TB Static Timing Verification Questions...

Alright all, everything thus far on the TB swap has gone very well and faster than I had thought. It's my second one, and all in all, it's not a very bad job.

I've used the guide on here thus far and it's been very good, but one thing I struggled with last night was actually getting the cam sprocket on after the TB was routed correctly. After about 45 frustrating minutes, I removed the top small roller, and easily was able to get it on, then install the roller. I forgot that critical step from the last time I did it.

I am using the Metalnerd tool kit.

So, prior to installing the belt, the cam was locked at TDC (lobes "up"), the IP pin was installed, and I had locked the crank at TDC. See photo below:



It is then that I was fidgeting getting the belt on for a bit.
When I finally got it all routed per the above critical step, I had the cam sprocket bolt on finger tight, and I loosened the IP sprocket to take any tension off the pin. Then I set the tension on my tensioner and then locked the cam sprocket using the counterhold tool and then locked down the IP sprocket.

One thing to note is I still had the crank lock on for all of the tightening of the sprockets so the crank stayed at "TDC".

I released the crank lock after that and went to check my TDC mark and it looks like this now:



You can see that it moved off the mark a hair.

Now, I remember fighting this the last time I did a TB job, and eventually gave up and left it like you see in the photo. It ran fine that way up to this point (60k miles).

What you see in the last picture is where I currently sit, PRIOR to spinning the engine by hand. It got late last night and I called it quits. So tonight I need to turn the engine over a couple times from the crank and re-check my mark and make sure everything (cam lock and IP pin) slide in.

Here are my questions:

1) I know that TDC mark is off slightly as you see in the photo with everything locked. I ran it this way before from the last TB job (ie, when I pulled the flywheel rubber inspection plug before tearing everything down, that is where the mark was). I am OCD, but should I try to align that perfect? I feel like the last time I did this, I could get it pretty dead on, but when I went to spin the engine by hand, it was always off by this little amount, so I left it.

2) If I do decide to re-align...
If my mind serves me correctly, if I want to get that TDC point aligned with the notch at this point in the build, I need to crack the cam sprocket free, crack the IP sprocket free, loosen the tension on the tensioner, THEN turn the crank so it sits at TDC. This should allow both sprockets to self adjust with the cam lock and IP pin in place. Then I would lock the crank down, re-tension the tensioner, and tighten the cam and IP sprockets. Hopefully my flywheel mark stays at TDC and then I crank by hand and re-check...

I just want to verify my thought process is correct.

Thanks in advance all!!

Afternoon bump, going to be trying to finish this up tonight...

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Sounds legit to me. As long as you don’t loosen any pulleys up too much; then re-check your marks. The IP gets verified with the VAG at some point; so it’s pretty much just between the crank and cam at that point. That’s probably 1 degree or less. Maybe a guru will chime in and have an opinion.

So I got home today and was able to rotate the crank by hand and re verify. I went something like 4 revolutions, then slipped the IP pin and cam lock back in and this was where I was at (really sorry for the massive photo, posting from my phone won't let me edit the img size):

I'm leaving the static timing there, I know if I try to tinker it'll likely be worse off.

It's all buttoned up except coolant and fuel lines. I'll bump it a few times tomorrow to center the belt then let er rip, and just adjust the timing with VAG COM after that

I've never used a crank lock.

With the cam and pump locked and both sprockets loose I tension the belt.

Then verify/return the crank to TDC.

Then torque the cam and pump bolts and verify the crank at TDC.

In your case I would have loosened the cam and pump sprockets but not the tensioner, returned the crank to TDC and torqued the cam and pump. I see no reason to relieve the belt tension for the readjustment.

You are rotating the motor by a wrench on the crank bolt, right?

your huge pics makes the thread close to impossible to read.

KLXD said:

I've never used a crank lock.

With the cam and pump locked and both sprockets loose I tension the belt.

Then verify/return the crank to TDC.

Then torque the cam and pump bolts and verify the crank at TDC.

In your case I would have loosened the cam and pump sprockets but not the tensioner, returned the crank to TDC and torqued the cam and pump. I see no reason to relieve the belt tension for the readjustment.

You are rotating the motor by a wrench on the crank bolt, right?

Click to expand...

Yes I rotated by crank bolt (19 mm, 12 point)

There seem to be some that use the crank lock and some that don't. The reason that I chose to use it is so once I got all lined up @ TDC with the flywheel, and the locks are in place IP and cam, when you install the belt, and tension (after the cam sprocket is installed), it should naturally float/spin the IP and cam sprockets with everything all locked and lined up.

If you don't have the crank lock on, you just run the risk of losing your TDC point in the window if you try to pull the belt enough to buy yourself some more room to install the cam sprocket. I opted not to re-adjust per the final pic above. Messing with it more would never get it perfect for me, but for those that can get it directly under there after rotating it by hand, more power to you!

As an added note, there is a slight amount of play in the machining tolerances of the crank lock and the end of the crank. Off by this little amount gets taken up in the play if I ever so slightly rotate the crank (crank lock still slides in and out fine)

Ol'Rattler said:

your huge pics makes the thread close to impossible to read.

Click to expand...

I realize this and apologized in the post above due to having to post the photo from my phone and not being able to edit it from mobile. I had to wait and get to a PC to make this change.

I'm finishing up the job this morning

Photos much better, thanks.
I think it's fine, but hopefully someone knows for sure.

Too Late to Turn Back Now...

Well, it better be ok haha!
Got the job finished up this morning.
Fired right up fine after per the static timing I had above. Almost instantly actually.
I did pull a vac on the return line from the IP pump to draw fuel through there, although it probably wasn't needed because I had line clamps and a 5/16 bolt in the lines after I took them off.
It definitely took me about 8 tries chasing around the timing adjustment to where I wanted it with VAG Com. It was @ about 83 with the static timing above, which was too advanced.

Eventually I drew it in right where I wanted it. It bounces around a bit from where you see it slightly higher, but stays in the graph:



Glad this is over with, probably took me about 8 hours total chipping away a couple hours after work per night. I could probably do it in less start to finish now.

It's unfortunate that the 100k kits come with components that fail @ 60k. The Geba pump gasket is what sprung a leak. The pump probably could have gone the other 40k, there was no shaft play or anything, but anything that has to do with the WP, you're pretty much at a timing belt job anyway.

Hopefully this kit lasts me a bit longer

Now that you mention it, my geba water pump had seeped from the shaft seal. It had 100k on it though. Not a noticeable leak, but it did leave some minor white buildup.

The o ring seal bore needs to be clean and smooth. The oring will get damaged during install if it’s not. I pull the oring off and grease it up with water proof grease. Lubing orings helps keep them from twisting or pinching and what not when the get pushed in.

Dieselmonkey02 said:

The o ring seal bore needs to be clean and smooth. The oring will get damaged during install if it’s not. I pull the oring off and grease it up with water proof grease. Lubing orings helps keep them from twisting or pinching and what not when the get pushed in.

Click to expand...

Did this last time and this time. Kissed the bore with Emery cloth both times. Smooth or not, o rings like that can take up a lot of tolerance mismatch. I've done a bunch of bulge forming in the aerospace industry... surprising what you can get away with. This one was damn near flat when I removed it.
New one was installed with evinrude marine grease.
We'll see what happens this go around

BTW I use a nice big screwdriver (with the crank lock off, of course) to "zero" that mark if it moves on me before I tighten up the pulley and IP bolts. You can get it bang-on that way and it's a LOT easier than trying to do it on the other end of the engine while not being able to see the mark!

Genesis said:

BTW I use a nice big screwdriver (with the crank lock off, of course) to "zero" that mark if it moves on me before I tighten up the pulley and IP bolts. You can get it bang-on that way and it's a LOT easier than trying to do it on the other end of the engine while not being able to see the mark!

Click to expand...

I can def see that. I've seen it for the autos... can you jam it in for the manuals as well?

Yep; it makes a decent crank lock. And if you're off a bit once the tensioner is set but before you lock down the cam pulley and IP bolts you can lever it against the housing and a tooth to move it slightly as well.

Excellent good to know!