khoward8509

iTrader: (3)

I put 2 in my old Camaro and now the one in my firebird is bad after only having about 4k on a rebuild with a new converter

I was wondering if 700r4 would drop right into there with no problems or what everyone suggests my car has heads and cam on it put 390 to the tires so its not crazy and I don't really beat on it that bad.... what do you guys suggest I don't wanna spend a fortune on this thing just seeing if anyone has any suggestions im in Michigan if anyone has anything for sale but I would need paperwork on what it is

jimmyblue

iTrader: (11)

If you're eating transmissions again and again, you need
to look for some reason other than the transmission. A
lot of failures are heat (trans cooler, fan settings?) and
state-of-tune (bogus low airflow readings, like you get
from some ghetto mods or letting your MAF get all gummy
from that sweet K&N horsepower sauce).

Letting it run hot and starving it for line pressure is not
going to change when you swap in the next victim.

mrvedit

What year were the 4L60E? What were the symptoms when they went bad?
390rwhp is too much for a stock rebuild. Was it a stock rebuild?
It needs at least a 7 friction 3-4 clutch and a bigger boost valve to increase line pressure.
As jimmyblue says, with that much HP and especially if you have a high stall converter, you need an aftermarket cooler. Line pressure should be checked to make sure the PCM is commanding the correct pressure and it isn't low due to a bad TPS or MAF sensor.

A 700R4 has basically the same internals, but an earlier and weaker version of them. IIRC, many use only a 5 friction 3-4 clutch (usually upgraded during a rebuild). GM hardened the sunshell around 2002 and failure of that are very rare after that, but common before that, e.g. in 700R4 at your power level.

Sure a 700R4 can be rebuilt to handle your power, but so can a 4L60E.

khoward8509

iTrader: (3)

it is a 98 and the tranny guy said he put a few lil things into it to help beef it up a bit not sure what they were though it just has a trailblazer ss converter 2600 stall I have a b&m tranny cooler with a fan and the fan has never kicked on from being to hot usually runs about 150 in the summer I have a new ls 6 with a new maf sensor and I have a new tps when I put the new t/b on it was probably basically stock he said since its the same tranny that goes in the c5 350hp vette it should hold for what im doing but that is 350 at the flywheel im probably about 430 at the flywheel

khoward8509

iTrader: (3)

i have heads cam intake t/b professionally dyno tuned by baker engineering (there a sponsor) on a dyno

mrvedit

It would be good to know what failed and exactly what "lil things" the rebuilder did. I also check the line pressure when I install a new trans, including checking it during WOT shifts.

Since you locally rebuilt trans failed, I would suggest getting one from one of the sponsors like FLT, RPM or Performabuilt.
I would also be willing to sell one of more "spare" (rebuilt every few months with performance parts and tested) 4L65E to a local person. I sent you a PM on that.

khoward8509

iTrader: (3)

appreciate the message im taking it back to the guy on Monday to see if he will warranty this thing first... if he doesn't then i will be interested in talking about your trans a lil more. i took it to aamco transmissions i paid to much and didn't get what i want i got a friend that works there i should not have taken it there. i have a local owned transmission shop i was gonna try and see what they say if he will not warranty i will keep all posted on Monday 3-4 are slipping and 2nd shifts really funny so im sure it is toast

mrvedit

Hopefully they will warranty it.

RevGTO

iTrader: (12)

Most of the rebuilt tranny failures reported on this forum sing the same old tune: local shop rebuild and the 3-4 clutch pack fries itself. Maybe he'll warranty it, but what good is that if the next rebuild is of the same quality as the first?

Mrvedit is right - if you want a reliable performance built 4l60e, look to one of our sponsors.

A 700R4 isn't going to do anything for you. It's an earlier non-electronic version of the 4l60e that won't work with an LS1 without a lot of senseless modifications.

khoward8509

iTrader: (3)

if they warranty it at least I should get another 5 k out of it then ill buy a new better one I don't feel like putting the money into it right now I just put heads on It and dyno tuned it and I just had a baby and im trying to do a long drive contest stuff and am trying to buy 15 cres so I got other things to put my money towards if he does not warranty it I might put it back into storage till next year