904 Lock-up Mods on the Cheap???

Been diggin' into rebuilding a couple transmissions lately and one is an 85 904 with the low gear set (2.77), 5 clutch front drum, and the lock-up converter.

I have another non-lock-up 904 to scavenge for the more common input shaft, hence, better converter selection, but would like to try the loosest lock-up style converter available along with some other mod's.

The car is basically,
3600 lbs
360
dual-plane
cam - 228@.050
600 Holley or a vac. 650 Spreadbore Holley
3.55 gear
28" tire
1&5/8's headers

Got any ideas for valve body mod's??????

Any shift kits out there that will fit this application or adapt?

So far I'll,

tweak the line pressure
4.2:1 kick-down lever
5400 rpm governor
blocker tube in the accumulator
reinforced strut at the 2-3 lever

Any stronger shims, wave springs, selective snap rings to beef up that big coil spring in the high/reverse clutch?? Or a stronger replacement coilspring???

Any constructive input will be appreciated.

Dean

B&M makes a trans pac and trans-go makes a shift kit. I used the transpac on my LU 904 and the trans-go on my A500....liked them both.

you'll want to put a stiffer spring in the lockup valvebody to raise the lockup RPM. my stock one wanted to lockup at 1200 RPM. there's a NS1 kit from chrysler that raised it to ~2000 RPM that consisted of a different spring and cover plate for the lockup valvebody.

Replace the coil spring with the retainer on the bottom of this page:

http://www.aandatrans.com/Departments/Chrysler-904-Trans/Aluminum-Drums.aspx

Everything you need is on this page

Check this out.

http://cgi.ebay.com/ebaymotors/ws/eBayIS...RK%3AMEWAX%3AIT

When I build them I replace all the wave snaprings with flat ones, the wavy ones fateauge and break plus they don't engage the clutches as fast. The acumulator blocker always goes in and a couple washers to eliminate the spring built into the low reverse piston to help it engage/dis engage faster. Turn the line preasure about two full turns. Everything else is stock on a stock or very mild build.

For a little bit stronger build I add in the trans go shift kit and drill the holes to the maximum recomended sizes, this will give you nice firm shifts but no u-joint snapping super hard shifts. This is about what I would do building yours.

Ok guys THANKS!

As ever, what I want and what's best isn't always the same thing. Those really brutal shifts can get annoying after a while anyways.

The replacement piece A&A sells to go to multiple coils for the high/rev clutch looks like a tempting upgrade. The rest is too pricy (aluminum drums).

I'm currently doing a Trans-Go TF-2 in a 727. We'll see how that goes.

Many of the shift kits involve opening up passages to remove pressure limiting orifices. Which, along with the blocker tube in the Accumulator, would make sense to make shifts harder/quicker. I don't have the time or unlimited quantities of trans fluid to try various hardware store springs and washers to try out in the valve body. I'll look into replacing the wave spring in the clutch. As long as the clearances check out I can see that it would certainly take one spongy item out of the set-up.

It doesn't look too good for converter selection though.

Thanks again.
Dean

Hey Dean, you want another 904? Its non lock up build year is 1974. You can have it! Your PM box is full

for the size of your cam, especially if you've done something to raise the compression beyond stock, a MP 166K converter will work well. it'll stall to about 2300-2400 RPM and flash to about 2800.

I had one, worked real nice with an XE262 in a stock long block 360 in my 3900 lb 5th ave with 3.55's and 27" tires. unfortunately, in such a heavy car with that much torque, after 6 years and ~ 26k miles, I found a crack in the converter hub.

OK, I just cleaned out my PM box. Sorry.

And I'll take that 904 if you don't want it. It looks like a mod'd 904 in a lite A-body with a good converter stub would be a very efficient link in the system. At least, as long it hung in there. Now, if i could just trade off my rust free GTS project for a caged roller.

Tell your husband I said "HI". Haven't seen you folks in quite a while.


Patrick, and everyone else,

Thanks for all the good info.