Volvo RWD 200 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 10/2021 200 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Removing J-type OD from M46 tranny 200

This may be a basic question, but I am a bit stumped. Even though I have been wrenching Volvos for over 30 years. First some history. Back in the late 90's, I had a 740T that lost 2nd gear on its tranny. So, I swapped in a M46 from a 240. There were some differences, such as the original 740 tranny had an Aluminum case with a P-type OD, and the 240 tranny was iron case with a J-type OD. Just had to swap the shifting cage and drive shaft coupling, and the 240 M46 bolted right up. Drove the car this way for a number of years. When it was time to retire the 740, I grabbed the tranny (240 M46 with J-type OD), and put it in the basement as a "just in case" spare. That was 2003.

I am now in the process of restoring a 1972 1800ES with a M41 tranny with J-type OD. Due to a storage mishap, the aluminum case of the OD is badly oxidized around the oil sump, and is not salvageable. I am looking to try using the J-type OD from the M46 tranny mentioned above. From my initial look, I think it will work. Will know for sure once I get the OD off the M46. That is where my problem is. It will not come off the M46. I had it off the M46 back when I was installing the M46 into the 740. But, it does not seem to want to come off now. It has been close to 18 years since the M46 was last driven and the OD energized. So,any pressure in the system would have bled off long ago.

Any suggestions on how to get the OD off the M46?
--
Gary D








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Removing J-type OD from M46 tranny 200

    Thanks for all the suggestions and pointing me to various sources of information.

    After doing more block and mallet banging with no success, I tried a different approach that I gleaned from more on-line research. I think it came from a Austin Healy site. I discovered the thread for the pressure gauge port is a standard 3/8" x 16 thread. I built an adapter that allowed me to go from a drilled out 3/8"x16 thread bolt (with head cut off) to a 1/4" FNPT pipe thread. The drilled out bolt went into the OD pressure gauge port with the copper washer as a seal, and the pipe thread connected to my portable hydraulic jack/ram set. Put 12 VDC on the solenoid to allow pressure to build from the hydraulic pump. A few stokes of the pump and the OD clutch popped free. Was then able to lift the OD off the M46 with no resistance. Besides getting the OD off, I confirmed the solenoid still works after all these years.

    This in hind-site was so easy once I built the adapter in the machine shop at work. Took about 15 minutes and a piece of 3/4" scrap aluminum rod and a 1" bolt of 3/8"x16.

    Will be using the trick next time I have to pull an OD off a tranny.

    --
    Gary D








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Removing J-type OD from M46 tranny 200

      Hi,

      A man after my own heart!
      A machine shop can melt together ideas, nicely, when standard tooling is incorporated.

      I can see where using the piece of raw stock would greatly facilitate combining the two threads.
      I’m curious how long was the scrap piece was, as you didn’t need all that much.

      I didn’t quite the follow the first adaptation of how the center of a 1/4 FNPT fitting held the 3/8” bolt diameter, head or no head, without welding the two. The base opening or tap drill size is a 7/16” diameter.

      From the way I understand it, you drilled and tapped the one end of the aluminum stock with a I/4” NPT.

      Did you turn down the other end for threading a 3/8”-16 male thread with a small hole in it or tapped out the Aluminum body’s base for the 3/8-16 threaded bolt and still use it with the copper washer as a seal?

      Either way it’s a neat package, so neat, I hope you don’t misplace it, like I do things and forget what the heck did I make that for?
      A word of advice I’ll share, is to attach a note to it and keep it with the Port-a-Power unit. (An old term used among mechanics over the years with out branding attached so much!)
      The adapter cannot be used without the pump.

      Thanks for sharing your experience with “unlocking” the overdrive mechanism!


      Phil








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Removing J-type OD from M46 tranny 200

    Thanks for the info. I will have another go at it some evening this week. It was surprising to have the od stuck. When I took the od off the 240 M46 years ago, I was thinking of swapping the p-type od from my problematic 740 M46. Quickly learned the j-type and p-type were not interchangeable. So, put the j-type back on, and put the 240 M46 and j-type in the car. Both of these ods came off with just a little wiggling. When I removed the od from the M41 last night (the one with the oxidized case), just a bit of wiggling and tapping with a block and mallet did the job. I remember seeing something about unloading the od, but figured that was due to hydraulic pressure holding something, and that pressure should have bled off over the years. I think I have a better understanding of what is going on, and will make another attempt.

    Thanks again for all the information.
    --
    Gary D








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Removing J-type OD from M46 tranny 200

    Duane Hoberg aka OD Guru used to be the go to guy for the M46. However a few years ago (2015?) it was reported that he was in ill health. Haven't heard from him since though DuckDuckGo search indicates that he is 71 etc.

    He did however provide write-ups as at
    https://www.brickboard.com/FAQ/700-900/FAQPDFVersions/OverdriveRebuild.pdf

    --
    1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    Removing J-type OD from M46 tranny 200

    It has been a lot of years, but I had a 240T with the M46 OD that I rebuilt.

    To remove the Laycock overdrive unit the first step was to start the car and put the transmission in reverse. At that point you quickly released the clutch which stalled the car. I can not explain the mechanics of what that did to the unit, but it did allow it to be unbolted and removed from the transmission.

    From what I remember if you didn't follow that procedure or if you encountered a nonrunning car it was a task of forcefully prying the unit off to make the separation.

    I hope you can find additional information and that brute force method isn’t necessary.

    Randy
    --
    Any twenty minute job is just a broken bolt away from a three day ordeal








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Removing J-type OD from M46 tranny 200

      According to the Volvo green books, the approved method is brute force as a slide hammer is the tool used to separate the O/D from the transmission.

      We use an old rear flange attached to our slide hammer and bolt it to the rear flange on the O/D.
      --
      Eric
      Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
      Torrance, CA 90502
      hiperformanceautoservice.com or oldvolvosonly.com







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.