M20 Timing Belt Pulley Breakage?

[Andre3127]

I've heard rumors that one type of M20 timing pulley (or "gear") is prone to failure. Can anybody confirm this? I have both cast and sheet metal pulleys, and I'm wondering which one to use on my car.

[jgilber0]

From Pelican Parts nice write up:

“E30 cars manufactured in 1986 and later years should have a tensioner marked with "Z 127." If your tensioner does not have this code, replace it with one that does. This tensioner design replaced an earlier, potentially faulty, design.”

Find it here: https://www.pelicanparts.com/bmw/tec...iming-Belt.htm

[e30davie]

i think OP is refering to the pressed vs sintered cam gear and idler gear.

this thread has a photo.

http://www.mye28.com/viewtopic.php?t=113757

my early model m20 has the old stamped ones, I didnt bother to change them out.

the later model is probably better if you have it, I personally wouldnt bother tracking one down but the internet is full of people that say the older style bend and break over time, Im not sure how many have actually failed. BMW did update it for a reason i suppose.

[ForcedFirebird]

Use the sintered (cast) gears!!!!

Yes, the intermediate shaft gear is a failure point. Seen a couple fail and take out the engine. They crack around the bolt hole, start wobbling and rip your belt cogs off.

Trust me, it's the best $30 you ever spent - after the timing belt itself....

[Andre3127]

Use the sintered (cast) gears!!!!

Yes, the intermediate shaft gear is a failure point. Seen a couple fail and take out the engine. They crack around the bolt hole, start wobbling and rip your belt cogs off.

Trust me, it's the best $30 you ever spent - after the timing belt itself....

My intermediate shaft gear, do you mean the cam sprocket or the oil pump drive?

Sent from my XT1053 using Tapatalk

[ForcedFirebird]

Correct.

[jeffnhiscars]

both gears were stamped steel and need to be replaced w sintered