QuestionQUESTION: I have a 1970 Midget that grinds terribly when I try to put it into 1st or reverse. It will shift fine for a few miles then will start to grind in those two gears. I bled the clutch a dozen times over and over and pulled the engine and trans and replaced the clutch and release bearing. The slave cylinder push rod appears to be operating well. Shifting from 2nd to first does not help the grinding at all. It grinds so much I can't even get it into gear (I know I have to be fully stopped). Could my problem be in the gear box or should I start replacing the slave and master cylinder?
Joel
ANSWER: Hi Joel,
You shouldn't replace anything until you find what is wrong.
It is obvious that the first motion shaft (that the clutch disk rides on) is spinning with the engine and not stopping when the clutch pedal is depressed.
You said you replaced the clutch and release bearing. Did you replace the pressure plate too? and did you check the pilot bearing? Next question, when it grinds does the clutch pedal have only about an inch of free play and then feel firm right away and feel the same all the way to the floor? and is the idle below 900 RPM and are you waiting a few seconds after you depress the pedal before you try to put it in gear?
Do this, After it is warmed up and is grinding going into 1st/reverse shut the engine off and on level ground and the brake off, put it in 1st or reverse and hold the pedal to the floor and start the engine and note if the car tries to creep any. If it does shut it off again and pump the clutch pedal several times and quickly start it up again and note if it creeps. One more, with it warm and idling below 800 RPM pump the clutch several times quickly and quickly try to put it in 1st gear. If it goes in easily get a slave and master cylinder and use DOT 4 brake fluid.
Howard
---------- FOLLOW-UP ----------
QUESTION: With my inexperience and just a hobbyist I did not look at the pilot bearing and honestly am not sure were it is located exactly. Is it also referred to as the pilot bushing? I replaced the gear ring on the fly wheel and had it resurfaced by my local machine shop. I replaced the clutch parts with a standard 3-in-1 clutch kit.
When cold I can start it in or out of gear and shift fine. After it is warmed up, it will grind if I start in neutral and try first or reverse. It will only creep forward if I try to start it in gear when it is warm. My RPM's are below 800.
:( I did find a ball bearing on the floor that could have come from anywhere. I replaced the rear seal on the transmission and had the transmission standing on end. I thought it either came from the donor car or the gear shift area.
Joel
AnswerHi Joel,
The clutch kit (3-in-1) is the clutch disk, pressure plate and release bearing so that is ok. The pilot bearing/bushing (terminology thing)is the bearing/bushing in the back of the crankshaft that supports the front of the First motion shaft/input shaft (another terminology thing)
You can't 100% rule out a pilot bushing/bearing as the cause but the fact that it seems to be a warmed up / cold system it is less likely so you need to search elsewhere.
Another factor is in place. It could be dragging all the time but when gearbox oil is cold it is very hard to rotate the gears and when a clutch pedal is depressed that cold oil stops the input shaft from rotating and thus it can be put into gear and as the gearbox oil warms up it can no longer hold all the gears still so that it can be shifted into a non syncro gear (1st & reverse)
After the engine is warm let it idle and then pump the clutch pedal several times and then hold it all the way to the floor and quickly see if it will go into 1st. One more thing, after it is warmed up and you have not touched to clutch pedal push the pedal down with your hand and note the amount of free play before it hits the firm section. (should only be about an inch or so) Then continue to push it to the floor and note that it is suppose to feel hard to push as soon as the free play is taken up and it should feel the same all the way to the floor. Now, have someone pump up the pedal several times and quickly feel the pedal by hand again. (note free play and hardness to push again) Let me know the results.
Everything is pointing toward the hydraulic system as the problem and that is all that is left of the system.
Some people accidently warp the clutch disk when installing a clutch but a warped disk drags all the time not just when it is warmed up. A normal car will give a slight crunch when shifting into 1st / reverse if the driver don't wait a couple of seconds after depressing the pedal before putting it into 1st / reverse. This is normal because the driver didn't wait for the gears to coast to a stop before engaging 1st/reverse. But because you get a "Creep" of the car starting in gear with the pedal down this is not the case here. That was the reason for that test. After you get this fixed you should read my tech tip on how to make a standard transmission last. http://mg-tri-jag.net/tech4.htm
As for your single ball bearing, there are single ball bearings in the gearbox but only in the shift tower and shift linkage and have nothing to do with clutch drag.
Let me know,
Howard
