Register now to get rid of these ads!

Technical flathead trans is kicking my arse - more questions

Discussion in 'The Hokey Ass Message Board' started by 1pickup, Jun 1, 2019.

  1. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    The last one I built went together easy & worked great, until I did a burn out in reverse. Don't do that. This one, is not cooperating. Now I've finally got everything together, it seems to be in 2nd gear, no matter where I move the synchro. If I move the 1st/rev slider out of N, it locks up. Seems to be in 2 gears at the same time. If I leave the 2/3 synchro in N, it looks like it's in 2nd gear. The output shaft turns. If I slide it into 3rd, it doesn't change. Still 2nd. Slide it into 2nd & it's in 2nd.
    For some info: 18 series case, '40-'48 gear set. WTF?
     
  2. Not sure how they did it back in the day 1950's to 1960's.....just guess there trannie's were more around in the day...wezz got's to be careful with them HP's.......
     
  3. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,453

    s55mercury66
    Member
    from SW Wyoming

    Sounds like you may not have enough clearance between the mainshaft and the input, but that is just a guess.
     
    King ford likes this.
  4. alchemy
    Joined: Sep 27, 2002
    Posts: 13,850

    alchemy
    Member

    You have the post-39 shifter housing and forks, right?
     
    town sedan likes this.
    Register now to get rid of these ads!

  5. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    I have the correct shift mechanism. This problem is BEFORE I put the shifter on.
    How do I check this?
     
  6. Angry Frenchman
    Joined: Feb 12, 2006
    Posts: 1,742

    Angry Frenchman
    Member

  7. King ford
    Joined: Mar 18, 2013
    Posts: 1,191

    King ford
    ALLIANCE MEMBER
    from 08302

    When you say it seems to be I second are you counting the revolutions of the input and output shafts? Mark both and turn the input ten times , I'm better the output turns ten times too and ergo you are in " high" gear..in this case third. The most likely explanation then would be the input and output shafts are jammed together, perhaps by a needle bearing caught in front of the output shaft instead of around the outside of the bearing surface. If this is the case, loosening up the bolts on the bearing retainers will most likely free it up and verify this possibility....
     
    Hnstray likes this.
  8. rusty valley
    Joined: Oct 25, 2014
    Posts: 687

    rusty valley
    Member

    are all the parts from the same trans? i once tried to use an input shaft from the earlier style syncros, with the 39 style trans, and the syncro surface sits farther back, and will take away free play and lock up in high gear as mr king ford suggests
     
  9. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    Here's a revision of what I stated before: when I slid the synchro into 3rd, it locks up, just like in 1st & reverse. It is stuck in 2nd gear.
    @King ford: I marked the input & output shafts. Turned. It's not 1:1, so can't be 3rd gear. It has caged roller bearings, so no needle bearing causing problems. But, I did as you suggested & loosened up the input. No difference. Then, I pulled the shaft out of the cluster gear & let it fall down into the case. Now, I can slide the 2/3 synchro & have it in high gear, or Neutral. So, its looking like maybe the cluster gear is the wrong one? There are no numbers I can see on it, so I suppose I will have to count all the teeth to identify it?
    @rusty valley: I was pretty sure all the parts were from a supposedly "rebuilt" '40-'48 side shift trans. However, I have had a couple different trannies apart, so not 100% on that.
    @s55mercury66: suggested not enough end clearance, and the only way I can think of that happening is that the rear bearing isn't pushed on the shaft all the way? But, after dropping the cluster gear, the main shaft turns smoothly.
    I'm tired of taking this thing apart so many times...
     
  10. rusty valley
    Joined: Oct 25, 2014
    Posts: 687

    rusty valley
    Member

    if you get mac vanpelts tranny book it has all the measurements to identify all the shafts, gears, syncros, etc. because many do not have a number so you need to measure to identify
     
  11. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    I have @Mac VP 's book. I completely took it apart again for the 20th or so time. Put it back together, just like I have previously, and it seems to shift now with the cover off. I can get every gear to work. Until I try to put the cover back on. When I line up the forks & push the cover on, it's about 1/4" - 3/8" too far back. Push it forward & get the bolts to line up, & it doesn't work. I'm seriously thinking of putting a T5 in this.
     
  12. 31 Chopped Coupe
    Joined: Aug 24, 2014
    Posts: 70

    31 Chopped Coupe
    Member

    Is there any way you could have installed the shift collar backwards?
     
  13. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,453

    s55mercury66
    Member
    from SW Wyoming

    Don't give up yet! As you have found and as mentioned above, it is probably something in the shifting department.
     
  14. rusty valley
    Joined: Oct 25, 2014
    Posts: 687

    rusty valley
    Member

    find out the trouble?
     
  15. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    @rusty valley Haven't got back out to the shop. Busy week. Has anybody run into the problem I have now? Seems to work, but doesn't line up with the shift mechanism. Seriously, can't see how that can happen.
     
  16. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,453

    s55mercury66
    Member
    from SW Wyoming

    Could you have a bent shift fork, a slider misoriented, a bent shifter handle, something like that?
     
  17. weeeeee love pictures.....kinda helps us look at what yer looking at.....just saying........
     
  18. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    I'm putting together an 80 year old tranny, what makes you think I have a smart phone? Maybe I can borrow my wife's, she is younger (by 5 months) than me.
    OK, here's a recap & where I'm at now: 78 series case, '40-'48 gear set, double detent shift tower with swan neck. Was trying to put the gears in a 48 series case. That was no bueno. 29 tooth cluster gear wouldn't drop far enough in the case to let me put it together. Got everything in for 37th time (now in the 78 case), & it seems to function, before I put the shift tower on. When I push the shifter on, I have to tap it down to make it seat. Then I can get neutral, but if I shift into any gear, it locks up. Seems to be in 2 gears at once, but not sure how. If I leave the shifter not bolted down, tilted to one side, so the other is about 1 1/2" above where it should be, I can make it shift all gears.
    I measured the (approximate) distance of the shift forks (center to center) at 3 13/16", but the distance between the synchro & R/1 slider (where the forks ride), looks to be 3 5/8". What am I missing? Does the '39 shift tower not work with the later gears? If I can't make this work, I'll probably have to go back to the early gear set.
     
  19. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    So.... Just because you have a double detent shifter, it might not have a 3" fork. The smaller shift fork will apparently, slide onto the late synchro (with some persuasion), but the offset of the fork will put you into 2 gears at the same time. I have another shifter w/ 3" fork, but it is rusted & currently soaking. I may have solved the problem...
     
    s55mercury66 likes this.
  20. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,453

    s55mercury66
    Member
    from SW Wyoming

    Awesome, keep us posted.
     
  21. John Stimac
    Joined: Jan 15, 2008
    Posts: 481

    John Stimac
    Member

    Its been a long time since I assembled one, but somewhere in the deep recesses of my mind I think I might have put one together and had the synchro in backwards and had the same problem. Or then again, maybe it was just a bad dream on my part
     
  22. alchemy
    Joined: Sep 27, 2002
    Posts: 13,850

    alchemy
    Member

    I asked you way back in post #4 if you had the correct forks. ;)

    Yes the earlier fork will fit onto the later housing and rods, but not work with the later synchros. That could be one problem, but it still doesn't answer why you were getting jammed up BEFORE you put the shifter housing on.

    Also, while you have things apart, make doubly sure the shifter is straight from the pivot ball down to the bottom tip. They can get bent there and make things not work as intended.
     
  23. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,503

    Atwater Mike
    ALLIANCE MEMBER

    I had this problem in '58, my friend around the corner had ground the 1938 shift fork out slightly to fit over the late ('41-'48) slider. Neutral didn't line up, and when shifted into high, (3rd) he said it 'locked in gear'.
    Removing the shift tower, I could see the mainshaft detent springs and balls had slipped out of their bores when the slider (2nd/high 'sleeve') went too far forward.
    Fortunately, I had seen this before...so I replaced the fork with the late '39, which had the 'offset' to account for the rearward placement of the later synchro sleeve.
    The early transmission had the channel for the fork more centrally cut.
     
  24. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    @alchemy Yes, you did. And, you are right on the other point as well. The first few times I tried to put it together, I was using a "48" case. When I figured out that wasn't gonna fly, I switched to the "78" case. Still had problems shifting it, without the shift tower on. Seemed like no neutral for awhile. Took it apart & put it back together about 5 times, before it started shifting, & I HAVE NO IDEA WHY. I honestly think I put it together the same way, every time. So, it's a mystery to me. Then, when that was working, I had the wrong forks. By then, I was so pissed at this thing, that I couldn't think straight. I incorrectly assumed the smaller fork wouldn't go on the later synchro. Most of the guys my Dad knew around here that could have helped me out, are no longer with us. Now, just waiting to see if I can free up the rusted 3" shift tower I have soaking.
     
  25. Mac VP
    Joined: May 13, 2014
    Posts: 281

    Mac VP
    Member

    Check out the early Ford trans identification webpages on our site. We break down the various gears and other components in the shifter housing. You could have some mismatched parts....or some damaged/defective parts as well. Your shifter housing and forks should drop right down onto the gear set without any forcing or misalignment. Here’s the link:

    http://www.vanpeltsales.com/FH_web/flathead_transID_3speed.htm

    If you are still stumped (and it’s happened to all of us) consider sending the trans to us. We’ve seen it all.......
     
    Rehpotsirhcj likes this.
  26. 1pickup
    Joined: Feb 20, 2011
    Posts: 812

    1pickup
    Member

    More questions: When should you rebuild the shift mechanism? I have the correct tower with 3" fork. It was rusted & wouldn't move. I soaked it in vinegar for quite awhile to derust it, & now after some penetrating oil & elbow grease, it seems to shift OK. There are some pits on the shafts, but that should (hopefully) just get more lube in there. Do I need to break it down & go through the whole thing?
     
  27. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,453

    s55mercury66
    Member
    from SW Wyoming

    Yes, I would at least take it apart and have a look, clean everything up, replace what I felt needed replaced and put it back together.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.