A/T won't shift out of 1st when cold

[KMinAF]

In the morning the trans won't up shift from first gear until I either floor it or drive it for several blocks and then the change is at a high RPM (3k +) and is extremely harsh when it does finally shift. It only happens the one time and shifts normally for the remainder of the day regardless of how long or short the drives are.

My thinking is that since there are no codes that it isn't electrical, and because of the high RPM shift point that maybe it is a valve hanging up?

It only happens after the car has completely cooled off i.e. over night and I have changed the ATF after adding Sea Foam and following their directions.

I am open to ideas and suggestions

 

[jdub]

You added Sea Foam to your ATF? :3d_frown:

Another victim of the snake oil salesman...I would drain the tranny, drop the pan and change the filter. Then flush with fresh ATF (not just fill)...make sure you use Dex III. I use Castrol Import ATF...Mobil 1 would be a good choice too.

I assume when you say "no codes", you are referring to tranny codes.

 

[KMinAF]

You added Sea Foam to your ATF? :3d_frown:

Another victim of the snake oil salesman...I would drain the tranny, drop the pan and change the filter. Then flush with fresh ATF (not just fill)...make sure you use Dex III. I use Castrol Import ATF...Mobil 1 would be a good choice too.

I assume when you say "no codes", you are referring to tranny codes.

Guilty as charged and $30.00 poorer
I did flush and clean as suggested but it made no difference and yes I was referring to tranny codes

 

[jdub]

You dropped the pan and changed the filter too? Before or after the Sea Foam?

How did you flush the tranny? Was it before or after the Sea Foam?

 

[KMinAF]

You dropped the pan and changed the filter too? Before or after the Sea Foam?

How did you flush the tranny?

It was a "clean and fill" not an actual system flush and it was done after the Sea foam. I was hoping that maybe I had a varnish build up in the valve body but there was no change after replacing the ATF.

The symptoms started suddenly i.e. it was working fine one day then the next and ever since, the problem has persisted. The original ATF was clean with no unusual discoloration.

 

[jdub]

Well...you need to change the filter and do a real flush. That is going to take at least 10 quarts of ATF. The Sea Foam may have broke some crap loose and restricted the filter screen. The drain and fill only replaced a third of the fluid...even though it looked clean, it wasn't if it had a lot of miles on it. You also contaminated the ATF with the Sea Foam.

Might be a good time to install a real filter in the cooler circuit as well.

 

[KMinAF]

Well...you need to change the filter and do a real flush. That is going to take at least 10 quarts of ATF. The Sea Foam may have broke some crap loose and restricted the filter screen. The drain and fill only replaced a third of the fluid...even though it looked clean, it wasn't if it had a lot of miles on it. You also contaminated the ATF with the Sea Foam.

Might be a good time to install a real filter in the cooler circuit as well.

Any thoughts on why it only happens the one time?

 

[jdub]

The fluid get hot and drops in viscosity like it's supposed to. Plus, who knows how the Sea Foam reacted with the old ATF. Hope this is a lesson...never use any motor oil or ATF additive/cleaner. For gasoline additives the only ones worth using are those that contain polyether amine. PEA is in Chevron Techron, RedLine SI-I and GumOut's Regane...the highest percentage is in the Techron Concentrate.

Here's how to do the ATF flush/change...pay attention to post #16. Do the flush with the tranny at ops temp.
http://www.supramania.com/forums/showthread.php?t=3179

 

[johnathan1]

I would just do as jdub suggested, then go from there.

 

[KMinAF]

I will give it a try and let you know what happens

 

[Kckazdude]

Mine was a valve that would stick until the pressure was enough to push it. It had to do with temprature and flow of the fluid. Once broken lose or warmed up it would shift fine. I want to say the primary regulator valve was the culprit. A freind that was coaching me through building my valve body was telling me how it all worked and I didnt grasp all of it the first time through.

 

[KMinAF]

Mine was a valve that would stick until the pressure was enough to push it. It had to do with temprature and flow of the fluid. Once broken lose or warmed up it would shift fine. I want to say the primary regulator valve was the culprit. A freind that was coaching me through building my valve body was telling me how it all worked and I didnt grasp all of it the first time through.

What did you do to fix the problem?

 

[3p141592654]

As a test, start out with the shift lever in 1st, then manually shift to 2nd. The shift lever bypasses the solenoids so if things work normally you have narrowed down the problem to the solenoid or electronics.

 

[KMinAF]

As a test, start out with the shift lever in 1st, then manually shift to 2nd. The shift lever bypasses the solenoids so if things work normally you have narrowed down the problem to the solenoid or electronics.

Did that. Trans won't shift unless rpms are high, I reason that it must be a sticking valve.

 

[Kckazdude]

When I rebuilt the transmission and valve body the problem was gone. I remember there was a few valves that were really difficult to get out for all the friction material built up in the bore.

http://www.supramania.com/forums/showpost.php?p=1076964&postcount=77