What clutch and transmission combination do I need

[Spunup]

I have an 85 e30 with an M52 and a getrag 260
i believe I need both a new transmission and a clutch
It doesn’t shift into first and input shaft feels rough when rotated and the fluid is very grey
i am trying to figure out what my transmission options are and what clutch I need to buy. Pretty sure it has a single mass flywheel now (am pulling it off tonight) and am wondering what model car I need to search for to get the correct parts.
sorry for the noob questions I have a long history with Datsun 510s but am new to e30s

[hopeful]

Switch to a zf 310 trans.

It's the 1998 328i trans and others. It'll work with an m20 flywheel as well. The clutch you'll need will depend on what flywheel is on there. The zf will work with either.

[varg]

Don't switch to the ZF unless you have or can source a low ratio diff (<3.25:1), the ZF does not have an overdrive gear like the G260 does. A G260 is probably cheaper too, since ZFs seem have started to pop up in the swap/drift kid circles and skyrocketed in price around the time I was gathering parts for my E34. In any case, any OE M50 car clutch should work with your M52 and a G260, M20 flywheels shaved down a bit on the back were a common cheap conversion for dual mass M50/52 cars, the parts mix and match. M50 cars came with ZF310/320s or G250s, all of them share a spline pattern. The main difference is in pilot bearing inner diameter so you'll have to make sure you get the right one when you do a frankensteined conversion. If your car had the big ZF pilot bearing installed with the G260, it would explain the trashed transmission bearings, since the input shaft would just be floating. Seen it before.

[Spunup]

ok I bought a new 260 trans and pulled the clutch
the pressure plate had broken in two so that explains a lot
now I am trying to figure out what clutch i need. it had a 6 puck disk in it and the flywheel looks like a single mass replacement for a dual mass flywheel. it is steel and is lightened with the back hollowed out and holes in the center section.
so now i am thinking easy i just need to buy a clutch for an e30 with a dual mass flywheel and i am done. however i also have a used early (thick) single mass flywheel and clutch sitting near by and i notice that the clutch disk in that one is a fair amount smaller diameter than the one i just took out.
both the ring gears look to be the same diameter (290 ish) but one clutch disk is like 215 mm and the other (the one i just took out) is like 240mm

sooo any ideas on what clutch I need to buy?

I appreciate any help!

[mtech325]

Lots to address here!

Based on the 240mm measurements, you may have had an e36 m52/s52 clutch & flywheel in the car before. A 215mm clutch is usually from a 4 cylinder car, whereas a 6-cylinder e30 would have a 228mm clutch. Pictures of the flywheel & clutch that came out of the car would help to start, and if there's a part number possibly on the starter which can help verify. The starters have to match the flywheel, and e30 m20 and e36 starters and flywheels don't mix and match, so it'll have to be one or the other.

Like Varg mentioned, if an e30 325i single mass flywheel was used, the back side would have to have been machine down to work with the m52, but seems like it might be an aftermarket flywheel based on your description.

Same with getting pictures of the transmission you started with and the one you plan to install into the car, as it will also help (cast numbers "1270" and port for a flywheel sensor are for an eta transmission, and "1346" is for a 325i transmission and look to see if the bellhousing depths differ as that can dictate the throwout bearing depending on the clutch/flywheel setup). The other things to note is early 325e transmissions use a different style shift linkage, so will need to make sure the linkage swaps over as well, and double check the output flanges match as there are later eta transmissions which need a different driveshaft to match.

If you want to keep it simple with a g260, then you'd want an e30 325 starter, e30 325i single mass flywheel with back side machined down near ring gear for clearance, e30 325i flywheel bolts, and an e30 325i clutch kit (which will also include the right pilot bearing for the transmission as well). If you have the 'deep dual mass bellhousing' then folks have been known to use an e21 323i throwout bearing when using the single mass flywheel.

[Spunup]

Thanks for the info!
so, looks like the clutch setup was all clutch max junk (including the flywheel) so we are going to need to start over completely.
we replaced the starter a while ago and installed an m52 starter so the clutch must have been from an e36

looks like a decent e36 clutch kit and light (ish) steel flywheel is about $1,000 and maybe that's not the best way to go?

Sounds like we might want to find a single mass late model (1990ish) 325i stock flywheel and the corresponding clutch kit and also get an e30 starter and new flywheel bolts
am I correct that the later model single mass flywheel is the thinner one compared to the earlier single mass?

the car has an aftermarket body mount shifter so the shifter differences aren't a worry and the output flanges on the old and new transmissions match.

thanks!

[hopeful]

Thanks for the info!
so, looks like the clutch setup was all clutch max junk (including the flywheel) so we are going to need to start over completely.
we replaced the starter a while ago and installed an m52 starter so the clutch must have been from an e36

looks like a decent e36 clutch kit and light (ish) steel flywheel is about $1,000 and maybe that's not the best way to go?

Sounds like we might want to find a single mass late model (1990ish) 325i stock flywheel and the corresponding clutch kit and also get an e30 starter and new flywheel bolts
am I correct that the later model single mass flywheel is the thinner one compared to the earlier single mass?

the car has an aftermarket body mount shifter so the shifter differences aren't a worry and the output flanges on the old and new transmissions match.

thanks!

Earlier one is a dual mass, there is no earlier single mass. But goodluck finding one. RHD sells them afm and people seem to be pleased with them.

[Spunup]

thanks everyone
I bought a hybrid flywheel from RHD and a sachs clutch set
This should mean I can keep using the M52 starter i bought a month ago and also use a 325i clutch
Hopefully replacing everything between the engine and the driveline will fix the issues haha