Belt change job - damaged balance shaft and crank key - Help!

[Porschamaniac]

Hi there,

This weekend, I got deep into replacing my belts, water pump and front engine seals.

To be fair, mostly it has gone well, however, two little (or maybe not) problems are giving me some cause for concern.

The first relates to the lower balance shaft. Once the front of the housing was unbolted, it moved easily enough and I was expecting it to slip right off of the shaft (as the upper one had). However, the internal collar bound onto the end of the balance shaft as it was being removed. In the end, I had to heat it up with a heat gun an then use the shaft itself as an improvised slide hammer to tap the housing off.

It looks as though a some point, the end of the shaft has been damaged (almost as if someone has drifted something against it and turned a slight lip at the end).

To get the housing back on, I guess that I'll heat the collar up (really hot) and drift it back into place. Has anyone else had a similar problem?

More worryingly, the woodruff key in the crankshaf is really beaten up. Looks like someone has used an implement (possibly a small screwdriver) and beaten the top of it up pretty badly. Having tried to pull it with pliers (as the manual suggests) I find that it is stuck fast.

I really dont want to damage it any further, so may just leave the crank seal (better to have the key still in place, rather than damage it and not be able to correctly relocate the crank pulley!

Again, has anyoe else experienced this? What's the consensus of opinion on the way forward?

Thanks,

Ian.

[Techno Duck]

Use a sharp pair of dykes (wire cutters, side cutters..whatever you wanna call them) to take out the crank shaft key. If its really beat up, buy a replacement.

Not to sure what you mean by the balance shaft issue, if you mean your having trouble removing the sleeve / race, i would use emory cloth to smooth out the end of the balance shaft.

[zedsn]

Would like to see a photo of your balance shaft problem but you could possibly use a dremel with a metal cutting rasp bit and get rid of the problem at the end of the balance shaft. Using heat to put the piece back on may mess up your new seal and the thin clear plastic piece that goes behind it. You will have to protect the balance shaft area with a rag to keep out the metal shavings if you do indeed dremel it.

[Porschamaniac]

Thanks for the replies guys. I'll try and post some pictures of the Balance shaft this evening - and the Crank key, also.

I guess that the distortion to the balance shaft is no more than a few thou - so it's kind of hard to see. I did wonder about using a Dremel on it (I guess that there's still plenty of metal there, given the limited load on these shafts).

To be honest, the crank key worries me more - it looks really, really jammed in there. I will try a sharp pair of dykes. I guess that if it came to it, I could even (carfully) drill some small holes in it - try to break it up and extract it.

Thanks again for the replies.

Best regards,

Ian.

[steveu812]

I found that end cutters worked well removing the keys. I found some at Sears, but HF has them too.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38496

[krystar]

yea end cutters work better than side cutters for wiggling the key out.

[Porschamaniac]

You know, it's strange, but the more that I think about this, the more I wonder if someone lost the previous key and 'fabricated' their own!

Judging by the Balance Shaft keys, I guess the crank key should be steel - and probably pretty tough steel. The one currently in the crank looks like it could be alloy. Also, when I pulled the pulley off (with a gear puller) it seemed to pick up a tiny bit of swarf off of the key - I guess that should never happen steel on steel.

I may be mistaken, but I also think that I see a very small (under 1mm) gap at one end - which I guess the key should not have.

Given that one of the balance shafts had been refitted about 15 - 20% out of synch, the job was clearly not undertaken by anyone with any great dilligence the last time, so I wonder if to save a few pounds, after misplacing the key, whether they cut and filed their own.

I guess this could fit with the marks on top, which could be witness marks to it having been drifted into the recess with a screwdriver.

[HondaDustR]

+1 on the dremel, or just a hand file or fine sandpaper would work, too. The mylar gasket is cut very close to the shaft diameter, so if the end of the shaft is mushroomed at all, you might damage it trying to slide it on.

[Porschamaniac]

Just thought I'd post a photograph of my crank Woodruff key.

Note also the damage to the oil pump cover (top left of picture). Looks like someone has alomst peened it right on the edge, trapping the oils seal - guess that this will be 'fun' to rectify!!

I would really like to meet the guy that did this job last time around!!!

[speedracing944]

If you need a replacement balance shaft let me know.

Speedy

[bleu951]

That is one buggered up crank woodruff key. A new one is only a buck or two. Part #900.117.045.00

Is the crank gear keyway damaged? If it is not perfect, replace it. What kind of shape is the cam gear and key in? Gears and woodruff keys are cheap compared to cam and crankshafts!

[Schumi]

So you just pull that guy out with some dykes and drop a new one in? Are they just supposed to press-fit in?

I have a similar issue with mine, only it is not that uniformly worn down. The front of my key, which the balance shaft gear uses, is worn and wore the balance shaft gear to allow a good 15 degrees of play in the balance shafts (that'll make her run rough). As far as the crank gear, that part of the key is good, and there is no play in the crank gear (lucky, that could cuase serious damage).

good thing these are cheap to replace.

[bleu951]

Yes, but cable end cutters work better. It is a slight interference fit.

[Porschamaniac]

Originally Posted by speedracing944

If you need a replacement balance shaft let me know.

Speedy

Thanks very much for the offer Speedy. If I were on your side of the Atlantic, I may take you up on that, but I dread to think what the mailing costs alone would be on a balance shaft

The shaft doesn't look too bad:



If you look top left of the shaft and on the right (almost at the 3 O-clock) you can see the 'damage' this doesn't look bad, but I guess that when the tolerances are in thou, it doesn't have to be much!!!

[Porschamaniac]

Originally Posted by bleu951

That is one buggered up crank woodruff key. A new one is only a buck or two. Part #900.117.045.00

Is the crank gear keyway damaged? If it is not perfect, replace it. What kind of shape is the cam gear and key in? Gears and woodruff keys are cheap compared to cam and crankshafts!

Well, the keyway on the timing pulley looks good - but I'll be replacing the balance pulley. The only reason for this is that, like a twat, I managed to drop it after removal.....DOH!! Only put a little dink in two of the teeth, but, over time, I guess they could shred the balance belt.

That was one expensive bit of butter-fingered clumsiness!!

[Porschamaniac]

Well, the key is out. Thanks for all of the tips guys - came out nicely with a pair of Dykes.

It's in a bit of a state - check this out!!!



Whilst I was in there, I removed the Crank seal. I had previously noted some damage to the lip of the sealing edge on the water pump. Well, I took the seal out and, lo and behold, cack-handed idiot has clearly dinked it as some point; a triangular chip of metal (about 1mm long) fell out. The damage does not intrude far into the seal recess and has clearly not been leaking, so I guess that I'll just add a little alloy filler before fitting the new seal.

I'll post some photos of the recess, with the seal removed later, but here's a shot I took before removing the seal. See the problem!

[Schumi]

I just checked and can't find the woodruff key here at Pelican. I see one, but it says they no longer carry it. I swear I just saw it a few weeks ago here.

Need to add it to my project list.

[krystar]

ace hardware/true value carries woodruff keys. maybe u can get appropriate one so u don't have to mail order and wait for it .

[Porschamaniac]

Thanks Krystar - if I were on your side of the Atlantic, I'd give that a go. As it is, my friendly local Porsche Dealer can get me the keys (original Porsche parts) for 28 pence each. Given the price, I've gone all extravagant and ordered two!!! Guess it'll be nice to have an official Porsche Parts receipt in my folder!

[krystar]

oooo big spender!