Ford Toploader

What's the difference between a single detent and a double detent on a toploader? Does it make a difference in performance?

 

It does, slightly! The double detant shift towers definitly "lock in" a bit better than the earlier singles. Finding the elusive 7222 tower is getting more of a challenge every day but they are out there. The later pickup towers work equally well but you need the proper shift forks for the gears your running. Basically you're just using a ball on both sides of the shift rail instead of one side so you have twice the holding power on the shift rail.

Would I be uncomfortable using a single in most apps, no. It the tran is in generally good shape and the synchros are nice and tight you'll probably never notice the difference.

 

***ume you're talking about the early Ford 3 speed toploaders here. The double detent (39 style) doesnt provide a lot of extra holding power for the shift rails. What you DO get is the positive interlock design, which guarantees that only one shaft can be moved off neutral at a time.

The single detent has one spring pushing on two detent "caps" into their respective notches in the shifter shafts. It works but it is possible (very rare) that both shafts could be shifted at once on a fast & hard shift. This would lock up the gears in the trans. This cannot happen on a double detent type due to the interlock "bullet" between the two shafts.

 

Good info. I always just thought the double detant just held the rails better. I have one apart on the bench right now and I see how this would work. Oddly enough, I've never jambed an early Ford box in two gears, I usually reserve that stunt for the Sparkomatic side shifters in the old days.

Thanks for the eye opener.

 

In measuring the "notch" in the shifter shafts, you'd notice a difference in the depth of that notch between the two type shifters. The '32-38 single detent shifter shafts have a shallower notch, which accomodates the cup-like plunger detent. The '39 style double detent shifter shafts had deeper notches and rode against the 7/16" steel balls.

Cutting the notches deeper (and/or using slightly smaller balls) will only make the shifting action much more difficult. This generally tends to make it nearly impossible to move the shift shaft from one gear to another. Our replacement springs are ever so slightly stronger than the original spring. Aside from that, we don't recommend any modifications to the shafts or balls themselves....