Input shaft "play"

[Alex "Berkowitz"]

This is a brazilian 4 speed, stock to our Mopars down here. I was cleaning it yesterday and noticed this "play" at the input shaft.Is it supposed to be there? The american 4 speeds, do they have any bit of play? I'm measuring it tonight, got so bummed yesterday I didn't even think of it, but guess its around 0,20", maybe a bit less. [ame]http://youtu.be/HfL6MUCejIo[/ame]

 

[67Dart273]

Radial play? Yes. "in out"? NO

"What supports" the shafts:

Out of the car, you have a "teeter totter effect. The main (tail) shaft only has one bearing, the big ball bearing between the main and tail housing. Then the front of the main is supported by needle bearings in the cavity in the rear of the input shaft

So the input shaft only has one bearing, the front ball bearing. "In the car" it's supported by the pinion bearing

So you can push up / down on the input and it moves. If you watch the tail, it will do the same thing and "follow" the input shaft

 

[Alex "Berkowitz"]

Got a little lost on the language barrier here.

So, if I understood, it is "ok" to move...to the sides, but not in/out?
Is that it?

Didn't understand that part about the tail moving.
It should move the same way I move the input shaft?

 

[nm9stheham]

Some side-to-side movement is normal. I have seen this as normal on all types of manual transmissions (execpt for a Celica Alltrac).

 

[abodylurker]

I just talked to Brewers today about this very problem. He said that there can be enough play to touch the side on the retainer and it is still alright because the bearing or bushing in the crank of the motor keeps it centered not the bearing. The teeter/totter comment was exactly what he said also. I bought a rebuilt tranny and I turned down the retainer to fit my bellhousing and noticed it had a Koyo bearing in it and I wondered if it was the cause of it but he said they all have some radial play to them. They use a different Chinese bearing and they have put in over 3000 and never had 1 fail. I was bummed at it also but feel better after talking to the expert.

 

[67Dart273]

Got a little lost on the language barrier here.

So, if I understood, it is "ok" to move...to the sides, but not in/out?
Is that it?

Didn't understand that part about the tail moving.
It should move the same way I move the input shaft?

You have two what amounts to levers. You have the end of the input you see, a fulcrum at the front ball bearing, and then the input shaft and main shaft are connected by the tail / main shaft in the end of the input shaft.

The main / tail shaft then has a fulcrum at the main bearing where the case / tail housing splits

So you have two levers there, connected at the rear of one and the front of the other

If you "look" at the side of the gearbox, and you force the input shaft tip DOWN, this makes the rear of the input go up.

Since the front of the main shaft is up, the rear bearing "teeters" the rear of that shaft DOWN

So yeah. You can either wiggle the rear of the tail shaft, or the front of the input shaft, and the oppisite shaft should "follow along."

I should mention this won't happen with the old 65/ earlier "flange drive" gearbox, because the rear of the main is supported by yet another bearing.

Frankly, ANY unknown box, I'd tear it down. You can download shop manuals. It's possible with no special tools. I used to put the needle bearings back in the cluster with grease and no arbor. Just normal hand tools and a shop manual.

You want to inspect the cluster shaft and needles, the interior of the rear of the input shaft and those needles, and the front of the main shaft. And, of course, inspect the two ball bearings.

All of the journals where the gears run, and of course wear on the shift dogs and stop rings.


I've been into older Chev 3 speed, a couple of old BW truck 4 speeds, and into T-10 and Muncie, along with at least a dozen excursions into A833 boxes. Neve used anything special, except maybe snap ring pliers for the mid bearing.

 

[acpat]

67Dart273 what he said. nothing special required but a service manual