61 ranch wagon with the trans. modulator, I believe 61 was the first year to use the modulator. My passing gear stopped working suddenly. When you go WOT the engine revs really high like it’s in neutral and no kick down. I believe 61 was the first year for the vacuum modulator. It seems to shift normally through the 3 gears, I only have a problem at WOT. My question is, does the modulator affect the kick down or just the normal shifts? If no, any ideas what is wrong. Thanks in advance.
So when you do a WOT kickdown, the transmission shifts into second gear by releasing the direct clutch and applying the intermediate band. It really doesn't have much to do with the modulator other than the trans operating pressure should go up as the vacuum drops. It sounds like you band is slipping in which case you are really in low gear instead of second. You have to drop the pan to adjust the band. This includes putting a 1/4 in spacer between the servo piston rod and adjusting screw (the body of an old Craftsman wrench is right at 1/4 in). Loosen the lock nut and tighten the adjusting screw to 10 in-lb (just a little tighter than snug). You then back the adjusting screw back one full turn and tighten the lock nut.
I am clueless on transmissions besides dropping the pan, changing filters. So you think it’s going from 3rd to 1st. That would explain the engine revs and lack of acceleration. I’m lost on the spacer. Temporary spacer with the wrench? Here are a few pics I could find( not mine) to help me understand your post. They are not the best but I’m going to need something to go by. Thanks
Thanks, it’s looking like the car is going to a shop. I’m not very experienced on this and I have a long trip coming up. I’m not a novice but transmissions are out of my comfort zone.
My 1962 medium case Cruise-O’s down shift is controlled by the arm on from the throttle to the side of the transmission where the gear selector comes out of the transmission. The shop which installed it had it come into too quick for me so I extended the length of the rod to have it right at full throttle only. The vacuum modulator has nothing to do with down shifting but it does control how long the transmission stays in gear when driving. As far as I know the governor in the rear tail shaft case does take over shifting under full throttle.
On your top picture, the adjusting screw you see is for the front band. You pull that back and place a 1/4 in spacer between the servo (the big aluminum piece) and the adjusting screw. You make your adjustment with the spacer in place. The important part of the adjustment is how much you back off the adjuster after tightening it on the 1/4 in spacer. I'm saying to do a band adjustment first because it is the least expensive repair and is the likely cause of your problem. It isn't the only possible cause, but you said you had all 3 gears under normal operation. That makes band adjustment likely.
Thanks for the explanation. I’ll give it a try if I can find any type F fluid. Napa down the road might still carry it.
That is a pretty easy transmission to go through. I haven't done one in close to 50 years and got away with just a general rebuild kit. The guys who did these on the reg are basically gone. I know one local shop that I'd trust with one.
@jaracer @Oneball and everyone else I did the front band adjustment yesterday and ya’ll were right on the money. Works great now and so far no leaks! Thanks for your input. It saved me a trip to the shop and some spending money.
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