Being a lock up does not make it a bad tranny. The only thing different is the converter has a clutch to lock up at cruising speed. If you want to run a lock up behind a high-po mill just drill the releif passages in the VB out so it locks up faster (buy the Trans-go TF 12 or 3 kit of your choice for details) drill the holes to max diameter or even one size bigger to really firm it up so it don't slip and burn. Also install the stiff spring to delay engagement untill a higher speed. I have built several for my various cars and a couple were race cars, all were strong street cars at the least and the only one that I ever had fail was one where my cooler line blew on the way to the track and I kept driving it, it wouldn't hardly move when I got there, I raced that night after fixing it at the track. And the next day the forward clutches gave out, I rebuilt it and used the same converter and never had another problem racing that trans till I sold the car. If you build the trans right the 904 is not a problem and LU is not a problem.

PS ask Andy Mayes about the LU 904 in his roofing truck I built with a TF3 kit. He still cusses at me for building a manual shift trans for a work truck, I just did it to see if I liked it and then he bought the truck from me and is still driving it years later, says hes going to put a 727 in if he can ever kill it

Drain the converter and look way inside at the splines that the input shaft engages into. Just replaced a converter in a customers car yesterday for that reason, sheared splines. Have seen alot of 904's with busted hubs too. Ya, a 904 or a C4 (ford) can be made to take abuse, but they are no 727 or C6. Anyone I've ever known with a hard driven 904 got it refreshed on a regular basis.

Don.

what truck apps had the 5 clutch drums? & I do have a 904 from a 318 laying around. If I end up really beefing this thing I'm going to have to romp on it just to check out my handiwork.

Not real sure, but I would guess 4wd trucks.

I thought the cordoba's had the 5 clutch direct drums but you need to machine the pump to fit the drum(non l/u)

the late 70s 360 4bbl motors and mabey even the 2bbl motors in cars had 5 clutch front drums with non LU trannys. They were called A-999s. They were a heavy duty 904 non-lu. Later LU 904s from trucks in the early 80s and later had 5 clutch front drums and low 1st and 2nd gears. The low ratio gears are the toughest stock gear sets also, 4 pinions and steel cages. I know there is some way to put these drums in a non-lu 904 but I don't remember exactly what needs to be done.

Thanks for all the reply's fellas... If the converter snout is fubarred like the previous picture than what is the best course of action??? 727?????? non lockup converter????? I have even been kicking around the idea of putting in a new 451, hyd roller cam, E-head motor that I have been sitting on for a few years now.... I even have an extra B-727 trans in the garage I could build..... I figure I could sell the new 390 and get the parts needed to convert the Cordoba over to Big Block power................
I won't have a chance to get the trans out until tuesday now I will have an update then.... TBF

A&A sells a special thin disk with grooves to install in a 4 clutch drum so you end up with 5 disks. The grooves evacuate the fluid fast when applied since its a shifting clutch.

The parts needed out of the A-999 are the front pump, Front drum (deeper) and rear drum (has a wider hub to engage all 5 disks).

Well.. I don't who the lucky winner is but it looks like the input shaft snapped in half...... The remaining threads show some evidence of twisting before failing.....

Now, If I put a new input shaft in can I expect the same problem to happen again?? I would think so... Is this problem associated with the lockup converter system?? Does a non-lockup have a solid style input shaft that is thicker and stronger??? If so can I install a non-lockup input shaft in this trans and just get a different converter????
Or should I just dump this whole mess and build a nice 727????? TIA TBF

input shaft end

threads are twisted a bit... kinda blurry.. TBF

way to go!!!

a 390 with 3.73 gears done killed flight 904

wonder if anything else was damaged?

full of shavings? pan still clean?

in the long run..I would go 727 IMO

dont guess your gonna get to drive up to big daddys this weekend

do you have a 727 core yet?

may find one quick at the clearwater u-pull it,holler if ya need a hand with it,may take friday off and be over there looking for one myself

turkey day weekend sale is a comin also

Thanks anyway but I am heading out of town until sat morning.. trans looks good except for a clean break in the input shaft... no debris at all.. TBF

replace shaft in it and hammer it again,

I let you know what I see there as far as 727s