release bearings

[calj]

hi everyone, im currently purchasing all the spares for my m52 conversion and cant seem to find a definite answer of which release bearing to use.

i have my getrag 260 from my 325 including the m20 flywheel so all i need to know is what bearing i need and most of all where do i get it?

any help appreciated

callum

[heathy325]

Standard release bearing from the e30 m20 cars so 325i or 320i

[jmc330i]

E30 M20 release bearing is too short if you use the M20 flywheel on an M5* conversion. It puts the clutch release fork at an odd angle, which brings the biting point high up the pedal and makes for a clutch with a snatchy feel.

You can either use the slightly longer E21 323i M20 release bearing (not cheap anymore) or you can use the E30 M20 bearing but you need to weld some tabs on to the release fork to space the bearing closer to the clutch fingers.
I'm not sure if the size of tabs needed is mentioned on here, but a quick google search for 'M52 M20 flywheel' will bring up the info and pics on some of the US forums.

I need to do this on my car so will get some pics when I get round to it.

[heathy325]

I have the standard m20 325i bearing in mine ever since I've done the conversion still have the 260 box and it's no different than it was with the old engine

[jmc330i]

Ah sorry, I didn't see the op had the M20 box.

[ashje]

Some more info on the DIY route would be excellent, i.e. How tall the tabs need to be or how far to space the pivot point for the release fork.

Can the pivot just be spaced with washers? If so this seams a slightly easier and safer route than welding tabs on.

[jmc330i]

I've not looked into it properly yet, but I believe the E21 M20 323i bearing is around 4.5mm to 5mm 'taller' than the E30 M20 bearing. So tabs of that thickness will be needed, although I've heard of some people adding them to the fork and others to the 'ears' of the release bearing. I'm not sure which is best or which I'll do yet.

If the E30 M20 Getrag gearbox is used, you use the standard E30 M20 bearing.

[nickso]

If it helps I welded my tabs onto the fork. I just cut up another fork and welded it on. When you look at it in front of you it's obvious what you need to do for sizes and position of the tabs.

[and1_e30]

i am also just about to tackle the flywheel clutch job i can't find much on modifying the fork so if anyone does it take some pictures

[HairyScreech]

Always best to modify a non wear part to take a standard wear part.
That way you only do the mod once and fit a standard bearing when you do a clutch change.

Mod the fork.

I have some pictures of the very quick and dirty job I did on mine a few weeks back just to get it back on the road. Has been fine for the last 1200 miles so I can't see any issues in the future.

[calj]

Thanks very much for the info everyone!

[jmc330i]

Always best to modify a non wear part to take a standard wear part.
That way you only do the mod once and fit a standard bearing when you do a clutch change.

Mod the fork.

That was my thinking about it. Not sure why people have modded the bearing.

Does 4.5mm-5mm sound about right for the tabs?

[rich318i]

you need to add 5mm to the bearing to match up with the M52 box