I just wanted to post about my most recent work. Did the "mild" jerry-mod or j-mod to my 97 4R70W trans and it's GREAT!! For $50 in parts and not a whole lot of work, it's a great improvement!! Anyone considering the mod, DO IT! Driving normally around town it's barely noticeable, but if you get your foot into the pedal a bit, the shifts are DEFINITELY more snappy. Manual 1-2 and 2-3 shifts at 4,000 RPM or more chirp the 295's I have out back, even at 3/4 throttle. When in "D" the 2-1 downshift when you mash the pedal from coasting breaks the tires loose pretty good, at least in the cold weather. The 4-2 (or is it 3?) downshift when you mash the pedal from cruising speed doesn't break the tires loose, but it's definitely a firmer shift. I get a nice little chirp, but not fully broken loose.
All in all, I'm really happy with it!! Definitely a recommended mod for any 4R70W out there!!
For anyone considering the J-mod but unsure which settings to use, I think these "mild" settings are perfect for a daily driver. Not too rough when easy drivin', but nice and firm when you get into the throttle.
Again, I went with the "mild" settings for the holes in the separator plate. I replaced the 1-2 and 2-3 accumulators with the updated rubber-sheathed ones. I also replaced both upper and lower 1-2 accumulator springs with updated ones. It says the lower 1-2 spring can be left out, but I kept it in and I'm glad I did. Might be a little too rough without it. I also took the 2-3 accumulator spring out and left it out.
Anyway, if you're thinkin about the mod but have questions, just let me know!! And DO IT!
All in all, I'm really happy with it!! Definitely a recommended mod for any 4R70W out there!!
For anyone considering the J-mod but unsure which settings to use, I think these "mild" settings are perfect for a daily driver. Not too rough when easy drivin', but nice and firm when you get into the throttle.
Again, I went with the "mild" settings for the holes in the separator plate. I replaced the 1-2 and 2-3 accumulators with the updated rubber-sheathed ones. I also replaced both upper and lower 1-2 accumulator springs with updated ones. It says the lower 1-2 spring can be left out, but I kept it in and I'm glad I did. Might be a little too rough without it. I also took the 2-3 accumulator spring out and left it out.
Anyway, if you're thinkin about the mod but have questions, just let me know!! And DO IT!
