Splines and retainer

[CherryBomb]

Hey all. Quick overview. Was originally going to 440, A833OD swap my small block auto 66 Charger. Got the motor done, got the transmission done, ready to roll. Since then, I picked up another 66 Charger, factory 383 4 speed car though. Two questions, hoping I can use the existing bellhousing, and possibly clutch/flywheel if they aren’t toast.

- My reading (Hemmings) says the 383 always came with a 23 spline input shaft, is that correct? I believe that’s what my new OD trans currently has as well.

- Is there any way to know the size of the alignment hole on the bellhousing before pulling it? I know I need to swap or machine to a smaller retainer diameter, but there appears to be a few options.

Normally, I would just pull the motor and check the stuff then order it. I have very kind family members who want to get me stuff for Christmas though, and there’s no way I will be able to have the 383 pulled by then to check

 

[dvw]

This should help. Go to the technical section sub heading bell Bellhousings - Mopar A833 4-Speed Transmission & Component Specialists
Doug

 

[pnora]

The way I read your post you already have a rebuilt 440 that you hope to put the 4 speed behind. Is your crankshaft correctly sized for the pilot bushing?

 

[PurpleBeeper]

1. Yes, all 383’s start life with a 23-spline transmission, but that doesn’t matter except matching the numbers mber of splines in the clutch disc.
2. I’m not sure, but I suspect you can determine the bellhousing hole by the casting number (?). Lakewood made some adapter rings if using a small hole transmission in a big hole bellhousing. Also, you can swap input shaft bearing retainers on the transmission to match the bellhousing hole you have

 

[4speed68rt]

You better talk to BREWERS.

 

[R413]

3 sizes of bell housing Holes. 4.35" 4.80" and 5.125"

Now we can only say what your Charger came with new which is a 4.35" No way to know what was swapped on there.

You need to make a bellhousing for a BB and OD 4 speed. Chrysler never made one. Don't know if there is enough meat on a small pilot hole bell to do it.

1966-67 has small pilot hole in bellhousing 4.35", SB, BB, even 440 and hemi GTX. I'm not making this stuff up I own these cars.

68 and up BB mopars had the medium size bell housing pilot. 4.80" 68 and up small blocks up still used the small size hole 4.35

The OD 4 speed has the largest size, 5.125" and only ever came with an OD 4 speed on a small block and slant 6. So there was never a BB bellhousing with the large pilot hole for an OD4 speed. You can get one machined bigger.

The adapter ring is from small to medium size. 4.35 to 4.80. Select by Category - Mopar A833 4-Speed Transmission & Component Specialists

 

[59pwrwgn]

The od bearing retainer can be cut to fit the 4.80. That's what I did with no problem. I think at 4.35 you either cut into the retainer bolt circle or maybe there isn't room for the bolt head, not completely sure on this

 

[R/T Boy 67]

The OD transmissions came with either a 307 or a 308 bearing. If yours has a 307 bearing then you can buy a retainer to fit any bellhousing. If it is a 308 then you can buy a retainer for only the 4.80" bel,housing.

 

[CherryBomb]

The way I read your post you already have a rebuilt 440 that you hope to put the 4 speed behind. Is your crankshaft correctly sized for the pilot bushing?

Pilot bearing is already installed in the motor, was built with the intention of a 4 speed going behind it

 

[CherryBomb]

The OD transmissions came with either a 307 or a 308 bearing. If yours has a 307 bearing then you can buy a retainer to fit any bellhousing. If it is a 308 then you can buy a retainer for only the 4.80" bel,housing.

I will look into this, if that is true and I have a 307 bearing, then I could get a 4.35" retainer and I am set? Based on another post, sounds like the factory bell housing has the 4.35" opening most likely.

 

[CherryBomb]

3 sizes of bell housing Holes. 4.35" 4.80" and 5.125"

Now we can only say what your Charger came with new which is a 4.35" No way to know what was swapped on there.

You need to make a bellhousing for a BB and OD 4 speed. Chrysler never made one. Don't know if there is enough meat on a small pilot hole bell to do it.

1966-67 has small pilot hole in bellhousing 4.35", SB, BB, even 440 and hemi GTX. I'm not making this stuff up I own these cars.

68 and up BB mopars had the medium size bell housing pilot. 4.80" 68 and up small blocks up still used the small size hole 4.35

The OD 4 speed has the largest size, 5.125" and only ever came with an OD 4 speed on a small block and slant 6. So there was never a BB bellhousing with the large pilot hole for an OD4 speed. You can get one machined bigger.

The adapter ring is from small to medium size. 4.35 to 4.80. Select by Category - Mopar A833 4-Speed Transmission & Component Specialists

Thank you for the detailed response, super helpful! I was looking at the 4.8" retainer, but it sounds like that won't do the trick. The car is numbers matching, so it is the factory bell housing for sure.

 

[59pwrwgn]

The small retainer has a smaller bolt circle. My 4 speeds are somewhat buried and it's 3 degrees out. But from what I could measure the early 70s sb had a 3 5/8 circle and the 69 bb 4 1/8 circle and the 70 np445 4 1/4. I think you will probably find that you either need to bore your bell, find a 68 up bell or swap cases. Swapping cases may be the smart choice. Unlike the iron cases, the intermediate shaft is not a press fit on the aluminum cases. Nor is the case bushed. Every time you shift and the harder you shift this clearance cause the intermediate shaft to oval out the hole in the case.

 

[R/T Boy 67]

Yes, if you have a 307 bearing you Can swap in whatever retainer you need.

 

[R/T Boy 67]

For easy ID, the 307 has a 3.70" bolt circle, and the 308 has a 4.16" bolt circle.

 

[R/T Boy 67]

The front of an overdrive trans is the same as most any four speed. Two bearing sizes and two corresponding bolt circles. 3.70 and 4.16. Brewer's should have all the different retainers, except the one that does not exist. The 308 bearing 4.35" outside diameter retainer.

 

[CherryBomb]

For easy ID, the 307 has a 3.70" bolt circle, and the 308 has a 4.16" bolt circle.

Now that is an easy thing for me to check! Thank you for the info, will measure that this weekend and chime back in.

 

[CherryBomb]

It will be interesting to hear what you find on this adventure.

We will will see what can be done. I didn't see any parts on Brewers for this swap

Brewers sent me a comprehensive estimate earlier in the year when I was planning on doing the big block swap into the small block car, it does appear they have all the parts. Budget is the real thing there, as always haha. I was hoping to get away with using some of the factory parts that came with the car to cut down on cost. The bellhousing and retainer Brewers offer would be $5-600 before shipping, and that's before I even touch the clutch and flywheel.

 

[R413]

The front of an overdrive trans is the same as most any four speed. Two bearing sizes and two corresponding bolt circles. 3.70 and 4.16. Brewer's should have all the different retainers, except the one that does not exist. The 308 bearing 4.35" outside diameter retainer.

Then why did they use that 5.125 retainer diameter? Is there some benefit that we don't know about?

 

[R/T Boy 67]

I don't know why they did it, I ask myself that question a lot about muscle era mopars. Here is a picture of a 307 bearing overdrive retainer. All that material outside of the bolt circle is doing nothing, and could be machined down to 4.80" or 4.35" to fit your bellhousing, or just replace it with a different one. Ignore the 2.125 in the heading, it is corrected in the text.!

 

[CherryBomb]

I don't know why they did it, I ask myself that question a lot about muscle era mopars. Here is a picture of a 307 bearing overdrive retainer. All that material outside of the bolt circle is doing nothing, and could be machined down to 4.80" or 4.35" to fit your bellhousing, or just replace it with a different one. Ignore the 2.125 in the heading, it is corrected in the text.!

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Next time I am at the shop where my transmission is, I will check that bolt circle and see what I've got. I did e-mail Brewers to see what they've got. Do you think it's worth it to go with the billet retainers they offer vs the cast ones? Not sure if that would help "rigid-ify" some parts considering it's an OD, or if I would be wasting my money.