Grinding sound when shifting
#1
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Grinding sound when shifting
So i noticed today and yesterday (thanks scionfred for helping with the header) That when i shift down in my automatic I.e engine brake. when i get to 2nd down to first. I hear this very odd grind noise from right underneath the pedals. or if i put it in reverse and accelerate. Its real quick. Anyone have any ideas, I have a header/cat/intake and all that but i dont think that would effect my tranny?
If i can i will get sound. Shifting up its only happened once. but def 2nd to first is a nice big grind n vibrate through the pedal area.
If i can i will get sound. Shifting up its only happened once. but def 2nd to first is a nice big grind n vibrate through the pedal area.
#4
Actually, within limits, shifting really won't affect the life of the tranny appreciably. The ATF fluid controls most of the transitioning between the gears in an automatic, yet it is possible to wear the physical parts of the tranny out. IMO, make sure you switch to a good quality fluid.
When I had a grinding like that before it was the A/C clutch.
When I had a grinding like that before it was the A/C clutch.
#6
well, in general, you don't downshift to 1st gear until you come to a stop. 1st gear is a very powerful gear there to get the car off the line from a complete stop. in the 5 speed tc, there is actually a gear guard to keep you from getting into 1st gear at too high of a speed, and it is very hard to get into unless you are nearly stopped. when you're engine braking a manual tranmission, you usually coast in 2nd gear until you come to a stop, and then put it in 1st gear.
my mom's subaru legacy gt has a 5 speed sport shift auto, and 1st gear in that car is very low, on it's own, the car actually starts in 2nd for normal driving it seems. anyway, the sport shift in the auto xb is really just a stupid add on that i really think toyota just added on because people wanted it and think it is better when it isn't. if you want to change your own gears, get a manual, if you don't, get an auto and then live with the buyers remorse for the rest of your life.
my mom's subaru legacy gt has a 5 speed sport shift auto, and 1st gear in that car is very low, on it's own, the car actually starts in 2nd for normal driving it seems. anyway, the sport shift in the auto xb is really just a stupid add on that i really think toyota just added on because people wanted it and think it is better when it isn't. if you want to change your own gears, get a manual, if you don't, get an auto and then live with the buyers remorse for the rest of your life.
#8
2nd to 1st should be done at a stop, or very low speeds, ie <10MPH if you really have to. Better to just leave it alone and let it do its job.
Also read my post in this thread: https://www.scionlife.com/forums/sho...d.php?t=162168
Also read my post in this thread: https://www.scionlife.com/forums/sho...d.php?t=162168
#10
Its not really a sequential shift transmission. Its just a plain old automagic slush box with a shifter that shifts +1 -1 at a time. Just like your grandma's Camry has D/3/2/L etc, the Scion only differs in appearance. You could do what the Scion does by going from D to 3, then one more to 2, then to L. The Scion's shifter is just another way of downshifting when going down a hill, etc.
Not to be mistake for a Porsche DSG or similar, actually built for high-performance driving.
Not to be mistake for a Porsche DSG or similar, actually built for high-performance driving.
#13
Could be some motor mount windup making something rub or you have a bad first gear or clutch - check your tranny fluid for darkness or tiny metal flakes. Downshifting an automatic should not be a problem since the gears are always meshing and it is just the clutches taking a little wear.
Try keeping it in first gear and accelerate and decelerate while getting the engine up to 4k rpm and see it it still makes the same noise - that would indicate it is the gears and not the clutch since the clutch would be constantly engauged . . . unless the clutch is slipping.
Try keeping it in first gear and accelerate and decelerate while getting the engine up to 4k rpm and see it it still makes the same noise - that would indicate it is the gears and not the clutch since the clutch would be constantly engauged . . . unless the clutch is slipping.
#15
#17
I totally agree with the idea that one should never shift from 2nd to 1st unless the car is essentially stopped -- shifting it at 5 mph is still too fast. Also, you should never select 1st gear for engine braking. 2nd is the lowest that should ever be used in that fashion. Be nice to your car and your wallet, only use 1st for pulling out from a stop, nothing else.
#18
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I totally agree with the idea that one should never shift from 2nd to 1st unless the car is essentially stopped -- shifting it at 5 mph is still too fast. Also, you should never select 1st gear for engine braking. 2nd is the lowest that should ever be used in that fashion. Be nice to your car and your wallet, only use 1st for pulling out from a stop, nothing else.
#19
Geee I go down my friend's driveway in Vermont that's about 900 feet long and in first gear it revs to about 4k - I'm talking steep - going up I am spinning the wheels most of the way up going 15-20mph in a manual tranny. This is second gen with more HP and the tranny should be able to handle a little deceleration without breaking apart since engine braking puts no where near the load on the gears as acceleration does.
The tranny dipstick should be to the driver side of the engine compartment - Engine oil dipstick to the passenger side.
The tranny dipstick should be to the driver side of the engine compartment - Engine oil dipstick to the passenger side.
#20
The question isn't referring to allowing the engine to provide braking when in first gear, but rather, deliberately downshifting into first for the purpose of using engine braking. If more braking is needed while in second, then apply the service brakes. Shifting down to first for engine braking isn't normally a good practice for either automatic or manual transmissions. You can't even expect to have the necessary gear synchronization to support that shift. It's just not a normal design intent for first gear.
PS. The true purpose of down shifting for engine braking is to protect against service brake heating, which can result in fading and possibly brake failure. It takes very little additional brake to augment second gear (no overheat risk), and so there's no practical advantage to selecting first gear for engine braking -- and so the design doesn't typically support it.
PS. The true purpose of down shifting for engine braking is to protect against service brake heating, which can result in fading and possibly brake failure. It takes very little additional brake to augment second gear (no overheat risk), and so there's no practical advantage to selecting first gear for engine braking -- and so the design doesn't typically support it.
Last edited by TrevorS; 08-30-2010 at 04:56 PM. Reason: added PS.