Mopar Muscle Association UK

Firstly,
just like to say thanks to all who talked me through (into) doing this myself - great day spend "bonding with my car !
Got all the tools, gaskets, filters and sealer needed and with my teenage daughter at a loss for something to do, grabbed her as well.
Dropped the pan and collected the fluid and noticed a HUUUUUGE amount of play on the reverse band activator - as well as NO locknut.....

Cleaned all up and removed the filter to get a closer look and feel - but nothing to feel where the grub screw should be.....
Looked in the bottom of the pan and saw a lump - pulled it out to reveal half a grub screw with locknut attached - clearly, the other half was still screwed into the recess.
So I guess what happened is that the grubscrew generally loosened itself over time (whilst driving forward) - I then engaged reverse one day, and when the band activator thingy swung out, the bolt and screw combination collided with the edge of the valve body and snap !
The small remainder of the screw just allowing me to feather reverse in at best.
Now, being the kinda chap who likes to open up and close on the same day, I had to do something .....
Angle grinder, bench grinder and original locknut later, I managed to fashion a thankfully same-thread HSS bolt and actually got away with it.
I now have reverse !!!!
Sadly, put too much fluid in so need to drain a little - US Quarts are less than a liter, not more !
Also need to replace one sump bolt on the accelerator attachment as the hole is stripping as it was over tightened in the past.
Steep learning curves - nothing like it .
Thanks again to all who gave their time.
Garp

Good fix! New one on me, I've never comes across a broken adjuster before. I assume it turned out to be a 904 'cos a 727 has a band strut that would probably have fallen out as well and that would have been no fun trying to refit...

Yup Blue - it is a 904.
By the tone of your reply, sounds like a stronger tranny ?

No the 727 is the stronger of the two but a 904 can be built to take some abuse. A 904 and a 727 are a very similar design but the bands frictions and most of the guts are double the size on a 727.

oh cock - well, that's what I've got and it'll do for now .....

The 904 is lighter, consumes less power and is fine in your application so it's all good. Had I been building the Valiant as an automatic, it would have got a 904 in it. For stock and super stock racing in the States they actually modify 727 cases at huge expense, to use 904 internals for those reasons.