Gear crunching

I have a '51 Pacemaker that I recently rewired and there are a few other projects I've been working on.  I took my wife for her first ride today but I encountered a problem that was a little embarrassing. 

The car has a three-speed manual transmission and it was in neutral when I started it.  I tried to shift into reverse but the gears started crunching and it would not go into gear.  The same thing when I tried to shift into first.  Second and third were no go at all.  After I shut off the engine I was able to move the shift lever into all gear positions with no trouble.  

I shifted into first and restarted the car.  No problem shifting into reverse and backing out of the garage.  Went for a nice ride and did not have any further problems.  I will also mention that I need to come to a full stop before shifting into first, otherwise I get gear crunching.

Does anybody have any ideas about what the problem could be?

Thanks!


Comments

  • Jon B
    Jon B Administrator
    A couple thoughts enter my mind.

    Do you have overdrive?  Sometimes reverse gear will stick when the car's in overdrive.  (That wouldn't explain your difficulty in all other gears, of course.)

    Also: when's the last time you changed your clutch oil?
  • Jon...thanks for your post!  I do not have overdrive on this car.  I have not checked the clutch oil since I bought this car last October but I will put it on my "to do" list.  
  • Your clutch was stuck. But when you started the car in gear, the clutch unstuck itself, therefore you were able to drive normally after that. Drain the old oil, put some solvent in there, run it for a while then drain it out. Refill with fresh clutch fluid, or dexron ATF. Should be fine after that. If you plan on storing the car for months or longer at a time, put a 2 x 4 between the seat and depressed clutch pedal to keep the clutch from sticking. 
  • bob ward
    bob ward Senior Contributor
    Going for 1st gear while moving will result in crunching unless you double declutch. You only have synchromesh on 2nd and 3rd gears, very typical for gearboxes of that era.
  • Old Fogey UK
    Old Fogey UK Expert Adviser
    I have a weird problem shifting between reverse and first when backing up my driveway and into the garage after a long ride in my '34.
    Gear changes are OK until then but I have great difficulty moving the lever between the gears. It either won't go into gear or I can't get it out of gear,sometimes not without turning the engine off and then moving the shift lever. Even then it can be hard.
    Next time I use the car, everything is fine until I put the car away and then gear changes become graunchy or impossible.
    My driveway is very narrow and twisting  and it requires a bit of manoeuvring backwards and forwards to get the car up it.
    And, yes, I am fully depressing the clutch pedal.
    Any suggestions as to what the problem might be, please ?
  • bob ward
    bob ward Senior Contributor
    edited July 2020
    I'd imagine your clutch linings are expanding during use and are dragging slightly. There is a threaded adjustable rod between the clutch pedal and the throw out mechanism, try increasing the length of that by a couple of turns. Much easier said than done.
  • Also, all the pins and pivots and linkages in the clutch system wear and get slop in them over time. You can partially compensate for that by adjusting the rod as bob ward points out, but the  only real solution is to take it all apart, build up the worn surfaces and put it all back together.  
  • Old Fogey UK
    Old Fogey UK Expert Adviser
    bob ward said:
    I'd imagine your clutch linings are expanding during use and are dragging slightly. There is a threaded adjustable rod between the clutch pedal and the throw out mechanism, try increasing the length of that by a couple of turns. Much easier said than done.
    I'll try lengthening that rod a couple of turns and see how it goes.
     I hope it does the trick.
     Thank you for the advice.

  • Old Fogey UK
    Old Fogey UK Expert Adviser

    I wound the yoke up the threaded rod 3 whole turns to shorten the play before the pedal starts to bite on the clutch.

     I haven't been out on the road yet but going backwards and forwards up and down the driveway, it looks like it has done the trick.

    Tomorrow will be the test because I'm finally getting the car into the repair shop to have the steering geometry set up, which is a 10 mile round trip.

  • Old Fogey UK
    Old Fogey UK Expert Adviser
    Just returned from the repair shop and I can confirm that the clutch behaved itself all the way there and back without a single graunch - even when reversing into my garage.
    Thanks for the advice !