'35 Gear Grinding in 1st & Reverse

[AnthonyG]

As stated by others if gear oil level is low the viscosity change as the oil heats up could be an issue. Check the tranny oil level first when / if correct if it still is doing the same it could be too much free play regardless of what the manual says. You indicated your using a later engine and I would suspect if previous owner upgraded to a newer engine probably upgraded to a later tranny as well. I did on my '35 ( went with a '39 tranny ) this requires some changes ( custom tweaking of a link or two ) to the clutch linkage enough that you may have to play with the free play to get it right. Again obviously predicated on whether the tranny is of a later variety. Remember half the fun is tweaking them.

[Mart]

The shift it into 2nd thing is a bit of a work around that may be masking a dragging clutch. If you press down the clutch pedal and wait just a few seconds you should be able to engage first or reverse with just the faintest snick as it goes in. If you try to quickly, yes it will clash.

If you press down the pedal and the clutch never really does disengage, it will always clash. Using 2nd first helps overcome this, but does put extra work into the 2nd synchro.

Here's how you test to see if your clutch is releasing or dragging, but it is not for the faint hearted.

With the engine running, move (carefully) the gear lever towards reverse. Don't ram it in, what we are trying to find is the point at which the gears are just touching and making a noise. Use both hands so you have better control. Hold the lever there and start to press down the clutch pedal. At some point the noise will stop. Hold the clutch there and put the lever back in neutral.

Now. this is where you have to make a judgement. You have to gauge how far off the floor your foot is. If you press down and have a good bit of movement before you touch the floor that is good. If you find you have hardly any movement before you hit the floor, that's not so good. What is worse, though, is if you reach the floor before the grating noise stops.

So, the question is, does the noise stop? If so how far off the floor. If it does not stop then it may just be a matter of adjustment.

If it should release, (the adjustment is correct) but it drags, then the lining or centre may be breaking up, or the linings are contaminated with either engine oil or gearbox oil. If the lining or centre breaking up it wouldn't be temperature related (I guess).

The clashing gear technique is a genuine process used in the auto industry (well it was 30 years ago).

If you could do the test (like I said, with care) and report back what you find that would be interesting.

Mart.

[rotorwrench]

Originally Posted by V8COOPMAN

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

Just like Marts Idea, it is troubleshooting. It's not something to do every time you stop the vehicle and it doesn't have to be for a stop light either. It could be on the side of the street or your own drive way. Jeez.

There could also be something going on with the pilot bearing. You have to find out somehow, what ever it is.

[Scott754]

Originally Posted by Mart

The shift it into 2nd thing is a bit of a work around that may be masking a dragging clutch. If you press down the clutch pedal and wait just a few seconds you should be able to engage first or reverse with just the faintest snick as it goes in. If you try to quickly, yes it will clash.

If you press down the pedal and the clutch never really does disengage, it will always clash. Using 2nd first helps overcome this, but does put extra work into the 2nd synchro.

Here's how you test to see if your clutch is releasing or dragging, but it is not for the faint hearted.

With the engine running, move (carefully) the gear lever towards reverse. Don't ram it in, what we are trying to find is the point at which the gears are just touching and making a noise. Use both hands so you have better control. Hold the lever there and start to press down the clutch pedal. At some point the noise will stop. Hold the clutch there and put the lever back in neutral.

Now. this is where you have to make a judgement. You have to gauge how far off the floor your foot is. If you press down and have a good bit of movement before you touch the floor that is good. If you find you have hardly any movement before you hit the floor, that's not so good. What is worse, though, is if you reach the floor before the grating noise stops.

So, the question is, does the noise stop? If so how far off the floor. If it does not stop then it may just be a matter of adjustment.

If it should release, (the adjustment is correct) but it drags, then the lining or centre may be breaking up, or the linings are contaminated with either engine oil or gearbox oil. If the lining or centre breaking up it wouldn't be temperature related (I guess).

The clashing gear technique is a genuine process used in the auto industry (well it was 30 years ago).

If you could do the test (like I said, with care) and report back what you find that would be interesting.

Mart.

Mart, I tried the test you suggested. When the noise stopped, I had very little movement before the pedal hit the floor. I tried a couple times to make sure it was consistent; it did stop the noise, but I'd estimate I had approx 1" before the pedal hit the floor. Does this sound like an adjustment issue? If so, do you mean adjusting the free-play of the clutch pedal to have less play? Thanks

[Mart]

More or less, yes.

Try taking a little free play out. But be sure that there is some free play remaining. One other thought - do you have multiple layers of carpet and mats in the car? Sometimes old cars get so many mats and things thrown in there it can limit pedal travel.

If the noise is stopping, the clutch is releasing. Maybe practice pressing the clutch down smartly all the way to the floor then after a count 1,2,3.. select first or reverse. You might be able to arrive at a count number that is acceptably short without excessive noise.

Mart.

[Scott754]

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I replaced the trans fluid with 80W-90 GL4 and while it was on the lift I adjusted the clutch pedal to reduce free play. I drove the car approx 30+ mins to see if the grinding went away when the fluid was hot... and I didn't experience any grinding when shifting into reverse or 1st, so either the fluid or adjusting the free play seemed to have worked/helped. I probably should have tried it after changing the fluid before adjusting the free play to see if the fluid did the trick, but I don't have my own lift so while it was on the lift I did both. I may have over-corrected the free play because I had 1-1/2" of free play and after the adjustment I have very little (almost no) free play. I know earlier posts said I need some free play to keep it from slipping in higher gears, but since this adjustment may have helped with the grinding, as long as I don't have any slipping, is it ok to leave it with no free play or does that cause some other issues or wear on 2nd/3rd synchro? If I need to I could adjust it so there is some free play.

[Bob C]

With to little free play you may not have noticeable slipping but the throw out
bearing could be turning which is not good.

Bob

[Mart]

You need to strike a happy medium. Some free play, but not grinding either. Having no free play will make the clutch slip. When driving at speed just tentatively put your foot on the pedal and see how much pressure you can apply before the clutch slips. If it slips with only a slight amount of pressure applied, then you really do need to add more free play before driving much further. If you have to apply lots of pressure (like normal) then chances are the adjustment is ok. You're the "man on the ground" you have to make the judgement.

Mart.

[funrunr]

I'm not familiar with 35's, however on my 40, I was able to adjust my pedal by removing my wood floor board, no hoist needed. It would've been easier with a hoist though. Perhaps it might be worth looking into.

[V12Bill]

Had a similar problem with a throw out bearing that was going bad.

[supereal]

One of the main causes of gear grinding is an idle speed that is too high. Reduce the speed as low as you can until the motor lopes, then raise it just enough to get a smooth idle. Using 140W gear oil also helps.

[Bluebell]

As the original poster said it only happens after 30 minutes of running, I have a question that is from a different angle.
How fast is the engine idling at when it's hot?
If your throttle spindle is worn, or the butterflys are worn, (or for what ever other reason) Is this engine running a bit fast causing the clutch arm counterweights to make the dis engagement more difficult. Isn't it a known characteristic with these Fords with Long pressure plates?

[Scott754]

Originally Posted by Bluebell

As the original poster said it only happens after 30 minutes of running, I have a question that is from a different angle.
How fast is the engine idling at when it's hot?
If your throttle spindle is worn, or the butterflys are worn, (or for what ever other reason) Is this engine running a bit fast causing the clutch arm counterweights to make the dis engagement more difficult. Isn't it a known characteristic with these Fords with Long pressure plates?

I don't think my engine is idling fast when it gets hot; I don't have a tach on it to know exactly, but by sound & feel it seems to be idling normally. When I was experiencing the grinding I was careful to make sure I had let the engine slow down before trying to put it in 1st or reverse.