Trans issue again

I just replaced my 4L60Eand the new trans feels like its trin to slip. I feel like maybe it's the tune, servo, or converter. It's only at 45 to 65 it feels like the converter in locks and it runs 200 rpm higher. I give it some gas n it goes from 2000 to 2400 be4 it starts gaining speed but its lacking power. Doesn't do it all the time just here and there. Changed converter with trans. Also it's been shifting really hard so I took out the corvette servo but that didn change anything. To day it shifted real soft a few times. When I went from OD to 3rd it was very hard at 40mph. This isn't norm for my truck. Any ideas?

I have noticed that when it feels like its slipping if I Gass on it n make it down shift n let off when it goes back to OD it's norm again

Damm transmissions , that sucks .... Who built the trans ? Or is it a used unit ? Definitely not normal

shift ur own gears! tko swap

The trans shop rebuilt it n sold it to me

It's in my Z71 I'm keepin it auto

If I was to guess just from what I'm reading I'd say epc solenoid there prone to go out

Well today 3rd n 4th went out same thing that happin 3 months ago to the other trans. Can my tune be causing this

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Originally Posted by bootlife

Well today 3rd n 4th went out same thing that happin 3 months ago to the other trans. Can my tune be causing this

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Not likely unless your tuner really blows. Sounds like its much bigger issues. Who tuned it? Sounds like the trans builder is shoddy or instal is being done poorly.

I was reading on here some where n some1 recommended doing a vette second. What is this mod n how does it help? Also I'm ordering parts to do a rebuild n where can I get it n what I need to make it work?

-A bad or dirty MAF can cause the transmission to go out fast...replace or check to see if its clean, have TPS checked as well

-ON your next trans build make sure you get a new EPC solenoid and TCC code 1870 fix valve..

These three little parts above can be responsible for a smoked rebuild..

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Originally Posted by bootlife

I was reading on here some where n some1 recommended doing a vette second. What is this mod n how does it help? Also I'm ordering parts to do a rebuild n where can I get it n what I need to make it work?

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Look up monster trans in a box. Everything you need parts wise to do it yourself. I wouldn't do it myself tho. Get a reputable builder to build and instal it for you. Not just any trans shop either. A vette servo replaces the stock one which firms up the pressure/shifts.

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Originally Posted by ls1ram

-A bad or dirty MAF can cause the transmission to go out fast...replace or check to see if its clean, have TPS checked as well

-ON your next trans build make sure you get a new EPC solenoid and TCC code 1870 fix valve..

These three little parts above can be responsible for a smoked rebuild..

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Ok thanks ill be sure to do that

I'm going to do my own rebuild this time, I have more than Enuff info and pretty sure I can. But if it don't work out ill be out 300 bucks but its worth a shot to me. I'm out 600 on the last 1 n it was done by a shop. Hard to get good work done anymore

I'm guessing that is with you taking trans out of truck, thats way to cheap for a proper rebuild in my opinion.

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Originally Posted by 96/chevy/pu

I'm guessing that is with you taking trans out of truck, thats way to cheap for a proper rebuild in my opinion.

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X2 too cheap.

If the fluid is dirty the clutches are burned up. It's very important to blow the transmission lines and cooler out completely.
Not doing this will just cause issues on the next rebuild.

A tune won't cause a trans to slip or burn up. A trans tune consists of adjusting shift points. Increasing line pressure for a better feel and removing TM.
Any tuning application available cannot change the function, the way a trans operates, so it's really hard for a tuner to hurt a trans.

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Originally Posted by farmtruc

If the fluid is dirty the clutches are burned up. It's very important to blow the transmission lines and cooler out completely.
Not doing this will just cause issues on the next rebuild.

A tune won't cause a trans to slip or burn up. A trans tune consists of adjusting shift points. Increasing line pressure for a better feel and removing TM.
Any tuning application available cannot change the function, the way a trans operates, so it's really hard for a tuner to hurt a trans.

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Ok, I was just trin to eliminate my options, I'm not sure why the same thing happind so quickly with a diff trans. I know what parts I need to stop the problems in for round 300 for parts I think I can fix it. I'm not a trans guy but Evan they started some where lol.

Reason I thot the tune could be an issue is at 20 mph when it shifts to second it barks the tires lol

You will soon find out there's much more to building a trans than you realize. I've destroyed 8 different trannies in my truck and decided to build my own. With the money I spent trying to save a few bucks I could have paid for a built trans by now. Everyone on this site can tell you about my trans troubles.

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Originally Posted by bootlife

Reason I thot the tune could be an issue is at 20 mph when it shifts to second it barks the tires lol

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the pcm at least in my tunes, isn't programmed to shift that hard.
a faulty epc or pcs, maf, tps, can cause this.
Generally speaking, if the transmission is shifting thru all gears the pcm and mechanics of the transmission are working together.
There are so many variables that can cause similar issues.

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Originally Posted by jansen

You will soon find out there's much more to building a trans than you realize. I've destroyed 8 different trannies in my truck and decided to build my own. With the money I spent trying to save a few bucks I could have paid for a built trans by now. Everyone on this site can tell you about my trans troubles.

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Well it's worth a try, I have 2 here if mine don't work out ill send the other off. Iv been working on cars for better than 15 years now, rebuilt many standard trans, ill give it a shot. Least I tried.

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Originally Posted by farmtruc

the pcm at least in my tunes, isn't programmed to shift that hard.
a faulty epc or pcs, maf, tps, can cause this.
Generally speaking, if the transmission is shifting thru all gears the pcm and mechanics of the transmission are working together.
There are so many variables that can cause similar issues.

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What do I need to look for, I can do some data logging. Was gonna do some anyway so I when I send my PCM in you can see what all needs adjusting

Make sure to flush cooler and lines like suggested, new are rebuilt converter, all gaskets, seals, clutches for sure I always replace front pump bushing and case bushing, but all need to be checked. I like the Z-pack for the 3-4 clutches, use a good kevlar band, .500 boost valve in pump, corvette servo, and a shift kit ( I like the superior hp kit myself easy install and works well). Everyone on this site seems to like Transgo hd 2 you make the decision. If you do use the superior kit skip the step were it tells you to turn EPS a 1/4 turn, way too hard of a shift. Also forward accumalator spring don't use theirs it give a harsh engagment. I'm no professional but have rebuilt plenty of these trannys for myself, family, friends and this combo seems to hold up good. replace EPS for sure, prone to problems. You can do it, it does require a few tools to make the job easier.

Thank you for ur In depth knowlage, it's very useful and will be sure to put it to good use. Iv been talking to a fella at true-tech transmission, he seem very knowledge able about it, I was pretty worried bout what all I needed to do valve body wise. I am gonna do the up graded parts internally I don't plan on cheesin the job at all. Parts seem awful cheep when u think bout havin to pull it out again lol

I found a bad MAF, its sayin the truck is at idle while giving it fuel. TPS is good, Can you explain how this would cause trans to fail I.E. Hard Shifts?