The Correct way to change your TIMING BELT!

greiswig · **Posted:** Wed Aug 27, 2014 3:52 pm

For those of us with head gasket failures, too:

I would want to rotate the crank to check and make sure all the pistons seem to come up level and even anyway. So getting it back to that starting position seems like a good thing to know how to do, and not just rely on it not moving.

flman · **Posted:** Wed Aug 27, 2014 4:51 pm

greiswig wrote:

For those of us with head gasket failures, too:

I would want to rotate the crank to check and make sure all the pistons seem to come up level and even anyway. So getting it back to that starting position seems like a good thing to know how to do, and not just rely on it not moving.

If I am going beyond a simple belt change, everything gets locked.

geordi · **Posted:** Wed Aug 27, 2014 5:24 pm

greiswig wrote:

For those of us with head gasket failures, too:

I would want to rotate the crank to check and make sure all the pistons seem to come up level and even anyway. So getting it back to that starting position seems like a good thing to know how to do, and not just rely on it not moving.

You can spin the engine 100 times if you want - you don't need the pins for that. If you are removing the valve cover, all you need is a long stick down the injector hole. It sits on top of piston #1, and as you rotate the engine, it shows you where TDC is. Rotate 1/4 turn clockwise past that, and you are perfectly positioned.

There isn't a 90 ATDC difference with intake or exhaust stroke, b/c the stroke is determined by the cams. So 90 ATDC on cylinder #1 is all that you need. Once the crank bolt holes are vertical / horizontal, it is perfectly positioned.

kjjet · **Posted:** Thu Aug 28, 2014 9:20 pm

geordi wrote:

greiswig wrote:

For those of us with head gasket failures, too:

I would want to rotate the crank to check and make sure all the pistons seem to come up level and even anyway. So getting it back to that starting position seems like a good thing to know how to do, and not just rely on it not moving.

You can spin the engine 100 times if you want - you don't need the pins for that. If you are removing the valve cover, all you need is a long stick down the injector hole. It sits on top of piston #1, and as you rotate the engine, it shows you where TDC is. Rotate 1/4 turn clockwise past that, and you are perfectly positioned.

There isn't a 90 ATDC difference with intake or exhaust stroke, b/c the stroke is determined by the cams. So 90 ATDC on cylinder #1 is all that you need. Once the crank bolt holes are vertical / horizontal, it is perfectly positioned.

geordi is correct. After the valve cover is removed (which encompasses the cams) the valves are all closed. You can move the crank with out any issues.

falcn · **Posted:** Fri Aug 29, 2014 10:38 pm

Hmmm.

I got the cam locking pins in on the intake and exahaust and found the hole on the flywheel (or indent)...but the cam timing marks are wildly not lining up to anything reasonable - which I guess is to be expected?

I will check my crank bolt holes in the daylight and see if they align in a +

I wish the timing marks in the cam ends could be somehow seen - it would make the job easier.

It seems like people don't use the belt tension tool to remove the belt, they just remove the tensioner and cams with the belt tensioned? I watched COrobotchicken Liberty Timing Belt replacement videos - wish he had someone to video him DOING the removal/installations instead of him talking about it after the fact.

flman · **Posted:** Sat Aug 30, 2014 8:06 am

falcn wrote:

Hmmm.

I got the cam locking pins in on the intake and exahaust and found the hole on the flywheel (or indent)...but the cam timing marks are wildly not lining up to anything reasonable - which I guess is to be expected?

I will check my crank bolt holes in the daylight and see if they align in a +

I wish the timing marks in the cam ends could be somehow seen - it would make the job easier.

It seems like people don't use the belt tension tool to remove the belt, they just remove the tensioner and cams with the belt tensioned? I watched COrobotchicken Liberty Timing Belt replacement videos - wish he had someone to video him DOING the removal/installations instead of him talking about it after the fact.

You can see the intake hole through the oil filler, once you get to 90DATC they usually go right in.

falcn · **Posted:** Sat Aug 30, 2014 10:30 pm

WOO! Done.

Started right up the first time after I got the belt replaced. Had to take it off once as I got 1 tooth off on the crank.

I love this FORUM!!!

I really liked the look of that Graff water pump. Rest of the reassembly is tomorrow

lacabrera · **Posted:** Sun Aug 31, 2014 11:39 am

falcn wrote:

Hmmm.

I got the cam locking pins in on the intake and exahaust and found the hole on the flywheel (or indent)...but the cam timing marks are wildly not lining up to anything reasonable - which I guess is to be expected?

I will check my crank bolt holes in the daylight and see if they align in a +

I wish the timing marks in the cam ends could be somehow seen - it would make the job easier.

It seems like people don't use the belt tension tool to remove the belt, they just remove the tensioner and cams with the belt tensioned? I watched COrobotchicken Liberty Timing Belt replacement videos - wish he had someone to video him DOING the removal/installations instead of him talking about it after the fact.

Horse and stable door comes to mind but if it helps factory markings on the cam sprockets are useless don't know why the markings are there.

greiswig · **Posted:** Sun Aug 31, 2014 11:59 am

I'm curious about this, too: I put a dowel in #1 I injector hole to find TDC, then went past it 90 degrees clockwise. I was able to pretty quickly feel the alignment holes for the intake and exhaust cams, but not for the crank flywheel. Yet the fuel pump mark was nicely lined up.

So I turned it one full rotation and repeated the process. Found the flywheel hole right away. No marks lining up anywhere. Don't see anything on the crank gear either.

A shop had replaced my timing belt and (theoretically) water pump just before 100k, so maybe they didn't bother to line up the fuel pump. And maybe it is coincidence that it seems to have been exactly 180 degrees out? Seems odd.

Clearly the cam gears just don't matter, except that you would want the same belt tension across the top of them as there was before, or at least very close. So you probably don't want to rotate one gear half a tooth relative to the other gear.

I gather that there is some debate about whether the fuel pump timing matters. It isn't like my Unimog pump, where the pulse from the pump opens up the injector and you change injection timing by rotating the pump. But I could maybe be persuaded that the pressure in the fuel rail isn't actually kept constant, and that there is a peak pressure caused by the pump action if it is a piston pump. In which case, timing wouldn't necessarily make it not run, but perhaps just not run at its best?

lacabrera · **Posted:** Sun Aug 31, 2014 12:41 pm

fuel pump timing is not necessary common rail pressure is constant, I have read comments on this about pumps being timed to injector timing but this falls flat on its face because the same fuel pump is used in 4 and 6 and maybe even 5 cylinder engines.

lacabrera · **Posted:** Sun Aug 31, 2014 12:50 pm

greiswig wrote:

I'm curious about this, too: I put a dowel in #1 I injector hole to find TDC, then went past it 90 degrees clockwise. I was able to pretty quickly feel the alignment holes for the intake and exhaust cams, but not for the crank flywheel. Yet the fuel pump mark was nicely lined up.

So I turned it one full rotation and repeated the process. Found the flywheel hole right away. No marks lining up anywhere. Don't see anything on the crank gear either.

A shop had replaced my timing belt and (theoretically) water pump just before 100k, so maybe they didn't bother to line up the fuel pump. And maybe it is coincidence that it seems to have been exactly 180 degrees out? Seems odd.

Clearly the cam gears just don't matter, except that you would want the same belt tension across the top of them as there was before, or at least very close. So you probably don't want to rotate one gear half a tooth relative to the other gear.

I gather that there is some debate about whether the fuel pump timing matters. It isn't like my Unimog pump, where the pulse from the pump opens up the injector and you change injection timing by rotating the pump. But I could maybe be persuaded that the pressure in the fuel rail isn't actually kept constant, and that there is a peak pressure caused by the pump action if it is a piston pump. In which case, timing wouldn't necessarily make it not run, but perhaps just not run at its best?

Hi Just read your your post again and you said you rotated the crank one full turn and found the hole? You must have just not found it the first time. Is your jeep manual or an auto trans flywheels are different.

greiswig · **Posted:** Sun Aug 31, 2014 1:34 pm

lacabrera wrote:

Hi Just read your your post again and you said you rotated the crank one full turn and found the hole? You must have just not found it the first time. Is your jeep manual or an auto trans flywheels are different.

You are absolutely right. I'll try it again.

In a way, it doesn't matter as long as you are making your own marks on an engine that is known to run well currently: all that matters is to get it back to the same timing you left it in. But I like not having too many marks everywhere.

Rotating the crank 360 degrees rotates the cams 180. So you have to get both lined up.

lacabrera · **Posted:** Sun Aug 31, 2014 1:59 pm

greiswig wrote:

lacabrera wrote:

Hi Just read your your post again and you said you rotated the crank one full turn and found the hole? You must have just not found it the first time. Is your jeep manual or an auto trans flywheels are different.

You are absolutely right. I'll try it again.

In a way, it doesn't matter as long as you are making your own marks on an engine that is known to run well currently: all that matters is to get it back to the same timing you left it in. But I like not having too many marks everywhere.

You may have the same problem I had. The timing was slightly out. With the two cams locked with the correct timing pins the crank shaft alignment hole/ dent did not line up about 3/16 inch out. Hence why I feel its best to undo the cam bolts and set the timing again plus its much easier to fit the belt and not to rely on existing timing. If only they used a key slot in those cam sprockets !!!

geordi · **Posted:** Sun Aug 31, 2014 2:09 pm

All USA CRDs are auto transmission. Rotating the crank 1 full turn after finding the two cam pin holes, brings the crank back to the exact same spot, but the cams would be 180 degrees out. That is why it takes 2 full turns to bring all three into alignment for testing after replacing the belt.

The crank pin is a bugger to find, but if you have the top completely off, there are actually two pinholes - for both times the crank is 90 ATDC in each full revolution.

Sent from my iPad using Tapatalk HD

lacabrera · **Posted:** Sun Aug 31, 2014 2:21 pm

Whats the possibility in the cam sprockets moving on the shaft? The shaft has no keys or tapered just the 80 lbs torque. I have tried turning the cam shaft and it takes a lot to turn them? dread the thought.

geordi · **Posted:** Sun Aug 31, 2014 3:46 pm

None of the ones I have done or heard about have had any problems, as long as the cam is tightened to the correct 80 lb-ft, that is sufficient. This is also why you have to use a counter-hold device and NOT the pin to keep everything stable while you tighten or loosen. The pin is nowhere near strong enough and you will ruin the threads in the valve cover.

falcn · **Posted:** Mon Sep 01, 2014 9:26 am

falcn wrote:

WOO! Done.

Started right up the first time after I got the belt replaced. Had to take it off once as I got 1 tooth off on the crank.

I love this FORUM!!!

I really liked the look of that Graff water pump. Rest of the reassembly is tomorrow

Welll CRAP!

Getting P1265 now which when doing research on here shows Glow Plugs need to be replaced. Not happy as I JUST had everything apart....BLAH!

geordi · **Posted:** Mon Sep 01, 2014 11:45 am

JEEP: Just Empty Every Pocket.

Now you know why I suggest to anyone doing the timing or rockers... Do everything else at the same time. ARP studs, rockers (if you aren't already doing them) clean the intake, Weeks elbow kit, glow plugs... You are gonna do it all eventually, might as well rip that bandage off quick and just suffer once.

lacabrera · **Posted:** Mon Sep 01, 2014 4:04 pm

geordi wrote:

JEEP: Just Empty Every Pocket.

Now you know why I suggest to anyone doing the timing or rockers... Do everything else at the same time. ARP studs, rockers (if you aren't already doing them) clean the intake, Weeks elbow kit, glow plugs... You are gonna do it all eventually, might as well rip that bandage off quick and just suffer once.

I used to think it stood for JUST ENOUGH ESSENTIAL PARTS

kjjet · **Posted:** Sun Sep 07, 2014 9:38 pm

[quote="geordi"]JEEP: Just Empty Every Pocket.

That's a good ONE! Very true.

Just oil changes for my VW TDI since I got rid of my CRD problem Jeep.

The Correct way to change your TIMING BELT!

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