All you need to know about the M90

[foggyjames]

I wouldn't say they're inherently noisy, having driven and ridden in various M90-equipped cars (with original DMF and dog-dish replacements) since 2001 or thereabouts!

cheers

James

 

[OttoB]

Two days ago i bought myself another M90, this time a H1 type.
I did the test on all gears by turning and all are just like in the spec's.
Next step will be opening the L2 box, since no one seem te have done this to count the teeth on 5th...
I re-tested and re-calculated over and over, still come to 0.7525 / 1 or 270.9 degrees on the in for a full turn on out.

Maybe l choose this one for replying. Shortly, I might be source of this missinformation. About 25 years ago I spent a lot of time in swedish Volvo Forum TPC. There were mucho conversation about M90, including ratios. From different Posts I created a ratio table and asked if it was correct. Someone copied that and it still floates in the internet.




Utväxlingar M90:

....................M90H... M90H2... M90L... M90L2

1:a växeln....3.54:1... 3.54:1... 3.91:1... 3,91:1

2:a växeln....2.05:1... 2.05:1... 2.20:1... 2.20:1

3:a växeln....1.38:1... 1.38:1... 1.38:1... 1.38:1

4:a växeln....1.00:1... 1.00:1... 1.00:1... 1.00:1

5:a växeln....0.81:1... 0.70:1... 0.81:1... 0.70:1

 

[gearbox]

These calculations might intrest you folks.
M90H is -94 and M90L is -97.

.....M90H....M90L
1=3.544....3.905
2=2.045....2.198
3=1.377....1.352
4=1.000....1.000
5=0.808....0.808
R=3.453....3.805

The transmission oil number has changed.
The oil sold in Finland has a number: Volvo 31280771
It´s full synthetic SAE 75W GL-4

Shift linkage oil seal: Volvo 947705, 15x21x5/7

Reverse light switch: Volvo 31437053

Gearbox weight without oil: 40,5kg.

I added information about bearings and seals to the pictures.

 

[gearbox]

Edit nov. 24 2022: I edited the image, 1st gear is 13 teeth (not 12) thus R = 3.46 (1st gear was already correct)

Are you sure about this?

 

[RolinOldies]

These calculations might intrest you folks.
M90H is -94 and M90L is -97.

.....M90H....M90L
1=3.544....3.905
2=2.045....2.198
3=1.377....1.352
4=1.000....1.000
5=0.808....0.808
R=3.453....3.805

The transmission oil number has changed.
The oil sold in Finland has a number: Volvo 31280771
It´s full synthetic SAE 75W GL-4

Shift linkage oil seal: Volvo 947705, 15x21x5/7

Reverse light switch: Volvo 31437053

Gearbox weight without oil: 40,5kg.

I added information about bearings and seals to the pictures.

New member, thank you very much for your input, all your data confirms my findings and all seem correct.
I would like to add that the marks M90H and M90L on the fotos don't distinguish the H1,2 and L1,2.
My strong belief is that your tooth count is for H1 and L1 (see why below).
In all gears except 5th the L1-L2 are equal and match the counts I did for my L2.
Also the reverse and the output end ratio are the same.
For the H1 I did not open mine up yet but since all other info matches I assume this will also be correct.
Thus remains only the difference on 5th Gear. This is where the H1 and H2 differ, and also the L1 and L2.
This explains my different findings for 5th gear.
So the statement I made before that all 'official' info is (partly) wrong is also correct, proven now by tooth count and your confirmation and pic's. On Reverse I made a mistake in calculations for the extra 'reverse' step, I corrected this on my side.
On the other side is proven that the 'official' info for reverse and 3th is wrong and also for 5th on the H/L 2.
Also very helpful the partnumbers for the seals, bearings etc...
Here's is the end result of all common effort:

 

[gearbox]

I would like to add that the marks M90H and M90L on the fotos don't distinguish the H1,2 and L1,2.
My strong belief is that your tooth count is for H1 and L1 (see why below).

To be precise, there are no H1 or L1 gearboxes, they are H and L.

 

[RolinOldies]

To be precise, there are no H1 or L1 gearboxes, they are H and L.

:-o I find that very hard to believe, i saw the labels on the tranies, find lot of info on line, and still have my own L2 box open with 46/30 5th gears tooth and 0.7525 : 1 ratio

 

[gearbox]

:-o I find that very hard to believe, i saw the labels on the tranies, find lot of info on line, and still have my own L2 box open with 46/30 5th gears tooth and 0.7525 : 1 ratio

Does the M90L-gearbox label on the gearbox say M90L or M90L1?
Bad english, sorry.

 

[foggyjames]

As far as I'm aware the "L1" was always labelled just "L".

I've never been convinced that there was anything special about the strength of the L2, as has been claimed over the years. Maybe there were improvements over the years, but I'm sure that would have applied to all versions, and there's nothing magic about a L2 (except that it's guaranteed to be from a later car, IIRC).

cheers

James

 

[gearbox]

As far as I'm aware the "L1" was always labelled just "L".

I agreed.
M90 gearboxes were M90H, M90L, M90H2, M90L2.
NOT M90H1, M90L1, M90H2, M90L2.

 

[RolinOldies]

I agreed.
M90 gearboxes were M90H, M90L, M90H2, M90L2.
NOT M90H1, M90L1, M90H2, M90L2.

True, L1 and H1 are labled just L and H, only improvement i know of is the synchro on 3th, and other difference is gearing on 5th but if that is an improvement or not is open for discussion.

 

[ZVOLV]

Mine just says:

M90M90M090M90M90M090M90M90M90



Hey does anybody know where to get new syncros!!???

 

[Black.Saxon]

Hi brickhunters,
I’m Harry, come from Germany and I’m new on this portal. In real life I’m used to work Rolls-Royce Trent 700 and GE CF-6 engines and performing technical training to customers who intend to operate an Airbus

My cool brick being close to inserviceable condition leads me to search some common drivers. I have: Volvo 940 II 1995 wagon equipped with B230FK, one mass flywheel and M90, 270000 km. Try to attach picture. My problem is the gearbox making noises. I’ve been on a lift, let the car drive through the gears and the noise apparent is proportional to speed and NOT to engine revs. The noise comes from centre of the gearbox. That means also that hints like change the oil with some additives do not impress me so much anymore. I figured out that this gearbox is not subject to overhaul anywhere. An interchangeable replacement unit is the only option to keep the moose on the road nowadays. Some guys in communities offered me units but on the same shout I was about to search for the correct designation at first. I’m lucky about having made the label readable. Please see attach.

P1208790
M90
T113712

Having read through the thread „all to know about the M90“, I’m not sure, which of the 4 mentioned configs I have installed and which one would be suitable to fit in despite label shows „M90“ only. Do I have M90H?
Could you perhaps help me, which gearbox unit types would be interchangeable for mentioned powertrain?

That would help us keeping another rear-wheel driven brick on the road

Thanks and have a nice evening!

NOTE: pictures taken 2014 in line with clutch replacement... happy to having taken them.

 

[Fa182]

1208790 is the Volvo part number.
As per the first page of this thread:


As far as I'm aware any Redblock M90 is physically identical.

 

[thermaq]

I have just finished swapping my m46 with m90 on my 940. Just so if anyone searches for things I couldn't find:
I heard output flanges on m90s can be different, but if you swap m46 with the rubber guibo for m90 with the same flange and guibo you can just elongate your driveshaft in your local driveshaft shop. Length differences between boxes:
- m46 is 235mm longer than m90
- m47 is 50mm longer than m90
- logically m46 is 185mm longer than m47, if you swap those

The thing I don't understand is I used my crossmember from m46 and it looks identical to eg. https://i.postimg.cc/rF62tPBn/m90-on1.jpg
The original post says I needed to use a crossmember from an autobox, but I didn't get the part that bolts to the gearbox with 4 bolts and the crossmember with 1, so I had to fabricate my own. After fabricating it my mount dimensions looked identical to a photo I found.
Are m46 and m90 crossmember identicall after all, or do I have some special 940 with m46 and a m90 crossmember?

I made a 3d printable fixture to make the bracket, so if anyone wants hole dimensions and positions there you go: https://www.thingiverse.com/thing:6777777/

 

[RolinOldies]

Hi brickhunters,
I’m Harry, come from Germany and I’m new on this portal. In real life I’m used to work Rolls-Royce Trent 700 and GE CF-6 engines and performing technical training to customers who intend to operate an Airbus

My cool brick being close to inserviceable condition leads me to search some common drivers. I have: Volvo 940 II 1995 wagon equipped with B230FK, one mass flywheel and M90, 270000 km. Try to attach picture. My problem is the gearbox making noises. I’ve been on a lift, let the car drive through the gears and the noise apparent is proportional to speed and NOT to engine revs. The noise comes from centre of the gearbox. That means also that hints like change the oil with some additives do not impress me so much anymore. I figured out that this gearbox is not subject to overhaul anywhere. An interchangeable replacement unit is the only option to keep the moose on the road nowadays. Some guys in communities offered me units but on the same shout I was about to search for the correct designation at first. I’m lucky about having made the label readable. Please see attach.

P1208790
M90
T113712

Having read through the thread „all to know about the M90“, I’m not sure, which of the 4 mentioned configs I have installed and which one would be suitable to fit in despite label shows „M90“ only. Do I have M90H?
Could you perhaps help me, which gearbox unit types would be interchangeable for mentioned powertrain?

That would help us keeping another rear-wheel driven brick on the road

Thanks and have a nice evening!

NOTE: pictures taken 2014 in line with clutch replacement... happy to having taken them.

According to my information, your M90 is the 'H' type, you can verify by cheking the ratio's described in my previous posts. All M90 are interchangable, overhauling should also be possible depending on the parts needed and availability. Bearings and seals slhould be no problem, synchro's i'm not sure.

 

[Black.Saxon]

1208790 is the Volvo part number.
As per the first page of this thread:
View attachment 29164

As far as I'm aware any Redblock M90 is physically identical.

Thank you! This part I've well read through. But I'm not sure, what the abbreviations "DRS", "CH" and the dash number in 1208812-6 mean?
Assuming that the T113712 means the serial number, it would mean to be within "5DRS CH 93624-161856". As of this matrix, 1208812 would be possible for replacement only? Maybe this is wrong then, because you were saying that Redblock M90 are physically identical. Then more P/N's than only 1208812 shall fit?

For replacement: I simply want to go on driving my 940. So if the M90 has slightly different transmission ratio, but the gearbox fits, would be happy probably. No higher power outputs, no modifications

 

[Fa182]

Thank you! This part I've well read through. But I'm not sure, what the abbreviations "DRS", "CH" and the dash number in 1208812-6 mean?
Assuming that the T113712 means the serial number, it would mean to be within "5DRS CH 93624-161856". As of this matrix, 1208812 would be possible for replacement only? Maybe this is wrong then, because you were saying that Redblock M90 are physically identical. Then more P/N's than only 1208812 shall fit?

For replacement: I simply want to go on driving my 940. So if the M90 has slightly different transmission ratio, but the gearbox fits, would be happy probably. No higher power outputs, no modifications

The number after the part number (-6) isn't important.
Yes, more part numbers will fit.
There are many - I'm not 100% sure on their difference, I guess it's the different versions (H, L and so on), that were put in cars for different years (and chassis numbers).




As for the abbreviations:

 

[Black.Saxon]

The number after the part number (-6) isn't important.
Yes, more part numbers will fit.
There are many - I'm not 100% sure on their difference, I guess it's the different versions (H, L and so on), that were put in cars for different years (and chassis numbers).

View attachment 29175


As for the abbreviations:
View attachment 29173

View attachment 29174

Thanks for your answer! Much appreciate the basic information.
I guess the listed P/N in the parts catalogue are kind of evolution of the M90(?) and for each P/N there is an exchange/replacement P/N that then are improved versions.

Does anyone know, which P/N's I can install, when 1208790 was installed before? As of know I assume the logic is "every M90 which is for redblock - fits"

As per first page
"The M90 comes in both a redblock and whiteblock version.
The redblock versions include M90L, M90H and M90L2.
The whiteblock versions include M90H, M90H2 and M90L2."

Since "M90H" and "M90L2" are mentioned for both redblock and whiteblock, how to separate them?

Does anyone know "EJNRPL24"? It's listed anywhere.

 

[foggyjames]

You want to separate whiteblock vs redblock, or H vs L2?

The former is fairly easy - whiteblock boxes have a round output flange (as do diesels, I think) and a different bellhousing flange (looks obviously not-Redblock), but the only real way to tell which ratio variant you have (assuming the label is long gone) is by checking the 1st and 5th gear ratios (i.e. rotations in vs out).

cheers

James