200r4 not holding 1st gear

[southpaw]

Hey there,

New to the forum and thought I would start it off with a real head scratcher. I have a 200r4 from a GN in my 1979 malibu. For the longest time everything was perfect until recently when I went to the track. Now when I hold in 1st gear the transmission automatically shifts to second around 3000 rpm even with the shifter still in 1st! I have no clue why this would happen but its costing me serious time at the track. Is anyone able to help me with this situation? Oh I should add the only thing that changed during this time was I added a new transmission filter and changed the oil....so not sure if its something to do with that.

Regards
SP

 

[charlief1]

It means you need to have it rebuilt. Sorry.

 

[southpaw]

Really? That is the one thing I was NOT hoping for....Isn't it $$$ to rebuild these transmissions? I was hoping it was just something to do with the valve body.

 

[charlief1]

I have been wrong before but usually when it skips like that it has to be rebuilt. Go to your user controls and add a loction in case someone near you can help out. If you check the tranny guys on the board one of them may be near you and can help diagnose it better.

 

[southpaw]

sorry I am a little new to this...how do I check the tranny guys on the board? Loaction has been updated...

 

[charlief1]

Go to the main forum page and go all the way down to the vendor section. The tranny guys are listed there, or go to the tranny section and read the stickys. One of them is about who does tranny work and location.

 

[drturbo69]

Had 1-2 shift valvle hangup in valve body that did this.
Doc

 

[southpaw]

is it an easy fix or is it something a shop has to do?

 

[drturbo69]

p.m. sent doc

 

[bison]

The easiest thing for you to do is swap out the vb for a known good one. You havent posted where you want it to shift so it's hard to advise

 

[quickt]

Hey there,

New to the forum and thought I would start it off with a real head scratcher. I have a 200r4 from a GN in my 1979 malibu. For the longest time everything was perfect until recently when I went to the track. Now when I hold in 1st gear the transmission automatically shifts to second around 3000 rpm even with the shifter still in 1st! I have no clue why this would happen but its costing me serious time at the track. Is anyone able to help me with this situation? Oh I should add the only thing that changed during this time was I added a new transmission filter and changed the oil....so not sure if its something to do with that.

Regards
SP

Readjust your shift linkage. I will bet Your linkage is not all the way in manual 1 exhausting low oil.

 

[southpaw]

The easiest thing for you to do is swap out the vb for a known good one. You havent posted where you want it to shift so it's hard to advise

What are the known good valve bodies? My engine redlines at 6000 rpm and right now I am shifting at about 5000-5500 rpm and seem to like it there, so lets go with that.

 

[southpaw]

Readjust your shift linkage. I will bet Your linkage is not all the way in manual 1 exhausting low oil.

I will check the linkage but it hasn't changed from before because I never took the tranny out of the car when i replaced the filter and such. Just to confirm thats the shift linkage you are suggesting to check and not the TV cable correct?

 

[quickt]

I will check the linkage but it hasn't changed from before because

The shift linkage if just 1/4 of a de-tent toward 2nd gear off will exhaust Lo oil and will not hold out the 1-2 shift valve. Rebuilding a transmission that is not slipping makes absolutely no sense. A change in the shift linkage just 1/8" is enough to cause your problem. Good Luck

 

[southpaw]

Thanks for the advice! I will check the linkage out first, and for the record no...the tranny isn't slipping at all...its still shifting really hard/firm under load but there is a possibility something could be hung up in the valve body correct?