New to Volvo and new to the site. We just got a 1973 145 with an auto trans. I spotted an M40 on ebay for $250 and snagged it. Now the fun of making it fit begins. The seller says it's out of a 1975 240. I posted a pic. I'm open to reading any insight or expertise anyone wants to post.

If anyone is keeping up, I figured I would post a pic of the clutch pedal. I actually scored this locally from a fellow Volvo enthusiast who posted an ad on Craigslist.

"making it fit" will not be a problem. Do you have the standard shift flywheel (six-bolt for a '73)?
Don't forget to install a pilot bearing into the rear of the crankshaft. Did you get the complete driveshaft? If not you can have your front section shortened and then balanced along with your rear section. Be aware the two have to be "clocked" properly. The very front of the front section (U-joint flange bolted to the trans output flange must "complete" a whole assembly when compared to the rear most flange bolted to the diff flange --horizontal to vertical. - Dave

Hello & welcome,

To properly convert your 1973 145 to an M40, you will need the following parts based on what I see in your picture.

Correct clutch and brake pedal assembly from a 1973-1974 140
Bellhousing from earlier B18 or B20 with cable operated release arm
Flywheel, should be 6 bolt, but could be 8 bolt
Clutch kit and pilot bearing
Retaining clip for pilot bearing
Flywheel and clutch bolts
Clutch cable
Grommet, washers and nut to mount clutch cable at firewall
Correct shift handle assembly and knob to match shift cover
Shift boot
Rear output flange if different size than driveshaft flange

You won't need to modify or replace the driveshaft as it's already the correct length.

Dave is probably thinking of the early automatics which had longer tailshafts, but the later BW35s got shorter tailshafts and used the same length driveshafts as the M40. If you were converting to an M41, the front driveshaft half is shorter because the transmission is longer.

You will have to do some wiring modifications to the starter and reverse light systems.

May I ask why you are trying to convert to an M40? Is your BW35 not working?

Every automatic to manual conversion I've done was to an M41, the overdrive version of the M40.

There is a slightly different list of parts needed to convert to an M41.


--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Thanks for the intel. Your question is valid... why swap out the BW35 for an M40? It probably won't make sense to anyone else, but the 4spd just seems like the right fit for this car. I could probably freshen up the auto, but that's not the experience I want when driving this one. The M41 is probably the better choice for bench racing, but the M40 popped up for sale, and it will be fun to drive to and from work and the beach. The point is to get back behind the wheel and enjoying my dream car.

The major advantage to the M41 obviously is having the overdrive. But if most of your driving is around town and under 55mph, then an M40 is okay.

I'm in freeway country so the overdrive is quite desirable in my neighborhood.



--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

I have had 2 M40 240s. A 75 with a B20, and an 80 with a B21.

Both made during the 55MPH Nationwide speed limit laws.
The 75 could do 75-80 but was a real real Loud. I felt like it could do 90 IF it had that OD. took it from MD to Colorado fully loaded 3 people camping gear 4 kayaks racked. No Problems at 65 to avoid speeding too much over 55.

The 80, I no longer take on the highways at 65 is the posted speed Limit-- 70 in WVa, and it's way too loud...it will sustain 80+ no problem. As noted around town under 60mph just fine.
I have another Volvo with an M47 highway driving.

PS...Remember Radar Detectors. Escort - US made by Cincinnati Microwave, hard wired and clipped to the visor. Never leave home without it.

“...The major advantage to the M41 obviously is having the overdrive. But if most of your driving is around town and under 55mph, then an M40 is okay...”

Especially when mated to the taller ratio differential in an originally-automatic car.

!40 series cars had a 4.10 rear whether stick or automatic (except for M41 equipped cars--4.3). A 160 model could provide a longer ratio. With those there is a difference between auto and stick --3.31 for auto and 3.73 with M410--I think. -- Dave

I should add--the earliest 145's with the M41 D-type OD came with a 4.56 rear. At least the '68 I had did. - Dave

Dave, thanks for the clarification. We had a 72 144 with an M40 and now that I think back I “think” it had a 4:10 just as you are saying.