140 Flange size on gearbox and diff

Hi there

I've got a 72 142 project car without driveshaft. I've measured the flanges and the M40 has the small flange and the diff has the larger flange. From memory it was something like ~80mm for gearbox output vs ~90mm for diff input.

I've made contact with someone who has a 74 142S that has a driveshaft. It's a fair drive and before I head out, I wanted to see if someone could tell me if this car is likely to have the same spec driveshaft? Ie. Small up front and big up back.

Also, if the box in the donor has a big flange output is it possible and or simple to transfer the bigger flange over to the box in my car. Or would it be simpler to just swap box?

Oh and just out of interest, does anyone know when the bigger flanges were introduced and which models they were used on? I'd heard it was a thing for the injected models. My car is an original GL though so either it doesn't have original box, the bigger flange was only on overdrives or it was introduced later? Or maybe it was just a bit inconsistent?

Appreciate all wisdom you can bestow.



  • SpacSpac (@Spac) Canberra-ish.
    I never got my head around this ... I think it was one of those Volvo things where they changed stuff when they felt like it.
    Auto vs manual, injected vs twin carb vs single carb, maybe sedan/coupe vs wagon... It all seemed to matter as to when they changed. Add in 240s moving to a larger flange at some stage, and my brain really hurt.
  • Thanks @Spac

    Yeah, I've asked a couple of Volvo gurus about it and they've basically said the same thing. Seems to be no real pattern. Just when they think they've worked it out, they see a car that deviates from the pattern.

    But that brings me back to that question.. is it a possible to just change the flange on the box? Or easier just to switch box?
  • RobRob (@Rob) - Lockyer Valley, SE Qld
    You can just change the flange.
  • Oh and just out of interest, does anyone know when the bigger flanges were introduced and which models they were used on?

    Smaller ones are known as the 1140. Bigger ones are known as the 1310.

    Group 4, Page 110 of the 1966-72 140 Parts Manual doesn't really show the differences; they just list the part numbers.

    However, in Group 4, Pages 64 to 75 of the 1973-74 140 Parts Manual, they describe the two types of tailshaft end flanges, and list the various applications and combinations. Picture pages 73 and 75 show the measurements of the 1140 and 1310 flanges.

    To work out exactly which types were fitted to what pre-1973 model and which chassis numbers, you'd have to compare the part numbers listed in the 73-74 catalog, because that's where they define them as either 1140 type or 1310 type, instead of just part numbers.

    As you can see in the catalogs, tailshafts with a 1140 flange up front and a 1310 flange at the diff end were factory, and common. Very generally speaking, the B20E engine cars got 1310s all round, as did the 164Es; everything else got 1140 /1310 except some S-xxxx (special vehicles). (Funny thing with 1800Es though - the B20E 1800E and ES got 1310s all round, but the B20F cars got 1140 up front and 1310 at the diff. Something to be aware of, if you ever have a US market 1800).

    Before you order uni joints or a centre support bearing, it's best to know if you need ones to suit a 1140 or 1310 flange. People get caught ordering the wrong ones for their need from FCP or whoever, because it's easy to do.
  • Legendary knowledge there Mr @bgpzfm142. Thankyou.

    And thanks @Rob. Good to know if I get in a jam.

    Anyone know if there are any internal differences between the 1140 M40 and the 1310?

  • M40 boxes varied between years. Earlier ones had plain bearings on the layshaft. Later ones had needle bearings. IIRC the later ones had a lower 1st gear to get going better with the extra vehicle mass (those HUGE anti-intrusion bars). Otherwise there are few differences in M40. IIRC again, the change was around 1971.
  • SpacSpac (@Spac) Canberra-ish.
    And the shifter position - went from the long 'magic wand' to the remote shifter in 1972.
    The tops can be swapped to make either box work in any model of 140.
  • Anyone know if there are any internal differences between the 1140 M40 and the 1310?

    The later M40 / M41 boxes went to (stronger) needle roller bearings in the later versions (71 on, IIRC without looking it up). Earlier boxes can be upgraded to needle rollers, as this was offered as part of an R-Sport upgrade. You really do have to check gearbox part numbers to see which bearings fit which boxes. As Spac mentioned, the top covers happily interchange, although there are (at least) two types of remote shifter covers.
  • I hadn't even thought of checking the part number on the box heh silly me. Someone did suggest to me the car might have an Amazon block in it as it has the earlier dipstick style. So if that's the case, maybe the box was swapped over from a 120 too.

    Anyone know how to distinguish an Amazon B20 block from a 72 model 140?
  • These things are 40+ years old now. Anything could have been changed from how it left the factory in that time, and probably has.

    Let's start with gearboxes, since they changed more than the blocks. You'll need to check the part number on the plate of the gearbox. That means an under car adventure.

    The part number and gearbox serial number are on a plate which is found under the output flange.


    JFTR, the first four digits cast into the block indicate the first 4 digits of the part number (either B18 or B20); the next two digits (i.e. the first two digits stamped into the block) indicate which induction setup was used on that unit, and lastly the remaining stamped digits are the serial number of that engine.

    e.g. 4969 29 2043 is engine serial number 2043; the numbers 4969 are cast into the block and indicate it's a B20 block; the "29" indicates the the rest of the part number for that engine - in this case, a USA-spec B20B with p/n 496929.

    A few combinations can be found below.


    The full list of engine part numbers can be found in Group 1a of the parts manuals
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