Trans acting funny

[MercuryLs]

So if your read my other thread I just finished an engine swap in a 2000 LS V8. I did a trans filter & fluid (Mercon V) change while doing the swap. The car has 145,xxx miles on it.

Anyway, the car is up and running. I filled the trans as your supposed to. When I drive the car it does not shift up into 4th or 5th, it will only go as high as 3rd. When going WOT the 1-2 and 2-3 shift feel sloppy.

The car throws: P0734, P0735, P0795 codes and of course says "Check Transmission"

So am i looking at a Valvebody & Solenoid Pack change? Or does it sound like a new trans is where I am headed?

 

[joegr]

Solenoid assembly or wiring to it, at the least.

 

[Robot]

So if your read my other thread I just finished an engine swap in a 2000 LS V8. I did a trans filter & fluid (Mercon V) change while doing the swap. The car has 145,xxx miles on it.

Anyway, the car is up and running. I filled the trans as your supposed to. When I drive the car it does not shift up into 4th or 5th, it will only go as high as 3rd. When going WOT the 1-2 and 2-3 shift feel sloppy.

The car throws: P0734, P0735, P0795 codes and of course says "Check Transmission"

So am i looking at a Valvebody & Solenoid Pack change? Or does it sound like a new trans is where I am headed?

Sounds like it needs a relearning session. Remember 4th nd 5th are considered overdrive. She will shift 1 2 3 until programmed to do the 4 5 by default. What you have now is a trans that is working like you have the selector in the 3 position. I was just in the library looking at a Chilton's manual that talked about the relearn procedure.

 

[LS4me]

Sounds like it needs a relearning session. Remember 4th nd 5th are considered overdrive. She will shift 1 2 3 until programmed to do the 4 5 by default. What you have now is a trans that is working like you have the selector in the 3 position. I was just in the library looking at a Chilton's manual that talked about the relearn procedure.

Not true. The trans is a 3-speed with each gear overdriveable. From the head trans calibrator:

The transmission in the LS is really two transmissions in one housing. There is a two speed in front and a three speed in back.

First gear has both the front and rear transmissions in low gear.

Second gear shifts the front transmission to high and leaves the rear transmission in low.

Third shifts the front transmission back to low and the rear to second.

Fourth leaves the front in low and the rear shifts to high. Both front and rear are now in 1:1 ratio.

Fifth shifts the front to high again and leaves the rear in high.

And:

There are two gearsets in the 5R55N transmission. In the front is a single planetary system with two ratios, 1:1 and 0.71:1.

In the rear is a dual planetary system. This is two planetaries tied together to give three ratios, 3.22:1, 1.55:1, and 1:1. This type of arrangement is commonly called a Simpson gear set.

This is pre-5R55S. The "S" is synchronous and the "N" isn't. The difference:

he '03 transmission eliminates the intermediate clutch and the one way clutch that was associated with it.

The intermediate was used with the forward clutch to create third gear ratio. Now the intermediate band is used instead of the clutch. The intermediate band was used in the 5R55N only to provide coast braking in third gear. It prevented the one way clutch from overrunning. The material on the band was upgrade for the 5R55S, recognizing the increased duty cycle.

Now the 2-3 shift is done by releasing the overdrive band while applying the intermediate band. This is harder to accomplish than the 5R55N's releasing the overdrive band while applying the intermediate clutch. The reason the harder shift can be done now is the improved control system.

The control system, also know as the valve body, has been simplified and improved. It is easier to get the pressure where it needs to be with this design.

That's about the changes. Most of the parts that rotate are carry over from the 5R55N, except the parts that were left out! The 5R55S is about 7 pounds lighter than the 5R55N, with the same torque capacity.

I trust Chilton's as much as I trust Pep Boys!

 

[BlackLS06]

No wonder its so damn slow.

 

[Robot]

Not true. The trans is a 3-speed with each gear overdriveable. From the head trans calibrator:



And:



This is pre-5R55S. The "S" is synchronous and the "N" isn't. The difference:



I trust Chilton's as much as I trust Pep Boys!

I will keep that in mind. I didn't delve into the innerworkings of the unit. I was referring to the electronics and programming of the thing. I like to keep things simple. I know I just have to cover my mouth to sneeze. I don't care about having to tighten my butt to keep from crapping my pants or blasting a big one in Publix. I don't care about having to close my eyes to keep my eyeballs from popping out. I will let the big engineer in the sky deal with those problems. Hey, when I crap my pants, I will come see you. JK

Really, all that info is great stuff man. Christ! Tomorrow, when I am driving my LS, I will think about all this info and have a BIG SMILE on my face. WOW!

 

[Robot]

Not true. The trans is a 3-speed with each gear overdriveable. From the head trans calibrator:



And:



This is pre-5R55S. The "S" is synchronous and the "N" isn't. The difference:



I trust Chilton's as much as I trust Pep Boys!

So, shouldn't there be a way to have 6 forward ratios? I used to drive a 5 and 4 that gave 20 forward ratios. Is there an overlap or can it be programmed to use 6?

 

[Robot]

Looks like we are missing 1.55(0.71)=1.100. I know that seems impractical but on the strip combined with adjustments to tire diameter and rearend ratio, it might make that difference. Is there a way to program that?

 

[joegr]

Yes, you can get six gears out of it, but two of them would be so close to the same that it's not worth it.
By default, with no learning done yet, the transmission goes through all five gears, if everything is okay. In this case, the pressure control solenoid is bad electrically (or at least that circuit is), so a lot of stuff isn't going to work.

 

[Robot]

Not true. The trans is a 3-speed with each gear overdriveable. From the head trans calibrator:



And:



This is pre-5R55S. The "S" is synchronous and the "N" isn't. The difference:



I trust Chilton's as much as I trust Pep Boys!

LS4me, does the trans shift the front gears automatically regardless of the selection for the rears? I ask this because with my car it will shift into a lower gear it seems when I am in 5 SST or 4 SST at lower speeds. I thought it was slipping at first but it most definitely a positive shift. I stand on it in 4 SST from 60 MPH and it just goes with no shift but if I do that from 30 MPH, it will feel like it drops a gear. Thanks

 

[Robot]

Yes, you can get six gears out of it, but two of them would be so close to the same that it's not worth it.
By default, with no learning done yet, the transmission goes through all five gears, if everything is okay. In this case, the pressure control solenoid is bad electrically (or at least that circuit is), so a lot of stuff isn't going to work.

That would be kind of like the INDY cars and the top 2 shift.

 

[LS4me]

LS4me, does the trans shift the front gears automatically regardless of the selection for the rears? I ask this because with my car it will shift into a lower gear it seems when I am in 5 SST or 4 SST at lower speeds. I thought it was slipping at first but it most definitely a positive shift. I stand on it in 4 SST from 60 MPH and it just goes with no shift but if I do that from 30 MPH, it will feel like it drops a gear. Thanks

I just copied that from the guy that calibrated the trans. The converter locking and unlocking feels very much like a shift, if that helps.....