4L60E Build Info
11-27-2017, 01:58 PM
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4L60E Build Info Just wanted to share my 4L60E experience for the benefit of anyone that may benefit from it:
Lost the sun shell in my Suburban at 185K
Post tear-down inspection was for the most part pretty positive. After having a local trans guy look everything over I elected to replace:
1. Sun shell with a hardened Delco unit.
2. 3-4 clutch frictions; refurbished the steels.
3. Band
4. Paper and rubber kit
5. Installed Sonnax pinless accumulators, all 3.
6. Corvette servo assy.
7. All bushings
8. Trans-Go valve body plate.
9. Castrol Syntech Dexron VI fluid.
Results:
Very firm 1-2, firm 2-3 and 3-4 shifts. Plus, the shifts firm up with increased throttle like they should. Re-installed the stock servo to try to soften the 1-2 a little, which it did, but ended up with severe flare-up on the 2-3 shift, and 3-4 turned soft. As I needed the Sub back in service ASAP I went back to the Corvette servo. The wife assures me that she can live with the firm shift, so I call it a win.
I had purchased a Trans-Go SK shift kit but thought I'd try it out with the Sonnax accumulators and Corvette servo first. I'll be returning it as I'm totally happy with it the way it is.
A special thanks to Tony and Ken at Transmission Solutions in Eugene, OR for helping me with this, my first complete auto. trans build.
Lost the sun shell in my Suburban at 185K
Post tear-down inspection was for the most part pretty positive. After having a local trans guy look everything over I elected to replace:
1. Sun shell with a hardened Delco unit.
2. 3-4 clutch frictions; refurbished the steels.
3. Band
4. Paper and rubber kit
5. Installed Sonnax pinless accumulators, all 3.
6. Corvette servo assy.
7. All bushings
8. Trans-Go valve body plate.
9. Castrol Syntech Dexron VI fluid.
Results:
Very firm 1-2, firm 2-3 and 3-4 shifts. Plus, the shifts firm up with increased throttle like they should. Re-installed the stock servo to try to soften the 1-2 a little, which it did, but ended up with severe flare-up on the 2-3 shift, and 3-4 turned soft. As I needed the Sub back in service ASAP I went back to the Corvette servo. The wife assures me that she can live with the firm shift, so I call it a win.
I had purchased a Trans-Go SK shift kit but thought I'd try it out with the Sonnax accumulators and Corvette servo first. I'll be returning it as I'm totally happy with it the way it is.
A special thanks to Tony and Ken at Transmission Solutions in Eugene, OR for helping me with this, my first complete auto. trans build.
11-27-2017, 07:21 PM
#2
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You need to calm that 1-2 shift down! In a heavy truck....It will break parts (again) & wear the hell out of various splines. It's also hard on your U-Joints, Differential & T-Case if equipped.
What did you drill the 2nd clutch feed hole to? With a stock converter & a Vette Servo, Using a TG Plate.....Leave the hole be (@.070").
A Sonnax pinless piston in the 2nd accumulator housing really restricts the range of the accumulator, Using a smaller ratio Accumulator Valve & Bushing in the Valve Body can help with this. "A" & "B" code accumulators can be scavenged from 700R4 valve bodies.
A lighter spring is a alternative as well.....But not as effective.
What did you drill the 2nd clutch feed hole to? With a stock converter & a Vette Servo, Using a TG Plate.....Leave the hole be (@.070").
A Sonnax pinless piston in the 2nd accumulator housing really restricts the range of the accumulator, Using a smaller ratio Accumulator Valve & Bushing in the Valve Body can help with this. "A" & "B" code accumulators can be scavenged from 700R4 valve bodies.
A lighter spring is a alternative as well.....But not as effective.
11-28-2017, 04:44 PM
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4L60E Build Interesting info clinebarger!
The VB plate was installed as delivered. I do have new stock aluminum aluminum accumulator pistons on the shelf, and looking the 1-2 unit I can see how it would have more travel than the Sonnax unit. Perhaps I'll get another couple of VB gaskets and experiment further this coming weekend. Thanks for the input!
The VB plate was installed as delivered. I do have new stock aluminum aluminum accumulator pistons on the shelf, and looking the 1-2 unit I can see how it would have more travel than the Sonnax unit. Perhaps I'll get another couple of VB gaskets and experiment further this coming weekend. Thanks for the input!
11-28-2017, 05:44 PM
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You need to calm that 1-2 shift down! In a heavy truck....It will break parts (again) & wear the hell out of various splines. It's also hard on your U-Joints, Differential & T-Case if equipped.
What did you drill the 2nd clutch feed hole to? With a stock converter & a Vette Servo, Using a TG Plate.....Leave the hole be (@.070").
A Sonnax pinless piston in the 2nd accumulator housing really restricts the range of the accumulator, Using a smaller ratio Accumulator Valve & Bushing in the Valve Body can help with this. "A" & "B" code accumulators can be scavenged from 700R4 valve bodies.
A lighter spring is a alternative as well.....But not as effective.
What did you drill the 2nd clutch feed hole to? With a stock converter & a Vette Servo, Using a TG Plate.....Leave the hole be (@.070").
A Sonnax pinless piston in the 2nd accumulator housing really restricts the range of the accumulator, Using a smaller ratio Accumulator Valve & Bushing in the Valve Body can help with this. "A" & "B" code accumulators can be scavenged from 700R4 valve bodies.
A lighter spring is a alternative as well.....But not as effective.
11-30-2017, 11:39 PM
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4L60E Build Info Yikes! I definitely don't want any more fragged parts! Tonight I pulled the Sonnax 1-2 accumulator piston and installed a new stock unit. This smoothed out the 1-2 considerably. It's still firm, but not neck-snappingly so; the Sub doesn't jump forward when it shifts.
2-3 seems to come 200-300 rpm earlier now under the same amount of throttle, but it's crisp and short; actually better than it was before.
Comparing the two, the Sonnax piston is about 25-30% longer.
I might take the Sonnax to work and machine it down to the same length as the stock one, but on the other hand, I'm in no hurry to go into it again.
Eventually, with enough time devoted to studying the hydraulic circuits on this thing and getting good info from you guys, I'll get a good handle on these things.
2-3 seems to come 200-300 rpm earlier now under the same amount of throttle, but it's crisp and short; actually better than it was before.
Comparing the two, the Sonnax piston is about 25-30% longer.
I might take the Sonnax to work and machine it down to the same length as the stock one, but on the other hand, I'm in no hurry to go into it again.
Eventually, with enough time devoted to studying the hydraulic circuits on this thing and getting good info from you guys, I'll get a good handle on these things.
12-01-2017, 10:07 AM
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4L60E Build Info 
Correction; the aluminum 1-2 accumulator has three legs on it that add approx. 3/16" to its length. Just got to work and compared the Sonnax to the original plastic piston on my desk; it's roughly twice as long as the plastic one.. Definitely a calibration-changer.
12-01-2017, 08:13 PM
#7
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Trans Go 4L65-2ACM is the correct aluminum replacement accumulator piston for your truck.
I use new AC-Delco plastic replacement pistons often, They last a long time! Sure they can crack around the pin bore....But I have never seen this below 100,000 miles & rarely below 150,000.
I use new AC-Delco plastic replacement pistons often, They last a long time! Sure they can crack around the pin bore....But I have never seen this below 100,000 miles & rarely below 150,000.