TF performance goodies

-
cudamark

cudamark

Well-Known Member
Joined
Mar 14, 2009
Messages
12,398
Reaction score
3,930
Location
San Diego
Is there a way of telling a low gear ratio planetary set from the others without having to count all the gears and taking off my shoes to do the math? Also, are there other factory 904 parts that are desireable for performance use or just go aftermarket? I.E. larger clutch pack drums or other hard parts?
Thanks, Mark
 
Mark I'm not a 904 guru by any means but it's my understanding that you can identify the low gear set trans. by the sun gear. On a standard ratio the sun gear is the same diameter on both sides. On a low gear trans. it's smaller on back side (less teeth). And as for HD/better parts, there is the 904, the 998, and the 999 trans. which are all based off the original 904 platform but the 998 and 999's have more discs in the clutch packs. You have to be careful mixing parts though as they made several changes throughout the yrs. Mostly in the front pump area. You can upgrade the front clutch pack to more clutch discs pretty easy by using thinner ones from the rear clutch pack. Oh yeah, it's also my understanding that the 999 is the only one with a low gear set. Again, I'm not a 904 guru so take this with a grain of salt. I'd love to learn more about them but information is spotty at best.

Here's a pic of a wide ratio gear set
 

Attachments

  • Torqueflite 904 wide ratio gear set.jpg
    93.6 KB · Views: 157
correct about sun gear.....

also the front clutch pac with 5 disc must be used with a matching pump....

also as noted you can put 5 disc in the front 4 disc clutch pac by using the thinner rear disc....
 
Good to know. I just pulled apart a 904 from behind a '75 360 and it has a 4 pinion rear planetary and a 5 clutch front drum. I would presume they would be more desireable than a 3 pinion and 4 clutch, correct? Do you need to use the whole pump assembly or just part of it with that front drum? Do all 999's have the low gear set? If not, can you tell which ones do without pulling the trans apart?
Thanks, Mark
 
Low gear sets started being used in the late '70's or early '80's, about the time lock-up converters started being used. But that adds another interchange problem since lock-up and conventional converters do not interchange. The differences may include the input shaft, pump and valve body. Sorry I can't be more specific but I'm sure someone can provide more details.
 
Yeah, hopefully there is an experienced torqueflite tranny builder out there that knows what to look for and can help us out.
Thanks, Mark
 
You must log in or register to reply here.
-

Back
Top