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Explain how the 4L80E 1-2 shift is adjusted, not tuning

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Old 04-29-2010 | 08:42 PM
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Default Explain how the 4L80E 1-2 shift is adjusted, not tuning

I have been working with Chuck, Vince, and Andy over at FLT. I feel like I'm bothering them to a point even though I know they'll will never tell me that.
My 80E shifts 1-2 like a Honda rear ended me, 99% of the time. The only time it’s not like that is the 1st shift of the day when everything is ice cold. I think it has to do with the fluid being a little thicker before getting warm.
Anyway dropped the pan/filter and sent some pics of the valve body to Andy. They said the Trans-go shift kit I have is the older style which is no longer available. So they are going to prep me a new valve body the way I want it.

My question is, how much does using 1 instead of 2 springs (on the accumulator piston?) and drilling the separator plate above .096 or whatever it is affecting the shift speed and pressure? What about the "washers" I have heard about, what's that?

I played with shift pressures in the tune and it made zero difference. I’ve lowered the part throttle shift speed to 9mph to keep it from breaking anything. When I pulled my drive shaft today the U-joint fell apart. It’s not that old. I’d say the hard shifts did it in…
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Old 04-29-2010 | 09:08 PM
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There are no "washers" in the 80e. I followed the instructions to the T with mine, no two springs under the 1-2 accum. Replace stock with the transgo one and drilled the 1-2 to .076. 1-2 is perfect for my tastes with a mild converter...... course a subjective thing. Not harsh, quick and firm.

I think the fluid hole size is key to shift tuning. I set my first up and 2-3 was soft. Next one I just stepped up the hole diameter there a bit and firmed it up to my likes.

Last edited by KySilverado; 04-29-2010 at 09:17 PM.
Old 04-29-2010 | 09:53 PM
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My understanding on the springs is they are a return spring. So 1 spring will make the shift harder than if you use both springs? Yes/no?

So the washers are a 60E/65E thing?

I'm gonna have Vince drill mine to the middle size, I think that's the .076. I loved they way my FLT 65# shifted , he said that it would be similar.

On the older kits, like I have, I remember seeing a setting for .120 which is probably why my truck breaks loose at 10mph on the 1-2 shift
At WOT it shifts real nice, well when its not bouncing off the rev limiter, but that's another issue LMAO
Old 04-29-2010 | 10:07 PM
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Chris don't you know that when signed up to be a sponsor here that gave everyone and their brother the right to call us with the F'd up transmission problems? Even worse when we did not build or sell them parts for it! I guess what I'm saying is tech calls get to be a PITA when it takes away from or daily routine. We help when we can but our customers come first. You are an old customer of ours and well that is why we help where we can.

Being that I did not build this unit I'm not sure how the valve body and what not was set up. I have never seen two springs for the 1-2 accumulator piston. With that kit there should be one orange spring in the accumulator piston located in the rear band servo. I think you might be making a reference to the accumulator valve in the valve body.

Here is my take on it. In the kit it comes with two blue springs for the accumulator valve. Two springs will be the lightest accumulation. One spring will be firmer and no spring will be killer! Now it is possible that your valve is stuck in a position that makes it shift hard all the time. This would be an area to look at if it were on my bench.

Also you mentioned feed hole sizes. In your case I would reduce the hole as small as I could. This can be done with a punch and solid surface. I use a vise mounted on my bench. Get a punch that is larger than the hole and basically peen the whole down. Then drill it to the smallest size the kit calls for. I believe that is around .080. This will only allow so much oil for the 2nd gear circuit. Be careful when doing this so the plate does not get bent to .

The last thing I would check is the transmission line pressure. When this trans shifts hard what is the pressure? Does the pressure stay this way basically in any TPS position? Two things I would look at in the trans. One would be to change the epc solenoid. The other is the condition of the boost valve in the pump and also make sure that the pressure regulator springs are correct. I know that there was some spacer thingy that was only used in early pr valve lineups. ( I have never used this nor do I know if it is possible)>>> If you have a later style valve and used the spacer it is possible that the pr valve is pinned in a high line pressure area.

Just throwing this out there....is it possible that the TCC is being applied when the 1-2 shift happens? Just a thought. Hope this helps and please don't take my opening statement the wrong way. Just being real! Vince
Old 04-30-2010 | 08:29 AM
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I had to refer to my 80e thread to freshen my memory. The 2 springs you and Vince are referring to are here. I chose the light setting there also. I don't know how much this affects the shift performance.

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