I have a 46re blown apart at the moment, and am looking to upgrade a few things.
I have a question about the low/reverse servo which is supposed to be the same from like 1967 to the end of the RE series according to the description. Looking at superior brand.
I see they have 2 different low/reverse servos, both advertised as fitting 727/a518/46re
One of them has to be wrong, either in listed application or measurements within the respective description.
Both are listed as "super servos" for the listed tranny's low/reverse.
One is 2.49"
The other is 2.81". I'm not by my trans to be able to measure.
Could the smaller one actually be the small case (904, a500 etc) and the fitment part of the listing description be mistaken? Or were there 2 different sizes of low/reverse band servos used in these tranny's?
I already ordered the anodized sonnax kit for the accumulator and the front servo. That kit doesn't contain anything for the rear servo though. I've used the sonnax parts before on another build, I like the idea of double seals.

what does sonnax list for a rear servo kit ?
i have a superior kit on the shelf for an A518, it's number is K029, while the 904 number is K030.
the od. is 2.810". however, i never got around to using it, so i can't tell you if it fits the A518/727 or not.
i measured an old 727 junk case on the shelf, and it looks really close to 2.810". hard to get really precise because it's so cruddy.
i don't know if this helps you or not.
mr. kunkle would know for sure.

Ok both here in my hand.... k029 says on box 727-518 Reverse servo.
Other one I got, k086, says a618/48re Reverse servo. The respective instructions don't give measurements but the k086 is definitely smaller than the k029. I cannot believe that a "618" (which is the heaviest duty version of this trans) would have a smaller reverse servo than an a518/46re....
On the K029 instructions it does mention the k030 on it, as being for a 904. So then I guess the question becomes what's the difference between a k030 and the k086?
Both instruction sheets are identical except for the header that lists the respective part numbers.
Do I have a misprint on one of them? Would the one marked k086, act be for a 904/a500? If yes all is not lost, as I have an a500 to rebuild and a 70s 904 to redo before the spring cruising season comes. If not then the k086 is a paperweight.

Since you are doing a 46re I would think the 086 is the one you want ?

Maybe. I'll have to match them up I guess. I always thought these parts of a 46re were still the same as a 727 or a 46rh or a 518.

Many parts are but the rear of the case changed to get OD on it so I can see why the rear servo might be a little smaller .

I'm pretty sure I used the K029 in my 727. had to use shim stock or thin feeler gauges to get the lip past the snap ring groove.
I think the servo might be different between the 727/518/47re and 48re transmissions? 48re uses a different pump too.
I have put a K029 in a 47re before. The 48re also uses the double wrap band.