Balance shaft hex key remedy

Hello everyone.

Past days I see a lot of cars which lose oil pressure because the damn hex key simply rounds off its edges to a point where it can no longer drive the oil pump.

I have heard of various possible remedies for this, such as thicker hex keys, welding them into balance shaft, etc... But I am not sure how reliable are those methods and which one should I go with.

So the question is what is the actual permanent and long term remedy for this? Replacing the hex key with a new OEM one usually just postpones the problem to next 40-60k km before it gets rounded off again (there is already some play inside the balance shaft and the new hex key, that's what causes wear IMHO).

Thanks.

deleting the balance module is a good solution.

CoolAirVw said:

deleting the balance module is a good solution.

Click to expand...

Yeah, basically turning a CBEA into a CJAA engine (or at least changing the way the oil pump is driven with CJAA parts).

Have Fun!

Don

CoolAirVw said:

deleting the balance module is a good solution.

Click to expand...

I have heard quite a few cases where crankshaft gets broken after this. Not sure how much is truth and reality in this.
Besides, it's quite costy and labour intensive operation. Not many owners will agree.

So any realistic solutions when the BSM stays in place?

If you search in the B5 forum (http://forums.tdiclub.com/forumdisplay.php?f=65) there seemed to be 2 hex key lengths for the BHW engine. The short key had a tendency to round off while the longer key was better because it went deeper in both the BSM and Oil pump. Not sure if the same is true for your engine, but it was a thought.

I have heard quite a few cases where crankshaft gets broken after this. Not sure how much is truth and reality in this.[/QUOTE]

There is none. I've done at least 15 (probably more) on Bhw (04-05 passat) Only way a crankshaft might break is if it was Butchered during the job. For instance if someone didn't have the right tool to get the crank gear off.

I just realized that I assumed you had a b5 passat when I answered. Is that what you have?

Henrick said:

Besides, it's quite costy and labour intensive operation. Not many owners will agree.

Click to expand...

I certainly dont agree. (b5 passat)

Henrick said:

So any realistic solutions when the BSM stays in place?

Click to expand...

If you have a b5 passat you just gonna leave the chain in there with the BM till the chain fails? If you dont have a b5 passat disregard most of what I said.

No, it's not the Passat BHW.

I'm from Europe, there are more similar engines, both PD and CR. E.g. CBBB.
I am aware of different lengths of keys, 72 mm and 100 mm. But You can't just toss longer key in into 72 mm balance shaft design...

Is it somehow possible to spot weld the key in place?

The hex shaft is probably what it is because it needs a little flexibility to the mechanism for ever so minor misalignments, or the like. They could have made some sort of press fit drive components if it was not.

Get rid of it! So much trouble and expense for a minimal return. Why don't the BRMs, BEWs, break crankshafts? None of the dozen or more cars that I've changed over have come back with broken cranks.

IIRC there is a boutique machine shop outfit in the UK and a few of them in the EU that will machine a larger hex recess into the BSM.

^-- yeah, that's what I expected to hear. In fact I think you need something like oversized hex hey, e.g. 6.2 mm or so.

Any links/hints on how to locate it? I've done some google as well as looked on ebay and found none...

Found this:

https://www.ebay.ca/itm/VW-Passat-J...ash=item25e75f0ad5:g:VDcAAOSwbtNaK6Ot&vxp=mtr

I have a gear driven module set aside with the 77mm key - thinking about having them quote on re-doing it with the 100mm key.

Right now I'm BSM deleted.

Interesting. Seems they somehow modify the shaft itself.