Gearbox casting numbers

[Ray Bell]

I'm trying to get some kind of identification on a gearbox and I can get casting numbers. But nowhere does it seem that anyone has any tables or pages with these on.

I can find plenty of sites with engine and rear axle casting numbers, but none for gearboxes. Am I just poor with google or is it just that we need to do it ourselves?

[John Kunkel]

The casting numbers are pretty much useless for identifying a transmission, if the trans is automatic the part number is stamped on the drivers side pan rail; if standard, there might be a raised pad on the passenger side with stamped data but earlier than '68 there will be no data pad.

[Ray Bell]

Are there ways of identifying what these numbers mean, then, the ones on the pad? Where can I get that info?

[dwc43]

There's a pad on the right side of the A833 with stamped numbers. 1st two letters will be the manf. plant (PP), next three are the tranny model (833),next four numbers are the manf. code and the rest is the last four digits of the dequence number in your v.i.n.

[Ray Bell]

Any idea what pp833 149 1 would mean then?

Just to save me waiting three months to find out... thanks...

[John Kunkel]

The digits following the 833 are the build date based on a 10,000 day calendar, the trouble with a 10,000 day calendar is that it's repeated every 27 years or so.

A build date 1491 would be in late '65 but there were no number pads on '65 transmissions so the date must be 149 which would be early '89. An '89 833 4-speed is the OD version, probably from a light truck.

[Ray Bell]

Thanks John, that's interesting...

According to the site I was reading yesterday, the overdrives came much later than that. Where is there accurate information on this subject?

[John Kunkel]

The overdrive 833 was introduced in '75 and shortly after that only the OD version was available; they were used up through the eighties, I believe '90 was the last year.

[Ray Bell]

This box, however, looks like it's been in the dirt for thirty years! It's a roughy...

Here's a pic of it:



So when did the aluminum case begin?

The guy says the input shaft doesn't turn... that doesn't bode well, does it? and there's a selector missing. But as a source for some parts, it was cheap. I reckon the alloy main case would be much lighter than the iron one.

[dwc43]

The whole rear shift fork is missing. Passon Performance will have parts for it.

[Ray Bell]

So will eBay... but this really is probably going to be a parts box... I'm just trying to establish what might be in it.

Nobody seems to care, actually. We've looked at a mass of these on eBay and asked seller after seller to let us know the low gear ratio. So far all we've ever been told is a stack of numbers from castings and stampings.

Doesn't anyone understand how to establish what a first gear ratio is? Or whether or not a gearbox has an overdrive top gear?

[dwc43]

That's could be an o.d. box. One of the easiest ways to tell if it's complete is that one shift lever will point up and one will point down. I'll look and see if I have an o.d. box. I know I have a 4 spd. and a 3 spd. but I am not sure if I have an o.d. box. I can get you the gear ratios if that's what you need, once I get home this morning. I have a book listing all 4 spds, and auto gear ratios for almost all the models.

[Ray Bell]

You have a book on these things? That's great...

If there's any chance you can scan the pages that give this detail and e.mail them to me as .jpgs I would be very grateful. I'm looking to find out detail like teeth numbers on different gears in the different gearsets and so on, and how to identify them if at all possible.

It's not just this gearbox, but I want to be able to pick all of them if I can. I think this one probably is an overdrive box because the bearing retainer base does look pretty big, which is the first identifying mark.

What I am saying is the difficulty I have getting answers as we browse eBay and find things, or follow up other advertisements on the net for A833s. Nobody seems to want to actually turn shafts and check things that way. It's so easy.

My e.mail address is r@ybell.net ...

Thanks dwc.

[dwc43]

I'll post it in a new post and put the link to it here. That way someone could sticky it to the top or put it in the tranny section and save it for all to use. I can't scan it right now, I have not set the scanner up to the new lap top yet since I have not needed it lately. I need a new usb cable too.

[dwc43]

There's the link to where I posted the info. For some reason after I posted it, my columns are no longer straight. If I got to edit they look perfect. Can't figure it out. Hope it don't hurt your eyes too much. I tried.



http://www.moparchat.com/forums/newreply.php

[John Kunkel]

More 833 info:

http://www.slantsix.org/articles/4-s...fourspeed1.htm

[Ray Bell]

Originally posted by dwc43
There's the link to where I posted the info. For some reason after I posted it, my columns are no longer straight. If I got to edit they look perfect. Can't figure it out. Hope it don't hurt your eyes too much. I tried.

http://www.moparchat.com/forums/newreply.php

The link's wrong, dwc... that's a link to the reply page...

John, I've looked through the Slant 6 page too. So far I've not found anywhere that lists all the important stuff.

And sellers simply won't tell us what they have either. They stop at casting and stamp numbers.

Now, we're looking for a gearbox for a race car, right? We've got a 9,000 mile wide ocean to bring the box across, so the freight is heavy... heavier than the gearboxes... there are several boxes, from what we've been able to establish so far, that would suit us. There are several, however, that would be useless.

Is it too much to ask of these people? Just stick it in first gear and tell us if one turn of the output shaft gives just under 2.5 or just over 2.5 turns of the input shaft... or just over 3 turns... to me, this seems easy.

The buyers can be equally crazy. One I pursued last week I could tell from the photos that it was an overdrive box. The seller was being asked by all and sundry about the build date and the bearing retainer size and input spline count... and by me, quite directly if it was an overdrive box. Which I told him I wanted, and I wouldn't mind having for my other project.

But he never answered that question, nor, to my memory, the bearing retainer size. But he answered plenty about casting numbers and stamped numbers and he told all it was a 23 spline, all of which is inconclusive.

You could tell from the questions that people wanted to know if it was an overdrive box or not. But nobody was asking that directly except me, and he certainly wasn't answering that question.

Anyway, thanks dwc, I look forward to seeing that post of yours... I might go hunting through with the search, anyway.

[Ray Bell]

Found it...

http://www.moparchat.com/forums/showthread.php?t=97532

If you edit it and use dots between the numbers instead of spacers you'll straighten up those lines.

Can I assume the first number in each line of the 'mainshaft gears' is the input shaft count?

Man, that is helpful information!

[Ray Bell]

Kind of condensing dwc's fine work and putting it into this thread...


GEAR TEETH COUNT (PRIM is input shaft/front gear of countershaft)
MAIN SHAFT GEARS ............................COUNTER SHAFT GEARS
........PRIM 3RD 2ND 1ST......................PRIM 3RD .2ND 1ST
2.44 ..22 ...26 ...30 ..33 .71/74 big block..26 ..23 ...20 ..16
2.47 ..25 ...29 ...34 ..35 ....70/74 T/A......30 ..26 ...23 ..17
2.65 ..21 ...26 ...30 ..33 ..-'70 Hemi etc....27 ..24 ...20 ..16
2.66 ..24 ...29 ...34 ..35 ....-'70 std V8s...31 ..27 ...23 ..17
3.09 ..22 ...27 ...32 ..35 ......Slant Six......33 ..29 ...25 ..17
2.65 ..21 ...24 ...28 ..33 ....RED STRIPE....27 ..26 ...22 ..16
3.09 ..22 ...18 ...30 ..35 ....OVERDRIVE*...33 ..37 ...27 ..17
* In overdrive, third gear becomes fourth gear, tooth counts shown for third are actually overdrive.

RATIOS IN DIFFERENT A833s:

SMALL SPLINE (23 spline input)
70 AND EARLIER .........2.66 1.91 1.39 1.00

'70 T/A '74 - '74 ........2.47 1.77 1.34 1.00

'65 /6, '74 - '75 318 ...3.09 1.92 1.40 1.00

'75 - '80 O.D. ...........3.09 1.67 1.00 0.73

COARSE PITCH GEARS (18 spline input)

'70 AND EARLIER .......2.65 1.93 1.39 1.00

'71 - '74 ..................2.44 1.77 1.34 1.00

RACE RED STRIPE
GEAR SETS ..............2.65 1.64 1.19 1.00

[Ray Bell]

Now that I've coerced that out of you... two more questions...

1. Can we get the tooth counts for the 3-speed boxes?

2. Which, if any of the 3-speed boxes have the same gear centres as the A833?

[dwc43]

I'm looking for it.

How about this little chart. 1.93 is 2nd gear and 1.39 is a typical A833 gear set.

TRANNY GEAR.........AXLE RATIO.......FINAL GEAR DRIVE
.....1.39.................3.00................4.17
............................3.50................4. 86
............................3.90................5. 42
............................4.30................5. 97
............................4.80................6. 67


.....1.93.................3.00................5.79
............................3.50................6. 75
............................3.90................7. 52
............................4.30................8. 29
............................4.80................9. 26

[Ray Bell]

You know, while the 2.44 first gear option is a pretty good one, and I mean here for racing of the kind we'll be doing, there's not much otherwise to give real praise to these as racing boxes.

But, let's face it, they weren't built for racing. They were built for road cars, and the Red Stripe box would have been, I would say, for Nascar type use. Otherwise top and third are just too close together. But great for picking up again after losing a tow, or for conserving fuel when you're in a bunch.

So, thanks to the good work dwc has done, I've been able to conjure up some possibilities for economical modifications that will give us pretty good ratios for our purposes... like this:

2.67 1.66 1.297 1:1

That, believe it or not, is using mostly 3.09 gears, the primary drive modified to take the 2.66 input shaft and primary drive on the cluster... and a special gear made for third with a (29/29) direct ratio. The 29-tooth gear is cut on a smaller diameter than the original 29 on the cluster (fairly easy to do) and, using the original third gear as a base, the gear is ground down, a ring shrunk and welded on there and the other 29-tooth gear cut into that.

Sure, a fairly big jump from first to second, but it would be great off the line, maybe lag just a little on that first gearchange, but you'd never see first again in a race on most circuits here.

I conjured up something different again for Bathurst.

[dwc43]

Glad that helped some. I did not find the teeth count for the 3spds though. I think I have then here somewhere, but I just can't find them.