Helping a friend do a conversion from manual trans to AT on a 1991. Using a transmission from a 1990 which includes the horizontal linkage rod, lever down to the trans, & lever up to the P-R-N-D-... shift mechanism. The shifter mechanism - complete in the cup - is from a 1986.

On 1st test run, couldn't get it to engage correctly in park. Pulled the front of the linkage rod and adjusted all the way in (shortest possible rod length). Not quite enough. You couldn't quite install the shift rod onto the trans with the shifter in park.

Rod length matched 2 spare rods I have (a 1985 and a 1992). Pulled a shifter cup from a 1992 parts car and finally saw the problem: the grooves on the pivot end of the shift-handle rods are at different angles 1986 vs 1992: the grooves are straight down on the 1986; angled slightly back (5-10 degrees counter-clockwise) on the 1992. So the rod comes back further on the 1992 which allows engagement of park.

The difference is visible and with a straightedge: the bottom rear of the 1986 lever is even with the back of the cup; the 1992 lever is ~3/8" back from that. The pic shows the right-hand (1992) assembly with a ~3/8" gap at the bottom.

I've swapped shifter assemblies from several cars including putting one from a 1984 into a 1989 last summer. I've never noticed a difference. I don't have the rod-lever assembly from the 1986 donor car but infer that either:

- a) it has a shorter rod; or
- b) the lever groove is cut on a different angle; or
- c) the 1986 had a transmission with the gear lever further towards the back of the car - not something I've not encountered before; or
- d) the shift-lever assembly is from an earlier car that used a different trans and/or linkage rod.

Options to make the swapped car functional

1) Shorten the linkage rod (I will try this)
2) Change the angle of the lever relative to the shifter mechanism - easily cut and rewelded
3) Find a shifter mechanism with the correct angles (I don't have a spare right now).
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240 drivers / parts cars - JH, Ohio