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What about the balance shaft bearings at the other end?

NotMyGTI

New member
I am normally a Mk3/Mk4 TDI person. My son, however, has a well-running 2011 GTI (CCTA) with 125K miles. It has only recently come to our attention that the TSI engine family apparently suffers from a few "weak" areas - in particular the timing chain and balance shaft systems, about which we have been attempting to rapidly educate ourselves.

Yeah....we're a little late to the party.

My son took the car to the local dealer and paid for a detailed evaluation. The dealer stated that the engine "failed" timing system check. They also said that cam cradle is leaking and recommended that the leak be repaired "at some point".

I performed my own checks when the car returned. Indeed, it has the old style timing chain tensioner. Additionally, VCDS 093-3 Phase Position indicates -5.03 degrees. So - it appears that timing chain system service is in order. The cam cradle is weeping as well. It seems to me that the best time to deal with the leak is when the timing system is already apart - not later when everything would have to be disassembled (again).

Given all that I have read concerning balance shafts and oil screen blockages, we are seriously considering proactively replacing them at the same time as the timing chain hardware. There are no indications of trouble with the balance shafts - but then it seems that there is little, if any, warning of failure.

I have been reviewing countless videos and pages regarding this work and noticed what seems to be a glaring omission in nearly all of them - I have found only a couple of references of any kind to the bearings at the far end of the balance shafts (pressed into the block?). From what little I have seen, they appear to be plain bearings. Even the local VW dealer parts department could not confirm. They took their best shot and gave me part numbers for needle bearings (with three different color codes) on the closest engine reference they could find to ours - a 2014 CNSA/CNSB engine. I purchased the electronic VW service manuals (erWin) and found that they had a glaring absence of information about this bearing as well. No bearing is apparent in the exploded diagram (unless I missed it). One would think that there is no bearing there at all! I know that the far end of the shaft has to spin in something - and I doubt that it spins directly in the block (surely not!).

So, assuming that there are bearings at the far end, my questions are these:
- what is this bearing (part number/description)?
- how does one inspect these bearings and what should the dimensions (clearances) be?
- how does one replace these bearings (if necessary)?
- where does one buy these bearings (they do not seem to come with the balance shafts)?
- why does no one talk about these bearings? It appears to be a normal plain bearing with no filter screens.
- what are the consequences of removing the filter screens on the balance shafts prior to installation? The bearings at the far end of the shaft do not appear to have filter screens and yet there do not seem to be any issues with scoring or oil starvation (at least none that anyone talks about).

I recently watched a joint video put out by the "Humble Mechanic" and "Deutsche Auto Parts" regarding timing chain replacement on a 2010 Tiguan (owned by Jalopnik senior editor) with similar mileage to ours. I know that it is a different vehicle, but it seems the base engine is from the same family with (presumably) similar issues as my son's GTI (in the info section, they did point to CCTA links and parts). I noticed that he did not proactively change the balance shafts, despite the known issues with the filter screens. I wondered why. I appreciate Charles' videos and I wanted to attempt to email him, but I do not know the best method to contact him and get a detailed and timely response. I'm sure that he is pretty busy.

Interestingly, I have found some Russian YouTube videos talking specifically about this bearing (in an Audi Q5) and even looking at it up close with a nifty bore-scope. The engine looked like the same CCTA engine family but, unfortunately, it did not involve actually changing it out. I saw another similar video (again, Russian) where the narrator made an extraction/installation tool on a lathe - but he had the engine out of the car. I don't believe that it should be necessary to remove the engine from the car, as there do not seem to be any shoulders in the bearing bore that would block extraction of the bearing out the front (with the right tool). Would have to pull it out.

Whatever we do, I want to give the engine the best chance of running another 100k miles without needing to go back and change something that should have replaced while everything was disassembled the first time. Is that realistic? What are the odds of the original balance shafts running another 100k miles? From what I have been seeing, I would say that it is unlikely. It almost sounds like this timing chain/balance shaft design needs to be viewed as a timing belt in terms of regular, scheduled replacement. Sigh.

So here we are. The dealer cost estimates for the basic timing chain work were pretty steep and I don't know about the quality of their work. So - we will be doing work this ourselves. We have not yet started the work and my son has stopped driving the car out of an abundance of caution. Fortunately, he is able to carpool while we are working this out. Trying to answer the last few questions and start moving forward.

We would also welcome GTI Mk6 parts supplier recommendations for this job - including being able to talk to someone knowledgeable on the phone. Our preference is for genuine parts where possible.

Apologies for the wordy description and all of the moving parts. I especially apologize if this info is already covered elsewhere on this site - just point me in the right direction, please.
 

aspro_gti

Autocross Champion
Dm'ing you since I'm in some ways in exactly the same shoes as you and have done timing service in the past.
 

aspro_gti

Autocross Champion
I'm pretty sure the balance shaft itself has the bearing built into it. Usually when taking them out, people replace them (so fresh bearings).

FCP Euro is great, ECS have some good prices too, and urotuning too. FCP is my go-to though. The dealer will cost a lot of money since they will use genuine parts and thus more expensive than if you choose to use aftermarket shafts/timing components which will save quite a lot.

How mechanically handy are you?
 

NotMyGTI

New member
The only bearings that I have seen built onto the balance shafts are the large aluminum units at the sprocket/drive side - which also happen to contain the infamous filter screens. The opposite ends of the balance shaft assemblies (that are inserted into the engine block first during installation), appear to be just exposed, plain bearing inner journals. They look like they are going to fit into outer bearing shells inside the block. For reference, one of those ends also has the smaller extension to which the water pump belt drive pulley is attached. I have only found a few videos where this bearing can be seen at all - and usually for only for a few frames. Only the one Russian video showed a good close-up of it (on the Audi Q5) and talks about it directly. None of the parts suppliers that I have seen show that bearing as part of the shaft set. I believe that it should be a simple, plain sleeve (at least for the CCTA). That far end has to be supported by something as it is carrying half of the counterweight load.
 

NotMyGTI

New member
Thanks for the supplier leads. I know that some of them sell "genuine" without dealer prices. I'll check them out.
How handy? Hard to say - hopefully just handy enough to find the right answers and do this job once. :)
 

aspro_gti

Autocross Champion
Thanks for the supplier leads. I know that some of them sell "genuine" without dealer prices. I'll check them out.
How handy? Hard to say - hopefully just handy enough to find the right answers and do this job once. :)
How handy as in what level of expertise of maintenance/jobs on a car? Oil change? Brake job? Opening up the motor?
 

Roadrunner_GTI

Drag Racing Champion
The balance shafts can last the life of the engine provided the screens are kept clean to allow proper oil flow. If you’re concerned you can remove the balance shafts and clean the screens and reinstall, which I’ve done before due to similar concerns. Check the cam bridge screen, which can blow out and block the oil passage in the head, again obstructing flow to the balance shafts. Once the timing chain & tensioner is replaced, I see no issue why it wouldn’t run another 100k+ miles.
 

NotMyGTI

New member
Hello Roadrunner_GTI. Thank you for your reply! A couple of things - first, my question is primarily regarding what I believe are plain (sleeve) bearings at the far ends of the balance shafts (opposite from the chain-driven side). The balance shafts have smooth bearing surfaces there that must fit into a corresponding bearings (pressed or shrunk?) into the block. The plain bearings are located at the far end of the shaft openings (wells) in the block. The balance shafts can't possibly be supported only by the bearings at the gear-side of the shaft. I've seen brief glimpses of these bearings in several videos that I mentioned - but not a lot of info. Additionally, doesn't the factory VW service manual state that these shafts must be replaced if they are removed? I suspect that this might at least have to do the idler gear for one of the shafts that "wears in" to the mating gear. Once installed, it should never be disturbed. Thank you for the reminder about the cam bridge screen - I'll definitely have to remember to check that as well. As a side note - just out of curiosity, what was the mileage on your GTI when you inspected the screens and how did they look? How often do you typically perform oil changes?
 

Roadrunner_GTI

Drag Racing Champion
Hello Roadrunner_GTI. Thank you for your reply! A couple of things - first, my question is primarily regarding what I believe are plain (sleeve) bearings at the far ends of the balance shafts (opposite from the chain-driven side). The balance shafts have smooth bearing surfaces there that must fit into a corresponding bearings (pressed or shrunk?) into the block. The plain bearings are located at the far end of the shaft openings (wells) in the block. The balance shafts can't possibly be supported only by the bearings at the gear-side of the shaft. I've seen brief glimpses of these bearings in several videos that I mentioned - but not a lot of info. Additionally, doesn't the factory VW service manual state that these shafts must be replaced if they are removed? I suspect that this might at least have to do the idler gear for one of the shafts that "wears in" to the mating gear. Once installed, it should never be disturbed. Thank you for the reminder about the cam bridge screen - I'll definitely have to remember to check that as well. As a side note - just out of curiosity, what was the mileage on your GTI when you inspected the screens and how did they look? How often do you typically perform oil changes?
The majority of the weight is supported by the front two needle bearings on the balance shafts. The rear is a plain style Babbitt bearing, with a pressed in bearing similar to an OHV camshaft.
The FSM does say to replace the balance shafts after removing, and I agree the to think this is because the idler gear wear pattern. For what it’s worth, I’ve removed both balance shafts and idler gear to clean the screens and reinstalled with new stretch bolts. The idler gear maintains the same location due to the timing alignment marks on the teeth. Popping the balance shafts in the freezer for 30 minutes makes install very easy. I’ve had no issues doing this while replacing timing chains, guides, and tensioners. Post-work UOA show all metals the same as pre-work for several thousand miles. So I’m of the opinion that done right, the balance shafts can be reinstalled. That said, if you have extra money then I can’t fault someone for installing new ones…I just hate to replace something that doesn’t need it.
 

NotMyGTI

New member
Ahhh...another piece of the puzzle! So those are needle bearings at the front of the balance shaft - I did not know that. Ok, good to know (as well as solid confirmation of a plain type bearing at the far end). I thought that perhaps the balance shafts may have rotated directly on that tubular aluminum housing. Most of the overhead camshafts that I have experienced have sat directly in saddles or bores machined on/in the aluminum heads. I thought that the balance shafts may have been the same way - spinning on an oil film directly upon the aluminum housing which, in turn, is inserted/bolted into the block. Interesting.
So that rear plain bearing - do you know the part number and are you able to point to any specifications of any kind (i.e. ID, wear limit, installation method, etc)? I could at least search on the part number if I knew what it was - it does not seem to be typically listed alongside of replacement balance shafts. I'm really curious as to how it is installed (shrink fit and/or driven with special tool?) and whether it needs to be reamed afterwards to final dimension (common for press fit bushings). I have found _nothing_ on the web about this. From the Russian YouTube video that I saw, there does not seem to be any seating step/ridge in the bearing bore (in the block) that would prevent removal/installation, with the right tools, from either side. Can you confirm?

Thank you!
 

aspro_gti

Autocross Champion
The balance shafts can last the life of the engine provided the screens are kept clean to allow proper oil flow. If you’re concerned you can remove the balance shafts and clean the screens and reinstall, which I’ve done before due to similar concerns. Check the cam bridge screen, which can blow out and block the oil passage in the head, again obstructing flow to the balance shafts. Once the timing chain & tensioner is replaced, I see no issue why it wouldn’t run another 100k+ miles.
I'm about to do camshaft replacement (VVT crapping out on me), and while I have the motor open I'll be inspecting the cam bridge, but I also want to check the screens on the balance shafts. I thought about just getting new ones, but after seeing that you've taken the old ones out, I think it'll be ok if I reuse the old ones too since they work just fine (and if I take them out and see they are cooked then I replace).
A question about the screens though. Did you keep yours in? Afaik, those screens are problematic everywhere because there is risk of them blowing out, or accumulating a bunch of garbage (which they're supposed to do, but can lead to sudden failure). I know a few other forum members have taken the screens out entirely, and haven't experienced any issues, so I'm curious if you'd caution me against removing the screens (I probably still will, but I want to understand your take on it).
Thanks in advance, your insight is fantastic <3.
 

Roadrunner_GTI

Drag Racing Champion
Ahhh...another piece of the puzzle! So those are needle bearings at the front of the balance shaft - I did not know that. Ok, good to know (as well as solid confirmation of a plain type bearing at the far end). I thought that perhaps the balance shafts may have rotated directly on that tubular aluminum housing. Most of the overhead camshafts that I have experienced have sat directly in saddles or bores machined on/in the aluminum heads. I thought that the balance shafts may have been the same way - spinning on an oil film directly upon the aluminum housing which, in turn, is inserted/bolted into the block. Interesting.
So that rear plain bearing - do you know the part number and are you able to point to any specifications of any kind (i.e. ID, wear limit, installation method, etc)? I could at least search on the part number if I knew what it was - it does not seem to be typically listed alongside of replacement balance shafts. I'm really curious as to how it is installed (shrink fit and/or driven with special tool?) and whether it needs to be reamed afterwards to final dimension (common for press fit bushings). I have found _nothing_ on the web about this. From the Russian YouTube video that I saw, there does not seem to be any seating step/ridge in the bearing bore (in the block) that would prevent removal/installation, with the right tools, from either side. Can you confirm?

Thank you!
As far as I can tell, the part number for the rear bearings is 06H-103-396J. I've never installed them, but I have to believe they install similar to traditional cam bearings in the block. which is that they are pressed in with a cam bearing installation tool to hold the bearing and a hammer. I can't confirm if it would be better to install from the front or the rear of the block, although I will say the exhaust side has a freeze plug that would allow easy access. The intake side has a smaller opening to allow the waterpump driveshaft pass-through, so installation on that side wouldn't be possible. All that said, I don't believe replacing this bearing is very common due to the fact that it doesn't usually see much wear. The balance shafts typically fail at the front needle bearings due to oil starvation. The rear plain style bearing seems to have adequate oil supply. The only time I would definitely recommend replacement is if the block is going to be hot-tanked at a machine shop during a rebuild. In that instance, the bearing material would be compromised and not fit for reuse.
 

Roadrunner_GTI

Drag Racing Champion
I'm about to do camshaft replacement (VVT crapping out on me), and while I have the motor open I'll be inspecting the cam bridge, but I also want to check the screens on the balance shafts. I thought about just getting new ones, but after seeing that you've taken the old ones out, I think it'll be ok if I reuse the old ones too since they work just fine (and if I take them out and see they are cooked then I replace).
A question about the screens though. Did you keep yours in? Afaik, those screens are problematic everywhere because there is risk of them blowing out, or accumulating a bunch of garbage (which they're supposed to do, but can lead to sudden failure). I know a few other forum members have taken the screens out entirely, and haven't experienced any issues, so I'm curious if you'd caution me against removing the screens (I probably still will, but I want to understand your take on it).
Thanks in advance, your insight is fantastic <3.
I cleaned and reinstalled mine, but I've heard of people simply removing them and the cam bridge screen without issue. At the time I did this years ago, I didn't really consider just removing them all together, but probably would if doing the job today.
 
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