Soft 1-2 Shift Problem

[Turbo6inKY]

So tell me about TV adjustment and low pressure... An incorrect adjustment in which direction will cause low pressure? Does the photo above support this (with the cable housing showing so many ridges?

The way it looks at the throttle body is a bit irrelevant without knowing the condition of the cable. The idea is to have the throttle valve in the transmission all the way open at WOT. When you pull the cable all the way back through the fixture, then crank on the throttle, once the throttle valve reaches it's maximum travel in the transmission, the sheath should click through the detents in the mount.

But it could be stretched or damaged, which is why the appearance up top may or may not mean anything.

Have you pulled the TV cable from the transmission yet? Is it even connected to the throttle valve?

 

[Tim_D]

I checked the TV cable today. It is hooked up properly in the trans, and when a helper fully opened the throttle, the TV lever arm went to full travel. So the cable seemed to be correctly adjusted.

However, I just got a chance to get a good look at the inside of the pan, as I was emptying the remaining fluid. There was some pretty dark sediment in the pan, along with some larger “chunks” (maybe half the diameter of a dime). This thing is not looking promising.

 

[TexasT]

This is why a pressure gauge is very useful. With the engine running and the tv cable disconnected from the throttle arm you can pull the tv cable and see the pressure rise. If the pressure isn't rising when the cable is pulled with the trans in park , d or od you have a problem. The pressure should be up when in rev, 1 and 2 when using a larger low/rev boost valve.

 

[gunzandgearz]

let's think about this for a second fellows we need to put our thinking caps on the line pressure in the unit whether it's a 200 4r or any other unit out there known to man if the line pressure is low it would affect every clutch in the unit including the band so if line pressure is low and TV cable is out of adjustment why would it just smoke the band the answer is it won't actually if line pressure is low the clutch that is always engaged is the forward, it is engaged the second you put that transmission in any forward gear this will be the clutch set that will fail if line pressure is low need to start looking in another area same thing with the filter situation the filter location is not the problem either because again it would affect reverse and all the forward gears not just second, the band is probably just smoked this is the area that you need to look in hope this helps

 

[hensleyt]

This is a good read

http://extremeautomatics.com/assets/pdf/2004R_Transmission_Install.pdf

 

[Tim_D]

Dropped off the tranny at a reputable builder today. We had a good conversation about it, which mirrors closely with some of the latter things discussed on this thread.

I'm a little disappointed in myself with regards to the problem solving. It took somebody on this thread to tell me to take a step back and analyze the symptoms, and let the data speak to the possible causes. The disappointment comes from the fact that I'm an engineer, and data-driven problem solving is part of my job!

When you whittle it down, I am having issues with the shift to second gear only. So what in the trans controls ONLY that shift? The band is the most obvious thing. And it got a little worse as time went on, which indicates wear (and coincides with the cable ratcheting another click when I recently adjusted it). The icing on the cake was the chunks in the pan (which is apparently band facing material).

Add these up, and the stretched cable was probably leading to too little line pressure, causing slip and wear on the band, to the point where the band eventually failed. Which is pretty close to the conversation that the builder and I had.

The builder should be able to dig into it by the end of the week. I'll report back then!

 

[Tim_D]

The inspection is done.

1) Smoked band
2) Slightly burned 3-4 clutches (a few)
3) Disintegrated 1-2 accumulator spring

The repair estimate is very reasonable, so I’m quite happy. I’ll report back in a week or so (after reassembly) to let all know how it worked out.

 

[Tim_D]

I got the transmission reinstalled tonight. In addition, I had a fellow user look at the TV cable housing and suggest it looked out of adjustment. If I’m not mistaken, the cable should provide full TV activation at full throttle. I adjusted accordingly, and now full throttle equates to full TV activation.

This trans had apparently never been right. It sure is now! It feels and drives like a new car - and each gear change is quick, precise, and firm. And I can even feel when lockup occurs.

My trans builder here in SE Michigan did a great job. I got diagnosis, all the new parts as described in a previous post, and reassembly for $285. I feel that was a great price.

Thanks to all for your advice -

 

[hensleyt]

Two thumbs up ,one doesn’t get service and parts that chip these days.Glad it’s is up and running.
TV cable adjustment is very important, I hind myself checking it frequently. My cable is old no fraying but it OE , Enjoy your car this summer.

 

[Turbo6inKY]

I got the transmission reinstalled tonight. In addition, I had a fellow user look at the TV cable housing and suggest it looked out of adjustment. If I’m not mistaken, the cable should provide full TV activation at full throttle. I adjusted accordingly, and now full throttle equates to full TV activation.

This trans had apparently never been right. It sure is now! It feels and drives like a new car - and each gear change is quick, precise, and firm. And I can even feel when lockup occurs.

My trans builder here in SE Michigan did a great job. I got diagnosis, all the new parts as described in a previous post, and reassembly for $285. I feel that was a great price.

Thanks to all for your advice -

Awesome!