M90 w/dog dish flywheel - spacer needed?

I'm looking to put an M90 in my 940, and something I read has me puzzled. Anthony Hyde says "Another issue is the length of the mainshaft - Initially the box mates to a thick dual mass flywheel (expensive), BUT if used with a Volvo flat flywheel the input shaft is not long enough to fit into the crank pilot bearing. An adaptor would be required, more info when a fix comes to light." regarding mating the transmission to the early style flat flywheel. I understand there are now spacers you can get from Sweden that address this problem, but I am mating my M90 to a dog dish flywheel instead of a flat flywheel. Do I still need this/any spacer?

We'll the m90 being a three shaft tranny, doesn't need a pilot bearing and isn't designed with one. That being said you can get one from retroturbo that will work with your dog dish.

http://www.retroturbo.com/?product=m90-mainshaft-adapter-prt

With a dog dish flywheel the clutch disc that works is the 7 or 9 series turbo diesel clutch disc 228mm and has the correct splines for m90 as you buy m90 turbodiesel clutch disc. Or have custom one made, m90 has same splines as m56 or 850 clutch discs also. So any 850 228mm clutch disc should work also. I opted for the 240mm TTv billet steel flywheel and 850R 240mm setup for m90 myself.

The M90 does not need a pilot bearing.

You do need to space the pivot ball or use a longer pivot ball or a longer pushrod.

The full DMF conversion kit has everything needed and a much lighter flyweel than the DMF or the Dog dish

https://www.classicswede.co.uk/B230_DMF_Flywheel_conversion_kit_with_clutch/p1733344_15039049.aspx

Pete and repete..


I said the same thing, same flywheel and 850r ha ha ha.

Course I bought the retro turbo m90 pilot bearing thing and guess what? It didn't fit in the TTV flywheel, now he sells one that does of course after I told him about that problem.

Some people have broken the front input shaft on the m90 dropping clutches and more power then stock is why real racers decided to want a pilot bearing anyway.. Yeah not the classic wales way I guess seeing as it ain't in there kit. Fortunately you can buy the kit and then buy the pilot bearing from retroturbo anyway and put it in if you want, it's your car!

Thanks for the help. For future reference to myself and others, I bought the retroturbo piece to go with my diesel clutch setup and if I move on from the diesel clutch (i.e. more power) I'll switch to the TTV flywheel.

Ive been running the stock diesel clutch kit and dogdish flywheel for 10 years, 80k km with a 3.31 LSD with a floating input shaft behind a mildly tweaked b230 ft. Not normally thrashed but certainly has experienced a number of good spirited driving events over the years with no noticeable issues.
Patrick

classicswede said:

The M90 does not need a pilot bearing.

You do need to space the pivot ball or use a longer pivot ball or a longer pushrod.

The full DMF conversion kit has everything needed and a much lighter flyweel than the DMF or the Dog dish

https://www.classicswede.co.uk/B230_DMF_Flywheel_conversion_kit_with_clutch/p1733344_15039049.aspx

Click to expand...

I fitted one of your lightened SMFs last year, I explained in detail to the mechanic that the pivot ball would need spaced out although of course he didn't do it, to avoid taking the box out he has extended the pushrod which has helped but it could really do with more to make it perfect, he suggested cutting a section out of the gearbox casing, would this work and allow more throw?

We'll you can just pop out the clutch fork and unscrew the pivot ball and modify that so it's longer or put a washer behind it and screw it back on. You don't have to take the trans out to do any of that.

I would not hack anything about. Do as above

sbabbs said:

We'll you can just pop out the clutch fork and unscrew the pivot ball and modify that so it's longer or put a washer behind it and screw it back on. You don't have to take the trans out to do any of that.

Click to expand...

Great, they had told me it was a transmission out job!