atoyot

while we are on this, is this the same method for a 00'? My car shifts too soft for me and holds a gear too long. I was thinking this is the exact adjustment i need to do, but i looked under the hood for a brief second the other day and didn't see the tranny cable?

3UZFTE

Wait... What? This isn't a trick... This is called the kickdown, as almost all non-electronic controlled transmissions have them to control the line pressure to be able to downshift correctly. There is a proper adjustment for it on TIS. If it is too loose it won't down shift on WOT, and if it is too tight it will try to down shift every time you touch the gas. It doesn't really make the transmission last any longer, what takes out trannys is heat.

PD would know, but I think in 98' the ECU controls the transmission completely, like my GS430. Everything is electronic,the kickdown and shifts, all it is doing it reading a number of sensors such as throttle position, etc., to apply a certain amount of line pressure to achieve the shift. The more line pressure, the harder the shift. I'm not really a genius, so I won't play one here, this is just what I learned in T10.

PureDrifter

iTrader: (10)

the 98 and up transmissions (A650E) are completely electronically controlled. there's afaik an electric kickdown switch, not cable.

atoyot

OK, that's what i was thinking. Mine does not seem to shift correctly. It seems to hold the gear long and then slip into the next gear. Plus, if i need to get on it for any reason, it doesn't want to kick down a gear.... then all of a sudden it will kick down two gears!

it's really weird in a parking lot. If i'm easing along and it's about to switch gears, and i come to a stop sign or light, it will then slam into a lower gear.

Checked the fluid and it is fresh and full. I may just do a fluid exchange as i don't believe in flushes.

PureDrifter

iTrader: (10)

did you try resetting the ecu, and reteaching the ECU? look for a link in the UCF2x faq in the OG sticky

willhickey

iTrader: (1)

I dont understand how firm shifts would make your transmission last longer , would somebody please explain for me

Zoidberg

sam12345 & PureDrifter were saying earlier that the same basic procedure applies to adjusting the cruise control cable.

Is it likely this cable needs an adjustment after 17 years?

Is there a tutorial for this?

My cruise works fine, but I use it a lot.

LiCelsior

iTrader: (32)

its actually recommended that u beat on the car for a little bit to give your AT a nice workout.

sam12345

iTrader: (1)

Not true I have it on the soft setting and it down shifts just fine. Yes, at wot it uses the cable to down shift but it will down shift. It is also adjusting the trans pressure to throttle position, therefore when the throttle is partially open and you do a 2 to 3 k shift the pressure is less if you adjust in the soft position so the shift is softer. At WOT you got max pressure regardless and it will down shift.

sam12345

iTrader: (1)

BTW look at the position I have it adjusted. Almost to the complete soft extreme and it down shifts same as before. And yes the shifts are softer. So please don't make a statement without knowing the facts.

As far as why do soft shifts make your transmission wear faster is because it takes more time for the clutches to engage therefore slipping longer therefore wearing quicker. How much quicker I have no idea but in theory it should wear quicker just like slipping a manual clutch too much when shifting.

sam12345

iTrader: (1)

On the cruise control I just reduced some of the freeplay when the throttle is in idle position. But make sure you leave some free play. Same with the throttle. I have an annoying issue with the cruise control in that when I am on cruise going down a long hill , even though the speed is steady, it feels like someone is letting completely off the throttle and then engaging the throttle on and off instead of a nice smooth feel. I thought reducing the free play a little may help, theory being that is was releasing the throttle completely and that due to the long free play it would have a delay re-engaging. I have not noticed much of a difference.

3UZFTE

I am sorry, I am not a genius, but I didn't spend a semester learning about Toyota transmissions for nothing. But when you say, "I have no idea, but in theory...", I feel compelled to say something, as I do have an idea and theories that required much skill and research. All your doing is adjusting the rate at which the the pressure is applied to achieve the downshift. Yes, it will downshift, it is an electronically controlled transmission. However, it is just that a kickdown. If you were able to present facts other than it feels soft, and I think that it wears it less, I could appreciate some new thoughts and theory. That being said, what controls the firmness of shifts are the shift solenoids and accumulators. Which is why I shimmed my accumulators for a firmer shift... Throttle pressure overcomes governor pressure, thus achieving your downshift... And if your adjust the throttle pressure at the throttle body looser, your simply reducing the amount of throttle pressure at any given time, thus reducing the ability for throttle pressure to overcome governor pressure, therefore... reducing the ability to downshift. This isn't to say your car will never downshift, it appears like its adjust ok, I am just stating that isn't controlling anything other then the throttle pressure to achieve downshifts. I know you mean well, but please... understand the facts before you make the statement.

sam12345

iTrader: (1)

While the primary function of the cable is for shift downs The cable adjustment adjusts the line pressure to throttle position relationship. The solenoids give the line pressure to the clutches. Less line pressure less pressure on the clutch softer shifts. And yes my shift is softer and it is not my imagination.

From http://www.autoshop101.com/forms/AT11.pdf


"The throttle cable is adjustable on all transmissions. And in each case it controls throttle pressure. Throttle pressure is an indication of load. When the throttle is depresse, the cable transfers this motion to the base of the throttle valve and moves it upward to increase throttle pressure. Throttle pressure causes the primary regulator valve to increase line pressure. As the throttle is depressed, greater torque is produced by the engine and the transmission may also downshift to a lower gear. If line pressure did not increase, slippage could occur with would result in wear of the clutch plate surface material.

Throttle pressure's effect on transmission operation differs between a hydraulically controlled transmission (non ECT) and an electronically controlled transmission (ECT). In non ECT transmissions, throttle pressure affects shift points and line pressure. Control in line pressure will affect the quality of the shift, not the shift point, in and ECT transmission

sam12345

iTrader: (1)

Question for 3UZTE why are shifts harsher when the car is cold compared to when it is warm?

3UZFTE

Ok, I am not sure where you got the above information, and it may be accurate but was hard to follow, But like you said, if you adjust the throttle pressure it will reduce the overall pressure causing more slip in your shifts, and reducing the rate at which your transmission will downshift. You aren't really adjusting the shift engagement, but are limiting the throttle pressure to apply the shift. Not all transmissions are adjustable as the A650e, 98+ Lexus V8s are all electronic, there is no kick down. Can you post the link where you got that information?

Because as the fluid warms up, the viscosity of the trans oil gets thinner as the vehicle warms the fluid up, it becomes easier to pass through the holes and smaller clearances in the valve body. Same thing for your engine during cold starts. If you have ever lived in less than 32* weather, it becomes more apparent, however when the fluid is at 70* it is going to be thicker than when it's at 200*.