01 corolla slams into gear

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651
Location
Chicago
what would cause an auto tranny to slam into gear when shifting from P to R or D? I just flushed the ATF and it still slams. something else must be wrong.
 
Messages
8,756
Location
RI
Yeah, its blown. Sorry, but changing ATF won't rebuild it. If you're lucky, it could be a solenoid(or other electrical issue) or dirty varnished VB. Excessive line pressure, excessive idle RPM, hung up PSI regulator,..... are some causes. If you're really lucky, maybe the tranny isn't slamming. Maybe your entire drivetrain is shifting/banging on broken mounts. What the mileage and maintenance history on your transmission?
 

sky jumper

Thread starter
Messages
651
Location
Chicago
mileage is 60k. no previous trans service. the fluid didn't look that bad coming out. dark red. just to be clear - once it is in gear it drives/shifts fine. it's just getting it into gear that it clunks. putting it back into park is also a clunk - almost as if the linkage is getting hung up or someting. (btw - not my car. its a friend's).
 
Messages
1,527
Location
Southeast United States
Check to see if it has a cable running from the throttle body to the transmission. This (TP) cable controls shift harshness (among other things), and might be in need of adjustment. Many of these cables have a button on top of the mechanism that you can push in, then open the throttle completely, and release the button to adjust.
 

sky jumper

Thread starter
Messages
651
Location
Chicago
aha! I noticed there was a second cable connected to the throttle lever, and it was sticky (i.e. it would pull out as you pressed on the accelerator, but would not go back in). it didn't seem to affect how it ran, so I ignored it. (I thought it had something to do with cruise control, which I consider non-mission-critical). great clue ranger. thanks.
 
Messages
8,756
Location
RI
Typically cables/rods connected to the TB/carb don't affect shifting into D from N or P. They will affect shift point and harshness during upshifts and downshifts while driving which you said was fine. I would also assume that by 2001 that the controls were electronic referencing TPS and VSS. You need to reference the factory service manual for debug of that issue. And, did you flush the transmission(full capacity) or did you do a drain refill using the drainplug? What fluid?
 

sky jumper

Thread starter
Messages
651
Location
Chicago
I did flush the full capacity with Penzoil DexIII, which is the spec. I first drained the pan, filled, and then pumped out the cooler line. also, while checking the OBDII codes I took a quick look at the live sensor data and noticed that the TPS value never went to 0%. it did go up when you pressed on the accel, but would only go down to about 9%. the car idled at about 700rpm. there were no trouble codes. thanks for the replys.
 
Messages
8,756
Location
RI
Factory fill was DexronIII? 60k miles was definitely pushing it. I'd drop the pan for varnish inspection, and that would be a good time for a filter kit. If pan drop is out of the question, throw in a bottle of lubegard, gunk, or smartblend, ATF protectants. And, in the future start a regular drain/refill regimen.
 
Messages
102
Location
Vaughan
TPS at 10% is normal for closed position. Have you checked your motor mounts, the torque rod, and trans mounts?? there should be slight give, in all directions. But not excessive motion in any one direction (forward more than back) Drop the pan again and take off the valve body and clean it properly.
 

sky jumper

Thread starter
Messages
651
Location
Chicago
I didn't check the motor mounts, etc. but something tells me that's not the prob. I'm not a tranny expert, but it's almost as if the clutch is already engaged when you go to shift, and it just slams into gear. my simplistic understanding of a tranny is that when you move the gear selector it disengages a fluid clutch or something (which then reengages when you select a gear). i'm sure I'm overlooking many complicated things. auto tranny are black magic to me. I'm still suspicious of that limp/lame cable connected to the TB. if it were my car I'd certainly drop the pan and do the filter. since it's not I am cautious about doing too much.
 

sky jumper

Thread starter
Messages
651
Location
Chicago
ok - I've learned that this tranny has a "throttle valve cable" that runs from the TB to a throttle valve inside the tranny, and it connects to a "detent spring" inside as well. this is the limp/slack cable I am talking about. I think the detent spring is broken, which is why the cable does not retract. I'm assuming this is the cause for the harsh engagement. does anyone have specific experience with this? how much to have repaired? thanks.
 
Messages
13,232
Location
ROCHESTER, NY
SKY, Although you have probably ruled this out already but, also check your idle and make sure that it isn't too high when going into gear from P or R.....I've had similar issues with Corollas' and the base idle was the cause and I didn't notice it because the engine was still so smooth and quiet while idling. Just my .02
 
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