OD manual trans into 73 Challenger

[S-S-P]

I am wanting to put a 340 and an OverDrive (Aluminum Case 1975+) 833 4-speed into my 73 Challenger and am running into potential trouble. I have two smallblock bellhousings casting #3743859 but they do not seem to fit my OD Tranny.

According to Brewers the Casting # 3743859 "small block bellhousing cast #3743859 to fit 1975-6 A-body/1975-80 F-body/1976-80 truck (can also be used in B/E applications with appropriate fork pivot bracket)318/360 A-833 overdrive applications, 5.125" bearing retainer opening".

http://www.brewersperformance.com/products.asp?cat=27

The Center hole on both bellhousings measures 5-1/32" or 5.03125" which is too small to fit the tranny bearing retainer of 5.125".

First, is Brewer's wrong? They claim the 3743859 has a 5.125" hole and neither of mine do.

Second, why such an oddball size? My references only show three Bearing Retainer sizes for almost all Mopar muscle-year combos: 4.35", 4.80" and 5.125"

Does anyone here have an 833 trans with a 5.031 BR size? Has anyone mounted an OD trans with the 5.125" BR in their 70-74 smallblock Cuda or Chally?

Any input would be appreciated.

 

[ramenth]

Nope, Brewers' isn't wrong. The 833-OD used a huge bearing retainer comparatively. You'll need the bellhousing to fit the OD trans. Or, if you have a good machine shop near you, you can check to see if they can cut one of your existing bell's to fit.

Now, more importantly, the 833-OD should be used for low horse applications. The aluminum case is the weak point in the design. Remember, these transmissions were designed when the CAFE laws were really kicking it, demanding a certain fuel mileage across the fleet. Manufacturers were forced to go lighter in a lot of places and substituting the cast iron case for a new aluminum one was the way to go. The horsepower wars were over and the OD was meant to help with the CAFE laws.

 

[Chryco Psycho]

Actually the far easier solution is to remove the front brg retainer & have it machined down to fit the hole in the bel you have , it is very simple to machine the retainer in a lathe .
Secondly do not believe the 833 OD is weak crap , the alum case is the problem but the 63 -66 hemis 833 used the alum case also , you can machine steel bushings into the alum case if you are worried about it . I have been using the 833 od in everything , maybe if you put 100,000 miles on one it would pound the case out ! I had a 440 Duster & no trailer so I had to drive the car to & from the race track with 4.30 gears , the car had over 500 hp ran mid 11s @ 120 MPH & pulled the front wheels over 2' on every launch for 9 seasons using 29 x10.5 slicks & ladderbar suspension , I distroyed 3 diffs & never hurt the trans. I later moved the drivetrain into a tube chassis cuda with 14x32 slicks , changed to a larger clutch with more bite as well , I launched the car on its first pass at 3000 rpm just testing the car & I tore 37 of 43 teeth off the ring gear & all 10 teeth of the pinion on the launch , still never hurt the 833 od

Weak Huh !!

You will have to modify the 3/4 shift rod , just needs a bend in it to clear the cross member as the shift fork points down not up

 

[ramenth]

Actually the far easier solution is to remove the front brg retainer & have it machined down to fit the hole in the bel you have , it is very simple to machine the retainer in a lathe .
Secondly do not believe the 833 OD is weak crap , the alum case is the problem but the 63 -66 hemis 833 used the alum case also , you can machine steel bushings into the alum case if you are worried about it . I have been using the 833 od in everything , maybe if you put 100,000 miles on one it would pound the case out ! I had a 440 Duster & no trailer so I had to drive the car to & from the race track with 4.30 gears , the car had over 500 hp ran mid 11s @ 120 MPH & pulled the front wheels over 2' on every launch for 9 seasons using 29 x10.5 slicks & ladderbar suspension , I distroyed 3 diffs & never hurt the trans. I later moved the drivetrain into a tube chassis cuda with 14x32 slicks , changed to a larger clutch with more bite as well , I launched the car on its first pass at 3000 rpm just testing the car & I tore 37 of 43 teeth off the ring gear & all 10 teeth of the pinion on the launch , still never hurt the 833 od

Weak Huh !!

You will have to modify the 3/4 shift rod , just needs a bend in it to clear the cross member as the shift fork points down not up

I stand corrected by the above experience.

I do, believe, that the bearing retainer being cut down or the bell being opened up is half a dozen of one, six of the other.

 

[Chryco Psycho]

It is easier to just clamp the snout of the brg retainer & just trim it in a lathe , I have probably machined down 30+ this way , trying to hold a bel on center & cut it is more difficult .
The Myth is that the OD is weaker & some of the later OD into the late 80s were weaker with 1/2 the splines on the syncro hub & some other internal changes but the majority of these can be found in wreckers for $150 or less & for the cost if you can break one just get another for $150 & bolt it in , They all use the HD Hemi brgs & steel shift forks . I have lost count of how many I have installed & I have yet to see a broken one in person . I had a slant 6 truck with the 833OD & I have no clue how many times the odometer had been around but I put close to 100,000 on it daily driving it with no issue from either the Slant or the 833OD , while getting 24 mpg !! I also shaved the head .100 to increase the compression added a 2 bbl intake & 500 cfm Holley 2 bbl carb , unlike most slants it had a ton of power above 70 mph !!

 

[S-S-P]

Thanks for the tips.

I am still confused about the oddball size. Surely not all my books and shop manuals are wrong.

 

[Chryco Psycho]

I have only ever seen the 3 sizes , 4.35 , 4.80 & 5.125

 

[S-S-P]

I just bought an OD bellhousing with the ball-type clutch fork setup.

I hope this is the ticket, because I hate cutting on good OEM Mopar parts. And I really thought this OD trans would be nice to offset my low rearend gears at cruising speed.

I'll post how it goes...

 

[Chryco Psycho]

That will work to a point , I think you have to shorten the release fork though , the truck one is too long unless you got a Aspen / volare one

 

[bad440]

If you are really serious about an overdrive for a Mopar, check out Passon, they have anything you need for a Mopar 833,(and O.D.) and also check their latest overdrive, the A855, a complete bolt in 5 speed overdrive, look's identical to the A833 with a bulge in the back end to accomodate a fifth gear. If I had a manual trans in my Challenger, I would definitely be going this route.

 

[Chryco Psycho]

Pricey but definatly a great option

 

[Big Jim]

Been a machinist for a long time- lot easier/quicker to chuck a bearing retainer in a lathe and dial in the run out to maintain concentricity than it is to indicate a bell on a lathe faceplate or cnc mill-if it's not perfectly centered when you cut it it'll always be off center. Here again, just my .02