'35 Gear Grinding in 1st & Reverse

Scott754

Scott754

Member
My '35 Fordor has recently started grinding when I try to shift into 1st or reverse. This only happens occasionally. I can't figure out why this would be, but each time it happens it is after I've had the car running for 30+ minutes. So it doesn't always happens, but when it does, even from a complete stop with the engine idling normally I can't get into 1st or reverse without grinding. I can't think of what would change when it's heated vs cold? I've read other threads that indicate it could be worn clevis/pin. I'm considering replacing those, and also adjusting the clutch pedal rod to reduce the free play...although the free play is approx 1.6" (within the 35 ford manual recommended play of 1.5-2"). My car is a '35 but the engine was upgraded to the '46-48 Flathead, but I don't know if the clutch is a '35 or '46 - is there an easy way to tell? Any thoughts on what would cause (occasional) gear grinding in 1st and reverse, but 2nd & 3rd are fine? Or what would cause this to happen when it is warm? Is it advisable to reduce the free play to create more separation in the clutch?
 
Hi Everyone. Scott754, I like your question and look forward to some thoughts from the mechanically skilled members.

To help them and fill in a couple of blanks: How many miles have you driven the car/years owned, is the car new to you? How many miles ago did the crunching begin?
 
How much free play do you have now, if over an inch I would adjust it
and see if that helps.

Bob
 
VeryTangled said:
Hi Everyone. Scott754, I like your question and look forward to some thoughts from the mechanically skilled members.

To help them and fill in a couple of blanks: How many miles have you driven the car/years owned, is the car new to you? How many miles ago did the crunching begin?
Click to expand...
Hi, to fill in some of the blanks: the odometer shows 85,000; I purchased it 2 months ago and have driven it approx 300 miles. The grinding started the last 2-3 times I've driven it, so I drove it about 200 miles before I started having this issue. To add a little more, as an example, yesterday I drove the car for about 20-30 mins, multiple times putting it in reverse and 1st smoothly with no grinding, then after it had been running for 30 mins, at a complete stop it was continuously grinding, not just a little as it went in gears but steady grinding so I couldn't get it in gear. So I shut it off, put it in 1st then started the car. Hope that helps.
 
I had a similar problem many years ago when I had a 34 sedan. It let go one day in town while driving. Got difficult to shift in any gear. Made it home and found that the clutch plate had let go. The riviots in the center hub of the pressure plate had turned loose .
 
Scott,
Sure seems as though the clutch is dragging a bit. Another thing occasionally
overlooked is the effect of the trans lube as it gets hot. Cold or even warm trans lube
definatly slows the gears down between shifts. When HOT even the old type 600W
lube is like water and presents very little drag on the gear teeth......when it's cold
it presents mucho drag.
Charlie ny
 
Have you checked the trans lube level ? I would agree with temp . Warming fluid making it thinner . Try adjusting your clutch , check trans fluid , if all checks out , I would try putting in second then down to first , or tear into it .
 
Bob C said:
How much free play do you have now, if over an inch I would adjust it
and see if that helps.

Bob
Click to expand...
The free travel now is approx 1-3/4", and the manual says on the ’35 it should be 1-1/2 to 2”. The only concern I have about lessening the free play is the manual says “the increased pedal clearance of the ’35-36 clutch is necessary to prevent interference between the throwout bearing and clutch levers at high engine speeds when the movement of the counterweights force the clutch levers back”. Is this something I should worry about?
 
Charlie is right re the temp of the lube. Don't adjust anything, but DO shift into 2nd gear (with synchronizer) just before shifting into 1st or REV. I've done this for 55 years, with more cars than old Fords, too. DD
 
Are you shifting into either 2nd or 3rd before trying 1st or reverse? If the clutch is out while the transmission is in neutral, the cluster gear will be spinning. Even when you push the clutch in, it will continue to spin, especially if the oil is warmed up. When you try to push the first/reverse sliding gear (it's NOT spinning) into the spinning cluster or reverse idler, the gears will grind. I was taught years ago to shift into 2nd and let the 2nd gear synchro stop the cluster gear from spinning. Then, the first/reverse slider should slip right into engagement without the grinding.

(Oops! I didn't see Coopman's post before I put mine up.)
 
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Scott754 said:
The free travel now is approx 1-3/4", and the manual says on the ’35 it should be 1-1/2 to 2”. The only concern I have about lessening the free play is the manual says “the increased pedal clearance of the ’35-36 clutch is necessary to prevent interference between the throwout bearing and clutch levers at high engine speeds when the movement of the counterweights force the clutch levers back”. Is this something I should worry about?
Click to expand...

Yes, it is something to be conscious of. To demonstrate, while driving 25 mph in high, touch the pedal enough to feel the free play. Then do it again at 60 mph. you will feel the difference. If you "hot rodded" the car and ran the engine to max rpm through the gears you would feel the free play nearly gone. When the free play is gone, the centrifugal force begins to apply force to the pressure plate release arms and possibly slip the clutch.

For a test at reasonable RPMs, no harm done.
 
Scott754 said:
Any thoughts on what would cause (occasional) gear grinding in 1st and reverse, but 2nd & 3rd are fine?
Click to expand...

Hi Everyone. Yes Scott. Not a mechanic, but as I understand it 2&3 have a synchronizer. First and Reverse do not. So to get into those gears the trans internals have to stop spinning or gear clash, not just synchro clash. If depressing the clutch doesn't stop the guts spinning, there's an issue.

By going to 2nd before the non-synchro gears, it lets 2nd do the stopping of the gears, so going to 1 or R will work.

Whatever CharlieNY says, listen and read twice. He's a good-un'. Rebuilt, exchanged, or provided several major components on my '36 Phaeton (steering, trans, rear, carb, & more) and no complaints after thousands of miles.
 
Thanks to all for the very helpful comments.
1) Charlie & others advice about the temp of the trans fluid explains why I was having the issue once the car had been running for awhile. I had wondered if someone had put in the wrong weight fluid when it was last changed.
2) I have not tried shifting into 2nd or 3rd before trying 1st or reverse... that's very helpful to know that may resolve the problem, and I will definitely try that and report back. I assume that's a good workaround but not how the transmission is supposed to work, and perhaps the fluid/viscosity is causing the problem?
Based on all the comments, I'll focus on making sure the fluid level/viscosity are correct, and also shifting into 2nd before 1st or reverse and not try adjusting the free play.
 
There is a small clutch inspection plate, held in place by two slotted head screws, on top of the transmission bell. With that plate off you might be able to see how the pressure plate and clutch disk are functioning when someone pushes the clutch pedal in and let's it out.
I agree with those who are saying the problem is in the clutch or the pedal to clutch linkage adjustment.
 
AS a teenager I always shifted it to 2nd before going to 1st. It works really well if you are in Rev, go to 2nd then 1st and it will go right in gear even if you are still moving backwards. You could spin tires that way, But you could also strip out a cluster gear if you were moving very fast backwards. As they say, ask me how I know. But when you are young and dumb you do these things anyway. Normal driving it will not hurt a thing but back then Cluster gears were only about $12 and you could buy a complete Trans out of a junk yard for about $15.
 
I always used the up into 2nd trick if I was in a hurry. The counter shaft cluster gear should stop turning though. The viscosity of the lube is a pretty good drag on the shaft and it should stop even if hot with minor variation in time to stop. It just takes it longer when hot but shouldn't be a lot longer. If you set at a stop light for a few minutes with the clutch disengaged and the transmission in neutral, it should be stopped in that amount of time. If it isn't, then the clutch would be suspect for condition or adjustment.
 
rotorwrench said:
If you set at a stop light for a few minutes with the clutch disengaged and the transmission in neutral, it should be stopped in that amount of time.
Click to expand...

I'm not sure WHY someone would sit at a light for a few minutes.....with the trans in neutral AND holding the clutch pedal down the whole time. Surely does the throwout bearing NO good. DD
 
V8COOPMAN said:
I'm not sure WHY someone would sit at a light for a few minutes.....with the trans in neutral AND holding the clutch pedal down the whole time. Surely does the throwout bearing NO good. DD
Click to expand...

I think it was Walt Dupont that mentioned to us that it also puts pressure on the thrust bearing. Think as you press the clutch, you're pressing on the end of the crank too. He said always idle in neutral when waiting. Makes too much sense!
 
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