wanting to fit a circa 1970 a-833 (has the 4.35 diameter retainer) to an OD slant six bell. From moparparts america I purchased a 3878596 bearing retainer, the one mentioned in posting as a 5.125 OD retainer with the bolt pattern from a 4.35

,, the box I received has the 3878596 part number, but the retainer looks to be a common OD tranny retainer with the 5.125 OD..and the wide mounting bolt spacing

in fitting the new retainer to the a-833,,
1) is there any reason why I could not have new mounting holes bored and threaded into the case, and use the OD bearing retainer, The transmission would need to be torn down,, it needs that any way,,
2) Would another option be to drill the small bolt pattern mounting holes into the OD retainer? With this change the bolt holes would be inside the gasket face, so I would need to fill the space around the bolt holes with a filler / epoxy.

Here are photos of the two retainers, the original 4.35 and the new 5.125.
the photo of the 5.125 by itself, I put grease on the face of the input bearing in the tranny and slid the OD retainer on,, to verify that the bearing contacts the machined ID of the OD retainer,, it does.
http://www.flickr.com/photos/13718356@N ... 651486955/

The A833OD bearing retainer is meant for a larger input bearing. The recess in the OD retainer for the input bearing is obviously larger. You could put the smaller bolt pattern on the OD retainer, but what would center the retainer on the input bearing? You could drill and tap the tranmission case, but again, what would center the retainer on the input bearing and keep them concentric? When putting a standard 4-speed behind an OD bellhousing I made an adapter ring to properly center the transmission.

Don't forget to read or reread the 4-speed article. http://www.slantsix.org/articles/4-spee ... speed1.htm

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Joshua

I eventually got the right one from Passion Transmission, but it cost 94.50 with a new seal and gasket. It's the one on the left below:



I'll update the old thread.

the importance of centering of the bearing retainer to the bearing housing is good point,,an off center shaft seal would wear prematurely,,

thanks

It's not just the seal I'd be worried about. If the crankshaft and the transmission are not concentric you'll wear out the pilot bushing, the input bearing, the pocket bearing that supports the main shaft and may have shifting and clutch release problems. Use the bearing retainer that's meant for the transmission and make a bushing to fit the bellhousing or get the correct adapter bearing retainer as fxmax did.

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Joshua

Josh,
I agree with the importance of keeping the transmission and crank-flywheel-clutch assembly aligned, I'm just not crazy about the idea of spending 90.00 for a 40 year old critical part. It may come to that,, just not yet..
Keep in mind the front bearing retainer does position the front seal so it is concentric to the outside diameter of the front bearing, it also keeps the front bearing from walking out of the case, it may also position the front bearing square in the bore. The front bearing retainer does not control the radial runout of the input shaft.
Check the side to side play on the input shaft of an a-833, remove the front bearing retainer and check the side to side play again,, if you see any difference it is due to the minor influence of the front seal. And the front seal certainly was not designed to control input shaft runout.

I know the input bearing retainer does not control the radial position of the input shaft. The pilot bushing and the input shaft bearing share that duty. This is one reason the concentricity between the input bearing and the pilot bearing must be maintained. The pilot bearing retainer must also be concentric to the input bearing and the counter bore in the bearing retainer must fit the input bearing to achieve that.

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Joshua

well said and I agree,