VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: Rabbit79 on April 29, 2010, 10:37:40 pm
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1984, 1.6 NA, JK engine code, in the midst of a re-build.
Well I took all my stuff in to the machine shop today to get all the machine work done, and they didn't want to have anything to do with my crank. The crank mics out within tolerances, but one of the rod journals was getting close so I thought I'd just go ahead and have them grind it so I'd have a nice clean crank when I put it all back together. Also in my original plan was to have them cut another slot for the woodruff key that holds the timing belt drive sprocket, and this is where we ran into differences. The original slot is wallowed out past helping, but I was thinking I could cut another slot 180 degrees out from the original, and it should work fine, since it doesn't really matter where it is on the crank, just that it doesn't rotate on the shaft. Am I off base here? He also said he thought the sprocket should be a press on fit. I do have to admit there is some axial play when you slide the sprocket on there but that goes away when you put the bolt and washer on hand tight. I don't recall seeing anything in the Bentley about that, and the Haynes doesn't say anything either (sorry I left my Bentley with them in case they wanted to use it for reference). If I have to get a new crank that's just how it goes sometimes and it's no big deal, although it would keep my costs down somewhat if I can save it, and I'm of the opinion that it can be saved. Thoughts? Comments? Opinions? All are welcome.
I'll try to get a picture in if I can figure it out.
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save the crank. have it machined for one of the TDI sprokets like this. Done:D
(http://www.vwteileaususa.com/images/028105263D.jpg)
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I'm not totally sure, but I don't think you can do that with this style of crank.
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I'll expand on that a bit, and this is just stuff I've gleaned from parts literature and reading on here, I'm certainly no aficianado on the subject so someone please correct me if I'm wrong. As I understand it, on cranks up to 82 the hub that the sprocket sits on was 22mm in diameter and the sprocket is held in place by a standard woodruff key. After 82 they enlarged the hub to 31mm and put a different locking mechanism on. I've never actually worked on one of the 31mm hubs so I don't know exactly how that works but from a few pictures I've seen it looks to be some sort of wedge shaped thing. I think to do the modification you're talking about I'd need to have a crank with a 31mm hub. Now according to the Bentley the JK codes start in 83 so I should have the bigger nose crank, but I don't. How the 22mm crank got in there is anyone's guess, but that's what I have so that's what I'm working with.
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Yes....Actual woodruff key.
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That's dis-heartening......Looks like I'm going shopping. Anyone know where I can find a crank?
Also that leads me to ask: Aren't the cranks for the 1.6 the same except for that hub the timing sprocket rides on? If so couldn't I upgrade to a new crank with a bigger hub and then do the TDI mod mentioned above?
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You could still have the woodruff slot cut anywhere on the crank, tho. I should have said, you're SOL WRT using the TDI sprocket.
You could upgrade the crank and then use the TDI sprocket.
That's what I'd do - get the 31 mm crank and upgrade to the TDI sprocket... my 1984 has the TDI sprocket :-)
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Save it. Here is another option:
http://www.vwdiesel.net/forum/index.php?topic=13828.0 (http://www.vwdiesel.net/forum/index.php?topic=13828.0)
Good luck-
Brendan
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I was pretty sure I could just cut another key slot in it and that would work.......... My other concern is the fit of the sprocket on the shaft. Should it be a press on fit on these early style sprockets? Mine definitely is not, it easily slides on and off by hand. There is some axial play when the sprocket is just on the shaft by itself. It almost seems as if that's by design though because the washer is shouldered and it fits tightly inside the sprocket and takes out all the play when you tighten it up. I just don't know for sure if that's how it's SUPPOSED to be. I don't see much in the books on this.
Brendan I looked at your thread on the dowel pins and I like the idea. It looks to be a little tougher proposition on the early style sprocket but I think it is workable. That raised shoulder around the bolt hole on the early style is only about 4mm thick, so if you wanted to stay inside of that you'd have to use a very small drill bit, or you'd have to bore out your jig so that it fits down over the shoulder and guides your drill bit all the way down til you hit the flat part.
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nope, not a press fit.
the early crank nose relies on the mechanical connection of the woodruff key, not the friction against the face of the crank.
as long as the pulley is not allowed to rotate any(with the key installed) you should be fine.
have them cut a new keyway and install a key that is wider than stock, as it will hold better than the narrow key originally there.
-Owen
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Well that news certainly makes my day a little brighter. I think if I can combine the new keyway with the dowel pin idea I'd have a pretty strong setup. If all goes well we may have just saved a crank from becoming a paperweight.
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i epoxied my keyway and installed a new gear. has worked for over 2 years now. it was either that or pull an engine that had 85k on it. but if i were you, i'd ditch the early crank. how ever i do agree with you that having the key 180 degrees off shouldn't make a difference assuming the gear has an even amount of teeth. i don't know if you can even cut the early crank nose into a tdi D style.
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I'm planning to pin my crank as well. Pinning should be stronger as the pin will be thicker than a bolt for the hole size due to no threads.
Probably do 3 extra pins, 90deg out from each other then the keyway. Also planning on putting on either red lock tite or some form of epoxy between the crank nose and the sprocket.
Between all of those, I figure it should hold.
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pic dont work :(
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Yes that's me trying to figure out how to do it.....think I'm getting there.
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Well this is turning out to be an interesting proposition. I'm hopefully getting my new key seat cut in the crank tomorrow. One little problem I've run into is that this being the good ol' US of A nobody here has metric key seat cutters. As best I can make out the original seat was cut by a 4 x13.5mm cutter (4 being the width of the key and 13.5 the diameter of the cutter wheel). I find that metric seat cutters are a bit hard to come by in the US and the ones that are sold here must be made out of gold cause they're all quite pricy. So I'm going with the next best fractional equivelant which is 5/32 x 5/8. The 5/32 key does actually fit in the keyway on the sprocket pretty snug, it's only 8 ten thousandths smaller than a 4mm, so I'm not too worried about that. The 5/8 diameter cutter wheel will just barely fit under the shoulder of the crank but according to measurements it should go. Also that 5/32 key is a little taller from top to bottom than the 4mm original so I might have to trim it down a little. We shall see.
As for pinning the sprocket that's turning out to be an adventure as well. I stopped in at the high school metal shop today and had the kids there make me a duplicate of my washer. I'll put that on the drill press tomorrow and get some holes drilled in it and use it as guide for drilling the sprocket. The shoulder that I'll be drilling into on the crank isn't very wide, so about the biggest pin I can use is 1/8 (just over 3mm). I'm not even sure if pins that small will help that much, but at least it'll give me a little peace of mind. It's going to be a very tight fit however I do have the old sprocket that I can practice on before I REALLY screw anything up.
I THINK I've figured out how to post pics so I'll give that a try so everyone can see where I'm starting from.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05010004.jpg)
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05030002.jpg)
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05010007.jpg)
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Pics worked!
I can think of another slightly more permanent option if you're stuck though... picking up a welder and tacking it on.
Obviously if you're planning to pull your engine apart again, that's not the best option but if you need to, you could grind the tacks out again and put a TDI crank in then.
Just thought I'd throw that out there as you don't have much metal to work with :(
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Yes that is always an option. Probably more of a last resort option. I did that to the brake caliper on a Ford pickup once. It worked.....but it was kind of a pain to have to grind and then re-weld it every time I changed brakes. I think perhaps if it got to that point I'd just get a new crank.
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Well for those who have wondered if you can pin a 22mm crank, the answer so far is turning out to be......yes. Here's some photos.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05040001.jpg)
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05040006.jpg)
On top of the pulley is the duplicate washer I had made to use as a jig. As you can see there was some trial and error getting the holes drilled in it. My drill bit had a tendency to want to walk towards the outer edge and a punch is too big to fit in there. I used a 7/64 bit on the washer and the initial holes in the sprocket, then I enlarged the holes in the sprocket with a 1/8 bit.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05040005.jpg)
The finished product.......I got a little closer to the inside on a couple holes than I would have liked, but I don't think that will hurt anything. I don't think it's any different than cutting a key way in with a broach.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05040002.jpg)
There's the shop supervisor stretching out...... He works hard.
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Well pinning the crank, 22mm version, has turned out OK so far. The biggest problem I've encountered to date has been getting a new key seat cut in the crank. When you live out in the middle of nowhere like I do your choice of machine shops is limited, and what I've run into is that nobody seems to have the right equipmet to do it. I finally found a guy that could do it and he did an excellent job. It ended up being kind of a 'buddy' deal, and he only charged me 10 bucks to do it, which I was needless to say happy about. I was prepared to pay alot more than that. We used a 5/32 woodruff key which we had to trim a little off the top of, but other than that it was pretty cut and dried. The 5/32 key is a little wider than the 4mm original so it engages a little more of the keyway in the sprocket, which should help a little strength wise. On the other hand the 5/32 key is not quite as thick as the 4mm so there was just a little bit of rotational play. The pins, as you'll see, took care of that quite nicely though. With the cost of the pins and the keyseat cutting, I'm into it about 25 dollars so far, so it has ended up being quite a bit cheaper than getting a new crank. Now on to the process.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05220004.jpg)
I used the already drilled sprocket as a guide to drill on the crank. I didn't want to wallow out the holes in the sprocket any more than I needed to, so I just got the crank holes started and then pulled off the sprocket and finished them. The crank itself is pretty hard, so the Drill Doctor saw a lot of employment on this job. Once I got them to approximate depth (about 1/4") I put the sprocket back on and put the bit in the deepest hole and then tightened up the chuck on it, and drilled them to final depth using the sprocket as a stop.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05230006.jpg)
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05230008.jpg)
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05230005.jpg)
There's how it turned out. The one piece of advice I can give on this is that if you miss on drilling your holes, miss towards the inside. If you get outside of that shoulder on the crank, that's where your seal rides....and that would be really bad.
(http://i859.photobucket.com/albums/ab151/08Hes_dead_Jim/Rabbit%20engine%20rebuild/05220003.jpg)
Sprocket on with pins in. Obviously I'll trim the pins later. Just doing a test fit at this point. With just the woodruff key in there I did have a little tiny bit of play, but once I put the pins in.... That baby is tight!!! No play at all.
In looking back on this, the one thing I'd do different concerns drilling the holes in my jig. In doing that I had made an exact duplicate of the washer that fits inside the sprocket to use as a drill guide. Instead of making an exact duplicate, I'd make the larger diameter step quite a bit bigger. The smaller diameter step has to fit inside the sprocket but the bigger one you can make as big as you want. If you keep it original size you have hardly any room to operate when you're drilling the guide holes. I had a little trouble with the drill bit wanting to walk to the outer edge, so I think a split point bit would cure that. I drilled from the inside out, using the smaller step to kind of guide off of. I just eyeballed it but I think if I had to do it again I'd use a feeler guage of .005" or so between the bit and inner step to keep the holes a uniform distance from the inner sprocket wall. It still has worked out alright so far, but those are a few adjustments I'd make.
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Well I know this is quite an old topic but I thought in case anyone was curious as to how this has worked out I'd post some results. The poor old car sat for almost a year because I was just too busy with other stuff to put much time into it but I finally got it back together a couple weeks ago. I'm happy to report that everything seems fine up to this point, the old girl is running great so far (knock on wood). Time will tell on how well it holds together as I only have about 150 miles on it right now, but with 4 pins and a new woodruff key it should be stronger than the original set-up, and that lasted for 26 years, so I'm confident. So if anyone feels they want to give this a go on a 22mm crank and you have questions feel free to ask and I'll try to help in any way I can.
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FWIW, the only engines ive seen with the keyed crank sprocket are only the oldest of the VW diesels.. like both of my 1.5D engines, and a couple really early 1.6Ds..
i guess it would be the same thing to pin a crank without a woodruff key tho..
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FWIW, the only engines ive seen with the keyed crank sprocket are only the oldest of the VW diesels.. like both of my 1.5D engines, and a couple really early 1.6Ds..
i guess it would be the same thing to pin a crank without a woodruff key tho..
Yeah this engine is a bit of a mystery. As best I can tell this is the first re-build on it. The bores were original size and there were, for instance, no marks on the rods and caps to match them up, so I don't think anyone has been in there before me. The guy I bought the car from told me the PO before him had pulled this motor out of an 84 in a junk yard, and just swapped it in for the old 1.5 that was in there originally.It's a JK block so that would tend to support that. With that being said..... A JK should have the later style crank though. How that early crank got in there I have no idea.
Yes I do believe it would be about the same thing on the later, non-woodruff key, style cranks. Biggest difference I can see is that you could use bigger pins and have a little more room to work with. There's a link on page 1 of this thread that shows it..... That's where I got the idea from.
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FWIW, the only engines ive seen with the keyed crank sprocket are only the oldest of the VW diesels.. like both of my 1.5D engines, and a couple really early 1.6Ds..
i guess it would be the same thing to pin a crank without a woodruff key tho..
Yeah this engine is a bit of mystery. As best I can tell this is the first re-build on it. The bores were original size and there were, for instance, no marks on the rods and and caps to match them up, so I don't think anyone has been in there before me. The guy I bought the car from told me the PO before him had pulled this motor out of an 84 in a junk yard, and just swapped it in for the old 1.5 that was in there originally.It's a JK block so that would tend to support that. With that being said..... A JK should have the later style crank though. How that early crank got in there I have no idea.
oddly enough, my book only shows the JK being available in 83 Jettas.. lol..
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That could easily be the case. Who knows how accurate the information through 2 POs is?