Amazon: New (to me) 1963 Volvo 122

[142 Guy]

The 1800 has the rear set shift mechanism so the PO / you have obviously fitted a cover and lever from a non 1800. My comment about the dog on the 3-4 shift rail was based upon the 140 parts parts manual 140 which up to 1972 would have the same shift lever / cover as would have been fitted to an Amazon. The 1800 M41 does have some differences beyond the shift lever / top cover.

Depending on the vintage of the 1800 it has a different reverse switch mounted on the side of the shift lever housing (not the common tin can mounted on the back of the transmission) and it might have a different OD interlock arrangement. I don't have an 1800 parts manual. Knowing the vintage of your 1800 M41 would allow you to check the parts manuals to see where the interlock switch is mounted. If the 1800 M41 in your car originally had its OD interlock mounted on the top cover (like the M41 in the 140 and Amazons that were factory equipped with an M41) then it will have the dog mounted on the 3-4 shift rail and from that perspective you are good to go.

Since your top cover is obviously not an 1800 top cover, the question remains does it have the boss for the switch? Based purely on anecdote, I was of the impression that all the covers had the boss for the interlock switch. However, with the car jacked up in the air and safely secured it should be possible to reach up with your hands and feel whether there is a boss present. On my 1971 142, I was able to replace a failed interlock switch on the top cover in situ, although the 140 may have a wider tunnel.

[Othen]

Originally Posted by 142 Guy

The 1800 has the rear set shift mechanism so the PO / you have obviously fitted a cover and lever from a non 1800. My comment about the dog on the 3-4 shift rail was based upon the 140 parts parts manual 140 which up to 1972 would have the same shift lever / cover as would have been fitted to an Amazon. The 1800 M41 does have some differences beyond the shift lever / top cover.

Depending on the vintage of the 1800 it has a different reverse switch mounted on the side of the shift lever housing (not the common tin can mounted on the back of the transmission) and it might have a different OD interlock arrangement. I don't have an 1800 parts manual. Knowing the vintage of your 1800 M41 would allow you to check the parts manuals to see where the interlock switch is mounted. If the 1800 M41 in your car originally had its OD interlock mounted on the top cover (like the M41 in the 140 and Amazons that were factory equipped with an M41) then it will have the dog mounted on the 3-4 shift rail and from that perspective you are good to go.

Since your top cover is obviously not an 1800 top cover, the question remains does it have the boss for the switch? Based purely on anecdote, I was of the impression that all the covers had the boss for the interlock switch. However, with the car jacked up in the air and safely secured it should be possible to reach up with your hands and feel whether there is a boss present. On my 1971 142, I was able to replace a failed interlock switch on the top cover in situ, although the 140 may have a wider tunnel.

I think I have to take the PO at face value and not jump to any conclusions, probably not much is obvious with 60 year old machines.

There has been a lot of discussion on this matter in this thread previously. The boss you talk of exists and has already been tapped (to the wrong size - the details don't matter here but are covered in previous posts above). Here is a photo looking down the transmission tunnel:



... the gearbox will have to come out of the car and the cover be removed to tap the hole to the right size and fit the inhibitor switch.

:-)

[dgbalfour]

I was sure I had taken some photos of the box when I bought it, so have just charged up a multitude of old mobile phones and unearthed these three images - they show the OD inhibit switch on the original P1800 top cover, before I put the cover from the car's original M40 on it.

I always assumed the gearbox was from a very early P1800 as it has the U bolt type coupling for UJs and no reverse light switch at all - I think somebody on this forum told me the very early P1800s had no reverse lights.

I also moved over the reverse light switch and mount from the M40, but in the process of fitting the gearbox I knocked the switch off. I couldn't fit the switch with the box in place, and was loathed to drop the box again simply to fit the switch.

David

Edit: The original thread is here: https://www.volvoforums.org.uk/showthread.php?t=102556.
It suggests I tested the switch so I'm confident the dog is present and you'll be able to make it work again Alan.

[Othen]

Originally Posted by dgbalfour

I was sure I had taken some photos of the box when I bought it, so have just charged up a multitude of old mobile phones and unearthed these three images - they show the OD inhibit switch on the original P1800 top cover, before I put the cover from the car's original M40 on it.

I always assumed the gearbox was from a very early P1800 as it has the U bolt type coupling for UJs and no reverse light switch at all - I think somebody on this forum told me the very early P1800s had no reverse lights.

I also moved over the reverse light switch and mount from the M40, but in the process of fitting the gearbox I knocked the switch off. I couldn't fit the switch with the box in place, and was loathed to drop the box again simply to fit the switch.

David

Edit: The original thread is here: https://www.volvoforums.org.uk/showthread.php?t=102556.
It suggests I tested the switch so I'm confident the dog is present and you'll be able to make it work again Alan.

How kind it was of you to contribute this David. I’m pleased this little tangent has been a wild goose chase.

Best wishes,

Alan

[142 Guy]

In post #957 I understated the differences between the M40 and M41. That is an embarrassment because having re gasketed my M41 that should have been obvious to me. The M41 main shaft / output shaft is significantly different than the M40 because of the need to fit into the OD unit. It is physically possible to fit the M41 main shaft into an M40 gear box to allow fitment of an OD onto what was originally an M40 box. However, sourcing that main shaft and the other related bits is a problem unless you had access to an M41 with some internal damage and were able to salvage the M41 specific parts to fit to an M40. The basic M40 case is also different, lacking the holes to allow oil to flow to the OD making filling the OD a challenge (I suppose a drill could fix that).

The short answer to this run around is that if your transmission has an OD attached to it, it is almost certainly a factory M41 and should have the dog for engaging the OD lock out switch.

[Othen]

Originally Posted by 142 Guy

In post #957 I understated the differences between the M40 and M41. That is an embarrassment because having re gasketed my M41 that should have been obvious to me. The M41 main shaft / output shaft is significantly different than the M40 because of the need to fit into the OD unit. It is physically possible to fit the M41 main shaft into an M40 gear box to allow fitment of an OD onto what was originally an M40 box. However, sourcing that main shaft and the other related bits is a problem unless you had access to an M41 with some internal damage and were able to salvage the M41 specific parts to fit to an M40. The basic M40 case is also different, lacking the holes to allow oil to flow to the OD making filling the OD a challenge (I suppose a drill could fix that).

The short answer to this run around is that if your transmission has an OD attached to it, it is almost certainly a factory M41 and should have the dog for engaging the OD lock out switch.

Thank you. 60 year old machines are often something of an enigma. The build plate does say M40 (part nr 254406) but it has the higher oil filler position and I'm delighted that David has confirmed it previously had an inhibitor switch fitted and so must be a M41 (if not in name plate).

I need to get on and sort this switch out before the winter.

Alan

[Othen]

Originally Posted by 142 Guy

A proper OD interlock switch fitted on an M41 is a normally open contact switch which only closes to energize the OD solenoid when the transmission is in 4th. At least on later M41 equipped cars the interlock only operates when in 4th gear. I seem to recall that some may allow operation in 3rd; but, I can't remember whether that was a Volvo or non Volvo application. On vintage Volvos, if the steering column / dash OD switch contacts are closed the OD will engage when you shift from 3rd into 4th. A not necessarily desirable feature if you are shifting up after you downshifted to pass a slow moving vehicle.

The later Volvos with OD use an electronically controlled relay configured as a latch to control the OD solenoid. The switch to operate the relay is a momentary contact switch and the relay uses the OD interlock switch on the the transmission cover as a permissive. When in 4th gear, operating the momentary contact switch will cause the relay to energize and stay energized putting the OD into operation. Hitting the button again or shifting out of 4th will cause the relay to de energize and the OD to drop out. Shifting back into 4th will give you 4th gear, not OD. To re engage the OD you need to operate the OD switch again.

All the details here including relay numbers and wiring diagrams

https://www.swedespeed.com/threads/a....408489/page-2

The latching relays are not particularly expensive. If you want to find a nice period correct momentary contact wand type switch to mount on the opposite side of the steering column - that is the expensive part. If you are OK mounting a pushbutton in the dashboard that will be cheap.

I was thinking about this problem with GAM lacking an OD inhibitor in the light of the system fitted to the Barge (1983 240 - I suppose with M46 4 speed + OD) the other day. I really like the way the M46 works with the momentary switch (on the gear knob). That got me thinking that rather than just fit the inhibitor the way it is (with a re-purposed HRW switch controlling it), perhaps I'd be wiser to take a more measured approach and fit a latching relay with a momentary switch at the same time. It would be a neat and tidy end to the job that would make me happy.

I'm thinking that a Volvo relay like this one should work:

https://classic-volvo.com/relay-rela...1347768_b.html

... with a momentary switch mounted just under the dashboard.

The Swedespeed article looked very useful, but I couldn't see the schematic for the 'Photobucket' watermark - does anyone know how I'd get rid of that (I do hope it is not a paid subscription - that would be tiresome)?

For the cost of a relay and a momentary switch (perhaps £30 total) fitting a M46esque control system at the same time as the inhibitor switch would be the right thing to do.

:-)

PS. I found a really good article in the Ron Kwas pages on this topic:

https://www.sw-em.com/OD_Retrofitting.htm#OD_Wiring_2

In particular this little diagram of exactly what I'm thinking of:



... that looks simple enough.

I was thinking of a small modification such that the tel-tale only illuminated when the OD was actually engaged might have more utility:



... particularly if I used a LED bulb with a large impedance.

[Burdekin]

Article how to install here as well. https://www.volvoamazonpictures.se/g...structions.php

An old thread https://www.volvoforums.org.uk/showt...ight=Overdrive Adam previously sent me a build doc he made, not sure where I saved it probably on my work computer.

[Othen]

Originally Posted by Burdekin

Article how to install here as well. https://www.volvoamazonpictures.se/g...structions.php

An old thread https://www.volvoforums.org.uk/showt...ight=Overdrive Adam previously sent me a build doc he made, not sure where I saved it probably on my work computer.

Many thanks,

A similar variation on a theme. The chap has used a pretty ancient (but I think still available) 3 pole relay like this one:

https://www.ipdusa.com/products/2131...-669102-109261

... that would look the part more than the one from a 240.

Alan

[Burdekin]

Originally Posted by Othen

Many thanks,

A similar variation on a theme. The chap has used a pretty ancient (but I think still available) 3 pole relay like this one:

https://www.ipdusa.com/products/2131...-669102-109261

... that would look the part more than the one from a 240.

Alan

Brookhouse sell the original style relays. https://classicvolvoparts.co.uk/sear...&Submit=Search