downshift grindd

00GTpony

Member
Mar 10, 2007
162
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Ok so all the sudden my car wont let me downshift into second without it grinding like crazzzzzyyyyy... if i want to down shift into second it will go in but with a rele bad grind and clunk. If im driving normal i can shift 1, 2, 3, 4, fine. Its only downshifting. What do u guys think.

Fluid Problem?

Rebuild?

- also i had just raised the idle on my car with the diablo from 700 to 900.. could that be why?
 
Clutch probably isn't disengaging all the way. The higher idle RPM shouldn't be an issue. See if you can adjust it. Depress the pedal then lift up toward you with your toe. You may hear a click when it adjusts. If it doesn't help it could be that it is already adjusted all the way. As the cable gets older it will stretch. You could get a new cable or a firewall adjuster.
 
Clutch probably isn't disengaging all the way. The higher idle RPM shouldn't be an issue. See if you can adjust it. Depress the pedal then lift up toward you with your toe. You may hear a click when it adjusts. If it doesn't help it could be that it is already adjusted all the way. As the cable gets older it will stretch. You could get a new cable or a firewall adjuster.
:Word:
And make sure you are rev-matching.
 
i'm having the exact same problem but with higher gears...when i downshift from 5th to 4th it will grind every once in a while....i got a new clutch cable and firewall adjuster maybe i need a new clutch??
 
:scratch: i would assume he means when going from say 4-3 to give it a little gas to bump the rpms up to where they should be for that gear compared to the mph... less stress on the clutch i would guess but would it make that much of a difference?
 
It makes all the difference in the world. It does a few things. One, its a road racing trick, it avoids upsetting the balance of the car when down shifting. Not much use on the road, but makes the shifting smoother. Two, the clutch and the syncros take the brunt of the force when a down shift occurs when the engine is spinning slower then the drivetrain. Rev match will match the RPMs of the rest of the drive train saving the syncros in the transmission. Ever drop from 5th to 3rd on the highway? yeah your syncros took a hard hit. Try hittin 4k, then hitting 3rd.
 
what ya mean rev match?


Blip the throttle so that when you let the clutch out while downshifting the flywheel and clutch are going to the same speed.



For example, on my car, the gears are roughly 1000RPM apart. 3000RPM in 2nd would be 2000RPM in 3rd.

So i'f i'm doing 2000RPM in 3rd and want to downshift to 2nd, i'll push the clutch in, shift to second and blip the throttle up to about 3000RPM and then let the clutch out. If i do it perfectly. you don't even feel the shift and only the change in RPM's gives you a hint i've shifted.
 
So i'f i'm doing 2000RPM in 3rd and want to downshift to 2nd, i'll push the clutch in, shift to second and blip the throttle up to about 3000RPM and then let the clutch out. If i do it perfectly. you don't even feel the shift and only the change in RPM's gives you a hint i've shifted.
Yep, and your synchros will thank you if you can blip the throttle as you are moving the shifter.