Phasing Front Balance shaft

[dsmgsx98]

I have searched and search here and google, and have come up with nothing on how to get the front BS in time. Does anyone know how to get the front BS aligned properly???

 

[newTSIguy]

Its pretty straight forward, line up the indicator marks on the crank and balance shaft sprocket together then tighten tentioner pully.

 

[dsmgsx98]

Its pretty straight forward, line up the indicator marks on the crank and balance shaft sprocket together then tighten tentioner pully.

Its sounds easy, but it can still be out of phase becuse of the counterweight! is there a way to tell like how on the rear you put the mark straight up and let it fall back towards the timing mark????

 

[99gst_racer]

Line up the timing mark and it will be properly phased. Nothing more needs to be done and there is no other method.


Assuming you have a 7-bolt:

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[dsmgsx98]

Line up the timing mark and it will be properly phased. Nothing more needs to be done and there is no other method.


Assuming you have a 7-bolt:

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No its a six bolt, and what about the counter weight? if its like the rear BS counter weight it has two ways it can line up with the mark, the right way and then 180 out and the marks still line up ????

 

[99gst_racer]

It's been a long time since I've even handled balance shaft components; but if I remember correctly, the sprocket for the front shaft can only go on one way, right? If so, then it's impossible to for the shaft to ever be 180* out of phase when lined up to the mark.

 

[dsmgsx98]

i thought it was like the rear with 2 ways, 1- the right way and 2-180 out.... sorry i am not trying to question your knowledge, just trying to make sure that this is right!!!

 

[99gst_racer]

I don't think it's like the rear. I could be wrong though. I don't have the parts to look at, so you'll need to check that out. Just see if the gear can even physically fit on both ways or not.

 

[dsmgsx98]

ill check it when i get to the house for lunch! I am going to put the timing mark straight up and see which way it falls and turn it 180 and see which way it falls again, ill report back after lunch!

 

[19Eclipse90]

Paul is correct. The front shaft is a simple matter of lining up the marks.

I'm having a hard time writing it out/describing it, so this may help and it may not. Hopefully it does.

The sprocket for the front balance shaft is directly on the shaft. One rotation of the sprocket equals one rotation of the shaft. At any angle of rotation of the sprocket, the shaft is at the same angle of rotation. Being that the sprocket can only be installed on the shaft one way due to the key/guide geometry, represented in the figure below, it's really difficult to screw the front up.

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The rear shaft uses a similar key/guide geometry so, again, it can only go on one way. The rear shaft is different than the front because it is not directly run off the crankshaft. The crankshaft and oil pump sprocket are linked, the sprocket to the oil pump drive gear (referred to now simply as gear), and the gear to the oil pump driven gear (referred to now as pinion) -- which is the one connected to the balance shaft. One rotation of the oil pump sprocket does not equal one rotation of the pinion. It does equal one rotation of the gear, however. But because the gear and pinion are not the same size (the pinion is smaller), it can take multiple rotations to correctly align the rear balance shaft with the sprocket.

That is the nature of gear ratios. In this case -- and being a bit hypothetical as I don't have the actual number of teeth for the gear and pinion in front of me -- the drive gear may rotate three times, causing the pinion to rotate 4.5. That is why the rear can be out of phase even when the timing mark on the sprocket is lined up. As a bit of an extra, anyone who's removed the oil pump gears knows that the gear and pinion have a timing mark to correctly align the two of them. This ensures that they are always in the same phasing and why it is critical to line them up properly when keeping the balance shafts installed.

 

[99gst_racer]

Thanks for the confirmation, Brian. That's how I thought the shaft was keyed, but I wasn't 100% sure.

 

[9!'clipseDOHC]

Taken from the VFAQ:

Remove the balance shaft plug bolt (Figure 12c) on the rear side of the cylinder block and insert a Phillips screwdriver through the hole. (The balance shaft plug is a bolt a couple of inches above the oilpan, about dead center driver-to-passenger side. It's a bolt on a flat machined surface that doesn't seem to belong there, because it isn't bolting anything down)

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The balance shaft is in the correct position if the screwdriver can be inserted at least 60 mm (2.4 in.). If the inserted depth is less than this only 20-25 mm (.8-1.0 in.), the oil pump sprocket must be rotated one full turn and timing marks realigned. Recheck the balance shaft position using the screwdriver to ensure that it can be inserted 60 mm (2.4 in.) or more. Keep the screwdriver inserted until timing belt installation is complete (Figure 13).

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NOTE that there is an easier way to do this. Simply rotate the mark on the oil pump sprocket until it is pointing straight up, and let it go. If the sprocket rotates towards (counterclockwise) the timing mark on the engine, the oil pump sprocket is aligned correctly. If it rotates away (clockwise) from the mark, spin the sprocket a full turn and test again, and it should properly rotate towards the mark now. Now line the mark on the sprocket back up with the mark on the engine. This avoids having to remove the rear access bolt entirely.

Caution: MAKE SURE THE BALANCE SHAFT IS PROPERLY POSITIONED. It is possible for the oil pump sprocket timing marks to be properly aligned, and have the balance shaft out of phase. This could result in a SEVERE engine vibration.

 

[99gst_racer]

^^ That applies to the rear shaft and the OP is asking about the front shaft.

 

[dsmgsx98]

Paul is correct. The front shaft is a simple matter of lining up the marks.

I'm having a hard time writing it out/describing it, so this may help and it may not. Hopefully it does.

The sprocket for the front balance shaft is directly on the shaft. One rotation of the sprocket equals one rotation of the shaft. At any angle of rotation of the sprocket, the shaft is at the same angle of rotation. Being that the sprocket can only be installed on the shaft one way due to the key/guide geometry, represented in the figure below, it's really difficult to screw the front up.

You must be logged in to view this image or video.

The rear shaft uses a similar key/guide geometry so, again, it can only go on one way. The rear shaft is different than the front because it is not directly run off the crankshaft. The crankshaft and oil pump sprocket are linked, the sprocket to the oil pump drive gear (referred to now simply as gear), and the gear to the oil pump driven gear (referred to now as pinion) -- which is the one connected to the balance shaft. One rotation of the oil pump sprocket does not equal one rotation of the pinion. It does equal one rotation of the gear, however. But because the gear and pinion are not the same size (the pinion is smaller), it can take multiple rotations to correctly align the rear balance shaft with the sprocket.

That is the nature of gear ratios. In this case -- and being a bit hypothetical as I don't have the actual number of teeth for the gear and pinion in front of me -- the drive gear may rotate three times, causing the pinion to rotate 4.5. That is why the rear can be out of phase even when the timing mark on the sprocket is lined up. As a bit of an extra, anyone who's removed the oil pump gears knows that the gear and pinion have a timing mark to correctly align the two of them. This ensures that they are always in the same phasing and why it is critical to line them up properly when keeping the balance shafts installed.

thank you guys for helping me understand!!!!!

Thanks for the confirmation, Brian. That's how I thought the shaft was keyed, but I wasn't 100% sure.

Thank you for your help !

 

[9!'clipseDOHC]

^^ That applies to the rear shaft and the OP is asking about the front shaft.

Ahh

 

[DSM1G90]

Ya, the front BS shaft is directly attached to the sprocket - not geared like the rear one.

This goes for the 4G37 (1.8L) motors as well.