All you need to know about the M90

[Volvorules]

It actually sounds like a rattling sound...like something is loose. That or the throwout bearing is just toast, or not lubed at all. We were thinking it could be a bolt that fell out of something in there, but the noise is too constant for it to be something like that. I'm guessing it's the t/o bearing, but may have some issue with the pressure plate. It made a much different noise when the clutch was depressed, but only 2 out of the 20 or so times we tried.

[SteveMD]

Originally Posted by Volvorules

It actually sounds like a rattling sound...like something is loose. That or the throwout bearing is just toast, or not lubed at all. We were thinking it could be a bolt that fell out of something in there, but the noise is too constant for it to be something like that. I'm guessing it's the t/o bearing, but may have some issue with the pressure plate. It made a much different noise when the clutch was depressed, but only 2 out of the 20 or so times we tried.

Thanks, Rob. The pressure plate is a standard volvo b230FT plate and the disc a 940 diesel sprung hub disc. I can't imagine MikeP and I missed a PP bolt or something. He made sure to lube the input shaft splines and the input shaft tube on the trans the TO brg slides on. I wonder if the TO brg came unseated from the fork. Will find out next week when I get under the car.

I hadn't driven it very hard yet really, the 13c is only putting out 6psi.

[ZVOLV]

I just got my M90!

1. Anybody have the Volvo part number for the 850 clutch disc that will work?

2. Part number for the pilot bushing

3. Alignment tool part number

4. M56 Tranny oil work fine?

5. Sources for clutch setups

6. How does the nub on the shift linkage mount. I think mine came with some bracket that mounts to the rear two shift boot threaded holes.

Originally Posted by ZVOLV

I just got my M90!

1. Anybody have the Volvo part number for the 850 clutch disc that will work?

2. Part number for the pilot bushing

3. Alignment tool part number

4. M56 Tranny oil work fine?

5. Sources for clutch setups

6. How does the nub on the shift linkage mount. I think mine came with some bracket that mounts to the rear two shift boot threaded holes.

Look at post #1 in this thread. It will tell you most of the stuff you want to know.

The only things that are not listed there are question 2, 3 and 5.

2: It doesn't use a pilot bushing.

3: Dunno... can you rent one from Volvo? I use a really cheap kit from a Swedish company (15 bucks).

5: It depends on what you want. Sachs, or some other brands?

[ZVOLV]

I'm obviously confused. Sorry.

1. I need to be very careful about not ordering the wrong clutch disc from the dealer because its non returnable since its special order. ($350) This pic also turns me off since it looks too small compared to the 740 disc.



2. The part number for this thing:



3. Looking for ideas on where I can get the right tool and the part number. Volvo definately doesnt have this tool.

4. I just bought 3 quarts of M56 oil at $22 each so I hope I made the right move.

5. I am looking for Sach's clutch or OEM clutch. Stockish since I am gonna be nice to my tranny for a while.

6. I have a bracket, but it doesnt look like the one in the VADIS pics above. That one looks like it hangs on the lip of the shifter hole, but I think I have one that mounts to the threaded holes for the shifter boot.

[foggyjames]

Hey Zach,

Fred sounds like he's got you covered on most of those points. Additional comments...

1) I just went and put an S70 NA clutch (228mm) in a dished flywheel, and it fits perfectly. My housemate's 740 (dished flywheel, M90 diesel plate) now runs a ClutchNet 850 (228mm) disc, and it works very nicely...very streetable. As long as that 850R clutch is 228mm diameter, you should be AOK. Were the 228mm FWD clutches always for a solid flywheel? If so, they should have a sprung centre, while the dual mass ones have a solid centre. You may need to make more or less of a leap of faith on this one, unless we can find someone actually running an 850R disc.

The other thing to bear in mind is that we got an M90 diesel clutch (complete) to hold around 300lbft before it started slipping. Quite independently, a clutch specialist said that the limit for a 228mm organic clutch will be around 300lbft. Unless the 850R disc friction material is made of something exotic, it may be no grippier than an M90 diesel disc, and any 'magic' is all in the 850R pressure plate...which won't fit the redblock dished flywheel. On that basis, I'd be sorely tempted to fit an M46 turbo plate with either a lesser 850 disc (if they're cheaper), a M90 diesel disc, or even a ClutchNet 228mm sprung 4-puck. The one in Ryan's car is very "streetable", given what it is.

2 and 3) I always align clutches just using a 3/8" extension bar. When it "wobbles" an equal distance up, down, left and right (pivoted from the pilot bearing), the disc is sitting centrally. The car I just did had an M46-style pilot bearing in place, which clears the M90 input shaft fine. The metal piece you've pictured there is only used for clutch alignment - the input shaft doesn't make contact with it (obviously, if you think about it ). If you already have an M46-style pilot bearing, I'd use that to align the clutch. If not, the PN for that metal jobbie appears to be 1397077...but that's all it's there for: clutch alignment.

6) The bracket you have is the same one in the Vadis pic...it's just a crappy drawing of it. You can either bolt it up to the underside of the shifter boot clamp bolts (once installed...using 10mm-headed (M5? whatever...) nuts), or slip it over the edge of the opening in the chassis before you bolt the shifter boot down. The latter is the stock setup, but it does make removal more difficult.

cheers

James

[swede242]

I run an 850R disc. Works perfectly.

Originally Posted by ZVOLV

I'm obviously confused. Sorry.

1. I need to be very careful about not ordering the wrong clutch disc from the dealer because its non returnable since its special order. ($350) This pic also turns me off since it looks too small compared to the 740 disc.



2. The part number for this thing:



3. Looking for ideas on where I can get the right tool and the part number. Volvo definately doesnt have this tool.

4. I just bought 3 quarts of M56 oil at $22 each so I hope I made the right move.

5. I am looking for Sach's clutch or OEM clutch. Stockish since I am gonna be nice to my tranny for a while.

6. I have a bracket, but it doesnt look like the one in the VADIS pics above. That one looks like it hangs on the lip of the shifter hole, but I think I have one that mounts to the threaded holes for the shifter boot.

No problems. We'll help you.

1: Yes, the 850 disc is a little bit smaller, but not much. I used both the 850 and 940 TDi clutch discs. They both work good. The TDi disc is actually a little bit smoother with somewhat better control.

2: The M90 doesn't use a pilot bearing or bushing. Only the M46/M47 boxes use those. Don't install one.

3: I don't know where you can get one locally, but here in Sweden, at a store called Biltema, we can buy a kit like this for 20 bucks: http://www.biltema.se/products/produ...&iItemId=82429

And a bigger pic: http://www.biltema.se/products/produ...?iItemId=82429

It contains all the clutch alignment tool sizes you will ever need.

4: If it has the same number as any of the oils listed in the first post, then you are set and good to go.

5: The stock Volvo clutch is Sachs. And I recommend you to get the TDi plate from Volvo (or anywhere else if you can get it cheaper there).

6: It looks strange in the picture, but once you are under there to install it, you will know how to do it.

[kildea]

Originally Posted by frpe82

2: The M90 doesn't use a pilot bearing or bushing. Only the M46/M47 boxes use those. Don't install one.

i completely believe you guys with this, but it comes as a surprise, i would expect the alignment of that disk/shaft to be a primary concern especially when loaded up.
is the snout just not long enough?
most manual transmissions do use pilot bearings/bushings for this reason.
it seems to be a simple mod that might improve input shaft bearing life and avoid potential internal flexing ... which of course has the potential to cause gear destruction (imagine the tranny loads up as the clutch disk works itself slightly off-center and the gears spread slightly due to the slightly off-axis torque, this is what kills the rx7 fd transmissions when failures due to flexing of the case occur).

so is it that the input shaft has no snout, or not a long one, something like this?

[Captain Bondo]

Originally Posted by kildea

\
so is it that the input shaft has no snout, or not a long one, something like this?

No snout at all. Basically a little chamfer and that's it. If you see a pic of the input shaft bearing retainer, it makes more sense as to why it doesn't really need one. Same goes for m56's.

Also it's a bit different since it's a 3 shaft box... they way everything is supported internally is a bit different, and more impoerantly the shafts themselves are half as long as a conventional box with a single mainshaft remember.

Not to say some sort of support on the input shaft would hurt though...

[kildea]

Originally Posted by Captain Bondo

No snout at all. Basically a little chamfer and that's it. If you see a pic of the input shaft bearing retainer, it makes more sense as to why it doesn't really need one. Same goes for m56's.

Also it's a bit different since it's a 3 shaft box... they way everything is supported internally is a bit different, and more impoerantly the shafts themselves are half as long as a conventional box with a single mainshaft remember.

Not to say some sort of support on the input shaft would hurt though...

yeah that makes sense, so it's more like a fwd box.

i'd really like to get my hands on one and see what's in there ...

[Asleeper]

I would imagine that an alignment tool from an 850 would work since the spline count is the same. The clutch disk is the same as any 850 and you can get them in many flavors from clutchnet...........cheaper than the dealer as well. I am currently using a clutchnet red PP&yellow 850 kevlar disk.

Whether or not the pilot bearing is needed on the M90 is up for debate but I went ahead and used one any. Not like its going to hurt anything and it cost a mere $10.

[ZVOLV]

1.Still kinda nervous on the clutch disc, but I might just buy one from local shop and see if its right.

2. Bushing 1397077. Want one. I don't like cutting corners. I doubt they can get one here in the US so paging Europe. I will ask the guy who is sending me ecodes if he can get me one. Or just say fuggit.

3. 850 Tool. Sounds like a good idea. Will check with IPD since they sold me the 740 one I use all the time.

4. Im just gonna run the oil I have. 850 oil should be the same.

5. I put an inquiry in last night to a clutch company, but big suprise, didnt hear from them today as they told me they would.

6. The bracket I have appears to be fine after further inspection.


The input shaft doesnt extent past the mating surface of the tranny and that bushing cant touch the shaft "Obviously "as Foggyjames said. Doubt the shaft would rotate in solid metal.

[Asleeper]

The oil on page 1 is all you need. The oil to use is listed on page 1 and it can be had at any Volvo dealer since 850's with manual trans use it as well.

[kildea]

Originally Posted by ZVOLV

...Doubt the shaft would rotate in solid metal.

plenty of applications call for a bushing rather than a bearing there - it'd rotate just fine in the solid bushing... if it only reached, heh.
keep in mind the bushing (on a typical application where the bearing or bushing is actually used) is only rotated with respect to the shaft when the clutch is depressed.

[Captain Bondo]

FWIW I just line the disc up so it is even around the circumference of the pressure plate, never have used a tool. Works fine.

Justin, I have some more misc pics of M90 guts from when i ripped it apart I'll post up soon..

[foggyjames]

Originally Posted by kildea

plenty of applications call for a bushing rather than a bearing there - it'd rotate just fine in the solid bushing... if it only reached, heh.

Well either it wouldn't touch enough to actually do anything, or it'll drag too much to allow the clutch to work, surely?

For an M90, that bushing is only there to aid clutch alignment.

cheers

James

[kildea]

Originally Posted by foggyjames

Well either it wouldn't touch enough to actually do anything, or it'll drag too much to allow the clutch to work, surely?

For an M90, that bushing is only there to aid clutch alignment.

cheers

James

i know what you are saying, it's just that plenty of oem manual transmissions use bushings rather than bearings, there is not any drag - it's not like it's press fit to the shaft it just slips in, keeps the shaft straight and is only slipping when the clutch is down.

before i ever did anything fun with my volvos (other than daily driving them) i built a couple of broncos - for these i just used t19 four speeds, this is an example where the pilot was just a brass bushing.
you just fill it with some grease and slip it in this is rather common really.

maybe not in european cars? ... sure is common in the cars i'd previously dealt with (my old chevelle too)

[foggyjames]

Fair play dude...not something I've come across over here, but I don't play with a particularly wide range of cars. If it's a slightly loose fit and it's greased, I can see it working...just adding a little support. However...M90s are 'isolated', with no stub on the input shaft. It seems pretty alien to me...but there it is! I figure they know what they're doing.

cheers

James

[kildea]

Originally Posted by foggyjames

Fair play dude...not something I've come across over here, but I don't play with a particularly wide range of cars. If it's a slightly loose fit and it's greased, I can see it working...just adding a little support. However...M90s are 'isolated', with no stub on the input shaft. It seems pretty alien to me...but there it is! I figure they know what they're doing.

cheers

James

i don't want people to confuse this discussion with the m90 though - i agree they have it set up differently, i just was confused by it at first

[JW240]

I just measured the M90 front drive shaft half. from the flange where the flex disc is mounted (gearbox side) to the end of the splined end (center bearing area) is 744 mm (that is without flex disc). Maybe useful for the ppl who need a custom drive shaft. For the people who have such a piece laying around, please double check my measurement.

[ZVOLV]

This is what I got. I will ask them for 1161745 instead of 1161645 and see what happens.

I added the technical info for both the 645 and 745 oils in the first post of the thread.

[Captain Bondo]

So M56's newer than '95 use something else, but it's ok for all years of M90?

I sometimes get the feeling volvo just makes this stuff up as they go along...

[JW240]

Originally Posted by Captain Bondo

I sometimes get the feeling volvo just makes this stuff up as they go along...

yeah.... same here. first the ....645 oil was for M90/M56 etc, aka 95+. now ....645 is for everything until 1995 (M90, M46, M56 etc), and the .....745 is for everything after that date. I think someone is having a lot of fun somewhere in Sweden, changing oil specifications and other stuff "just because he can".