• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

M41 into a Duett

TR Conn

Member
Joined
Dec 13, 2006
Location
Long Beach, Ca
I started measuring and researching how to install an M41 behind the B20 in my ’58 Duett. I didn’t expect it to be easy, but the modifications to the trans tunnel look like quite a challenge. I need to keep the removable inspection cover if I ever want to remove the transmission.
I also found photos on Garaget that make me think that frame mods are also necessary.
Does anyone have experience doing this?
My fabrication skills are mediocre and I’m afraid of botching it up.
Unlike the PV444 and PV 455 the Duett has a “real” frame.
Would I be better off re-gearing the Dana 27 rear end (4.56 -> 4.10)?


10hpx0i.jpg


nlrhom.jpg


1zvy0qc.jpg


2gybrjk.jpg


Thanks for any insight or information
TR
 
We didn't have to do any frame mods to the P210 that we installed a J type M41 into. I wish I had pics but the hard drive they were on died 20 years ago. That truck got a custom fuel injected B20 using SU style throttle bodies, 4 wheel power disc brakes using 1800E calipers and rotors up front and complete rear end. The booster and master were reverse mounted under the drivers floorboard and the clutch linkage was converted to hydraulic.

I think the trans is sitting a little low in the Garaget pics. The driveshaft is definitely too close to the frame.
 
An aftermarket OD is a possibility, but I have an M41 sitting on the bench that I just finished going through.
Looking at aftermarket ODs, it seems that most all of them are for high power hot rods and are beyond my hobbyist budget.
 
Last edited:
Here are some pictures of the 1961 P210 hiperauto and I modified.

We used an M41 with a J O/D and we had to modify the tunnel and IIRC, the modified portion was behind the removable cover.

Don't forget the adaptor that connects the O/D to the transmission puts the O/D back farther than the stock output flange location.

1961P210a.jpg


1961P210%20%282%29.jpg
 
I put an M41 in my 544, but as already mentioned, it's pretty much entirely different. I had to replace roughly the same section of tunnel though. I think the 544 floor pans are just a bit deeper/lower vs. the drivetrain than a Duett's.
 
Cameron,
Do you happen to have photos of the tunnel?

I'm sorry - I don't. The cuts I made were very similar to the tape outline shown above, and I used a second removable tunnel lid to make the 'new' section of tunnel.

Once you get past the first cut, it will come together more easily than you expect.

Cam
 
Thanks for the words of encouragement. I’ve been fabricating a new tunnel before cutting anything.
I’ve swapped M41s into two automatic 122S’s without much forethought. Duetts are quite a bit harder to come by.
 
I ran into a bit more of a project than anticipated.
The PO had screwed and pop riveted "new" floorboards in.
I already knew this was a problem, just didn't want to deal with it right now.

2qltq9v.jpg
 
I'm following this because I also have a '58 duett and my short list of modifications includes an m41, and disk brakes.
 
122 discs go on pretty easily, only issue being that 122 rotors and calipers aren't all that easy to find these days, and new replacements ar pretty pricey.
 
If you are going to install disk brakes, go all the way and include a booster.
Another possibility I considered was the remote boosters made for drum brakes. I don't know of any one that has used one. I had most of the necessary parts on hand for the disks and found a NIB Lockheed booster for $110 on ebay.
I'm on a deadline for the transmission/floor project. I'm taking this car to San Luis Obisbo for the show in September.
 
122 discs go on pretty easily, only issue being that 122 rotors and calipers aren't all that easy to find these days, and new replacements ar pretty pricey.

i dont remember the guys name for some reason, but theres a guy sorta near riverside with a YUUUGE yard of old volvos. i was gonna go to him for a driveshaft for my 66 122, but ended up selling the car. great guy.

post on the San Diego Volvo Sports America facebook page and mention that, theyll know who you (OP) need to talk to
 
I think I know who you're talking about, but if it is, that source is no longer available. Believe it or not, the local government got on his case for having an unauthorized junkyard and he wound up dumping just about everything. Even though you couldn't see the site from ground level because it was in a small gulch/valley, they used pictures from an airplane or helicopter to justify their actions.

Was the guy's name Terry?

i dont remember the guys name for some reason, but theres a guy sorta near riverside with a YUUUGE yard of old volvos. i was gonna go to him for a driveshaft for my 66 122, but ended up selling the car. great guy.

post on the San Diego Volvo Sports America facebook page and mention that, theyll know who you (OP) need to talk to
 
Yes, the parts are pricey, no they are not hard to find.

VP now sells repro brake rotors and drums for $100.00 each. They aren't made the same way Volvo STILL makes them, but they are a lot cheaper.

VP also sells repro 3 piston calipers now, but I still prefer to have my old cores rebuilt. I try to keep a set of rebuilt calipers in stock as it sometimes takes over a week to get them back from the rebuilder. And in fact, I just sold the set I had in stock 2 days ago.


122 discs go on pretty easily, only issue being that 122 rotors and calipers aren't all that easy to find these days, and new replacements ar pretty pricey.
 
I have the M-41 in and working, new floors looking pretty good and everything else back together.
Turned out to be quite a project.
I was able to cut out part of the trans tunnel, reshape it and reinstall it in order to provide clearance for the overdrive.
Before:
m8WEQXO.jpg

After:
BqUlaku.jpg
 
Back
Top