1978 5-speed transmission Tail-Housing Removal?

[chaseincats]

7 hours ago, Zed Head said:

Are you going to take the shaft apart to get to oil seal #19?  I got rid of my pile of 5 speed parts or I'd have done it already.

Nobody has really dug in to that possibility as another source of the oil in the shifter cavity.

yep thats the plan!

[jonathanrussell]

Just reading this. Great that you got the wedge bolt out. I had a hell of a time with this about a year or so ago. I ended up doing multiple heat cycles on the fork, followed by using a hammer to hit the side of a long socket extension that was resting on the threaded side of the bolt. I rested the socket side of the extension on the loosened nut and hit the part of the extension that was outside of the housing with a hammer. In other words, the extension was reaching into the housing from the front / big opening...parallel to the shift rod. Like you, my transmission didn't have the convenient hole in the housing like the zx transmissions do. 

I ended up replacing the seal and the o-ring. No shifter leaks now.

[zKars]

I’m imagining a tool to make this easier. Imagine a forked body that hooks over the shaft, each side of the bolt, and a threaded bolt like thing that presses on the end of the stud to push it through. 

kinda like this tie rod ball end remover thingy, but with bigger better wrap around fingers spaced further apart.  Nice cupped end that snuggles over the threaded end of the stud to keep it on. 

Gonna go ‘play’ tonight and see if I can make one. 

Edited February 16, 2020 by zKars

[Zed Head]

How about your concept but in a "jaws-of-life" type mechanism?  Tiny "mandibles of convenience".

[Captain Obvious]

I was thinking the same thing when I was reading about the difficulties of getting that pin out. Seems like it should be a relatively simple matter of pushing that pin backwards using the shaft as the "anchor" for some kind of device to hook on*.

In fact, if the large end of the pin (the non threaded end) is not proud of the surface on the fork casting, you wouldn't even need a recess for the pin to press through. Since it's tapered, all you need to do is break it free a little and it should move much easier after that.

 

* Proof is left to the student? 

[Captain Obvious]

Snuggles.

[zKars]

I’ve been slaving on a proto type. Room is tight in there, but I have something that seems to work. Lots of trial and error. Yes a welder was required, cut off wheels, carbide bit in a die grinder, used a lathe but you don’t “need” to (to make a nice centered hole in the end of the threaded press screw)

Started out as one of these. 

Pictures of the final thing in action coming.

I used a tail housing from a late zx trans with the reverse lock out thingy, so getting the pin out initially to have an assembly to play with was easy. As long as you support the shift finger casting on the shaft very solidly against the inside of the housing, you can smack the end of the pin with the female end of a 1/4 drive 6” socket extension (so it stays on the end of the pin) with a 3 lb hammer and it pops right out. Any amount of bounce in that shaft and you’re banging on a loosing proposition. I used 1 minute of propane heat on it first. 

Edited February 19, 2020 by zKars

[zKars]

Ok, here is the beast. Bit rough, it has been through many changes on the way to a working model.

Here is how it fits and sits on and around the rod and lever arm.

And here is it in action inside the tail housing/

The nut on the threaded pusher is 19mm, so had to make a custom bend on this 19mm open end wrench to allow access and at least 1/6 turn.

The nut is very close to the raised casting area around the reverse lockout assembly hole in the case. Had to get the length of this pusher bolt just right to allow you to put it on the wedge bolt tip and still get you enough room to push it off. The tail housing without this reverse lockout thingy would have much more room. You might even get a box end wrench on it.

Here is the SFT’s for the project

The bottom chunk is the part of an intermediate plate from a junked 4 speed. It has the hole for the end of the shift rod. Helps to keep the shift rod supported if you using the 1/4 socket extension whacking method to remove the wedge pin. I still needed a firm support behind the wedge pin area to the case to prevent the rod from just flexing when you hit with the sledge. That is what the 3/4” wide 1/8 thick angle iron piece does. Sits in there real nice.

Design wise, the biggest change I had to make to the original tie rod end puller was to cut the legs off close to the threaded end and shift the whole body down about 3/16” then re-weld. This is due to the fact that the wedge pin sit below the centerline of the shift rod by about that much. Your threaded pusher bolt has to be in-line with wedge bolt or you risk bending, well actually, snapping it off. You will be applying considerable compression on that little M6 threaded pin.The 1/4 hole in the end of the pusher bolt makes sure the pin end stays straight and engaged.

Now the real test is to try it on fresh untouched pin in another housing. This test pin was never re-inserted with the same pressure as it had from the factory. At least there was zero, and I mean zero signs of rust or pitting, or roughness on the pin. Being bathed in oil its whole lift kept this one clean. If you have a wet rusty one, you’re in for a fight. Heat, penetrating oil, time, the usual....

I still think the “best” approach is to use the pin punch (1/4” socket extension) from outside the case through a hole. Easy on a trans with the reverse lockout, but you’d have to make a hole in the same spot for the earlier ones. I don’t think this such a big deal. We have the exact location from any trans with the reverse lockout, and making NPT threads and plugging it is pretty benign. 1/4 or 3/8 NPT is a plenty big hole.  Or you spend a day or two making a custom puller. Your choice.

 

Edited February 19, 2020 by zKars

[Zed Head]

"Turnbuckle" popped in to my head when I was looking at your device.  Maybe? Still need to support the shaft on the other side to keep it from bending.

http://www.anchorboltexpress.com/5-8-x-6-turnbuckle-body/

[zKars]

11 hours ago, Zed Head said:

"Turnbuckle" popped in to my head when I was looking at your device.  Maybe? Still need to support the shaft on the other side to keep it from bending.

http://www.anchorboltexpress.com/5-8-x-6-turnbuckle-body/

Aha! Push the tip of the wedge bolt using the case opposite as the base.

If you can get it to seat nice and tight against the case where it can’t slip, this could work. There is lots of rotation so you could find the spot where the case surface is orthogonal to the turnbuckle axis, or a ridge to catch against. Would need to find a good quality turnbuckle with fine threads. Naw, just make one. Drilling holes and making threads is basic work.

And yes, the backside would need to be well supported just like the  “whacking it out with a pin punch“ case. I think I have a better solution for that too than a chuck of angle iron crudely propped behind it. Something that slips over the shaft and has a threaded bolt in it that you unthread until the bolt head touches the case.

Probably still easier to drill the hole, whack it, then plug the hole. But not as much fun!

[Captain Obvious]

Nice. I was sure you could come up with something!

I've got some small suggestions to make it better now that proof of concept has been successful, but none of that matters until you decide to make the next one.    Good work!

I'm happy that this is one of those "difficult Datsun jobs" that I've never had to deal with!

[chaseincats]

What I believe the person working on my transmission did was wedge a block between the shaft and housing after removing the nut and stuck an air hammer in there.

Blasted the pin right out.