Auto won't shift into 3rd and 4th

[n/a]

280SL automatic operates normally when selector placed in 2 (low). Shifts from first to second. If selector is placed in 3 or 4th, keeps jumping into lower gear or sliping. Reverse works but seems to slip resist as if emergency brake was left on. problem started suddenly.  Maybe 3 place solenoid or modulation pressure.  Any other ideas?  Thanks!

[ja17]

Hello T3,
Make sure the three position solenoid is moving as it should. Next change the transmission fluid and change the filter. Retorque the valve body bolts while the trqnsmission pan is off. Also look for debris in the transmission pan.

Joe Alexander
Blacklick, Ohio