Shift Problems

#1 05-21-2004, 07:00 PM

My transmission has just started to act up. When I am cruising along in 4th, all of a sudden it will down shift into 3rd for no reason. I dont notice it slipping, it will just donw shift. Does anyone have any ideas. I hope the tranny isn't going, I definatly dont have the money for that now. Please help.

drivemusicnow · #2 05-21-2004, 10:02 PM

ummm from what i understand either the tranny resister/ Shift kit from small car, or a band adjustment can correct that... not sure which one, but i know the feeling you have right now, and want to say that i don't believe it to be a dying tranny sign.

#3 05-22-2004, 08:06 AM

If it is the bands, how do I tighten them? Is it a hard job to do, or am I better off taking it to a shop and having them do it?

I'm not sure if the shift kit would solve this problem. It is my understanding that the kit disables the shift soliniod resistor under ligth to medium throttle, and only enables it when the vaccume goes below a set point. My SVX will upshift under light throttle. Please let me know what you think, if the kit will help, I will buy one.

Thanks

UberRoo · #4 05-22-2004, 11:30 AM

Are you sure it's downshifing? The SVX kinda has this fifth gear: torque converter lockup. It's usually very subtle when it locks up, but it's pretty obvious when it unlocks. When it unlocks, it feels very much like a downshift.

The next time you think it's downshifting, pull back on the shift lever to manually put the car in third. If it shifts again you weren’t really in third, but just in fourth without lockup.

The only thing I know of off the top of my head that should cause an actual third gear downshift, is when the transmission overheats. When it gets too hot, it downshifts to get things spinning faster, ATF and coolant moving more quickly, and thus better cooling.

One possible cause is that your gear switch is misadjusted. The shift lever in the center console just operates an electric switch on top of the transmission. If the linkage between the lever and switch is misadjusted, it may not move the switch completely into drive when the lever is in that position. To test this the next time it downshifts, slowly move the shift lever into neutral and see if it goes back into fourth.

The shift kit will not help.

#5 05-22-2004, 12:28 PM

The transmission is deffinatly down shifting. I tryed down shifting into 3rd before, and the rpms dont change. I could understand the cooling problem, but it will only shift into 3rd for about 10-30 seconds, then it shifts back into 4th. If I let off the trottle it will shift back into 4th too. I cant see it down shifting into 3rd for 30 seconds realy helping cool the tranny down. Any more ideas?

UberRoo · #6 05-22-2004, 02:28 PM

The faster the engine and transmission turn, the faster their ATF and water pumps spin. The faster the pumps spin, the more coolant and ATF they pump through the radiator. I don't know how significant this is, but apparently Subaru though it made a difference, so they programmed the TCU to do this. Is thirty seconds long enough? I don't know. It depends on how sensitive the sensors are and how effective the cooling system is.

If letting off the throttle allows it to shift back into fourth, then it's almost certainly not an overheating problem. (You'd also probably get the "Hot ATF" light.)

Whenever the TCU detects a problem with either shift solenoid, it automatically disables both of them, which locks you in third gear. When it does this, it will generate a code and store it in memory. There are other reasons it will disable the solenoids, but I don't know of any list of reasons, so just check the codes.

Don't forget about the possibility of misadjusted linkage.

oab_au · #7 05-22-2004, 06:20 PM

Hi, The transmission will downshift from 4th to 3rd if the band is released or is slipping.

This is the same problem that Lee has been having for sometime. If the band does not slip, when it is kicked back from 3rd to 2nd, then it may not be adjustment. If it does then a band adjustment could fix it.

I tend to think it has more to do with the throttle position sensor, or related responses. The throttle signal controls the line pressure, that clamps the band. If the throttle signal drops low, because of a open circuit spot, then the line pressure follows, and the band may slip, then the transmission goes back to 3rd.

The best way to check is to have a line pressure gauge conncted, to show the pressure, as this event occures. This would narrow it down to either the line pressure droping or some other obscure cause. This is best done by a transmission shop.

Harvey.

#8 05-23-2004, 11:12 AM

Hey thanks for the input guys. I guess I will have to take it to a shop. Would I be better off going to a dealer, or to a transmission shop. I know the dealer charges an arm and a leg for any repairs, but I want it done right.

oab_au · #9 05-23-2004, 06:02 PM

Quote:

Originally posted by xtremeSVX
Hey thanks for the input guys. I guess I will have to take it to a shop. Would I be better off going to a dealer, or to a transmission shop. I know the dealer charges an arm and a leg for any repairs, but I want it done right.

Don't know the area, some member in that area may know a good one. An auto transmission shop that is aquanted with modern boxes would be able to troubleshoot it.

Harvey.