2.0T Balance Shaft

[linet90]

Has anyone ever replaced the balancing shafts and intermediate sprocket while rebuilding their motor?

The Audi manual states that all 3 items must be replaced once removed, but this seems unnecessary to me.

[Smac770]

I assume you mean to ask the opposite question: has anyone reinstalled used balance shafts and intermediate sprocket and been fine.
Because there's almost certainly people who have followed the instructions and been fine.

The engine mechanical repair manual explains why the intermediate sprocket has to be replaced if the bolt holding it is loosened. And it states the four step tightening sequence of that bolt.
I assume the balance shaft replacement is more a preventive concern. I assume the bearings are made to take the push one way but not the pull back out. Kind of like all the rubber gaskets that Audi says are must replace if loosened. Yay.

[Allowencer]

I'm going with all new balance shafts on my rebuild. Bottom line, for all the effort and cost put into rebuilding the whole lower end, 80$ to replace them is not worth the savings for a piece of mind.

Unless you can rebuild the bearings and flush them out, which is the biggest cause of failure because of oil starvation as the tiny oil filters are prone to get clogged, forget it. To add, its not just rebuild them but possibly replace the bearing as its tolerances might be jacked.

Here are some pics of my old balance shafts; note, on one of them, the oil screen started to break apart:


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[linet90]

I assume you mean to ask the opposite question: has anyone reinstalled used balance shafts and intermediate sprocket and been fine.
Because there's almost certainly people who have followed the instructions and been fine.

The engine mechanical repair manual explains why the intermediate sprocket has to be replaced if the bolt holding it is loosened. And it states the four step tightening sequence of that bolt.
I assume the balance shaft replacement is more a preventive concern. I assume the bearings are made to take the push one way but not the pull back out. Kind of like all the rubber gaskets that Audi says are must replace if loosened. Yay.

Thanks for the note, I was looking at the exploded view and missed the detailed note.

[linet90]

I'm going with all new balance shafts on my rebuild. Bottom line, for all the effort and cost put into rebuilding the whole lower end, 80$ to replace them is not worth the savings for a piece of mind.

Unless you can rebuild the bearings and flush them out, which is the biggest cause of failure because of oil starvation as the tiny oil filters are prone to get clogged, forget it. To add, its not just rebuild them but possibly replace the bearing as its tolerances might be jacked.

Here are some pics of my old balance shafts; note, on one of them, the oil screen started to break apart:

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I didn't even know these were an engine failure mode, good to know. I can see how the screens can cause damage just like the cam bridge one does. At the moment all of my screens are in tacked, and my motor is an 09. Where are you getting a price point of $80? The lowest I was able to find is $350 for the pair.

[linet90]

I finally found time to get some dry ice to shrink the new shafts for installation. Now they are in the block and warmed back up to room temperature, but they don't move at all. It's as if they are seized. I'm starting to think that I have a dimensional issue.

Has anyone replaced these and had the same problem?

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[linet90]

Bump for any bright ideas

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[dimab]

That's weird. I don't have any ideas really. Except maybe making sure the balance shafts are inserted all the way into the block - so that the balance shaft mounting plate (the one securing it to the block with a bolt) is flush with the block surface with no gaps.
And you haven't put the chain on them yet, right - so these are balance shafts themselves both stuck in block and not let's say idle gear causing the whole assembly to be stuck?

[Allowencer]

If you had to use dry ice to freeze it to gain some thousandths in tolerance, that is NOT good. I'm wondering if the block is tweaked or if the balance shaft line is off. That can cause this.

What happened to the block?

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[Smac770]

That's actually part of the installation procedure:

Because of the small clearance between the balance shaft and cylinder block, the balance shaft may need to be cooled in order to install it. Check if the balance shaft can be inserted into the cylinder block without forcing it in. If this is not the case, then the balance shaft must be installed cooled.

Place the new balance shaft in a freezer for 30 minutes or spray it with commercially available cooling spray.

[Spawne32]

That's actually part of the installation procedure:

That seems very sketchy to me tbh. Especially for something thats supposed to ride on a film of oil.

[dimab]

I think shrinking is required due to small clearance between the aluminum housing of the balance shaft and block. The aluminum housing here stays stationary to the block and the actual front bearing of the balance shaft is inside it.

[Spawne32]

I think shrinking is required due to small clearance between the aluminum housing of the balance shaft and block. The aluminum housing here stays stationary to the block and the actual front bearing of the balance shaft is inside it.

Ah I see what you are saying, that would make sense.

[flowhigh]

Isn't there supposed to be a ball valve in one of those ports or am I missing something

[dimab]

As long as these are OEM balance shafts, inserted all the way to the end and there is no debris or rust in the block (in case it was in machine shop and wasn't cleaned properly) they should run smoothly by hand.

[dimab]

Isn't there supposed to be a ball valve in one of those ports or am I missing something

The ball valve is supposed to be in the camshaft bracket, which also has a screen.

[flowhigh]

The ball valve is supposed to be in the camshaft bracket, which also has a screen.

No, I'm pretty sure there supposed to be one in there

I'm not talking anywhere near the cambridge you mean

[dimab]

Not sure. I didn't take those apart. This is Audi's 2.0TFSI lubrication system schematic below and it doesn't show any valves there.

[linet90]

If you had to use dry ice to freeze it to gain some thousandths in tolerance, that is NOT good. I'm wondering if the block is tweaked or if the balance shaft line is off. That can cause this.

What happened to the block?

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Nothing happen... doing a full build on the motor.
It is standard operating procedure per the Audi manual to chill the shaft before installing. It is a shrink fit, but I think the hole that supports the shaft at the back end of the motor is the problem. I could also just have a bad batch of balance shafts.

That's weird. I don't have any ideas really. Except maybe making sure the balance shafts are inserted all the way into the block - so that the balance shaft mounting plate (the one securing it to the block with a bolt) is flush with the block surface with no gaps.
And you haven't put the chain on them yet, right - so these are balance shafts themselves both stuck in block and not let's say idle gear causing the whole assembly to be stuck?

The securing screw is in so I know that it is fully inserted. No other gears installed. I tried to move it with the chain but even with all my force it would not give. Probably need to hand this over to the machine shop.

[flowhigh]

Sorry, I think just the screens with no valve. You're right

[flowhigh]

I'm wondering if the plastic oil baffles where in the way of the balance shafts. I've never done the job, but they' supposed to be oriented properly before putting the shafts in. It shouldn't have been that hard. Odd

And just for info purposes and really a REAL important one for those that do this...That idler pulley beneath the balance shaft on the intake side has to be timed properly with the shaft visa/versa. There's tiny markings on the gearing that you need to align. Something like this could make or break a lot of hard work.

[Smac770]

The intermediate sprocket has to always be replaced if it's loosened or if the intake balance shaft is removed (which means it, the balance shaft, has to be replaced):

Always replace the intermediate sprocket. Otherwise the backlash will not adjust itself and it could result in engine damage. The new intermediate sprocket has an anti-friction coating that wears off after a short period of use, which automatically adjusts the backlash.

[dimab]

linet90, sorry to hear that. Was the block taken to the machine shop before or nothing has been done to it yet during the rebuild?

[linet90]

linet90, sorry to hear that. Was the block taken to the machine shop before or nothing has been done to it yet during the rebuild?

It has. The block has been washed, decked, and overbored. The odd thing was when I was dismantling the block, the original shafts came out by hand. I will need a slide hammer to get them out now.

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[dimab]

Hopefully they will come out without any damage. The OEM puller tool is T10394, but it may be too expensive.

There are 3 bearings for each shaft. Two are inside of the aluminum housing. The third one is where the end of the shaft is inserted into the block.

Upon shafts removal I would check all 3. The first two by rotating the shaft inside the aluminium housing.
For the third one, the only thing I can think of is visual inspection of contact surfaces on the shafts and inside the block. It may be possible to see the block surfaces for the intake shaft without an inspection camera/endoscope by looking through a hole in the block from water pump pulley side.

[linet90]

Hopefully they will come out without any damage. The OEM puller tool is T10394, but it may be too expensive.

There are 3 bearings for each shaft. Two are inside of the aluminum housing. The third one is where the end of the shaft is inserted into the block.

Upon shafts removal I would check all 3. The first two by rotating the shaft inside the aluminium housing.
For the third one, the only thing I can think of is visual inspection of contact surfaces on the shafts and inside the block. It may be possible to see the block surfaces for the intake shaft without an inspection camera/endoscope by looking through a hole in the block from water pump pulley side.

I finally got my slide hammer and VW tool in the mail this weekend. I pulled one of the balance shafts out, I can now see the 3rd bearing using a camera - I initially thought it was part of the block machining - but no visual damage. I measured the balance shaft to the original and dimensionally it seems fine. I tried to even install the original and it also locked up. Seems that the bearing has shrunk. I found replacement ones from this unknown supplier. I think it might be my only hope.... but now, how do I even get it out without making a huge mess.

Link: https://www.aliexpress.com/item/32870292840.html

Side question - I have a B8 (09) A4 which I believe has a EA888 Gen 2 motor, is that correct? Couldn't find anything on when the production transition occurred.

[Theiceman]

Correct gen 2 if it is only exhaust with variable lift.

Personally I would never put AliExpress parts inside my block.

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[Smac770]

If it's a US MY09 sedan or wagon, yes, it will be a CAEB engine (EA888 Gen2).
If it's a US MY09 convertible, no, it will be a BWT engine (EA113).
But if you're this deep into an engine and you don't know which it is, ....

[Theiceman]

If it was an ea113 his balance shafts would not be removed with a slide hammer as they are down in the oil pump assemnly. So thought maybe he thought he had a gen one used in a vw.

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[Smac770]

Ok. Turns out the balance shaft repair kit is the same for Gen1 transverse 2.0T (Mk2 A3/TT, Mk1 Q3 - CCTA/CBFA) as well as Gen2 longitudinal 2.0T (B8 A4/A5/Q5, C7 A6 - CAEx(CDNx)/CPMx(CFKA)) -> 06H 198 205 F, currently 06H 198 205 N.

It seems like the shafts were originally available separately before being combined into the repair kit part number:
06H 103 273 AN -> BG
06H 103 273 AP -> BH
then combined into 06H 198 205 A -> F -> G -> N

I didn't realize the plastic tube, 06H 103 199 K, is only used on the exhaust side balance shaft.

On the thing the OP was linking, these rings, 06H 103 396 J and L, I don't get where these are supposed to go. These are rings inside the balance shaft cavity pressed into the block? Good luck.

[linet90]

Ok. Turns out the balance shaft repair kit is the same for Gen1 transverse 2.0T (Mk2 A3/TT, Mk1 Q3 - CCTA/CBFA) as well as Gen2 longitudinal 2.0T (B8 A4/A5/Q5, C7 A6 - CAEx(CDNx)/CPMx(CFKA)) -> 06H 198 205 F, currently 06H 198 205 N.

It seems like the shafts were originally available separately before being combined into the repair kit part number:
06H 103 273 AN -> BG
06H 103 273 AP -> BH
then combined into 06H 198 205 A -> F -> G -> N

I didn't realize the plastic tube, 06H 103 199 K, is only used on the exhaust side balance shaft.

On the thing the OP was linking, these rings, 06H 103 396 J and L, I don't get where these are supposed to go. These are rings inside the balance shaft cavity pressed into the block? Good luck.

That's some part number history searching. How did you find all this data?

I took this picture from the back side of the motor. You can see the (tile) bearing in the block here.



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[Theiceman]

that looks like green bearing retainer... hope you can get those bastards out .. green bearing retainer can be a nightmare..

[linet90]

that looks like green bearing retainer... hope you can get those bastards out .. green bearing retainer can be a nightmare..

Learned something new... The green is assembly lube. I put some on the shaft before installing it.

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[linet90]

If it's a US MY09 sedan or wagon, yes, it will be a CAEB engine (EA888 Gen2).
If it's a US MY09 convertible, no, it will be a BWT engine (EA113).
But if you're this deep into an engine and you don't know which it is, ....

Good to know, thanks.

I've always ordered per the engine code, but these bearings were listed by the engine gen. Given that I have a 09 I wanted to make sure it wasn't a gen 1.

Also, based on the other responses there were no balance shaft design changes.

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[Theiceman]

Learned something new... The green is assembly lube. I put some on the shaft before installing it.

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oh good . green bearing retainer is used in close quarters ( 2-3 thou max ) and its like uber red loctite but 10 times the stregnth .. gald its just assembly lube..

this is a great follow as we have not done a whole lot with balance shafts, you are leading the herd, keep up the great work.

[dimab]

I finally got my slide hammer and VW tool in the mail this weekend. I pulled one of the balance shafts out, I can now see the 3rd bearing using a camera - I initially thought it was part of the block machining - but no visual damage. I measured
Side question - I have a B8 (09) A4 which I believe has a EA888 Gen 2 motor, is that correct? Couldn't find anything on when the production transition occurred.

The engine code that the car was equipped with from the factory can be found on the vehicle data label http://wiki.ross-tech.com/wiki/index...cle_Data_Label.
Code of the actual engine installed on the car can be found on the bar code label located on the top (plastic) chain cover.

The two codes above may not necessarily match if the engine was swapped/replaced before.

I took this picture from the back side of the motor. You can see the (tile) bearing in the block here.

It's hard to tell from the picture, as there seems to be some assembly lube, but the surface doesn't look good in my opinion. I think it may be oxidized. If that's the case, cleaning it with scotchbrite may solve the problem.
As for the replacing these bearings, I see a number of issues here:
1. There is no OEM part available. Using a chinese replacement poses reliability/quality concerns in my opinion.
2. Removing and installing the bearings seem to be a complicated procedure. Especially on the exhaust side.
If I were in your position, before messing with bearings replacement I would try cleaning the bearing on one of the sides with brake cleaner and scotchbrite, probably the intake one as it's easier to reach and inspect. Then try fitting the old shaft again. If that doesn't help then replacing the bearings or machining the old ones may be the only option.

[dimab]

If you decide/will eventually have to go with the bearings replacement option, I would suggest considering Kolbenschmidt bearings. This is a reputable manufacturer and as fas as I can see from their catalog, this is the part number from Kolbenschmidt - 72 388 690 (contains one bearing):



The bearing material from Kolbenschmidt appears to be steel+aluminium per the catalog above (St/A), assuming the bottom part is steel and the top is aluminium. If that's the case for the OEM bearing as well, then the oxidation (if any) will be easier to remove using white vinegar - in case you consider cleaning the bearings before going the replacement route.

Good luck.

[Theiceman]

so stupid question ., lets get back to basics .....

did the shafts turn just fine before you removed them initially ? if so something else is going on and i think the bearings are fine ...

[linet90]

Finally got some time to work on this again. I got the intake shaft out and inspected the bearing. It was rough to the touch, cleaned it with scotch-brite, and put the shaft back in. Everything went together smoothly since I also cleaned the front journals. Looks like that did the trick. Now I need to get the exhaust side done and move on with this build.

In the meantime, one of the engineers at work and I were game planning as to how to pull and install a new set of bearings. Fun exercise for what it was.

General feedback, what are everyone's thoughts on using assembly lube on the bearing vs engine oil? I am leaning to stay with assembly lube.

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[linet90]

If you decide/will eventually have to go with the bearings replacement option, I would suggest considering Kolbenschmidt bearings. This is a reputable manufacturer and as fas as I can see from their catalog, this is the part number from Kolbenschmidt - 72 388 690 (contains one bearing):



The bearing material from Kolbenschmidt appears to be steel+aluminium per the catalog above (St/A), assuming the bottom part is steel and the top is aluminium. If that's the case for the OEM bearing as well, then the oxidation (if any) will be easier to remove using white vinegar - in case you consider cleaning the bearings before going the replacement route.

Good luck.

Thanks for the bearing info!

I did a safety buy before reading your message from Amazon to get a set in, although the bearings do have a Audi logo on them - for what that is worth. If I was going to change them I would dig into the German manufacturer more.

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