jackalope

When Im driving, and I downshift, should the front end get kind squirrilly? It happens just about anytime I downshift from speed, say going fifty, downshifting from 5th-4th, or 4th-3rd (passing)

same happens just about anytime there is a large rpm change.

Is this somethign I shoudl worry about, or is it natural for our cars to jerk around a bit when downshifting? I almost hit a truck I was trying to pass when I downshifted because the car jerked to the right when I shifted to 3rd, so I've gotten a little nervous about this



also, I have always been told to downshift when I am going to stop, using the engine to slow th car down as well as the brake. is this okay, or should I just rely on the brakes by themselves?

HvRRZ

wow I have never experienced my car jerking around on a downshift, strange. As far as downshifting while braking, that's only done so your engine and brakes work together in braking, so that the stress on them is less.

Fongu

Are you blipping the throttle while downshifting? You must rev-match when you change gears or it is a very jerky ride.

If you don't match the higher revs required for the lower gear the car will "jerk" when you let the clutch out. The engine speed will be slower than the transmission speed and the clutch will slip/grab which will cause the engine to rev higer and the back wheels to speed up. If this is severe enough and/or the road is slippery you might even spin the rear tires and cause the back end to wag.

bliss at 9k

^^^He is correct. If you don't match the revs the car will get unsettled and cause the car to get upset and move around on you. For correct downshifts practice heel and toe...

S2kracka

Like the others said, you must rev-match when downshifting. I do not like downshifting to slow the car down, it wears your clutch a lot faster. Unless its a real emergency, just use the brakes....pads are cheaper than a clutch.

ZSAK

also check tire preasure, ive noticed the car jump around more with low tire preasure while shifting

HvRRZ

but he said going speed of fifty, and down from 5th to 4th. it should not jerk at those speeds from fifth to fourth even without rev-matching.

xviper

Go try it sometime. At 50 mph, your engine speed in 5th is what ............. about 3500 to 4000 or more? Now, drop it down to 4th, lift off the gas and don't touch it, drop the clutch rapidly with the gas pedal untouched. Tell me if you jerk.
You are letting the clutch out when the engine is at idle (less than 1000 rpm), you are slamming the clutch out and immediately putting the revs up to around 3000 rpm (80 mph in 4th gear).

Nobody

Engine makes you go. Brakes make you stop.

HvRRZ

yes but what does that have to do with his front jerking. I know what it feels like, but it's the back wheels that lock up. Unless it does it while ur turning then i understand why you feel the the car slide.

and ok so im in 5th going 50 at .....3500.. then i go to 4th and stay off the gas and drop the clutch and the rpm's go up to what....4200. the difference isn't enough to jerk the cars front to the side to where it's hard to control.