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Good Morning All,
Hey my 2006 BRM Jetta is almost 10 Y/O, I love driving this things and love the fuel mileage!!! Needless to say maintenance is expensive, I have paid to do the cam, a turbo, clutch and the timing belt twice as the Jetta has 214000 + - miles on it… so the car is old enough that I should be able to do my own maintenance… I have rebuilt older diesels before and I’m mechanically inclined; as of now I do all my own “regular” schedule maintenance, but always been afraid of getting any deeper than oil, filters and brakes… With that said I have been reading a lot about T/B replacement tread and there are two things which confuse the most… with everything indexed in place by means of the T/B tools, why do we have to mess with the cam sprocket at all? If everything is being held in place the cam should have not moved at all…second do I need a VCDS after the procedure is done???

Great question, one I wish more wold ask before discounting. Simple answer is timing adjustment is precise, with variations measured in millimeters. Indexing tools are less precise.

I think I understand what you are saying. It seems like a small change can be dealt with. I think though that a few millimeters movement could change things by a degree or more, and with the locking pin in and the rest of the procedure done properly you should be relatively certain that you've got it all lined up. I just did my first BRM TB change last month and believed the hardest part to be the engine mount, but all things went well. I did have to stop in the middle to get a short extension for my 1/2" drive to break the engine mount bolts loose, so it is important to have what you need available before you start or a way to go get it when your car is apart.

any thing on the VCDS?? or cam sprocket adjustment?

Sorry, overlooked your last question. Yes, VCDS necessary to read timing, also known as 'torsion'. Many who don't properly set timing regret it when winter arrives (hard/no start).

I think everyone has missed your point with the cam sprocket and it is something I have thought about as well.

Assuming you do not loosen the three sprocket bolts holding the outer cam sprocket to the hub and assuming the torsion value was originally set to its optimum position, replacing the belt should bear no change. It is true the indexing tools are not precise. They insure your cam rotation is correctly timed to the crank rotation with respect to the indexing positions. This is all that is needed if you can confirm all other variables remain fixed or unchanged.

I have changed several timing belts without removing the cam sprocket and timing was not negatively effected. The belt will (could? my assumption) stretch to some degree during its life cycle so there could be a recorded change but it should return the torsion back to where it was originally.

It would be wise to check torsion value either way since there are several variables involved and because the above information may be completely wrong....

I don't remove the cam sprocket when changing the TB, but I think it would be in your best interest to use VagCom / VCDS to ensure your timing (torsion) setting is correct. 3 changes under my belt and hoping and planning for another two.

Don't forget the tensioner adjustment, which indirectly impacts timing. Again, we're talking about millimeters. Tensioner is not precise... just eyeball the variation when motor running.

No, if you understand the T/B procedure and follow it, you do not really need VCDS. It would be great to tweak Torsion, but doing the T/B procedure correctly with the indexing tools will get you within 1 unit of Torsion of zero every time.

It is so friggen stupid that folks refer to the indexing tools as lock tools. They don't lock anything and if you are putting any sort of load on them, you are doing it wrong. Indexing tools should ALWAYS be a slip fit during a T/B change.

Not loosening the 3 cam bolts during the procedure is completely contrary to doing the procedure correctly.

Really absurd statement. The indexing tools are extremely accurate and will get you within 1 unit of Zero Torsion every time if you do the procedure correctly.

Folks that have to hammer in the indexing tools are doing something wrong.

MyAvocation said:

Don't forget the tensioner adjustment, which indirectly impacts timing. Again, we're talking about millimeters. Tensioner is not precise... just eyeball the variation when motor running.

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Huh? makes no sense. if you adjust the tensioner correctly during the procedure it will be correct anytime you check it if you check it in the same way which is with the engine cold. You turn the engine in the direction of rotation from the crank some to get the slack on the tensioner side of the belt.

If you are evaluating the tensioner adjustment with the engine running, you are doing it wrong.

Actually, the tensioner indication is extremely accurate if you understand and follow the procedure. The tensioner indication is irrelevant when the engine is running.

Just a thought,
Changing belts on my BRM & BEW both cam tools were a little snug with original belts. Once belt removed tool moved easily in and out.
I did not loosen cam pulley, installed new belts over water pump installed roller, set adjuster. Both cars run perfectly.
Followed what Rattler has posted many many times.
no vcds

Correct. First you install the crank tool when it is a slip fit and then adjust the belt tension and then adjust the cam until the the cam tool is a slip fit. 2 more turns from the crank and both tools should come back to a slip fit.

Really stupid simple if you understand the intent of VW's reqirements for the procedure.

deeslman said:

Just a thought,

Followed what Rattler has posted many many times.
no vcds

Click to expand...

Thank you so much.

If you are doing it right, there is never a reason that the indexing tools should not be a slip fit.

The term "lock tools" is so misleading. The tools don't lock anything. What they do is index the crank to cam relationship.

Once you pin the crank, if the cam is off you need to adjust it which might be a reality on a car with some miles on the T/B. So if you want to replace the T/B, pin the crank and just note the cam position because it may be slightly off.

It is just amazing how accurate the procedure is if you understand it and do it the way VW's engineers envisioned it to be done.

Ol'Rattler said:

No, if you understand the T/B procedure and follow it, you do not really need VCDS. It would be great to tweak Torsion, but doing the T/B procedure correctly with the indexing tools will get you within 1 unit of Torsion of zero every time.

True, if you take your time and make the necessary minor adjustments to achieve a slip fit of both indexing tools, your cam timing will be "close enough" and your engine will run fine (FYI, mine was verified at -2 after a slip fit and yes, I understand this procedure) . Since you are so hung up on doing this correctly, why would you tell anyone not to finish this procedure by making the last fine tune adjustments with vcds? Sure you don't have to check it and many don't, but finishing this procedure "correctly" requires the use of vcds!

It is so friggen stupid that folks refer to the indexing tools as lock tools. They don't lock anything and if you are putting any sort of load on them, you are doing it wrong. Indexing tools should ALWAYS be a slip fit during a T/B change.

Lets not get our panties in a wad over a simple case of semantics...jeez. When people say "lock tools", everyone knows what it means, however annoying it may be to those so concerned.

Not loosening the 3 cam bolts during the procedure is completely contrary to doing the procedure correctly.

Yes, it is usually necessary to loosen the sprocket bolts in order to make the minor adjustments of the cam for the pins to slide into place or when performing the vcds torsion value adjustment . My point was simply, if you do not have vcds and you do not have a number of these jobs under your belt (pun intended ), leaving the cam sprocket well enough alone will get you close as long as your timing was correct before you started. If the cam indexing pin doesn't slid in, don't be absurd by golly, loosen them bolts!

Really absurd statement. The indexing tools are extremely accurate and will get you within 1 unit of Zero Torsion every time if you do the procedure correctly.

Your lack of insight into what people are really saying is absurd. They are relatively accurate yes, enough to ensure your pistons will not collide with the valves and that your engine will start. They are not precise enough if one wishes to achieve a certain torsion value, which was my point exactly.

Folks that have to hammer in the indexing tools are doing something wrong.
You lost me on this one. Did someone say they had to do this?

Click to expand...

Step down from your soap box and stop being so patronizing! People come here to learn and while your statements usually hold merit, your presentation is very unprofessional and at times, downright demeaning. I have watched you do this time and again, sometimes being completely wrong. I'm guilty of it too at times (a lot of us are), and I have certainly been wrong on more than one occasion but of course that doesn't make it okay. Point being, it robs everyone else of a pleasant learning environment and that just isn't fair. Lets all be civilized so that everyone can realize the amazing value this site has to offer.

Well Ok, I guess you got me. I'm not a car mechanic as such, however I do rig aircraft flight control cable actuated systems on a regular basis. the methodology I present is derived from my own aircraft experience.

To do any procedure following the procedure as the engineers defined it is really paramount in doing it correctly.

No pantie twisting involved. If you can have your "rig pins" never bind, the rigging job you do will be spot on.

Getting within 2 unit of zero is still within limits, but leads me to believe your process was flawed in some way. I can get within 1 unit of zero all day long. Check it with VCDS? Sure why not, but not really all that necessary.

The term "lock tools" is really so very far from the truth. Like I said, the timing tools are the same as aircraft rigging tools. If you have a slip fit when you are done, you are golden.

My point is that without VCDS your car will be well within spec and in most cases will not require additional adjustment.

I guess if you are a complete hammer head and can't do the T/B change procedure correctly you may need to check/adjust torsion with VCDS.

My "soap box" is just an extension of understanding the process being debated. A lot of folks will jump into this stuff with no clue. My job on this community forum is to help them get to were there need to be in understanding their issue.

I guess if truth is foreign to you, what I post is irrelevant. Just some cold hard fact from someone that has actually been there.

I must apologize for my presentation. Sometimes the lunatic in me does come out. Sorry about that. Just the way my brain works.

If you have an issue with me try to forgive my personalty and concentrate your reply on what I post and not how I post it. I do try to be 100% correct with my understanding of a problem with everything I post. Fred's is such a great resource and my only intent is to make it a better resource for all of us.

Almost forgot, what I posted previously is 100% within my knowledge of mechanical processes. If anyone can dispute what I posted, I'm all ears.

I've tried three times from my phone to post this. Lost what I typed the first time, but got the basic idea below. After the first time I copied the text, finally had to email to myself and post it from the computer.

With a BRM engine, once you have the crank and cam indexed and the indexing tools in place, you are free to spin anything else in that path with no effect on timing. So loosening the cam bolts allows for everything but the crank to move slightly while the belt tensioner is tightened, without disturbing the cam timing as well. If you left the cam sprocket bolts tightened, you would have two anchor points instead of one, and any tension on the other side would only come out when turning the engine over, and that could play a part in changing the timing of the cam vs crank more so than if you only had one anchor point

Anyone familiar with the TB change procedure on the 1Z/ALU/ALH should understand this. There you loosen the cam sprocket too and remove the injection pump locking pin when tightening. That way you are more likely to have the cam and sprocket timing correct, but then you go back and check the injection timing. Because the injection pump sprocket could turn slightly during the tightening procedure is why you would check it with VCDS and make adjustments as necessary.

Anyone reading this is free to do what they want with the information. I just wanted to provide more of a "why" than a "you must do/don't have to" answer. I've done "mark and pray" timing belt changes on a couple of 84 diesels with no issues, but having the amount of information available now and how easy it is to get the correct tools I wouldn't do that today. Also, I've already sent the OP information on some less expensive indexing tools that I've verified work just fine.

Rattler,
No apologies necessary, we all have issues. I do not explain myself well after the first time.
As far as sensitivity, this is the internet right................