4l60e Refresh Issues
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From: Massachusetts
4l60e Refresh Issues Pulled my 4l60e and freshened it up when I built new motor. It will not shift into third under WOT and is slipping in 4th under hard throttle. I must have put something back together wrong because it's new 3-4 clucth pack. Thoughts before I tear this back out of car and rip it apart?
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From: Ann Arbor, MI
This sounds like the 3/4 clutch is slipping.
Did you air test the input drum before final assembly?
What 3/4 clutch clearance did you have?
Did you use a stock or performance clutch pack?
A leak in the 3rd accumulator check ball, a leak in the 4th accumulator or a ripped teflon seal on the input shaft could cause 3/4 slippage too.
Did you air test the input drum before final assembly?
What 3/4 clutch clearance did you have?
Did you use a stock or performance clutch pack?
A leak in the 3rd accumulator check ball, a leak in the 4th accumulator or a ripped teflon seal on the input shaft could cause 3/4 slippage too.
Thread Starter
Joined: Jun 2011
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From: Massachusetts
I used Raybestos 7 disc setup this time, new 3rd check ball, and all new teflon seals. I did check with air and the clearance was within what the ATSG manual called for. Could that clearance be too much for this setup? Can't remember what it was off the top of my head, I did check clearance dry.
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From: Ann Arbor, MI
Wow, sounds like you built everything very carefully.
Clearance isn't critical, anything in the .025 to .090 range will work (many recommend in the .035 to .050 range), but if you accidentally used thinner frictions or steels, you could end up out of range.
I have not replaced a 3rd check ball myself yet, so don't know how error prone that might be.
Other than perhaps checking for a leak on the 2nd servo piston, I cannot think of anything else that could be checked before removing the trans. I'm hooking up with my local trans builder friend today; I will ask him too.
Bummer!
Clearance isn't critical, anything in the .025 to .090 range will work (many recommend in the .035 to .050 range), but if you accidentally used thinner frictions or steels, you could end up out of range.
I have not replaced a 3rd check ball myself yet, so don't know how error prone that might be.
Other than perhaps checking for a leak on the 2nd servo piston, I cannot think of anything else that could be checked before removing the trans. I'm hooking up with my local trans builder friend today; I will ask him too.
Bummer!
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From: Ann Arbor, MI
I just talked to my trans builder friend and had him read this post.
He wanted to know if the 1-2 shift is firm and double check that there is no slippage in 2nd. Next, a pressure check in Park and Reverse would be useful; your local trans shop could do that in 10 minutes.
Even if you decide to just pull the trans and rebuild it again, the problem might not be obvious. Therefore, the more info we have from your "semi-working" trans, the better we can pinpoint the likely problem area.
Checking the servos is certainly a good idea. With the servos out, you can also verify that the 3rd checkball is loose.
He wanted to know if the 1-2 shift is firm and double check that there is no slippage in 2nd. Next, a pressure check in Park and Reverse would be useful; your local trans shop could do that in 10 minutes.
Even if you decide to just pull the trans and rebuild it again, the problem might not be obvious. Therefore, the more info we have from your "semi-working" trans, the better we can pinpoint the likely problem area.
Checking the servos is certainly a good idea. With the servos out, you can also verify that the 3rd checkball is loose.
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Thread Starter
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From: Massachusetts
1-2 shift is fine, didn't notice any slippage in 2nd, well, except the tires. 
Under normal driving it shifted fine, just slipping in 4th and no WOT 2-3. I wouldn't waist time rebuilding again just pull apart for inspection. I'm going to replace the separator plate to see if that changes anything. I did use the torlon ***** this time with the old plate. Didn't change it before cause it only had about 10k miles on it.
Under normal driving it shifted fine, just slipping in 4th and no WOT 2-3. I wouldn't waist time rebuilding again just pull apart for inspection. I'm going to replace the separator plate to see if that changes anything. I did use the torlon ***** this time with the old plate. Didn't change it before cause it only had about 10k miles on it. LS1 Tech Stories
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From: Ann Arbor, MI
No harm in putting in a new separator plate and gaskets.
Transgo sells a good "universal" plate. You will probably want to drill out the 2nd and 3rd gear feed holes a bit. Drilling out the 3rd feed hole will help overcome any small leaks in the 3rd clutch circuit. IMO at least .082 and perhaps even .091. (More if you use the Sonnax check valve.)
I'm using the torlon ***** in my current trans.
(I'm trying to finish another trans, but keep taking it apart to answer questions here.)
Transgo sells a good "universal" plate. You will probably want to drill out the 2nd and 3rd gear feed holes a bit. Drilling out the 3rd feed hole will help overcome any small leaks in the 3rd clutch circuit. IMO at least .082 and perhaps even .091. (More if you use the Sonnax check valve.)
I'm using the torlon ***** in my current trans.
(I'm trying to finish another trans, but keep taking it apart to answer questions here.)
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From: Ann Arbor, MI
I have it in my current trans which I took to the track last week. I programmed the shift points at 6500 RPM and my scanner shows the max rpm at those shifts was 6550; no flare at all, even with torque management disabled. Of course for a real test I would have to remove it and test it at the track again; not doing that. I do find that all Sonnax products are well engineered.
I wasn't really recommending it; I was just trying to be very careful about the 3rd feed hole size. I know hundreds of other people read these threads and I try to be very thorough and accurate.
BTW - If you are running a 11.6 ET, IMO you really should have a shift kit in the trans. At least to increase line pressure with a .500 boost valve and/or stiffer pressure regulator spring.
Thread Starter
Joined: Jun 2011
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From: Massachusetts
Oh, should mention this is not the first time the trans has been touched. I simply did a refresh and added a few more performance hard parts since it was out of the car.
Parts List:
Partial Transgo HD2 Shift Kit
All Sonnax accum pistons
Dual roller sprag
Torlon *****
All Molded GM steel pistons
Sonnax 2 and 4 servos
HD reinforced band
HD pump slide spring
Rapid release valve
Beast sunshell
Boost valve... that's all I can remember off the top of my head.
Parts List:
Partial Transgo HD2 Shift Kit
All Sonnax accum pistons
Dual roller sprag
Torlon *****
All Molded GM steel pistons
Sonnax 2 and 4 servos
HD reinforced band
HD pump slide spring
Rapid release valve
Beast sunshell
Boost valve... that's all I can remember off the top of my head.
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From: Ann Arbor, MI
Good you know all the parts before I suggest how to drill the separator plate.
I would first check the servo seals very carefully. 2nd get a new separator plate and drill it according to the Transgo HD2 kit directions, but go to .101 on the 3rd feed hole.
Something people miss is that even in 3rd and 4th gear, the 2nd servo is full on; however since the 3rd fluid has more surface area on the back of hte 2nd servo, it pushes it back and releases the band. IMO, the bigger the 2nd servo is, the bigger the 3rd feed hole should be.
Unfortunately this does not explain the problem of slippage in 4th.
Still, check the servo for leaks which can cause all kinds of strange problems.
I would first check the servo seals very carefully. 2nd get a new separator plate and drill it according to the Transgo HD2 kit directions, but go to .101 on the 3rd feed hole.
Something people miss is that even in 3rd and 4th gear, the 2nd servo is full on; however since the 3rd fluid has more surface area on the back of hte 2nd servo, it pushes it back and releases the band. IMO, the bigger the 2nd servo is, the bigger the 3rd feed hole should be.
Unfortunately this does not explain the problem of slippage in 4th.
Still, check the servo for leaks which can cause all kinds of strange problems.
Thread Starter
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From: Massachusetts
IT'S FIXED!!! I pulled the Sonnax 2-4 servo setup and swapped it for a Fairbanks setup I had in another trans, new separator plate, and just for insurance I changed the EPC solonoid and the pressure manifold. Shifts through 1,2,and 3 at WOT without a hiccup. Holds 4th locked up perfect.
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From: Ann Arbor, MI
Glad to hear you got it shifting and holding 4th now.
Congrats!
Did you use the separator plate as-is, or did you drill it? If drilled, please tell me the hole sizes for the 1-2 and 3rd feed holes.
Congrats!
Did you use the separator plate as-is, or did you drill it? If drilled, please tell me the hole sizes for the 1-2 and 3rd feed holes.
