4L60E No 2nd Gear
09-07-2024, 05:06 PM
#51
On The Tree
Thread Starter
1-2 still too hard
Since my last post, I've had the trans retuned and put a few thousand miles on it. The tuner said he commanded zero pump pressure using HP Tuners and retuned the trans. It still shifts VERY hard 1-2. It's worse when the trans is cold. Under normal acceleration it shifts very hard. I'd be very curious to see a video of my leaf springs to see what it's actually doing. If I accelerate hard enough to chirp the tires, that is a little bit more comfortable. Ironically, with the accelerator pedal on the wood, it feels just like it should. This is exactly the opposite effect of what Sonnax's pump pressure regulator is supposed to have.
Otherwise, I'm very happy with the result. All other shifts are firm but not jarring. The 2-3 shift clunks pretty hard at slow speed and light throttle, similar to but nowhere near as hard as the 1-2 shift. It's a little bit slow to engage Reverse, making me think I probably have a leak in that circuit somewhere. I had difficulty with the reverse drum piston seals; in fact, I destroyed them on my first attempt at assembling the drum and new seals. I was very careful when doing it the second time around. I used aluminum flashing to make a seal guide for the outer piston seal and a plastic water bottle to make one for the inner seal and used lots of lube. I was very confident in this during installation and air tested the drum with success, though it was difficult to get a leak free seal with the blow gun, so I couldn't tell by listening if it seemed to be 100% sealed.
I haven't checked pressures since the re-tune. I'm going to have to do that and see what pressure is at idle and in Reverse. Probably it would be worth knowing the pressures in various gears while driving, though I'll need a longer hose for that.
At some point I'm going to remove the wave spring from the 1-2 accumulator and see if that softens up that shift tolerably. I'll probably also need to buy HP Tuners and learn how to use it. I've thought about maybe switching from Type F fluid, which I'm running on the suggestion of ACC Performance, the Boss Hog converter manufacturer, to Dexron IV and see what that does. But I'm concerned about mixing Type F and Dexron. There's a lot more fluid in the converter than the pan, so that would be a gradual - and very expensive - process of dilution, and no way to know when 100% Dexron is achieved. So, first thing: check pressures. Second, remove wave spring. Possibly followed by replace Sonnax 1-2 accumulator spring with stock spring. It'll be a while before I get to any of that, but I'll post updates when I do.
But for now, I'm driving it.
Otherwise, I'm very happy with the result. All other shifts are firm but not jarring. The 2-3 shift clunks pretty hard at slow speed and light throttle, similar to but nowhere near as hard as the 1-2 shift. It's a little bit slow to engage Reverse, making me think I probably have a leak in that circuit somewhere. I had difficulty with the reverse drum piston seals; in fact, I destroyed them on my first attempt at assembling the drum and new seals. I was very careful when doing it the second time around. I used aluminum flashing to make a seal guide for the outer piston seal and a plastic water bottle to make one for the inner seal and used lots of lube. I was very confident in this during installation and air tested the drum with success, though it was difficult to get a leak free seal with the blow gun, so I couldn't tell by listening if it seemed to be 100% sealed.
I haven't checked pressures since the re-tune. I'm going to have to do that and see what pressure is at idle and in Reverse. Probably it would be worth knowing the pressures in various gears while driving, though I'll need a longer hose for that.
At some point I'm going to remove the wave spring from the 1-2 accumulator and see if that softens up that shift tolerably. I'll probably also need to buy HP Tuners and learn how to use it. I've thought about maybe switching from Type F fluid, which I'm running on the suggestion of ACC Performance, the Boss Hog converter manufacturer, to Dexron IV and see what that does. But I'm concerned about mixing Type F and Dexron. There's a lot more fluid in the converter than the pan, so that would be a gradual - and very expensive - process of dilution, and no way to know when 100% Dexron is achieved. So, first thing: check pressures. Second, remove wave spring. Possibly followed by replace Sonnax 1-2 accumulator spring with stock spring. It'll be a while before I get to any of that, but I'll post updates when I do.
But for now, I'm driving it.
The following 2 users liked this post by Northeastconfederate:
shakenfake (09-09-2024),
wretched73 (09-07-2024)
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