I'm thinking of installing a used Hurst Promatic 2 shifter on my TH400. Although they used to make a version for 4-speed automatics, this one only works with 3-speed automatics. Down the road I'd like to upgrade to a 700R4; any idea how easy it might be to hack the shifter to fit? Thanks.
the cable bracket might be different, and it might not get first gear....other than that, is it the same shifter?
In promotional pictures they are identical, but I've only seen the TH400 version in person. The 700R4 version was discontinued a while back so it has become unobtainium. If I could put them side-by-side that would answer a lot of questions.
it's been my experience that when they went to the 4 speed automatics, GM just added another gear, they didn't change the distance between gears. so if your shifter can physically move past the 3 speed version of 1st, it will probably work ok with the OD trans.
It should work as is or with some minor tweeking. I am looking at a 3 sp shifter for my 700R4 and if it goes from park to at least 3rd then it should work. How often do we really use the first gear selector when starting off. Let us know.
Bringing up an old thread, but here’s a pic of my 700R4 Promatic 2: Does someone have a pic of a TH350/400 version? I was thinking one could be used on a Ford-O/Merc-O-matic. Sent from my iPad using The H.A.M.B. mobile app
Have a 3 speed promatic truck shifter from a c10 that I sold a few years ago. Wanted to use it in my 09 Silverado that has a 4l60e. Was gonna use it as is because I dont really need to drop it to first gear but then I googled and came across this old post. Compared 700r4 version in above post and looked identical to mine. Then I stared at mechanisms for a few minutes while cycling through gears and noticed that ratcheting couldn't grab first gear position because there was a tooth missing. I have access to a welder at work so I cut a gear tooth sized/shaped piece of washer that was about the same thickness and my coworker welded it onto ratcheting plate. First try was almost perfect had to add a little more on the contacting face of the gear tooth to get shifter to drop into first gear. So if anybody wanted to use a 3 speed shifter that can't be easily converted to 4 speed just weld a tooth on it.
As an old post I’ll respond a Ford-O has 5 positions and a TH350/400 has 6. A Cruise-O has 6. Better for it.
Yes, but the idea was to shift the Ford-o quickly. The speed trick was to start in Low (1st), bump up to Drive to get second and quickly go back to Low to hold second. Then back to Drive for third. A ratchet shifter would be a natural for this operation. I was thinking the TH350/400 shifter could be used by blocking the last detent. Maybe like a shifter for a Powerglide. The biggest problem is the ratchet shifter just doesn’t fit the look of my car.
Here's a FYI. I've just been through a similar exercise. I'm using an Aussie Ford column shift steering column with linkages and a Morse cable actuating a TH350 transmission. I found that the angular displacement between each gear, 1st through Rev was the same between the Ford column and the TH350 transmission. But, when you shift between Rev and Park the story changed, the GM transmission required ~10 degrees more sweep than the Ford column detents provided.
I understand what you are describing. The detents need to be spaced correctly to give the right amount of linkage or cable stroke to engage each gear position. In my case the TH350/400 ratchet shifter may stroke too much when moving from Park to Reverse for the Ford-O to engage Reverse. Basically, passing it up. It sounds like the detent comb on the shifter would just need to be re-profiled to match the Ford-O’s gear positions. It’s an interesting issue but more than what I want to get into for something I’m not really wild about how it would look in my car!
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