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Discussion Starter #1
Last fall My 2004 Sierra ecsb 4x4 lost all oil pressure one day. I decided to replace the motor. I went with a rebuilt lq4 with a mild cam. Figured the stock trans had 160k miles on it, and with the added torque of the cammed 6.0, I better replace it. Went with the top of the line monster trans rated for 650 hp/ 600 ft lbs. and extreme abuse. Well 6500 miles later the trans has failed.

I did a bit of research and the general consensus seems to be install a 4l80e if you want a trans to handle anything. My only problem with the 4l80e is the less gearing in first gear. I liked how my truck pulled in first, don't want it to be a dog now. Should I just consider getting my 4l60e rebuilt then?

I have seen where companies make the 4l80e into 5/6 speeds, but these seem to be uncommon and expensive. But I do like the looks of the gear ratios with the aftermarket planetaries. Any first hand experience from anyone with these 5/6 speed conversions?

Trans has went over a week ago and I still am having trouble deciding what I want to do to repair it. Any advice/ opinions are appreciated.

Thanks,
Josh
 

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Discussion Starter #5
Decided to rebuild. Trans guy tore it down while I was there and was surprised by monsters quality, or lack thereof. He said he can get me setup correctly and it will last.
 

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im running a stock 4l80 " will build it before to long" for about 9 months now with my current set up " 630/700" and its holding up just fine. If you need more in first get a bigger stall and gears? before I was boosted my truck would still leave hard and my converter would flash @ 3000 rpm and im running 3:73 gears. now its a different story, but my HP almost doubled.
 

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You can get a 4L60 to hold power. It just takes a LOT of $$$s. I should have done a 4L80 and I could have for less money considering my trans has $3,000 in just parts dumped in it. So far so good though. Rear has 4.88 gears and I wanted the .70 overdrive.
 

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You can get a 4L60 to hold power. It just takes a LOT of $$$s. I should have done a 4L80 and I could have for less money considering my trans has $3,000 in just parts dumped in it. So far so good though. Rear has 4.88 gears and I wanted the .70 overdrive.
not a if but when.... lol although some guys somehow seem to have bullet proof ones most will hold up for a bit, but its still a ticking time bomb. A 4l80 with a shift kit is pretty much as a fully built 4l60
 

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its cheaper to do a 80e then to build up a 60e
stock 80e with a shift kit will handle a lot of power
sucks you bought a monster trans, a lot of us could have warned you.
my fully built FLT 65e handled my H/C/I 5.3 but it was only a matter of time before it couldn't handle the power anymore
 

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Most of those Custom built transmissions are junk. A well established local shop usually trumps a shipped trans.
 

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my FLT was far from junk, I still have it kicking around cause I know I would kick myself if I ever sold it.
 

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Discussion Starter #12
Well we will see how it goes. I am not making much power and have little plans for more. This truck was just suppose to be my winter vehicle...
 

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a built 4l60e will handle power. a lot. BUT!!!! in a truck what the battle is is weight. the weight of a truck is killer on trannies. my first built 60e handled the heads/cam/intake/exhaust/gears for about a year. 3000 stall with the same killed it in about a month. second 60e with the same lasted till i went to 100 shot. shattered the tail end. my truck was a 2002 silvy with a denali front clip and weighed in at 5100 pounds. dropped the serious cash for a built 80e and never had a problem even when i set it up to a 175 shot of spray. the difference in the tranny gears isnt all that much. like stated before an 80e with a shift kit will handle a lot. more than what most people have. have seen a built 80e handle twin turbo trucks with ease. pick what you are trying to do. if you are going to keep modding and going higher then go 80e. in my opinion.

1. bolt ons and pushing it 80e and shift kit.
2. any type of boost or nitrous then build it.'

best of luck. also you will enjoy the fact that an 80e will shift hard in all gears when built correctly instead of the dreaded 60e 1-2 bang.
 

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my FLT was far from junk, I still have it kicking around cause I know I would kick myself if I ever sold it.
Mine was plagued with issues. I somehow managed to destroy it 3 times. I sent it back to FLT each time. I would ride it for a few months and it would let loose again. The last time it broke, I decided to demod the truck and sell it. Sent the 60E back to FLT. They went through the entire thing and I sold it on PT.net. The guy that bought it (mind you, it was completely refreshed from FLT) said he had it in his truck for about two months before it let loose on him. :mad:
 

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Mine was plagued with issues. I somehow managed to destroy it 3 times. I sent it back to FLT each time. I would ride it for a few months and it would let loose again. The last time it broke, I decided to demod the truck and sell it. Sent the 60E back to FLT. They went through the entire thing and I sold it on PT.net. The guy that bought it (mind you, it was completely refreshed from FLT) said he had it in his truck for about two months before it let loose on him. :mad:
that really sucks to hear man
 

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Discussion Starter #17
Well broke the output shaft on the trans and it wiped out a bunch of other stuff...

So where do you guys get 4l80e's from? And how much do they go for? What years and models fit? How hard is it to convert a 2wd to 4wd?
 

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Just get a 2nd version. Not worth swapping. Most fullsize work vans ran the 4l80. You will have to have your ecm modified to include the segment for the additional vss sensor and add the wiring for it
 

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Discussion Starter #19
Truck is already 4wd.

I meant 2wd to 4wd on the 4l80e. From what I saw it is only the output shaft and transfer case adapter instead of tailshaft housing. If I am going to get it rebuilt anyway it seems I can buy a 2wd trans that are abundant for <$300 instead of the harder to find 4wd and pay >$700
 
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