transmission interlock.

[Deleted User]

I have looked at the interlock parts and I see that the rails have a notch and their is a ball that is spring loaded that holds the rail from moving but how does all that work? I can move the left side shifter fork fine with the cover off but the right not so much, with the interlock ball out it moves fine. (this is on a 34/37 trans) and one have some good advice on how to make sure it works well as I am not quite following it other than in principle.

Park_W

There is linkage that connects the clutch mechanism to the vertical sliding piece on the tranny that holds the ball in the locked position. Your puzzlement may come from the absence of some of that linkage. The purpose was to lock the shift rail in position unless the clutch pedal was depressed to a certain point (which is adjustable). Eliminates the "jumping out of gear" that was common in a worn tranny in those days.

Uncle Josh

Sounds like maybe there is dirt/rust in the ball interlock system on top of the tranny. You may need to take the top off the tranny and take all that apart and clean it good and oil it then put it back on and adjust it. Been there had to do that.

Jon B

Have you consulted the 1934-37 shop manual on this? It's on line at the Club website (assuming you've registered to use it). There are adjusting nuts on the vertical threaded linkages at both sides of the transmission, to align the vertical bars. The bars have slots in them, which (when they have been raised to the correct height) allow the ball to slide out of the transmission and into the slot.

[Deleted User]

I have taken a look in there and it describes function well, I have to look through everything to make sure I have the linkage but even manually working the parts does not seem to allow the right side to operate as it should. The left side works well, I am going to try re cleaning and adjusting it to see if something is going on there but with the bar in the correct position it should allow it to shift, or at least I think it should and so far that is not the case.

Uncle Josh

The balls and link inside the top of the tranny are rusty.

[Deleted User]

I had the balls out and they look nice and shiny, but I am going to have at that again just in case.

ski4life65

"I had the balls out and they look nice and shiny"
Funniest thing I've seen all week! Yes, my wife often asks me "how old are you?"

Uncle Josh

Well, then, if everything is nice n shiny b'golly, the side rails are out of adjustment, unless something is hung up inside the tranny. Depressing the clutch should line up the notches with the interlock pins.

[Deleted User]

I re read that and ummm well not exactly what I meant. The trans is on the bench and with the "balls out" everything moves well, put them back and there is alot of unhappiness in the whole operation. the left rail moves well but not the right. Just thought someone might have run into that. This trans is either a 36 or 7 as I was told they are better than the 34, although the interlock is a bit different.

Uncle Josh

I hate to state the obvious, but you did remember that each rail has to be in the neutral position to move the other.

[Deleted User]

Yes I did ensure that as well with the right side interlock ball out the rail moves nicely, the left moves properly with the interlock set up right. So I think the problem lies with the interlock itself based on my tinkering, and I will go in a clean it again. I am wondering if it lies in the adjustment of said piece?

Jon B

Wish we could be standing there to advise you....this sounds like a really simple problem.

At the risk of going over what we've already covered...you do have threaded vertical adjustment rods on both sides of the transmission, correct? One rod controls the left bar (with notch for the ball), the other controls the right. Each must be adjusted by means of the nuts, so that the notch on each of the two bars aligns with the ball protruding from that particular side of the transmission, thus allowing the ball to move outward when the notch is aligned with it. This occurs when the clutch has been depressed about 1/2-way, as I recall. The purpose of course is to allow a gear change to be made only when the clutch is depressed, so that the car does not drop out of gear.

There....more than you ever wanted to know!

[Deleted User]

Any type of problem causing this type of confusion is all ways is a simple problem.
Just need to find where its hiding,
Roger