307/308 cases

[Bobfish]

Question One.... Whats the difference between the 307 and 308 cases and how can I tell them apart?? Casting #'s?? Thx, Bob

[Changin Gears]

I just look at the hole that the bearing goes in with my calibrated eye.  Don't know about casting numbers but, if  its an aluminum case, chances are its an OD case with foating counter shaft which I don't like.

[Bobfish]

So your saying they have a different input shaft bearing??

[Changin Gears]

Right, the 18 spline trans and some of the 23 spline big block trans used the 308 bearing.  All the small block (non-OD)  trans used the 307.

[Bobfish]

Would I be corret then in infering ( not assuming!) that OD cases were 308?? Bob

[Changin Gears]

I believe so, all the ones I have seen are.

[rallye73]

I think my trans had both the 308 and 307 in it. I'd have to ask the  guy who rebuilt it. Pretty sure that's what he told me. The original 308 bearings made by SKF are not longer made. I think Passon snatched up all the remaining one out there. What is left is chinese bearings which I wouldn't use unless I absolutely had too. We got lucky and found a couple of the SKFs still out there. BTW my trans is a 23 spline none-OD small block.

[Changin Gears]

All A833's have 2 of the 307/308 bearings.  The one in the main case is the one discussed so far.  There is another in the tailhousing.  A/F bodies use the 307, B/E bodies use the 308.

[Bobfish]

Do either of you have the SKF,OEM or other 308 part numbers  I can use for a cross reference to Timken, BCA, INA, Ford, GM, AMC etc?? Sometimes ya never know what ya can find out there! AND yes Ford, GM, and Chrysler did use some of the same parts. Thx Bob

[Changin Gears]

307/308 is the part number, with different suffixes or prefixes for # of balls, with/without snap-ring groove etc.

By the way GM actually used the a833 behind diesels in trucks in the 80's.  They have the GM input shaft and bolt pattern.