Wont shift out of first on hard acceleration

[graphic66]

My 66 230SL automatic wont shift out of first on hard acceleration. If you floor it on takeoff it shifts to first but if you hold it floored it revs way past redline and you have to let off the throttle to get it to up shift. Any ideas?

[hill]

What gear are you selecting before you nail it?

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

[graphic66]

The shifter is in drive, it kicks down to first when you floor it but unless you let off it wont upshift.

[hill]

I have the book on auto trans assembly and repair and have built a few trans myself. This book has me baffled. Flush it fill it. Check for vacum leaks if the vacum is low it will think that it is still accelerating. If you need the the book info PM me.

It can be low pressure. How are your shifts otherwise?

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

[psmith]

Could it be that the kick down switch is holding it in first?

Pete S.

[graphic66]

It seems to shift fine other than first. Good idea to check for vacuum leaks. I have flushed it and changed the filter. I have checked the 3 way solonoid and kickdown switch and the idle switch on the manifold.

[hill]

What is your vacum reading at idle assuming 700-800 rpm?

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

[graphic66]

Pulled the vacuum line leading to the transmission and took a reading at the intake  and it had 7.5 inches of vacuum at an idle. Seemed pretty normal. I next will check the vacuum line going to tranny for blockage

[hill]

quote:Originally posted by graphic66

My 66 230SL automatic wont shift out of first on hard acceleration. If you floor it on takeoff it shifts to first but if you hold it floored it revs way past redline and you have to let off the throttle to get it to up shift. Any ideas?

Dude mine is 15" at 600 rpm you got a leak.

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"