I got a 55 88 with manual three speed. hard to shift into 2nd. any ideas?

 

The first think I would check would be the linkage. It probably has some wear in it. I imagine there are some bushings in it at the steering column and the levers on the side of the transmission. It could also need adjustment. I would try these before I went into the transmission.

 

I agree; start with the simple things. The transmission will not go into the 2nd gear if it is already in another gear. Before going after the transmission get the linkage right. The 1955 Oldsmobile Shop Manual covers the linkage adjustment and transmission work thoroughly from page 11-1 to page 11-12 with drawings and photos. Also be sure that the transmission's lubricant is correct.

 

what is the correct fluid? 90?

 

90 weight gear lube should work.

 

Page 11-11 of the shop manual specifies SAE 80 Multi-Purpose Gear Lubricant, but if you're in one of the warmer parts of the world, 90 or one of the multi-viscosity gear lubricants should work satisfactorily, as long as it doesn't produce hard shifts. The transmission should hold an approx. total of 2-1/2 pints.