Installing M40 transmission in PV544A   B16B

PV444 and 122 with B16B and possibly PV - B14 should be similar,

Check every thing before you cut, drill or grind!

The M40 has better spacing of gear ratios.

Speed in Gears Chart

Click on thumbnails for larger photos


M4 & M40, The differences


The M40 that fits!  -  Uses this Bell housing

from PV 544 "B" with B16B

1961 only (544 Chassis #s 295500 330099)

(very rare, this is the only one I have ever seen!)

No modifications necessary

(must check input shaft pilot length)


Shorten only pilot  end

Do not cut back splines

(check out before you cut as this may not be necessary)


The Template

(use to locate drill holes in case and slot in bell housing)

Rent mine for $10.00 + shipping,  $30.00 deposit,

$20.00 less shipping  refunded when returned in good condition


You could drill without dismantling  transmission, but since

I was overhauling the transmission

it was much easier to handle the bare case

If you do not know the true history and condition of the M40

that you are installing you should tear it down and inspect

all parts as just pulling cover off and looking in

does not give you a good inspection of cluster gear

shaft & needle bearings, input to main shaft roller bearings,

bronze synchronizers or even main ball bearings.

Swedespeed Transmission Overhaul Posting

The very best Vintage Volvo parts source:
Susquehanna Spares 

Joe Lazenby 
3725 Elder Road 
Harrisburg, PA  17111 


        <1960 "M4" Bell housing        

Must be fly cut 3/16" deep for shift shaft plug clearance

Consider Speedometer hook up and drive ratio, to use M40

Speedometer cable you must use: p# 669020-0

for speedometers with small threads (standard on PV544A),

PV544B should already be M40 equipped .

If you are using a later speedometer head with larger threads use

Speedometer cable : p# 670506-5

M40 use 16T cable gear for 4.10 rear axel ratio, Pt# 380164-4

M40 use 17T cable gear for 4.30 rear axel ratio, Pt# 380166-9

M40 use 18T cable gear for 4.56 rear axel ratio, Pt# 380168-5


This information was obtained by actually making conversion to my B16B

PV 544"A", The M40 I used is part# 254249, I think out of a pre 1967 122 ?

Volvo  had many versions of this transmission (used in 544, 122, 144 etc.)

and to the best of my research it seems

that they all use the same input shaft (pt# 380136-2),

this is not true for the output shaft as they list at least 2 different splines,

if the donor transmission has the correct flange for your driveshaft

you will probably be OK, if you must change flange from your

old transmission make sure splines are correct!

Large rear spline 1967>

Check rear tail housing to make sure speedometer drive is at correct angle!

You should not consider a M41 (OD) for a B16 PV

as it would not have enough torque to handle the

higher gearing.

A B18-B20 should have a 4.56 - 1 rear axel ratio

when using M41,

I had a B20 - 144 that I installed a M41 with "D" OD

with 4.10 axel gearing and it was much to high,

It was quieter at cruising speed but less economy

and always had to shift down for any acceleration!


EMail Me at:

or call: 217-562-4444

  My 544 B16B Sport site


Raging Moose Productions