904 swap help.

Posted By: shamefulcuda

904 swap help. - 06/08/13 09:22 AM

I'm wondering if a 904 trans out of a 85 dodge truck will work in my 72 challenger? He also has a 904 out of a 78 dodge but he doesn't know if it works, would that also work in my car ok? I'm just trying to get my chally moving this weekend. The 904 in truck I can drive so I know it works. Just seems to new to work in my car as I wasn't aware they still were producing 904s then. Thanks for any help

Posted By: meep_meep

Re: 904 swap help. - 06/08/13 09:54 AM

It's the same transmission, except for the speedo gear and housing will have to be swapped from your old transmission...

Posted By: scratchnfotraction

Re: 904 swap help. - 06/08/13 12:54 PM

use the TP valve lever and the gear selector lever from the trans in your car along with the speedo gear/housing.

that keeps the linkage correct for the car and speedo correct.

85 truck may or may not have the lock-up trans,you tell by the input shaft on them.

your 72 904 would be non lock up,the 78 904 maybe non lock up

lock up =better MPG

non lock up = more perfomance

splines to the end are non-lock up

1.5" smooth end on tip of input is a lock up

the TC between the 2 do not mix.

Posted By: shamefulcuda

Re: 904 swap help. - 06/08/13 05:12 PM

So my 72 is non lock up trans, but if the truck one ends up being a lock up trans as long as I use the converter out of the truck as well I'm ok? Thanks this is really helpful

Posted By: Supercuda

Re: 904 swap help. - 06/08/13 11:40 PM

Quote:

So my 72 is non lock up trans, but if the truck one ends up being a lock up trans as long as I use the converter out of the truck as well I'm ok? Thanks this is really helpful

Maybe.

Depends on what engine is in front of the 904, 318 in both then yes. I'll assume it's a V8 here, I suppose it could be a slant 6 in both.

They make 904 type transmissions till 89 in the M bodies,

Posted By: scratchnfotraction

Re: 904 swap help. - 06/09/13 12:22 AM

Quote:

Quote:

So my 72 is non lock up trans, but if the truck one ends up being a lock up trans as long as I use the converter out of the truck as well I'm ok? Thanks this is really helpful

Maybe.

Depends on what engine is in front of the 904, 318 in both then yes. I'll assume it's a V8 here, I suppose it could be a slant 6 in both.

They make 904 type transmissions till 89 in the M bodies,

you wont really know till you pull it out and ID it...72 could of had a trans replaced with anything by 2013.

post the # along the edge of trans pan rail from driver side..this will tell what yr the case is. but agian, many things could have been done to it since then on the inside.

Posted By: cudazappa

Re: 904 swap help. - 06/09/13 01:11 AM

If your 72 is a floor shift the truck trans may not have the boss cast in it for the floor shift bracket. BTDT.

Posted By: scratchnfotraction

Re: 904 swap help. - 06/09/13 01:48 AM

Quote:

If your 72 is a floor shift the truck trans may not have the boss cast in it for the floor shift bracket. BTDT.

thats a very good point and something to watch for with floor shifters