904 low gearsets

904 low gearsets - 03/17/14 07:29 PM

I've got several mid-late 70's 904's.
I'd like to know if there is a way to find out if any of them have the low gearsets without having to tear them down.
Does the pan rail # stamping give that kind of information?
Any other way to tell short of disassembly?

Thanks!

Here's one:

Attached picture 8077831-100_3639a.jpg

Posted By: John_Kunkel

Re: 904 low gearsets - 03/17/14 07:38 PM

The low gearset didn't arrive until '80, the one pictured is a '71.

Posted By: nomore65BelvJim

Re: 904 low gearsets - 03/17/14 07:52 PM

Thanks for the info John.

Odd on the date though, I pulled that trans out of a 79 Volare.

Posted By: 360view

Re: 904 low gearsets - 03/17/14 09:01 PM

Is there any way that the
low gear planetary out of a 904
could be used to replace the
planetary gears in a 46RH overdrive unit?

As i understand it,
to create the
0.69 ratio overdrive unit
in the 518/46RH/46RE
Chrysler engineers re-used the
1.45 ratio planetary gears out of a 727

1 divided by 1.45 equals 0.69

a low planetary set of 1.54 would create a
1/1.54 equals 0.65 overdrive ratio

Posted By: GO_Fish

Re: 904 low gearsets - 03/17/14 10:47 PM

Quote:

Thanks for the info John.

Odd on the date though, I pulled that trans out of a 79 Volare.

Just means the Volare owner decided to replace his failed lockup 904 with an earlier non-lockup version... And it could have the low gearset installed if he wanted performance...

Posted By: John_Kunkel

Re: 904 low gearsets - 03/17/14 10:54 PM

Quote:

Thanks for the info John.

Odd on the date though, I pulled that trans out of a 79 Volare.

My bad, I read the wrong number...build date is Feb 6, 1979

Posted By: John_Kunkel

Re: 904 low gearsets - 03/17/14 10:55 PM

Quote:

Is there any way that the
low gear planetary out of a 904
could be used to replace the
planetary gears in a 46RH overdrive unit?

No, way different in size.

Posted By: nomore65BelvJim

Re: 904 low gearsets - 03/18/14 04:21 AM

Quote:

Quote:

Thanks for the info John.

Odd on the date though, I pulled that trans out of a 79 Volare.

My bad, I read the wrong number...build date is Feb 6, 1979

So, if it was an 80 or newer, would there be any way to tell by the numbers?

I do drag home an 80's car occasionaly

Posted By: John_Kunkel

Re: 904 low gearsets - 03/18/14 07:31 PM

From what I understand, '80 and '81 were "maybe" but by '82 all transmissions in the 904 family had the low gearset.