Welcome to Magazine Premium

You can change this text in the options panel in the admin

There are tons of ways to configure Magazine Premium... The possibilities are endless!

Member Login

Lost your password?

Not a member yet? Sign Up!

E30 M20 often missed important part of a timing belt job (intermediate shaft sprocket gear)

March 8, 2023

So you’ve heard that you should change the timing belt on an M20 every 50k miles or 4 years (whichever comes first), because in case of failure the valves will hit the pistons, rocker arms will break, and you’ll be looking at a top end rebuild or a new engine.

But what many people, even seasoned miss is that there was a late revision to the intermediate shaft sprocket gear; from stamped metal to sintered.

Left old style (11311713351), right new style (11311717398). Ensure to also order bolt 11311714798 as it is a slightly different length.

**During install, on the new style, the casted in nub goes into a matching hole on the intermediate shaft.


What happens with the old style? Catastrophic failure from rust and fatigue leading to the same result as the timing belt breaking:


Although many 1988+ cars should have the new style, its possible to have the old style all the way up to 2/16/1989 (some MFG plants switched over before others):



Much less common is for there to also be a stamped gear on the camshaft; generally only on 1986 cars; if that is the case, also change to the newer style sintered gear (11311714988):


Leave a Reply

Your email address will not be published. Required fields are marked *

About us


29 visitors online now
13 guests, 16 bots, 0 members
Max visitors today: 72 at 09:54 am UTC
This month: 272 at 07-05-2024 06:24 pm UTC
This year: 514 at 01-19-2024 07:18 pm UTC
All time: 514 at 01-19-2024 07:18 pm UTC