5 speed worn bushing prevents reverse?

[Civilizedape]

I have 5 speed transmission that is giving me trouble. After a rebuild it is really hard to get into reverse and if it does its gets stuck there. After taking it apart and putting it back together a couple times I noticed a lot of play in the shift linkage. Has anyone dealt with this?  I assume next step is get a new bushing pushed in.

 

[Zed Head]

Did you try it with the front case off?  Just the forks and shifting rods?  Separate the potential causes.

[Civilizedape]

Everything shift smoothly into all gears with the front and rear cases off. Its only when bolted up that it binds into R.

[Zed Head]

3 hours ago, Civilizedape said:

it is really hard to get into reverse and if it does its gets stuck there. 

I noticed a lot of play in the shift linkage. ....  I assume next step is get a new bushing pushed in.

It's odd that it gets stuck in reverse.  Sounds the shifting rod is binding.

There's no bushing that needs "pushing" in with tools.  There are are two plastic bushings, one on the end of the shifter and one (two piece) bushing at the shifter's pivot point.  Take a picture of your shifter and the bushings, we'll see how worn they are.

[Civilizedape]

The bushing I am referring to is deep in the rear case. If you look at the link you can see the play in the bushing down the shift rod. The front of the shaft is supported by the center plate. I am starting to think the problem is else where. 

As for the shift rod bushing #31 is new and #32 fine and tight. They move with no restriction when the case is separated. 

How about the reverse lockout do they fail? 

Edited January 15, 2020 by Civilizedape

[Zed Head]

@Dave WM and @EuroDat and others have rebuilt their transmissions.  Might have some ideas.

Here's a good site for browsing parts.  Better exploded diagrams than the FSM.

http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train

[Dave WM]

I am lost. there should be ZERO play in the shift rods, they are all held fast with the springs and balls in the plate. the Striker rod and lever are responsible for pushing/pulling the shift rods. I recall a guy had the shift dogs in backward on the rear syncro, caused a lot of problems for him. this is the video I did for that

 

[Dave WM]

oh and the assumption is you have the correct shifter for the trans. I know they are different, length of the short side of the pivot, the spring loaded one, etc... there maybe interference with the actual shift shaft that requires some grinding if you have the wrong shifter. to know for sure once you get into 5th or reverse does the shifter feel tight? it should not, there should be some play since the shift rod is locked in by the balls (ha). if its tight the shift rod may not be getting enough throw from the striker lever, so the balls are fulling seated into the notches on the shift rod. the result is a rod that is pulling on the striker lever constantly keeping everything in tension, result in a tight feel at the shift knob.

Edited January 16, 2020 by Dave WM

[Civilizedape]

Thanks for the tips and all your videos. I'm sure they have helped many others. I'll take a look this weekend at the things you mentioned. When I said shift rod before I am referring to the striker rod.

Edited January 18, 2020 by Civilizedape

[EuroDat]

The movement you see the your video is normal. The hole "bushing" where the selector shaft goes through in not a tolerance fit. It has a large clearance so splash oil can pass through to the striking guide and striking rod contact points.

When the transmission housing is bolted together and the striking rod is supported by the front housing section the excessive movement will be gone.

 

Did you have this problem before the rebuild?

Did you replace any parts in the reverse gear section?

Like Dave mentioned. Is the selsctor rod hitting and binding in the striking guide?

Other things that can cause difficult shifting:

- Tolerances in new parts

- Bent selector fork rods

- Worn or damaged interlock springs or balls. See SMT137

 

 

[EuroDat]

Another thing to check. It doesn't have anything to do with your problem, but the stopper guide pin is a common source for oil leaks.

I use a silicone type sealant suitable for oil environments to cover the exposed ends of the pin and create a good seal.

 

Edited January 16, 2020 by EuroDat

[Dave WM]

I could not see a video of the problem, clicked on a link, but it just came back as a blank screen.