Has Anyone Ever Seen This - Timing Belt

[Peelsbimmer]

Wish I would've known about the sprockets, possibly braking, before I had changed my t-belt!

[turbo55]

^^^ Correct. The sprockets themselves can shear. They are just stamped sheet metal vs. the newer style which is a LOT beefier.

Here's an older thread on the topic with comparison pictures:

http://www.r3vlimited.com/board/show...hlight=stamped

So only the oil drive sprocket needs to be replaced (based on the thread link above)? And also it looks like its something you get from the stealer? Any idea how much?

[nando]

No, both the cam & oil sprockets should be replaced.

[Mwishlist]

The spring and pin are sold separately from the timing belt kit. Around $5 for both from the stealer.



I've seen M20 engines where the spring is missing. I had one. While I understand that once the tension is set the spring really doesn't do anything more - it basically remains there in case the bolts holding the tensioner in position would ever back off.



I also always replace the stamped camshaft and oil pump drive gears with the updated cast ones when I encounter them. It looks like you have the stamped gear on your oil pump drive.

Do you have the part numbers for those? I thought the stamped oil pump gear looked weird when I did mine but it felt solid. If I had known there were updated versions I would have changed that one while I was at it.

[Mwishlist]

Never mind, just caught the link to the other thread.

[101]

$42.53 list price for the cam gear

$23.51 list price for the oil pump drive shaft gear

I replace the attaching bolts as an added measure of caution.

http://www.realoem.com/bmw/showparts.do?model=BB23&mospid=47326&btnr=11_4365&hg=11&fg=25

[turbo55]

Just ordered the camshaft and oil sprockets from TurnerMotorsport for $36.95 and $23.95. They also had the spring, pin, and camshaft seal/oring for good prices too.

[estoguy]

Here's a related question - camshaft seal - how often should this be replaced?

[Andy Mechnic]

Every time youre in there, provided you're not going back in there because you monkeyed something up.

[turbo55]

Here's a related question - camshaft seal - how often should this be replaced?

Mine is leaking, I'm gonna replace it. It looks like it should be pretty easy to do if you're already in there for the timing belt, and the seal and o-ring was $4 and $1 from Turner. So yeah I'd say you might as well do it every time.

[turbo55]

Update: the belt was rubbing because the belt tensioner had failed and was cocked to the side. Here's a side-by-side with a new Gates one: