65 4-speed transmission

[brumbach]

When I shift to third gear (normal driving), I hear a groaning noise. The noise is NOT a gear raking sound that one would experiences when a synchronizer is bad or going bad. It's more of a moan or groan sound that seems to only occur when I've been driving for a while in a hot humid environment. Never hear it during the winter months. Any idea what might cause this? Thanks -- Bill

 

[JohnZ]

What kind of trans lube are you using?

 

[brumbach]

I've only owned the car for a couple of years and have only checked levels at this point. Not sure what the previous owner used. Do you think this might be be problem? I can drain and refill. What transmission oil do you recommend?

What kind of trans lube are you using?

 

[rohard]

I use Penzoil 80-90 multipurpose gear lubricant.

 

[brumbach]

Thanks. I'll change the gear oil and see if this takes care of the noise. If not, I'll ask for more advise. Bill

 

[brumbach]

Well I changed the tranny gear oil and the noise continues. I'm thinking the noise is related to the clutch. After the car achieves running temp, I can depress the clutch while in gear and rev the engine and hear the groaning noise. If I shift the car into neutral while on the move and keep the clutch depressed and rev the engine there is no noise. The clutch was replaced at the time I purchased the car two years ago. I've not driven the car more than 3000 miles since purchase. The shop seemed reputable, capable, etc., but they're 5 hours from my location. Returning it to that shop to resolve is not feasible. I can have a local mech look at it but would like to have a good idea of what the problem is before seeking professional help. Any ideas as to the cause? Keep in mind, this noise only occurs when the outside temps are hot. Absolutely no problems when operating in the cooler temps of fall, winter and early spring.

 

[JohnZ]

Symptoms are confusing - you say if it's in gear and you depress the clutch pedal, you hear the groan - is that with the car stationary, or on the move? Then there's no groan when you're on the move and put it in neutral and depress the clutch pedal? And it only occurs when everything is completely warmed up, never when it's cold? Weird...

Is your clutch linkage adjusted so you have 1" to 1-1/2" of pedal free play at the top of pedal travel between fully up against the bumper to where you feel resistance from the throwout bearing?

 

[brumbach]

The groaning occurs when moving and not stationary. (Hope readers know we're talking about a car). As for free play, the z-bar immediately engages with any depression of the pedal. I don't know enough about throwout bearing to comment but assume it reacts to the linkage movement of the z-bar.

Doctor, am I giving you enough to go on? I can clearly see where to adjust to create the free play but you best define free play. If this means to enable movement of the clutch pedal without causing movement of the z'bar, then I can handle that.

Bill

Symptoms are confusing - you say if it's in gear and you depress the clutch pedal, you hear the groan - is that with the car stationary, or on the move? Then there's no groan when you're on the move and put it in neutral and depress the clutch pedal? And it only occurs when everything is completely warmed up, never when it's cold? Weird...

Is your clutch linkage adjusted so you have 1" to 1-1/2" of pedal free play at the top of pedal travel between fully up against the bumper to where you feel resistance from the throwout bearing?

 

[brumbach]

Disregard my stupid question regarding free play. I think I get it. With the pedal fully depressed, it will travel approximately 1" to 2" before any resistance is detected. And yes the noise occurs while the car is in motion. Haven't heard it yet while stationary.

Symptoms are confusing - you say if it's in gear and you depress the clutch pedal, you hear the groan - is that with the car stationary, or on the move? Then there's no groan when you're on the move and put it in neutral and depress the clutch pedal? And it only occurs when everything is completely warmed up, never when it's cold? Weird...

Is your clutch linkage adjusted so you have 1" to 1-1/2" of pedal free play at the top of pedal travel between fully up against the bumper to where you feel resistance from the throwout bearing?

 

[JohnZ]

Disregard my stupid question regarding free play. I think I get it. With the pedal fully depressed, it will travel approximately 1" to 2" before any resistance is detected. And yes the noise occurs while the car is in motion. Haven't heard it yet while stationary.

"Pedal free play" is how far the pedal moves (from the fully up position, against the bumper) downward toward the floor before any resistance is felt (which is when the throwout bearing contacts the clutch fingers). The adjustment is on the pedal pushrod where it connects to the top lever on the Z-bar. The linkage MUST be adjusted so there is 1" to 1-1/2" of pedal free play; if free play is not present, the throwout bearing will be in constant contact with the clutch fingers, and the bearing will be fried.

Pedal free play is measured with the pedal fully up, not "depressed", which is down on the floor.

 

[brumbach]

After sending my TWO dump responses earlier, I found "clutch adjustment procedures" and corrected last night as you addressed here. I have driven and there is no more noise. I didn't measure the free play before adjusting. I just followed the procedures as described. I did, however, note that before making the adjustment, that the wheel well was marked where the tip of the adjusting rod was hitting when the clutch pedal was fully depressed. Does this explain what may have been causing the noise? Thanks for the help (and patience). Bill

"Pedal free play" is how far the pedal moves (from the fully up position, against the bumper) downward toward the floor before any resistance is felt (which is when the throwout bearing contacts the clutch fingers). The adjustment is on the pedal pushrod where it connects to the top lever on the Z-bar. The linkage MUST be adjusted so there is 1" to 1-1/2" of pedal free play; if free play is not present, the throwout bearing will be in constant contact with the clutch fingers, and the bearing will be fried.

Pedal free play is measured with the pedal fully up, not "depressed", which is down on the floor.

 

[JohnZ]

Sounds like it - inadequate free play will eventually fry the throwout bearing, and that's preceded by howling and screeching; if the end of your clutch fork or the rod was touching the floor pan with the pedal fully depressed, it was telegraphing the clutch and engine vibration through the floor until you released the pedal. Glad it quieted down for you