Overdrive relay -- m46 5th gear
 

http://www.swedishautoparts.com/740/...ion-parts.html
Could you confirm which one of these would be the proper type (color?) of OD relay for me? Mine is a 1986 converted 745 gasser with a 1985 d24t engine with its m46 tranny. My overdrive (5th gear) is not working right now. I think my od relay retired.

I got confused... Mine is brown. I`ll give it a shot tomorrow and see if resoldering cures my overdrive problem. (no 5th gea at all and the green light does not come up either) I did find some of the lines faded or slightly broken inside the relay. Nothing is burnt but minor crack or imperfections are visible. The car has the Made in Germany brown type od relay and that might be the original setup, i dont know.

I also suspect that the button on the shifter went bad but that would be the last thing to malfunction I guess. I checked voltage at the very end of the cables that run to the top of shifter and it was fine.

Most of my relays are not tightly in (loose) and there is a large amount of dust in there. I did not want to touch anything yet, just removed the od relay itself for a clean up and inspection. I prefer to deal with one issue at a time but later on I will take them all out and airblast the gaps and holes and will try to fit all relays back somehow tighter and clean all connections as well. Is there a method to test the od relay itself? That would be great to start with. ...
I also think about the solenoid might be acting up a bit. I have no 5th gear for now. There is no relay click when I press on the od button on my shifter.
Interesting that I was never able to see/activate the green 5th gear light on my dash unless the car was running. My other m46 Volvos always let me try 4th position+OD even if the car was not running (of course ignition on)... In RedArrow , my 745 d24t m46, I could never do that but my od was fine and functioning well once I got to 4th gear and touched the button for 5th gear. I will start with testing the relay if there is a way to do so. Thanks for your ideas and advice!

Manual M-46 Overdrive Fails to Engage: Basic Diagnostics
http://www.brickboard.com/FAQ/700-90...sicDiagnostics

m46 OD bad wiring
 

Thanks for all your ideas and the great info. I found the problem as I was dealing with something else around the shifter area. The od`s wiring was too old, cracked and it probably grounded here and there, under the shifter`s rubber boot it even broke so I had to rewire it and use new connectors but now it is working fine, the relay is ok too (resoldered :) ), the fluid level checked, shifter lubricated, connections cleaned and the wires replaced... the 5 light does come up and I have 5th gear! Hurray. I might go fishing for chain pickerel tomorrow...
Anyone having od issues, should first check wiring in/around the shifter. My wires chaffed against something, I guess, as they were cut too short, so the shifter`s movements affected them a lot and they started showing intermittent malfunctioning.
Attachment 56

Out of 5th on huge bumps
 

Looks like it solved the problem. Occasionally the car jumps out of 5th gear by itself but ONLY on very bad roads (when I hit a deep pothole once a month :) ). Can this be related to 4th gear switch on the transmission? (tr.mount is fresh)

Sometimes the wires in the shifter chafe.

Yes
 

That is exactly what happened before... Also, there`s a small spring that is responsible for the reverse button`s up-down movement. Mine is extremely tired. How would you replace that and where to buy? I never saw it listed anywhere. Thanks!

When my overdrive was cutting out over bumps in the road, reflowing the solder in the relay did the trick.

The switch is probably something you can get from IPD.

EDIT: Yep, here: http://www.ipdusa.com/products/6138/...witch-m46-1981

x2. .

M46 joy
 

A few months ago I wasn`t able to drive in 5th. Yes, I also started with resoldering the relay (but od issues were still present so) after that I replaced some wiring, connectors mainly in and around the shifter (found cracked wires and half-`burnt` connector plugs) Those being fixed it is perfect now 99% of the time. (if not: then in 4th position pushing the shifter towards the right gets me the 5th, my 240 liked playing that)

Thanks for the ipd link. I might need this 4th gear contact switch instead http://www.fcpeuro.com/products/volv...ission-1324496 I just wasn`t sure how easy (or not) it is to put the new one in. I can`t drop the tranny now while parked on the street (garage is taken by hoarder landlord until Sept) :)
The 5th gear button on shifter has been `fully refurbished` recently:) Pilots use such a thing. (and I do have a sunroof) So Red Arrow got some red.

PS how about that previously mentioned spring in shifter? I can`t find it for sale anywhere... (BUT what I found today is a white `90something grey leather inside 940 AT sedan for $300 at a NJ junkyard, nice condition even inside, NothinG missing! >YET< and running smoothly)...
I am wondering why not a diesel in such a great condition!? We all wish the smoky tanks were much more common in the usa, right?!