At this point things are getting put back together. Worst case scenario my timing is off and I get CEL and have to go back in. But, I am feeling pretty good about my timing at this point.

What I don't like however, is how the damn manual is so freakin' vague. Finding the torque specs for certain things is a MAJOR pain. I might have to call Merlin tomorrow and see if I can talk to someone who can tell me torque specs for certain parts.

Right now I am replacing the Serpentine Belt Tensioner and pulley. There is 1 bolt holding the top part of the tensioner assembly to the housing. There is also a large allen bolt in the center of the tensioner assembly that I had to remove and for the life of me I cannot find the right torque specs for these bolts. Furthermore, what is the correct torque for the tensioner pulley itself? This is where I have stopped for the night.

But I am getting there and I should hopefully be done tomorrow after work or Tuesday at the latest.

Bart

PS - A friend of mine told me I should probably change my "heater hoses" as well. I have no idea what he is talking about. Anyone??

[SoTxVx]

The harmonic balancer is the big round piece of metal that was on the end of the crankshaft. It had the large bolt going through it to the crankshaft end that you probably had fun getting loose. It had the lower sepentine belt pulley bolted to it. It had to come off before you get the lower cover off to completely expose the belt.

If you feel real good about the timing then you may not want to start the engine before reassembly. I just know that the first one I did, I ended up doing twice because I got the crank pulley one tooth off and had to tear it all back down. Thank goodness it was on a 2.6L older trooper that was not as involved as the 3.2L and 3.5L motors are. And the second time you do it, it goes faster after you stop cussing.

I don't believe there are any heater hoses that are easy to replace at the same time as the timing belt.

John

[nfpgasmask]

Well, like I said, EVERYTHING lines up. So, I am pretty confident, and I am not worried about the timing at this point. But then again, I have never done this before so who knows.

I do however have the following questions:

1) Once everything is back together, do I just fill the radiator with coolant through the fill cap on the top? I have 2.5 gallons of coolant ready.

2) Torque specs, how important are they? I am stuck on the serpentine belt tensioner assembly. To remove the tensioner assembly, you have to remove a single bolt in the upper corner of the assembly. You also have to remove a large allen bolt from the center of the tensioner assembly. This will allow you to remove the assembly, however I cannot find the torque specs for these parts.

3) Should my timing belt be slightly off, what will happen when I crank the engine over for the first time? Will I simply get a rough running engine and a CEL? Will is just stall out? What should I be prepared for if I effed up somewhere? I won't do any serious engine damage, will I?

Once I figure all this out, I will be able to finish.

Thanks - Bart

[SoTxVx]

Bart,

If you still have time and feel uncomfortable about the radiator condition... Take it to a radiator shop. They will pull the tanks and will rod out the core cleaning all of the cooling tubes. When you put it back together, just fill the radiator and when the engine gets up to temperature, the thermostat will open and you will need to top it off again. Should cost no more than ~$100 (at least in this part of the country). If you don't have time, it will only cost you another $40-$70 to have the shop take it out and do the work later on.

If you can't find the torque specs, crank it down. you may want to use a small amount of loctite blue. Here is a rough guide. Note that fine threaded bolts withstand higher torque values than rough threads.

http://dodgeram.org/tech/specs/bolts/M_bolts.html

There is some debate if the engine is an interference of non-interference but searching on the subject, Tone (RIP) posted that our engine is a non interference engine. That's good enough for me. You should not have any valve to piston contact even if the timing is off.

You might want to read this post and give a second thought to starting up the engine before you get it all back together. It can't hurt and may save you an additional teardown to get it right.

http://www.vehicross.info/forums/showthread.php?t=8070

John

[nfpgasmask]

Hey John,

Thanks for all your help.

Here is what the manual says for the serpentine belt tensioner:

"Install auto tensioner assembly and tighten the fixing bolts to the specified torque:
Shorter Bolt: 20 N.m (14.8 lb ft)
Longer Bolt: 39 N.m (28.8 lb ft)"

This confuses me because:

a) There is only one bolt that holds the tensioner assembly that can be replaced with a torque wrench

b) The other bolt is a large (14mm iirc) allen bolt, how does one torque an allen bolt?

c) What is the torque specs for the bolt that holds the actual pulley to the tensioner assembly?

This is driving me nuts! I hate how freakin' vague the manual is.

Bart

PS - When using a torque wrench, how do you adjust it down to numbers like 28.8? Ugg.

[Travelin2]

Bart; you can get allen sockets that fit on your torque wrench and the 28.8 is probably just a conversion number from the Newton scale or something. I read that as 29 lb/ft.

[nfpgasmask]

You might want to read this post and give a second thought to starting up the engine before you get it all back together. It can't hurt and may save you an additional teardown to get it right.

http://www.vehicross.info/forums/showthread.php?t=8070

John

I just read this whole thread, and right from the beginning, when I read what Kyle did, I understood that he did it wrong.

In my case, I already had the TSB read and re-read in my head. I absolutely did not rotate the crankshaft or the pulleys AFTER the original belt was removed. I'm going to outline everything in my how-to (provided I successfully finish ) but here is a quick breakdown:

After I opened up the timing belt compartment by removing the three covers I rotated the engine by hand with my breaker bar. This was where I first got confused. There are reference marks on the camshaft pulleys and on the engine housing. The passenger side reference mark is at 10 o'clock while the driver's side pulley is at 2 o'clock. While cranking the engine over by hand before the original belt was removed, every complete rotation yielded the same results, the pulleys lined up with the reference mark on the engine housing at the same time, every time. What confused me, was that I *thought* the old mark on the belt needed to line up as well. But, after talking to a mech friend of mine and reading and reading, I came to the conclusion that the marks on the belt are for REINSTALLATION only. I hope I am not wrong here, but I rotated the engine by hand (prior to removing the original belt) damn near 15 times, and the lines on the belt NEVER lined up with the marks on the pulleys and the housing together.

So basically, you need to line up the marks on the pulleys with the marks on the housing, ignoring the marks on the original belt. At this point the mark on the crankshaft pulley will be at 3 o'clock. Now you are ready to remove the belt. Loosening the bolts on the tensioner, the belt will come loose, and the camshaft pulleys will SPRING to the 12 o'clock position. This was confusion point #2 for me. Again, after talking to my mech friend it all started to make sense. So now, you have the old belt off. All you do at this point, is put the new belt on, starting with the passenger side camshaft pulley, aligning the white line on the belt with the notch on the pulley, and hold it in place with a binder clip. Then, do the same with the driver's side pulley. To do this however, you need to have a wrench (and a helper if possible) to pull the passenger side pulley BACK to the 10 o'clock position. You may need to play a little with the driver's side pulley as well. So once you get all three marks lined up correctly on the camshaft pulleys, you will need a helper to pull the camshaft pulleys back to their reference marks and hold there so you can get a little slack in the belt. Then you can crawl under the VX and carefully align the dotted lines on the new belt with the notch at the 9 o'clock position (180 degrees from TDC) on the camshaft pulley. Once you have the belt on all three pulleys, the tensioner will need to be replaced. To do this, you need to wrench again on the tensioner pulley to give yourself enough room to put the new tensioner in place, bolt it down and pull the pin. At this point, you can rotate the engine by hand again, the marks on the camshaft pulleys should align with the marks on the engine housing together, at every full revolution. You will also notice that the white lines on the timing belt do not align the same after every revolution, just like the original belt, but as long as the pulleys consistently line up together, you are good.

***To anyone reading this, I am not done yet and the above statement is speculative!

Bart