Author Topic: AAZ camshaft woodruff or no woodruf? Help. (Read 7139 times)

haybayian · « **on:** May 23, 2008, 08:51:49 am »

I am a bit puzzled about my camshaft sproket. The camshaft has a slot, presumably for a woodruff key. However the reman shop where I bought this engine delivered this AAZ (long block) to me without a camshaft sproket key. Haynes is rather uncommited and not much help. Now what should I do? I have already set my engine on TDC to time the IP and I think that the camshaft is sliding in its sproket.

Your advice will be appreciated.

Haybayian

jimfoo · « **Reply #1 on:** May 23, 2008, 10:29:33 am »

No key, friction fit on mine as it has to be to time the crank to the cam.

RabbitJockey · « **Reply #2 on:** May 23, 2008, 02:43:23 pm »

thats right! make sure u loosen the sprocket when you time your motor other wise it won't be dead on.

jtanguay · « **Reply #3 on:** May 23, 2008, 05:11:13 pm »

i think ETKA only shows the need for a woodruff key on the injection pump sprocket.

Torchd · « **Reply #4 on:** May 24, 2008, 05:50:01 am »

Theres no wooddruff key in the 1.6 as well.... i dont knw abt the 1.9... i havn;t opened up mine yet!

burnt_servo · « **Reply #5 on:** May 24, 2008, 08:01:57 am »

funny thing is my brother has been acumalting 1.6 turbo engines for his samurai ... one of them has a keyed camshaft and sprocket , it came out of a 1986 jetta .........

theman53 · « **Reply #6 on:** May 24, 2008, 09:57:20 am »

that is weird. I don't see how you could time it perfectly like that. I know you could get it close, but the whole deal with having no key is so it slides on the nose for perfect timing. Let me/us know what happens with that one. I am very interested in it for some reason. Or if someone put it in there as "upgrade" thinking it needed it.

the caveman · « **Reply #7 on:** May 24, 2008, 10:41:55 am »

All vw diesel do not have a key. They are all wedgemated.Sometimes people will mix the pump and cam gears then wonder why it's so hard to get the belt to line up or it'll run until the pump gear gets loose. That is also why once you get used to or understand the trick it's so easy to get the belt lined up right the first time.

haybayian · « **Reply #8 on:** May 24, 2008, 11:22:53 am »

Quote from: "theman53"

that is weird. I don't see how you could time it perfectly like that. I know you could get it close, but the whole deal with having no key is so it slides on the nose for perfect timing. Let me/us know what happens with that one. I am very interested in it for some reason. Or if someone put it in there as "upgrade" thinking it needed it.

My engine (1993 AAZ from a Jetta)came out as a long block from a reputable remanufacturing shop in Toronto. The camshaft sprocket was bolted on the tapered end of the camshaft with no woodruf key. However, I noticed in the inside of the sprocket mating part that traces of a forced in key were present. I consulted my Haynes manual that implies that some VW diesel engines have a key, some don't and that in any case one should make sure that the bolt (lug) is of the right length so that the sprocket will be forced in . Bentley describes the AAZ as having no woodruf key at this place.

What I think and what I have done:

I think that both should work fine, hence the Germans' soul searching. My camshaft end is tapered with a keyway. I have called my VW dealer explaining my dilema and they sold me a woodruf key. I have set my crank /cam/IP on TDC slid the timing belt without forcing the camshaft sprocket too much over the key (in other words leaving the sprocket in a wobbly position). Then I have tightened the camshaft sprocket bolt to torque and checked the IP timing. The engine has not been fired yet but I expect that everything is in order. A final word. the woodruf key IMHO does not prevent proper TDC positioning on the camshaft.
Hope this is useful.

Haybayian.

jimfoo · « **Reply #9 on:** May 24, 2008, 12:40:06 pm »

Does your camshaft have a groove for a key? If not, you should not put a key in the cam. Personally I trust myself far more than some dealer grease monkey as at least around here, they know little to nothing about the older engines. With a keyed camshaft there is no way to adjust cam timing relative to engine timing. Maybe they designed the keyway to have the cam in the general vicinity of correct timing, but there is no way it can be right on.

RabbitJockey · « **Reply #10 on:** May 24, 2008, 12:51:43 pm »

yeah, i feel a woodruff key would definitely would effect cam timing since then u are timing it by the tooth of the belt as opposed to the cam being locked exactly at tdc and the sprocket being bolted down to exactly that.

haybayian · « **Reply #11 on:** May 24, 2008, 02:31:30 pm »

Quote from: "jimfoo"

Does your camshaft have a groove for a key? If not, you should not put a key in the cam. Personally I trust myself far more than some dealer grease monkey as at least around here, they know little to nothing about the older engines. With a keyed camshaft there is no way to adjust cam timing relative to engine timing. Maybe they designed the keyway to have the cam in the general vicinity of correct timing, but there is no way it can be right on.

Thanks for your input.
As I have indicated my AAZ's camshaft came with a keyway or a groove . As there is no keyway in the sprocket the woodruf key is probably meant as a "locking device", as in to prevent the camshaft to slide in the sprocket.
The sprocket is to be pushed first with little pressure over the end of the camshaft which allow for a fair bit of play and then once the three TDC positions are acertained the sprocket is driven in to 33 f-lbs with the bolt.

I am not being judgemental of VW engineering all I am interested is to make sense of what I have. It seems to me that both (key or no key)approaches are workable. I chose to use a woodruf key because this is what my camshaft called for and as far as I can tell it worked for me.
Hope this is of some use to anyone.

subsonic · « **Reply #12 on:** May 24, 2008, 07:35:17 pm »

Quote from: "jtanguay"

i think ETKA only shows the need for a woodruff key on the injection pump sprocket.

My alternator has a slot for the key.

burn_your_money · « **Reply #13 on:** May 25, 2008, 06:37:50 am »

In all the diesel VW engines I have ever taken apart the cam is slotted for a key but the pulley is not. It`s my opinion that if you used a key in this situation you would be reducing the surface area of the cam and cam pulley and thereby increasing the chances of it slipping. I think this would be especialy true after adjusting the timing several times and causing many indents in the cam pulley.
Plus, I`d expect the cam gear to be off center and would cause timing belt tracking issues.

On a different note, the tapers/shaft size are completely different on the cam/pump and could not be mixed up

jtanguay · « **Reply #14 on:** May 25, 2008, 09:56:06 am »

Quote from: "burn_your_money"

On a different note, the tapers/shaft size are completely different on the cam/pump and could not be mixed up

yea the camshaft sprocket hole is huge while the pump sprocket hole is small. idiot proof :lol: