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Down shift problems


Jonas720

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Ok so my 84 720 has some problems. When I drive at high revs it's impossible to shift without grinding the gears. If I drive slow it's no problem. Also If I have do down shift it's impossible! Is my clutch done??? I tried adjusting the clutch and nada!

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Down shifts like going from 4th to 3rd? Most likely the syncros are worn. If so you can either drive it with the noise, or replace the transmission which is cheaper than fixing it.

 

 

If I drive slow it's no problem.

This suggests the clutch is not the problem.
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Place in neutral idling, then depress clutch and shift slowly into reverse. Does it grind? If there is a steady light grinding as you shift then the clutch disc is dragging and/or the PP is damaged.

 

Down shifting to slow the vehicle is a racing maneuver to help extend brake life during a race and is totally not needed on the street. On a street car replacing the brakes is much easier than the transmission. Car and truck engines are designed for lots of low speed torque so you can drive them slowly in higher gears. The lower the speed the easier it is to down shift when you really need to.

 

What you can do is learn to 'double clutch'. This is a shift into neutral, let the clutch out, rev the motor to speed the counter shaft up, depress the clutch and down shift and let the clutch out. Increasing the counter shaft speed more closely matches the speed of the next lower gear and makes the job of the synchro rings much easier. Takes some practice and hand/foot coordination and should be done 'smartly' before the counter shaft slows back down, but easy enough to do. Best to avoid high speed down shifts all together.

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This is also very true. Lack of hydraulic clutch pressure won't allow the PP to fully disengage the clutch disc. Hydraulic fluid should be changed every 3-5 years anyway. Bleeding it won't hurt anything.

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What would I do without ratsun????

 

1st Buy a owners manual then read it multiply times naked!!! then ask a old guy thaen get your friend to help then try it out. then when dont work buy another car.

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