Loose shifting, linkage, column, tranny problem

[Montierth]

Hi all,

I have been searching to find an answer or explanation but the terms or way of describing my issue turns up wrong topic of stuff like a tranny slipping etc. Hopefully I can explain this and someone can help.

My truck is automatic with a TH350 tranny and 350 crate motor. I have an original steering column and shift linkage. I have a couple questions.

1. When I shift into drive and start driving, when I hit a bump or accidentally hit the shift bar on the column, the bar can move and shift into D2 or even can be D1 because it is pretty loose. Does that make sense? It is almost like there needs to be more tension in the shift mechanism to make it more difficult to manually shift from P to R to D. I am trying to figure out if the problem is in the shift linkage or an adjustment in the column? Or could it be something inside the tranny that is weak or loose (a detent spring?)? If anyone has any ideas or pics of a solution it would be appreciated.

2. Kind of the same line of issue. I know how to adjust the shift linkage but when I shift from P to R or N or D it is almost more of by feel. For example: I shift from P to D then give a little gas. If it goes forward then I know I'm good! If goes backwards or sits there then I know I gotta keep trying to find D! Would a new steering column be more accurate with the shifting in to R or D or is that a linkage and or Tranny issue? Is there a fix for it or is this how it works?

Thanks

[Montierth]

Anyone else notice this with their automatic column shifting being too loose?

[notsolo]

What year?...there should be indents...Stopping points for each gear. Does your shift handle have a spring pulling forward on the handle?..column has spring at bottom for tension....I Think the actual indents are in the trans, not positive, look at all your linkage points for wear, and movement....Use the search bar column shifter loose etc.

[rpmerf]

Not sure if this is it, or your problem is elsewhere. On my 70, if you look at the steering column, near the brake booster, there is a thing for selecting gears. It determines when you need to pull the lever vs when you can just push the level into a position. You should need to pull the lever to go from D to 2. The spring on this mechanism might be weak or broken.

This thread references the piece I am taking about:
http://67-72chevytrucks.com/vboard/s...d.php?t=491049

[rpmerf]

Another note. Whenever you are playing with shift linkage, be sure to set the parking brake AND use wheel chocks. Don't need the truck accidentally rolling away.

[Montierth]

Truck is a 1970. Yes I have the spring that requires me to pull the shifter toward me. I have looked at the column at the firewall by the booster and it looks pretty good. It doesn't look to worn. I almost think it is inside my tranny. Like the detent inside the tranny are look or worn?

[68 P.O.S.]

I had a similar problem on my 72 and it ended up being bad motor mounts. The bad mounts allowed the engine to move just enough to downshift the tranny.

[Montierth]

Wow that's nuts. My motor mounts are brand new. Ill have to keep looking more. I know going from D to 2 i don't think it needs to be pulled fwd.

[notsolo]

You could try, block the wheels, separate the linkage at the trans. You should feel a crisp click for each gear as you rotate the 2 prong piece on the side of the trans....also if you pull on the bottom of the steering column below the big washer, it should not move.

[Montierth]

I'll check those out. Thanks for tips.