View Full Version : A-833 overdrive

it's all dodge
01-31-2013, 04:04 PM
Can the A-833 overdrive handle a well built 360 (built for torque and towing, not racing) ? I have heard the aluminum case might be the issue, I have a cast iron 833 case from a B body that the gears can be swapped into.

When I say well built: 360 with Lunati voodoo cam 253/258 208/213 @ .050 454 lift on 112, would be .485 with Magnum heads, need some heads with quench. Either those or some ported 318 1.88/1.60 302 closed chamber heads, mass airflow is not everything. Velocity.

Long tube headers. Injection with beer barrel or a 600 carb on a factory dual plane.

7200 pound (empty) class C 20 footer Dodge B-300 based 1972 RV. To tow 6,000 and less pound combo. 4.10 gears, with 29" 8.75 16.5 tires.

01-31-2013, 07:07 PM
hello I used one in a 360 12/1 street stock motor with 370hp at the rear tires .on dirt with 11" wide tires and now its behind my 1973 340 dusters about 450hpwith a 456 rear 8.5 rear I do use syn trans fluid in it.the input shaft is the weak link (they say) its not the full thickness from the piliot bearing to the gear end,.which is true,


01-31-2013, 07:20 PM
I don't see why a cast transmission combined with the reversed #3/4 O/D gear and lever wouldn't work in your RV with those 4.10's.

A833's are all relatively stout transmissions. The aluminum case O/D trans was a late model F body production, but they did equip some A body vehicles with a cast iron housing. All of the weak points that these transmissions have are in the aluminum case variations. The cast iron transmissions can take an insane amount of torque behind big blocks.

The A and F body O/D cars had 3.23 and 3.21 8 1/4 axles, some with V8 engines, so I would imagine that the O/D gear can handle your outfit.

I also understand that there are a couple of outfits (I may be thinking of passion performance) that sells the O/D gear and lever/linkage sets. If you already have a builder, that may be the better route, because then you know the history of the synchros and gears would be new.

I'm going to buy an O/D unit, but only because I don't have an 833 to work with for my project. If I had something at my disposal, I'd probably just buy a new gear, synchro and linkage set.

it's all dodge
01-31-2013, 09:06 PM
They did also get used in 1/2 ton trucks and lighweight vans. The van clutch linkage is questionable, but stronger rods can be put in. I am not looking for something to go on a 2000 mile trip, but something to get a racecar to a track with, or to take the rv by itself. I brought it home 110 miles or so with no working speedo, and my lady was behind me in my 2010 Ram. We would stop and I was like, "was I going about 60?" "No, you barely hit 55", she said. It had the power but the 360 was screaming, I thought this aint good to run 3000 rpm or so all the time, lol.

I know it would need 1 to 1 to get up many hills towing, if not second gear for the steepest. But any flat or slight incline/decline she could be towing in overdrive!

I don't mind shifting, much less gears then the trash trucks and 18 wheelers I drove needed!

01-31-2013, 09:15 PM
Yeah, I hear you! Those 4.10's are killing your top end, but you need them with it, especially for towing. I think you'll be fine with a factory O/D gear set. The O/D gear replaces 3rd and they reverse the swing on the 3/4 lever, so the trans actually upshifts 1-2-4-3 if it were coming from a traditional A-833, so if you make the modification, don't forget that your 3/4 shift lever has to swing in the opposite positions.

it's all dodge
01-31-2013, 09:18 PM
Would anyone dare say it is tougher then a NV3500 (which was used behind 318s and 3.9s in 1500 & LD 2500?s

01-31-2013, 09:19 PM
I think with some minor adjustment in the threading on the shift linkage, you could just flop the shift arm upsideown and it would work.
I'm not sure how strong the NV3500 is, but I do know a guy running an A833 behind a ten second bigblock coronet that pulls the wheels a foot at launch with no problems. The cast iron 833's can take some serious punishment. More than I think your RV would be dealing out.

it's all dodge
01-31-2013, 09:32 PM
I think I even have the proper shifter for a van, it's a Hurst with a plate that moves it up and forward about 3 inches.

Other options are swap to A-518, or NV3500, or the expensive option: Gear Vendors. I'm sure that's nice, but $3,000 and I would still want to go thru my 727!

Here's a differant option: a non overdrive NP435 4 speed, IF I had the 1.31 third gear, swap to 3.54 gears (the 435 has steep gears in 1st and second, and I know where 3.54s are on the cheap.) Then use 1 to 1 for flat/slight incline, slight decline, downshift on steep hills. The same truck I know of that MIGHT have the 1.31 gears also has a 4.56 Dana 70 and a 308 headed 360 (89 D-350)

But that's alot of mights and I can probably make what I have work.

it's all dodge
01-31-2013, 09:36 PM
Will, I sure wouldn't be hammering on it! The 3500 is rated at 300 foot pounds, that's why they never put it behind a 360/5.9.

Is that Coronet running a 23 x 1" spline? Or 18 x 1 3/16?

01-31-2013, 09:55 PM
7200 pound (empty) class C 20 footer Dodge B-300 based 1972 RV. To tow 6,000 and less pound combo. 4.10 gears, with 29" 8.75 16.5 tires.

So, we are talking about over 13,000 lbs and haven't even started to count passengers, luggage, supplies and toys?

You sir, are out of your mind to attempt to use that transmission. Either go with a Torqueflite or put a "truck" as in pickup top loader New Process behind it.

If the gearing doesn't suit you either change the rear gear, the tires, or both. If you have the money, there are aftermarket, add--on OD units, with various opinions.

01-31-2013, 09:59 PM
it's running the hemi 18 spline, but the casing and gears, just the same, take the abuse. I'm guessing in the range of about 700-800 ft lbs. I don't think you will have a problem.

01-31-2013, 10:01 PM
I've seen torn 727 bellhousing/ bodies from cars launching hard. I've never seen a damaged 833 casing on shock with 18 spline. Impact torque is a lot harder on parts than sheer torque. I don't think the trans would be a concern. I'd be more concerned about getting a high rate torque clutch in there.

it's all dodge
02-01-2013, 12:34 AM
"So, we are talking about over 13,000 lbs and haven't even started to count passengers, luggage, supplies and toys?"

Passengers: Me driving, and my lady. Less then 375. Now if he sone and his gf came along, add 325. It's a four passenger (legally) but who knows, might see 6, tops, but mostly two.

If it was towing the 6000 and less pound car, I would only go to the local racetrack, so you don't need to pack it full of food, and luggage. A racing suit, a helment, a clean pair of pants. Some food, but not much. Some drinks. Not something we would live in for a week, just an overnight deal, or maybe not even overnight.

Toys? It would be the 3100 pound racecar, on the 1700 pound trailer, and I figure near 1200 pounds for the box on front of trailer, generator, small welder, toolbox, jackstands, lights, floorjack, fuel, 26 gallon air compressor, and extra wheels.

The tires are new. It originaly had 8.00 x 16.5s, but it's hard to get those tires, so I bought seven NEW Firestone Transforce 8.75 x 16.5s. The tires it had were accidents waiting to happen. No more bias ply for me. So I upped it by a half inch or 3/4 inch.

Switching to 3.73s would be only a 10% reduction in rpm, so that's do able but it won't give as good of performance (wouldn't pull as good, won't mileage as well), and it would suck with the 727s low 2.35 or whatever reverse, not that I back up alot, lol. I would still berunning 2600 rpm when not towing.

Switching to 3.54s would only be an option with the above plan and the 435 four speed. Lots of ifs.....

If I went the automatic route, it would be A-518. Too bad the top gear is so low, .69, instead of the .73 of the overdrive A-833, or the NV3500, which is low torque rated. If I went the auto way, I would really want the above mentioned 4.56s, so it could tow in OD, yes, you read that right. The days of the three speed are not so many. Good for racers!

02-01-2013, 02:48 PM
These transmissions were KNOWN to have problems when they were used "back in the day" with trucks. The thing you need to remember is that when you are in OD with one of these YOU ARE using 3rd gear. The transmission is MUCH stronger when pulling in "straight through" which is 4th in the A-833 4 speed, but is 3rd with the OD.

Let's not play weight games. Even the MT weight you posted is quite a bit. Mopar never put these in such a heavy rig, and the ones they WERE used in gave trouble. Used to be common to see these with some wear, and would not stay in gear.

it's all dodge
02-01-2013, 03:41 PM
Well it's either the OD 833 in a cast iron case, or a NV3500 (I am not shelling out $750 or so just for a NV4500 that I dislike the ratios of)
OR, an A-518, and the way I would do a 518 would be with better clutches, a rebuild, a new convertor, and a deeper pan. I already have the huge cooler. Didn't the '94 and up A-518 have bigger lines?

John Kunkel
02-01-2013, 04:00 PM
The problem with the aluminum case 833 is the floating countershaft gear, sleeving the case to make the shaft a press fit makes it as strong as any other 23-spline 833.

it's all dodge
02-01-2013, 04:43 PM
Well I was going to put it into a cast iron case.

I did check the NV4500 gear ratios out, they are about like the A-833 OD, with just a really low 1st gear.

02-02-2013, 11:19 PM
An A-518 would be a sound choice too. I think you will be OK with the 833 O/D as long as you were smart about the 3rd O/D, like I had mentioned it would be in and like 440Roadrunner mentioned. If you basically left it alone in 3rd (final, straight through, 3rd gear for an O/D) when you were towing and climbing or needed any kind of torque, you should be fine.

If you neglect it up big hills or other torque abuse situations, it could pop out of gear. The A-518's can be built to be insanely strong with aftermarket planetaries and rebuilt overdrives. Just be sure to use the right tool to pull the O/D spring or have someone do it who has the right tool. They put 518's behind Cummins Diesels.

it's all dodge
02-04-2013, 10:02 AM
If I had a 518 I would get my step brother who has about 30 years of trans experience, rebuild it. I think they found the 518s limits behind the Cummins, but I was thinking alot of the Cummins 518 stuff would work in the 5.9 518.

I sure wouldn't expect it pull any steep hills in OD, maybe an INCLINE, but there is alot of places it could be in OD towing, mostly flat or decline that aren't steep, because I would use gear to keep her whoa'd down on steep hills.

My friend has a quadcab dually 4x4 (4x6) with a Hemi and a NV4500. The 5th gear is .73, same as the 833 OD is, and it has 4.10s. He also has about a 31" tire. (compared to my 29" tire) He says he can't tow in 5th, well, he can, for some times, but he can't just leave it in 5th. I know that, I don't mind some shifting.

Of course, a mildly built 360 built for torque, will make more low speed torque then a 2005 Hemi. His truck weighs about what the RV does, and has a 4x4 drivetrain power loss.

mopar mad
02-04-2013, 11:14 AM
had a stepside back in the day ,put a 360 in & left the 833 behind it,tore up a trany about ever 6mo. input shaft&front bering

02-04-2013, 01:51 PM
Not sure if you can get a NV5600 6 speed to house up to a 360. I think some have with the NV4500 5 speed. My NV5600 manual 6 behind the Cummins 5.9 has towed far more than 13000. My gooseneck race trailer with it's compressor are generator weights 10,000 empty. My max total weight with truck and towing 3000lb car was 20,700. The trans and clutch hoisted up and over the Denver mountain pass on it's way out to Vegas with no problems. (Though I would not recommend on a winter night. Was a little spooky. I took the northern Wyoming pass on the was back. Farther but flatter.)

The 6th gear is .73 which should suit your overdrive needs. I have been very impressed with the NV5600. I bought because of fears of Chryslers automatics. So far the choice seems to have been correct.

Ray Bell
02-05-2013, 06:39 PM
Originally posted by mopar mad
had a stepside back in the day, put a 360 in & left the 833 behind it,tore up a tranny about ever 6mo. input shaft&front bearing

There'd be two contributors to that...

Applying lots of torque in indirects, and that means extended periods in overdrive with the revs right on the torque band. And not taking notice of the previous post about putting an insert into the front of the main housing to stabilise the countershaft pin.

John Kunkel
02-06-2013, 02:33 PM
Front bearing failure can also be attributed to misalignment, very few people dial in the bellhousing after an engine swap.

And, of course, a missing pilot bushing will do the same. (auto trans motor installed with stick transmission)

Ray Bell
02-06-2013, 05:23 PM
Of course, I should have mentioned that...

Had that problem once myself when I adapted a Fiat gearbox to a Renault engine. We tried to get away without welding the pieces together, it didn't work.