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Technical So, what all has to happen to make this overdrive happen?

Discussion in 'The Hokey Ass Message Board' started by Roothawg, Jul 8, 2016.

  1. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,820

    Roothawg
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    I bought a BW T86/R10 tranny the other from an old hot rodder. Hee sold me the tranny, and a box full of crap that may or may not be useable. This is all slated for my 1955 Ford Customline. I have been reading all the old threads on OD, but most only cover wiring etc.

    Here's my question, what else has to happen? Does the driveshaft get shortened or is it generally a 1 for 1 swap?

    Can you bench check the OD portion ? I wanna make sure I am covered before I tear into a perfectly good running car.

    If I opt for a toggle versus all the sitches etc, is that all I need? Any certain type of toggle required?

    Is the cable a requirement or optional?


    I have never owned an OD car in my life, so don't assume I know anything about them.

    All I know is I need OD in a bad way.
     
  2. bchctybob
    Joined: Sep 18, 2011
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    There are others on here who know a hell of a lot more than I but....
    I bought the manual from Speedway. Between it and my '57 Ford manual, I got mine set up and working fine. I did use the cable since I wanted the car to have that little accessory visible under the dash. I believe the cable is necessary or some other method to hold the lever in the correct position.
    You can test the big solenoid easily enough on the bench but I think that's about it. I do know that the 6V version of the solenoid doesn't last long on 12V.
    Not sure about the driveshaft length.
    I didn't want to dick around with toggle switches and stuff, all it takes is one brain fart and you're under there fixing a trans that's hard to get parts for. I did it all just like the factory. Good luck!
     
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  3. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,820

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    One thing I haven't been able to nail down is how you know what you have. I don't see any serial # etc. on the tranny case. It has a model number but BW made the same tranny for 50 years apparently. I don't know what interchanges or if it's 6V or 12V.
     
  4. miker98038
    Joined: Jan 24, 2011
    Posts: 408

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    It's been 15 years since I pulled the T-86 O/D, so we'll try my memory.

    You need the cable. The o/d freewheels when engaged mechanically but disengaged electrically. It won't back up in o/d, although I seem to remember some of them had an internal (mechanical) disconnect when you shift to reverse.

    The solenoid is a fairly big drop-in load, you're going to want a relay. The OEM set up used a relay and a kick down switch. The relay was controlled by the governor. Putting a sw in that line was how I used to override the system. I'd suggest using the governor, the kick down is optional. I had them, but rarely used them. They open the relay, and momentarily short out the ignition to let the solenoid drop out. Some electronic ignitions don't like that.

    As bob says above, it doesn't take that much to do the basic wiring, and it's pretty obvious how to leave the kickdown out.

    Measure your existing trans and the o/d one. Driveshaft will probably need to be shortened. Check the output splines, they may be different also, you might need the matching yoke.

    I seem to recall the solenoids were stamped 6 or 12, kinda faint if it's covered in grime, but I'm not sure. The governor doesn't care.

    Once installed and working, you'll love it. The only reason I got rid of it was I'm in an area with heavy traffic and lots of hills. Double clutching to low was a pain, and a T-5 solved that.
     
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  5. bchctybob
    Joined: Sep 18, 2011
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    Does it have the Chevy/GM bolt pattern where it mates to the bellhousing or is it Ford?
    Other than that, I don't think there were any significant changes over the years. Some had crazy long tailshaft extension housing (Ford) and some (Chevy) were shorter.
    I believe it says 6V or 12V stamped on the solenoid somewhere - mine did.
    I've had several and the OD units were always fine, it was the transmission where I found damage, if any. Front bearing and synchros. I used to grab 'em up for $15-$25 when no one cared about OD. I kept the spares for parts since some stuff is expensive.
     
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  6. Well, in order....

    1. The driveshaft should be a direct swap, assuming you have a OEM manual in there now and you have a 'matching' OD trans.

    2. You can bench test the OD solenoid to make sure it goes in/out, but the rest will need a teardown to check. The governor should be checked to make sure the contacts are in good shape. The solenoid should have the voltage stamped on it if it's 12 volts.

    3. If you decide on a simple toggle switch control (and I wouldn't recommend this for the same reason Bob above gives), use a 30 amp rated SPST switch. This is large enough to handle the current inrush and give good switch contact life. Or use a relay.

    4. The cable is a requirement only if you want to be able to defeat the 'freewheel' feature of the trans. I would consider this mandatory for driving safety. Going down a long hill in 'freewheel' could cause you to run out of brakes... AMHIK. With the OD lever 'engaged', when parking you'll have to use the parking brake or shift into reverse to prevent the car from rolling.

    These really work best if wired as per the factory. Then all you have to do is decide if you want OD or not, and the controls will switch it in/out as needed automatically. Almost no risk of damaging the trans by mis-operation.

    As noted, some electronic ignitions won't like being shorted to ground if you use the OEM type wiring, but this can be addressed with an additional relay. Check with your ignition manufacturer for the best way to do this.
     
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  7. Lost in the Fifties
    Joined: Feb 25, 2010
    Posts: 393

    Lost in the Fifties
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    I had a 55 with OD and replaced with a non-OD out of a 56 after losing the transmission. Direct replacement, same length. Maybe I was just lucky, though.
     
  8. squirrel
    Joined: Sep 23, 2004
    Posts: 43,642

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    I found the numbers on the two solenoids I have, and looked them up and figured out that one was 6v, the other was 12v. I used the 12v one.


    If you wire it to a toggle, you will forget and leave it on, and you might crunch the planetary by starting out in low gear.

    I like to be able to lock it out...you can get away without, but be careful when you park if you don't have a parking brake, because the car can roll.

    It's pretty easy to wire the governor up to a relay, to energize the solenoid at 30 mph, like it's designed.
     
  9. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,820

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    It's a Ford bolt pattern. It has T86 FA1 cast into the case.
     
  10. squirrel
    Joined: Sep 23, 2004
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    What is it replacing?
     
  11. Roothawg
    Joined: Mar 14, 2001
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    Roothawg
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    The guy gave me a box of crap that some of it looks trashed. The switch under the pedal is bound up and I am not impressed with the quality of the harness. I'll just build my own.
    Mainly kept it all for the brackets and such.
    I have a coulmn shift 3 speed behind my 292.
     
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 43,642

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    That's in a 55 ford car, right? I went the other way, swapped a 55 ford type OD trans into my 59 edsel to replace a T86 od, and the driveshaft needed about 3" lengthening. So you might have to shorten yours. Tape measure time. And the splines were wrong, both the clutch and the driveshaft yoke.

    you need the trans I have...I needed the trans you have...ain't life wonderful?
     
  13. Roothawg
    Joined: Mar 14, 2001
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  14. Roothawg
    Joined: Mar 14, 2001
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    I'll snap a pic of it later.
     
  15. They're really a great trans for cruising, offering a near-perfect blend of mileage and snappy acceleration when everything is right. Their major flaw is they don't suffer abuse well (and is one reason the major manufacturers stopped using them) so they're not a trans you want to beat on. The lack of a synchronized first gear is another 'flaw' but this can be lived with.
     
  16. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,327

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    I think the 86 series had a top inspection plate that trans was used mostly after ford went to 12v.
     
  17. Roothawg
    Joined: Mar 14, 2001
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    Roothawg
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  18. 302GMC
    Joined: Dec 15, 2005
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    from Idaho

    [. Maybe I was just lucky, though.[/QUOTE]
    Maybe ... the '55 and '56 speedo drive go in from opposite directions, so a '56 up trans subtracts miles, and speedo only works in reverse.
    Assuming you're still 6v pos, I'd wire it up as the factory did, changing only the kickdown switch, which you'll install in a location you like. You don't need to floor it to shift to direct. Your KD sw. can very likely be worked back into shape, & new ones are still on the market.With the points in the relay cleaned and a 30a fuse you're on the road enjoying clutchless shifting and a 2nd gear good from 5 to around 80 MPH ...
    And Jeep shift lids fit with a little grinding if you want a floor shift ...
    And if you decide to pull the solenoid when you clean & test it, make sure the lever is in disengaged position or you have a junk sol. the make into a tool.
     
    Last edited: Jul 8, 2016
  19. Roothawg
    Joined: Mar 14, 2001
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    My car has been converted to 12v.
     
  20. Stay away from clutchless shifting... that will kill the OD unit....
     
  21. squirrel
    Joined: Sep 23, 2004
    Posts: 43,642

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    Is the output shaft coarse or fine spline?

    Is the input shaft 1" OD, or bigger?

    might want to measure the length of the trans, as well as the mount location.

    Oh yeah, I forgot about the speedo gear. The T86 I have uses a normal modern one, relatively easy to find. Might need a new cable.
     
  22. Roothawg
    Joined: Mar 14, 2001
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    Looks coarse Jim. I may throw the 55 on the rack tomorrow so I can lower the suspension, I'll check some dimensions when I do.
     
    Last edited: Jul 8, 2016
  23. miker98038
    Joined: Jan 24, 2011
    Posts: 408

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    Kinda hard to see, but it looks like the box has most of what you need. At least enough to buy a replacement and duplicate the harness. IIRC when I pulled the FOM and put a T-85 O/D in my 55 bird back in the late 60's, the mounting boss for the kick down sw was stamped in the floor pan under the throttle, and the holes to mount the relay on the firewall were there. Just had to X cut the carpet. O/D cable length might need to be looked at, but those are available. I never had a speedo problem on the old fords, just changed gears on the cable and got close enough.
     
  24. 42merc
    Joined: Dec 19, 2010
    Posts: 600

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    To check for voltage on the solenoid look at the end bell (cover).
    12 volt solenoids will be stamped 12 volt.
    6 volt solenoids will have no voltage marks or stampings.
     
  25. EZ Cool
    Joined: Nov 17, 2011
    Posts: 260

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  26. I had a 55 custom line in high school with the 272/3 speed O.D. and loved it. It had all the factory stuff which meant I couldn't use O.D. in first gear. I wanted it so I could split shift and make all the big guys think I had a 4 speed.
    Fast forward to about 1987 when I replaced the 3 speed in my shortbox chevy pickup with an overdrive trans from a 55 chevy car. I used a quality switch with no relay and a Morse cable for a truck PTO. Worked great and I now had 6 forward gears with a super close ratio! That's how I found out a fresh 292 chevy motor will trash the sprag unit in the overdrive......best not to use 1st and over. Otherwise it was fun to drive. Takes about 10 minutes to become adept at upshifting, downshifting and split shifting....
     
  27. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,820

    Roothawg
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    ImageUploadedByH.A.M.B.1468097292.574709.jpg Took a peek inside today.

    ImageUploadedByH.A.M.B.1468097339.925769.jpg output shaft is 1-1/8".

    ImageUploadedByH.A.M.B.1468097376.611961.jpg . Here's a better pic of the box o crap.

    The solenoid says 12V.
     
  28. squirrel
    Joined: Sep 23, 2004
    Posts: 43,642

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    I think you'll be able to make it work...wonder about the length?
     
  29. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,820

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    I was wrestling with the 327 today, so I didn't get to throw it up on the rack.
     

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