Goin' through a 904

[monoptn]

Recently I bought a 76 360 with a 904 tranny from the junkyard. It was in a 76 cordoba. I took the 904 to the trans shop today for them to go through it. I'm building the 360 to between 300-350 hp...nothing spectacular. Do I need to do anything special to the 904 to beef it up? This will be a street cruiser, not a drag car, and I will occasionally boil the skins, but not rag it too much.

Suggestions?

Also, I'm looking at a 2 for 1 deal. The other day when I got in my 69 GTX to back out of my garage, reverse was gone. The 727 laid down on me. I'm hoping for nothing major, but guessing a band broke, and that after the 904 is back, I'll be pulling the 727 from the X. Any hope for an easy fix? The fluid is topped off.

 

[fishy68]

I don't know 904's well like 727's but I've heard they should have no problem standing up to anything up to 350 hp stock. I would still put in a Trans-go TF-2 kit just to eliminate any overlap and make it shift better. I think just doing this you should be fine.

Have you drove your GTX to see if it has all 3 forward gears working? If all the forward gears work it is a rear band/servo problem. If you don't have 3rd gear and reverse it's the front clutches. About the only way it will be an easy fix is if it's a rear servo problem. Anything else and the trans. has to come apart.

 

[monoptn]

The day I pushed it back, we were recovering from a light snow, and there was dried salt on the roads. I only drove it around the block, and don't know if 3rd works yet or not. Should I hope that 3rd is, or is not working?

 

[fishy68]

You should hope that it is working. Like I said above if 3rd isn't working you for sure have to pull the trans. for a rebuild. If all forward gears work correctly you still have a chance that it is just a rear servo problem that can be fixed without removing the trans.

 

[66dartman]

That 904 will be fine behind your 360. Use the good racing clutches and Kolene steels as well as racing bands (the red lined ones). Chris at Andrews set me up with the parts for my 904 and it works great. The 727 is just a bigger version of the 904 so building it will be very similar. The ATSG manuals are good building info.

 

[djwhog]

Agree with dartman, also you should get the better servos and intermediate band apply strut and they do make a forward drum piston that supports an extra disc too. Many of these HD 904's were in Taxi cabs and some trucks. Go with a good TF2 kit and a decent torque convertor too. I would also install a good trans cooler if you live in a warm climat or drive in heavy traffic.

 

[AdamR]

I agree, a good rebuild with quality parts and maybe a TF-2 Trans-Go shift kit. My 904 lasted years behind a low 10 second Duster. No reason your would be fine behind a mild motor.