Another SM465 question - top covers interchangable?

[djohnsn]

I have a SM465 that came out of an 89 1-ton. The top cover is broken around the shifter and will have to be replaced. I have not been able to determine whether or not the aluminum cover and cast iron cover are interchangable. Can anyone tell me for sure?

 

[Seventy4Blazer]

they should be.....
but i have never seen an aluminum cover 465....
so what im really saying is i got no clue...
sorry
Grant

 

[djohnsn]

My information could be flawed, but from 89 and up an aluminum top cover was used. What I have not been able to determine, is if there are any significant differences in the later model transmissions to make the covers not interchangable

 

[dyeager535]

Anyone got a 1989-91 parts manual?

I've got '85-88, so if AL was in place from '89+, we could cross reference some part numbers.

I have a feeling very little changed.

 

[djohnsn]

I do not have a parts manual but was told that the 89+ number was 8672011 or 8672111. It has been discontinued by GM.

 

[dyeager535]

3952668 is what was used '85-88.

That number doesn't show in gmpartsdirect, but 3rd/4th shift fork does. (for example) Unfortunately at $70.

 

[jarheadk5]

I will do my damndest to remember to ask at work on Monday.

 

[jarheadk5]

OK, I asked the gurus at work, and the answer is "You should be able to". To the best of their knowledge, there weren't any major changes to the main case casting that would require a different top cover casting (especially near the end of the production run of the tranny). The material change (Fe to Al) was probably driven by weight- and dollar-saving efforts.

Hope this helps...

 

[djohnsn]

Thanks for the information. Someone else told me that the shifter location changed between the two tops, but I can't verify this.

I was not able to find a replacement aluminum cover, so I picked up a cast iron one. It looks like it should work, but I have not had time to try it yet.

 

[jarheadk5]

That's cool.
Even if the shifter location changed between Fe and Al covers, they should still be usable on any 465 trans. The relative locations of the gears and housing bosses are consistent among all GM-version 465's (at least that's what they told me at work).

 

[spoolnaround]

shifter location did change. The cast cover is appx 3 1/2 inches further back than an aluminum cover. I have one if you need it, PM me.

 

[imiceman44]

[ QUOTE ]
shifter location did change. The cast cover is appx 3 1/2 inches further back than an aluminum cover. I have one if you need it, PM me.

[/ QUOTE ]

The shifter is more forward but the rails are still the same place so they are interchangeable.
The only problem I had when I switched covers although both Fe was that the new one sometimes gets stuck in neutral, it might need some fine tuning with a file or emery cloth to be lined up perfectly, it works again after I remove the shifter and wiggle it in the hole then put it back in.
Tolerances is the only explanation I could give this issue.
/forums/images/graemlins/dunno.gif

 

[jarheadk5]

Could be a burr in the cover where the rails ride, or a rough spot on a rail itself. Emery cloth would be the best bet; I revive at least 1 Roadranger topcover a week this way.