timing belt trouble -- please help!!

[tntdifan]

Trying to change the timing belt on my 2006 BRM Jetta, I ran into some difficulty. The new belt was very stiff. To get it on, I had to remove the camshaft sprocket, put the belt on the sprocket, and put the sprocket back on the hub.

Unfortunately, I think I didn't get the sprocket all the way back on the hub. When I attempted to tension the belt and torque the sprocket, the misaligned sprocket swaged a "lip" of metal on the bronze colored portion of the hub. Picture:

(Picture somewhat exaggerates the size of the "lip" due to perspective effects. It's about a millimeter high or bit less.)

After three fruitless attempts to get the belt + sprocket on straight, all of which resulted in the sprocket being out of "true" and the belt wandering off the sprocket in the direction of the cylinder head, and the last of which culminated in the sprocket requiring a couple of taps with a hammer to release it from the hub ... I tried to just press the sprocket on by hand, and discovered that it doesn't go on the hub anymore in any mode except "wobbly".

I need this car to be functional asap. What should I do ... (a) try to carefully file down the "lip" enough to get the sprocket to mount flat on the hub; (b) try to buy a new hub and get it airfreighted; (c) give up, put the motor mount back on, and have the car towed to a VW shop.

 

[whitedog]

File down the high points and move on.

 

[tntdifan]

picture (try # 2)

 

[whitedog]

 

[slamhouse]

You may have bent your sprocket when you tried to tighten it down while mis-alligned.

 

[hughball65]

Did you get the lip filed down? How does the sprocket side look?

 

[tntdifan]

sprocket warpage?

Slamhouse, do you think it's sufficient to check the sprocket by laying on a table or other flat surface to check for warpage? It's pretty hard steel and looks undamaged, but still ...

Anyone have any good tricks for getting a new timing belt on? I got the old one off starting at the water pump with no trouble, but the new one wouldn't go that route. This is with the idler roller off and the tensioner de-tensioned as far as it would go. Should I use the sprocket holder tool (once I have the sprocket on true!) to pull some extra slack on the water pump side?

 

[hughball65]

Verify correct belt p/n... could be a case of wrong part in the right box... where did you purchase belt?
With idler roller off and tensioner at full "de-tension" and still having trouble.

 

[D-Cell_Mekanick]

Slamhouse, do you think it's sufficient to check the sprocket by laying on a table or other flat surface to check for warpage? It's pretty hard steel and looks undamaged, but still ...

Anyone have any good tricks for getting a new timing belt on? I got the old one off starting at the water pump with no trouble, but the new one wouldn't go that route. This is with the idler roller off and the tensioner de-tensioned as far as it would go. Should I use the sprocket holder tool (once I have the sprocket on true!) to pull some extra slack on the water pump side?

Are the two belts the same length?

 

[tntdifan]

Belt is a Gates T333 purchased from Dieselgeek. Gates' application catalog indicates that it's the correct part for the 2006 1.9 diesel.

 

[oilhammer]

You are doing something wrong if you had that much difficulty. I really would suggest letting someone more experienced go over the job so you are not pulling your cylinder head off during the holidays.

 

[hughball65]

Are you able to get cam sprocket on, without belt, and fitting flush yet?

 

[tntdifan]

"someone more experienced go over the job" = the tow-truck option ?

I will check tonight to verify that the belt is the same size and has the same # of teeth as the old one.

 

[Henrick]

Not sure about the real problem but I might give you a tip on putting a new belt:
remove the idler, tensioner, water pump (assuming you're replacing these). Install water pump. Tighten to spec. Install TB tensioner. Don't tighten, leave it hand tight, you'll need to apply tension here. Put the belt on the crankshaft, put the belt on the camshaft and water pump at the same time. Make sure the camshaft three bolts are hand tight and are slightly towards the left side of their windows. Now it should be easier. Then install the idler, tighten to spec. Tension the tensioner. Tension the cam bolts. Make several turns of engine by hand. Apply the remaining +45 degrees to the idler and tensioner nuts. Job done.

 

[slamhouse]

The new belt should be slightly smaller than your old one as your old.one has accumulated a slight stretch to it. Maybe 3/8 " shorter than the old one.

 

[SilverGhost]

I would be hesitant to file or otherwise modify the sprocket as a lot of VW cam sprockets are pressed sintered (powdered) metal. Safest suggestion, at this point, is to replace the sprocket and verify no damage to nose of camshaft.

Yes, the belt on a BRM can be EXTREMELY hard to get on. I have resorted to putting the belt on the crank and water pump only partially before attempting to start the belt onto the cam sprocket. Then working it onto each sprocket a little at a time. The other method I use is leave the tensioner off, start the belt onto the sprockets, then put the tensioner in place and rotate to engage locator pin.

I used the trick you tried on a 1.8T and ended up buying a head. The key way on the sprocket sheared off and the sprocket rotated enough to hit valves. I had started the engine and it idled perfectly about 30 seconds then just stopped. First thing I did was recheck timing and found it off a couple teeth.

Jason

 

[Growler]

all you have to do is use the pin that comes with the tensioner properly and the new belt slips over the waterpump easily.

slip the belt over the crank pulley, the lower roller, the tensioner, and the campulley, leaving all of the slack on the waterpump side and the campulley bolts centered and loose.
you rotate the tensioner CCW to expose the pin hole. insert the pin, then torate the tensioner as far as it will go Clockwise, thensnug down the tensioner nut until it holds the tensioner in this position.

you can then easily slip the extra slack you gained over the waterpump, then release the tensioner nut and remove the pin. takes 15-30 seconds.

 

[oilhammer]

Or, you can take 5-10 seconds and leave the lower roller off, slip the belt and tensioner in place, while pushing the lock tab in place, THEN slip the lower roller on.

Either way, this is a silly easy timing belt... by far one of the easiest there is, even for a Volkswagen.

 

[Henrick]

Or, you can take 5-10 seconds and leave the lower roller off, slip the belt and tensioner in place, while pushing the lock tab in place, THEN slip the lower roller on.

Either way, this is a silly easy timing belt... by far one of the easiest there is, even for a Volkswagen.

That's what I was talking about. I also knew the tensioner pin trick but forgot to mention that

 

[tntdifan]

The sprocket does not appear to be damaged. The damage is to the hub that the sprocket mounts on. I'm concerned that if I file off any of the metal ridge on the hub that the sprocket will not mount stably on the hub anymore, and will end up slipping.

Do I need to try to replace the hub, or should I file and hope for the best?

Oilhammer, your idea about mounting the tensioner and belt together was the next thing I was going to try before I discovered that my sprocket was not seating correctly. I'm also going to warm the belt up; I was working in a cold garage and the belt was about 45 degrees F.

 

[tntdifan]

Okay, after examining the sprocket carefully, there's no noticeable warpage, but there is a small gouge on the inside rim. I can probably smooth that down with sandpaper fairly easily.

The ridge on the cam hub is rather prominent, actually. I don't know if I can really fix that with a file.

Bentley indicates that special tools are needed to remove the hub, and there's no part number visible on mine, so I can't even research ordering a replacement.

Starting to look like I've bricked my car, and there's a tow truck in my future.

 

[SilverGhost]

Aw crap, brain fart! I was thinking of the one piece cam sprocket, DUH!

I like Oilhammer's idea, though Growler's is the method in the repair information. It is a stupid simple design, but can kick your arse if you don't do everything just right. And working in a 45F garage does complicate manners a little.

The main issue I have seen on the BRM is the wide timing belt does not like to bend much. And that is pretty much what you are asking of it when you start the belt on a couple sprockets then try feeding it onto the last one (usually the cam). Keeping the belt flat (IE; picture it laying flat on its side on the table) as much as possible while going on is the key.

Jason

 

[tntdifan]

Been working for an hour with the file. Ridge is smaller; sprocket doesn't go on yet.

 

[hughball65]

A coarse sandpaper should work well on soft metal too... perhaps better than a file.
Don't throw in the towel yet, probably closer than you think to that sprocket fitting back on.

 

[tntdifan]

Fellas, thanks for the advice and concern. Even if I sanded down the ridge successfully, the sprocket won't necessarily end up centered on the hub, which will cause vibration, etc.

I'm going to (partially) admit defeat, and order a replacement sprocket and hub by express shipping tomorrow. I found (I think!) the part number for the hub. Both parts together will run a little over $200. That's not much more expensive than getting the car towed to the repair shop.

I will have to come up with some counterhold trick to loosen the sprocket hub, since the sprocket itself likely won't be available. May need some help from y'all then. For now, I'll put the motor back on the motor mount so I don't have to worry about my jack failing.

Object lesson: despite what you may read on the Internet, NEVER, EVER try to put a timing belt on a BRM by taking the cam sprocket off the hub and trying to put it back on together with the belt. The hub is soft metal and will deform if the sprocket is not squarely on it.

 

[slamhouse]

<snip>

Object lesson: despite what you may read on the Internet, NEVER, EVER try to put a timing belt on a BRM by taking the cam sprocket off the hub and trying to put it back on together with the belt. The hub is soft metal and will deform if the sprocket is not squarely on it.

This is actually how alot of people put the belt back on, just use better judgement when putting it back on to prevent unwanted damage.

 

[oilhammer]

This is actually how alot of people put the belt back on,.

Which goes to show you there are a lot of stupid people out there (no offense to the OP).

Man these are SO EASY!!!

 

[Henrick]

OP: looks like you're not experienced enough to do the belt job yourself. Don't heat the belt, it won't help, it might only damage it. I have my TB job dome at similar temperatures and there were no problems installing the new belt.

Seek for professional help before you spend even more money on repairs!

 

[tntdifan]

Camshaft hub ...

AAAGGHHH!!!

Can any part of this %!@$ job be EASY???

Camshaft hub ... how do you remove it? The bolt is loose, but the hub sticks tight. People say, "Hit it with a brass drift after loosening the bolt". Where? between the head and the hub? I don't want to damage my valve cover, etc.

The VW specific tool is apparently available for $55.

 

[slamhouse]

AAAGGHHH!!!
Can any part of this %!@$ job be EASY???
Camshaft hub ... how do you remove it? The bolt is loose, but the hub sticks tight. People say, "Hit it with a brass drift after loosening the hub". Where? between the head and the hub? I don't want to damage my valve cover, etc.
The VW specific tool is apparently available for $55.

Congratulations on your German vehicle ownership, you have succesfully passed "initiation"