A833 Transmission

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Kraftei

Kraftei

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Stony Plain, Alberta
My 72 (second last owner) had the A833 gone over over a few times for making noise. He also balanced the drive shaft and had the rear end looked. I adjusted the shifter linkage and changed the oil, the oil looked like someone put gold sprinkles in it. I thought I might get lucky with a few changes I made.

I finally finished with my restoration/mods and took it out for some carb tuning (new carb) and the 4 speed was thumping like a disco (after a few hard runs). I am getting 3rd gear rubber now. There is no doubt now.. where the noise is coming from.

Because the transmission has been gone over so many times I would rather just swap it out. I am going to send mine back to the shop that built it (and rechecked it numerous times) for analysis. The second previous owner would like to resolve this, as it only has 200 miles on it since he had the 4 speed built.

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AJ/FormS said:
I have a 2.66low gear, 1x23 input, A-body unit with low-mileage bearings. But IIRC, I street slick shifted 2nd and 3rd in it.. I am fully trained in rebuilding those.
Click to expand...

I dont think I want slick shifting for this application. I pulled the tranny last night and it has serious play where the input shaft connects to the output shaft ?. I suspect there is a bearing located there. The tiny teeth (pre 4th gear) are damaged on the input shaft.

So it looks like it needs a total rebuild plus a input shaft. Not sure why they could not find the issue, that said it became very noticeable after I did a few 5k speed shifts.

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Kraftei said:
it has serious play where the input shaft connects to the output shaft ?. I suspect there is a bearing located there. The tiny teeth (pre 4th gear) are damaged on the input shaft.
Click to expand...
Some play at the input, by pusking it sideways ... is normal. The ball bearing that supports it has a tiny bit of axial play
that amplifies out to serious sideways motion, at the end of the input shaft.
Damaged "splines" on the front end of the output shaft arev no big deal.
The clutch teeth on the gears themselves are easy to repair, also no big deal.
The pilot on the front of the M/S can also be repaired
About the only parts in that trans that need to be periodically changed are the brass synchronizer rings, and occasionally, the cluster-pin. And bearings of course. But if you start grinding gears, or have to hold it in a gear because it likes to jump out, well then, before long, yur looking at forks and sliders

BTW
I've never heard an A833 "thumping like a disco" so that will be interesting to see what caused it. I'd be more inclined to think that was in the clutch. But you said;
Kraftei said:
There is no doubt now.. where the noise is coming from.
Click to expand...
so I guess we'll see.
BTW-2
I hated pulling the trans out on the floor when I was 17,
and 50 years later, I know I would still hate it,lol.
 
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AJ/FormS said:
Some play at the input, by pusking it sideways ... is normal. The ball bearing that supports it has a tiny bit of axial play
that amplifies out to serious sideways motion, at the end of the input shaft.
Damaged "splines" on the front end of the output shaft arev no big deal.
The clutch teeth on the gears themselves are easy to repair, also no big deal.
The pilot on the front of the M/S can also be repaired
About the only parts in that trans that need to be periodically changed are the brass synchronizer rings, and occasionally, the cluster-pin. And bearings of course. But if you start grinding gears, or have to hold it in a gear because it likes to jump out, well then, before long, yur looking at forks and sliders

BTW
I've never heard an A833 "thumping like a disco" so that will be interesting to see what caused it. I'd be more inclined to think that was in the clutch. But you said;

so I guess we'll see.
BTW-2
I hated pulling the trans out on the floor when I was 17,
and 50 years later, I know I would still hate it,lol.
Click to expand...

I have a thumping noise, the tempo increases or decreases with speed.

Clutch engaged, disengaged, engine on / engine off, gear engaged / disengaged same noise. Vibration in shifter. Stereoscope has noise at transmission output.

Gets worse after shifting hard, calms down a bit after. The previous to the previous owner had pulled the transmission pulled twice (pulled the trany down once (warranty), replaced the throw out bearing etc the other time), drive shaft balanced and the rear end pulled and checked.

Still had vibration and noisy after. I have replaced the rotors (rubbing on calipers) and changed the rear end to a 373 posi (it was a 323 open). I found the the shifter was not set up right, the reverse rod was way out. It seemed better after, I changed the oil and thought I maybe had it, but I could not test drive as it was winter. Had one test drive last week, no power, changed the carb and lots of power but the noise got 10x worse... after hard shifts.
 
I bet the driveshaft is whipping around in a bad rear bushing, and the rear mount is sending that vibration straight into the chassis. I wonder if your driveshaft is too short. If so, you will need to fix that or it's gonna happen again.
 
AJ/FormS said:
I bet the driveshaft is whipping around in a bad rear bushing, and the rear mount is sending that vibration straight into the chassis. I wonder if your driveshaft is too short. If so, you will need to fix that or it's gonna happen again.
Click to expand...

When I wiggle the output shaft the input flops around like a joystick. The driveshaft is 50 inches long from knuckle to knuckle and the extension is 9 1/2 inches knuckle to end. Installed it looks normal to me, a couple inches of silver showing. 59 total.

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Too late to measure the driveshaft for correct installed length.
listed for a 71/72 demon for a 340/ manual trans, I have
pn 2883760, which is
48.96x2.75
But that yoke I have never seen in any A-body .
Unsupported like that, Floppin' around to some degree is normal.
But if the input gear moves in the fore and aft plane on a straight push-pull,more than say ~.002inch, that is a worn input bearing. Worn far enough to warrant replacement? Not to me,lol.

Consider how that floppiness is created. The front and rear bearings are the fulcrums, and the output shaft is about a 3:1 lever. So if the back-end of the M/S moves say .32 from min to max, then the nose of the M/S moves ~.107.
Which moves the input gear also .107. But the front ratio is more like 4:1, so the tip of the input could move ~.428.. Of course the input shaft is restrained physically by the retainer... so you might not see the whole .428inch, but to you it looks floppy. This test, IMO, means very little.

But the real test is to stick that elephant trunk into the back of the trans, and wobble it in the same way. The rear bushing is maybe 3 inches long, and a close fit on the yoke, so there should be very very little wobble there.

And, I would inspect the rear mount very closely for a reason not to throw it away.
One more; inspect the oil that came out of the trans. Put it into a shallow pan like a frying pan with a shiny bottom. Shine a light in it and swirl it around with a tool. You might see a tiny amount of brass glittering back at you, but no silver glitter. If you see silver, it's tear-down time. If you don't see silver, chances are there is nothing wrong with the gears. If you can't find the source of the thumping externally,like in the yoke or mount, that is the only reason I would tear it down.
Well unless you told me it was:
grinding on the shifts, jumping outta gear, or the bearings were singing,lol.
 
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Check for runout. Use dial gauge on flywheel and with bell housing mounted check that hole in bell housing is centered.
 
A friend of mine in Red Deer had a spare tranny, his mechanic (expert) checked it over and it needs a rebuild so he is waiting on parts. Once he has it done I am going to give him this one (as a core) and he can check it over. That transmission is the new style, mine was a 1970.

The transmission was only bolted in with 3 bolts as the RL bolt hole was stripped out. I put in a heli coil and I also noticed the bolts were a mixed bag and two of them were too long. I have new bolts now.

I flushed and changed the transmission oil approx 20kms ago, it was loaded with brass glitter (just like before). There is no way that is normal. I ordered a new poly mount as the the original looked haggard (although it was still solid). The rear yoke has no play with the shaft installed. I put a light on the input shaft bearing and it is badly pitted. I "face timed" the red deer mechanic and showed him the front input shaft and he agreed with you folks, the play is normal. I dont want to tear down the tranny anymore as the the original shop may come good on it and I want this guy to document it as he knows a lot more then I do, he may discover a obvious problem.

How do I check the bell housing alignment and runout in layman terms ? I have a magnetic dial gauge.

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Remove clutch and pressure plate. Reinstall bell housing. Attach dial gauge base to flywheel. Set pointer on inside of bell housing transmission hole. Rotate engine which will rotate dial gauge along inside of bell housing hole. Check for runout
 
I am still waiting on the rebuilt tranny, the fellow is still waiting for parts from the US.

I pulled the clutch today and everything looked good except the bearing was loose, it would be able to walk out. I imagine that would cause some problems. I could see a unusual wear pattern on the bearing carrier.

I ordered a new one and I will add a sealer if it is not a press fit. What sealer should I use ? I am not sure why a bushing is not there unless the crank is for a automatic and this is a conversion ?

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I put the new pilot bearing in yesterday, it was loose as well so I used Permatex Bearing Mount #60950 to secure it. I am curious what experience others had with this bearing , was it a press fit, did you use a bonder ? I believe that the loose bearing was contributing to my issues. I researched this bearing application and no one mentions bonding it, I suspect one should.

I ordered #60950 as no one carried it. I also tried to find the Loctite #609 but no one carried it either. My research indicated these are the two best products for this application.
 
Mine went in snug. I'm not a fan of that roller bearing in the first place, for that application, but I wanted to give it a chance. So far it has gone over 100,000 miles, and the last time I looked at the input shaft (2005), it was fine....... but,
I had left the pilot bushing in the crank, just in case
 
Time to remove this thread from the wanted forum. Looks like @Kraftei is getting some good technical information. If you still need a transmission after your work here just start a new wanted thread without conversation.
 
Pilot bearing should need to be tapped in.
Otherwise not good. IMHO.
 
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