Scary situation

Frank, I know it's not the tensioner. It almost never is the cause of a failure. And regarding the sprocket, I'll admit our evidence is anecdotal, but so is yours, for that matter. Odds are some sprockets may get replaced that don't need to be, but it seems to be a reasonable precaution on an older car with unknown hands working on it during its history. And of course it's up to the owner.

I only replace sprockets that have been damaged by some idiot in the past bashing it with a hammer or air chisel to get it off, and it has been mangled.

But a lot of idiots who come in contact with these cars never even get to that point, because they never take it loose because they are doing the M&P anyway.

It would seem the ALH's biggest enemy is idiots with tools. The engine itself is fantastic, and in my opinion a well engineered example of an engine that is both old school enough to be relatively simple but new enough to enjoy things like electronic controls with OBD.

After a while, I just stopped getting to involved in crime scene investigations for past services. It just angers me too much that there are so many hacks out there (both amateur DIYrs and "professionals").

The ALH is an EASY engine to work on, and EASY to service. No idea why so many get screwed up, but they do.

Peter, first I want you to know I respect the business you have created. The business model of yours, I understand. You design to sell parts, and have found an anecdotal way to sell cam sprockets. I have an entirely different set of skills. I've made tapered shafts and bull gears, up to one that was a 150 lb gear. I know how they work and my knowledge on them is not anecdotal, as you put it. It is factual. Straight out of the Machinist's Handbook. Add that to a little bit of metallurgy and this cam/ sprocket connection is very solid.

So, what I indicate I have no reason to retreat from. I certainly understand the issue. I have no reason to alter my opinion and have Jmodge and oilhammer, whom I respect, in agreement.

In addition, if there is any wear issue, it's the cam sprocket teeth. In which case, the crank sprocket has twice the contact and wear potential. Maybe you should sell more crank sprockets, Peter.

So, I do try to make 'idiot proof', but there is always a 'new and improved idiot'. Ignorance can fixed. Stupid cannot be repaired. My objective is to shed the light on an issue so people will not be ignorant and avoid the issues that 'Jack' was dealt. It does not help to muddy the waters with an ancillary concern that is really not the issue.

Oilhammer, I think it's funny that a poor timing belt job is so prevalent that it deserves an abbreviation. As for the TDI-CSI, this one started out simply enough; trying to keep a hack from replacing a relatively low mileage engine and then it spun way out of control. I hate to see people being bilked.

I loved this car and it loved me back. It always turned on, got me where I needed to go and got me back. It gave its last breath to get my family and me to safety. There was a short break in the cement barriers that had access to a shoulder and that's were it finally died. I can think of no better memorial than to hand it over to a nice young man and his father who can bring it back to life. I hope he will enjoy it for another 19 years.

It was my 1984 Rabbit that had the timing belt go - I gave it to my dad after I fixed it - he ran it past 600,000km then gave it to my sister. It finally just wore out at around 750,000km.

These cars are remarkable if you can keep the rust away.

I have never had my IDI or TDi leave me beside the road except for that day the timing belt went and that was my fault for leaving it well past it's scheduled replacement. Little Jack - you are what epitomizes TDIClub and makes it a great place to hang out. Thanks for sharing your story and enjoy your new ride!

IndigoBlueWagon said:

We recommend it as an option on our high mileage timing belt kit. And although Frank says it was left loose, it's just as likely it was over-tightened previously causing it to slip this time. May have been over-tightened this time, too.

I've always had the best of gurus replace timing belts on my TDIs, so I don't worry about the sprocket. in 10+ TDIs the only timing belt related failure I've experienced was a seized water pump in my son's car after it sat for 8 months. Stripped all the teeth off the belt, but the engine didn't lose time. New belt kit and it was good to go. Don't expect to have that good fortune again.

Click to expand...

Here's my experience with over torquing...

The one time I over torqued the sprocket I had hell to get it off. I realized i had torqued it beyond the proper torque level because the cheap torque I was using had failed while I wasn't paying attention. The internal click stopped working and it became apparent I had overdone it. I know it was somewhere around 60 ft lbs because I used a good torque wrench later and kept incrementing up but I stopped checking at 60.

Anyway, I wanted to make it right so when I went to remove it with the cam sprocket tool, it broke one of the sprocket legs and wouldn't come off. Bought a new sprocket from you all. I ended up removing it using a punch from the valve cover side, but it took a few good raps.

Never had a problem with the camshaft holding on after that, but your commentary would make me concerned if I did that again.

I've always over torqued them to 40ftlbs, but always do it slowly. I've also reused my sprocket, plus many others many times. No issues yet knock on wood. As someone said before, the AHU had a higher torque on a similar design. I wonder why they lowered the spec.

It is an interesting setup to me, but not foreign. On the 15L Cummins engines I work on, the cam sprockets are keyless and are tapered just like these. Except you have to use Locktite 609 compound and torque to 109 ftlbs for the valve cam. Injector cam is a lot more plus a 90 degrees lol

I have been doing 38ft lbs, but I think i will go to 45 from now on.

I've said it before, but if one more person avoids the issue, it's worth saying again..

The AHU was a torque spec of 54 ft lbs on what is basically identical cam/ sprocket parts.

I think the 33 ft lbs is simply a mistake by VAG, but there is no interest in correcting the mistake. First, you would have to get them to admit they made a mistake.

The years following the ALH engine, was the PD motors, which are still an overhead cam, but now with a cam pulley that the cam sprocket attaches to. Regardless of the cam sprocket, which now bolts onto a pulley, the cam taper is now either cast steel or billet, but the cam is very much the same materials as before. The sprocket pulley bolts on at 74 ft lbs.

When comparing these torque numbers, it is hard to ignore what appears to me to be an engineering error. Just the fact each of the three cams is the exact same 14mm bolt, it is hard to understand the logic in under-torquing the ALH sprocket. I don't think I can make it any more plain.

Jokila, although the sprocket buster is a tool that you keep cranking the bolt until the sprocket pops off, it should not necessarily be used that way. The same as with my ball joint removal tool, you can keep torquing it until the joint blows off with a pistol shot and the tool and ball joint flies across the room, or you can smack it with a hammer and make it's removal more predictable and safer. Sometimes a little shock to the part is very helpful.

I'm moving all my chips over to the square that says the mechanic snugged up the bolt after he put the pulley with the new belt on it onto the camshaft and went about checking the alignment of the belt and the other pulleys and rollers and just flat forgot to go back and set torque on the bolt. 33, 38, 42, 45....whatever. Do I think he torqued it to 33ft.lbs. and it went 170 perfect miles and then let go? Give me a break! Camshaft pulley torque settings are a topic for another thread!



And do you think that when that big, shiny Triple A Hook came slipping into the parking lot and dropped the Golf that he had just done a timing belt job on the mechanic didn't even raise an eyebrow? No, that same day, at lunch, at break, after work, he went out and popped off that top timing belt cover to have a look before anyone else did. All that about getting it into the bay after 5 days and a possible fuel delivery issue, but they weren't sure, was all CYA, kick mud in the water, BS.
My apologies in advance if I've offended anybody.

From my long time around inboard, straight-drive boats (nearly all of which are morse tapers similar to this) I can tell you that the failures are always UNDERtorqued; the wheel rides on the key and winds up cracking the shaft right at the keyway.

Put together properly you don't even need the key and there's a clean argument you shouldn't use it because you might be able to salvage a shaft and wheel where they spin. If it breaks you're out the shaft for sure and in virtually every case the prop too.

I never let anyone else put mine on, and never had a problem with them either. They were always a whole lot of fun to get apart when I needed them to come for reconditioning or similar, even with an Algonac (massive A-frame device that exerts crazy leverage on the hub to get it off.) It is not uncommon to turn the blades into pretzels when a boat is grounded under load yet the taper joint doesn't move AT ALL.

Frank, not sure about a 'machinist handbook', but for sure there is the Machinery's Handbook...a small beast with a special drawer in the Kennedy top boxes sized just for it. I have Pop's 11th, and the 21st I bought at a HamFest for $4. Best money I ever spent!

I thank y'all for showing me some more stuff I need to watch closely. I have my son's ALH and my BEW that I hope will continue service for the forseeable future. Hope that by the time I need another, I'll be able to find one. Will likely get after the ALH's injectors, as I *REALLY* don't want to have to worry about this happening. I am not sure about Lurch the cummins; He takes the large, early, non-IC'd tips.
cheers,
Douglas

PakProtector said:

I am not sure about Lurch the cummins; He takes the large, early, non-IC'd tips.
cheers,
Douglas

Click to expand...

Luckily the injectors for that beast are relatively inexpensive. I had to start a second bank account as a safety net just in case (when) the injectors start to go in my commonrail Cummins (>$3,000)

PakProtector,

Ok, I have been wrong before and you have caught me. It's not Machinist's Handbook...

It's Machinist's and Took Makers Handy Book, 1942 printing, which 'Covers modern machine shop practice in all it's branches. 5 practical books in one'.

My original leather-bound version sold for $4 in 1943. I don't remember giving that much for it, but I wouldn't take $1000 for it (well, maybe...).

I do still have the mail order sheet in the back of the book if you want to get a copy...

U4ick,

Yes, that is exactly what I think happened... the pulley wasn't tight enough. And another part of the story that you may not have considered, the mechanic just put in brakes and what do you think he did? Jack Little is what I would refer to as a conservative driver, but I doubt when the mechanic who did the brakes took it out for the test drive has similar driving habits...know what I mean? He probably gave it the gusto and yes, if the cam sprocket was tightened marginally, it would let go.

So you know, this is not the first time we have seen this happen... far from it. In the earlier years of our business, we calculated there were about 6% of the cylinder heads per year, coming into the shop with the same tell-tale sign of a spun cam sprocket. We suggest any of you that have a torque chart that shows that sprocket torque should be 33 ft lbs, CHANGE IT. 45 lbs is perhaps a bit light, but certainly not unreasonable. As for the reasons, I've explained myself very clearly.

Frank,


Yeah, I've been setting it at 45 every since I read it in one of your posts quite some time ago.


Unfortunately, the business practices of this shop seem to be way more the norm than the exception these days. I was taught when you make a mistake own up to it and do whatever it takes to make it right, even if it means coming out of A$$ National. No reasonable customer would hold that against you, and you would probably gain his respect, his repeat business, and the business of his friends and family. A good reputation is the most valuable asset of any business, it takes years to earn it and seconds to lose it.

Frank, I will take a piece of being wrong if you don't mind...

'mail order sheet'...LOL. I have some warranty return cards for some ancient Hytron transmitting triodes, HY51A, HY40...those cards have been ornaments for decades.
cheers,
Douglas

Yesterday my Golf was packed into a trail and carried off to its new home. In my final moments with the car, I placed my hand on the driver's door and thanked it for many years of trusted service and for saving our lives. Apparently the young man who now owns it has plans to do some power enhancements to the engine. I'm sure the Golf will give him a lot of enjoyment.

Thank you all for a great run. It's been an honor. Long live the TDI.

Thanks for the update - glad it's going to a good new home.

Jack, I'm just now seeing this. So sorry you had this happen and came to the end of the road with your Golf. I live in the Springs, and we connected by phone about a year ago. Best of luck with your Crosstrek, and sorry to see you go.

--Dan