thats right folks. Just won a 4t40e off of ebay for 128.88 with 20k on it. I blew my last trans in 200 miles. i hope to get a few more out of this one. Maybe like 300 miles or so. Nah jk but yes this is no lie . This will be the 3rd trans in the car in three weeks. Dont boost your 4t40e and think it will last long. Just expect to be going through what I am . Only a couple people have been lucky enough to not need a rebuild. Good thing they are cheap. Shipping cost more than the trans itself. 150 shipping for local warehouse pickup.


<img src="http://img.photobucket.com/albums/v292/dragmyz24/shoppedcav2.jpg">
01 Z24 Turbo with a snail shaped power improver.

I need to find out about this i have a 05 sunfire that im really looking forward to boosting but dont plan on tranny mods besides a b&m. How much boost are you runnig will i be safe at six

at 5 to 6 psi my trans held up for over a year, (weekend driving only) as soon as I could tune the car properly I upped it to 9 and also put cams in. Ran 100 octane most of the time too. And thats when all the troubles started.


<img src="http://img.photobucket.com/albums/v292/dragmyz24/shoppedcav2.jpg">
01 Z24 Turbo with a snail shaped power improver.

your profile says you have a built 4t40e...

if it was really "built" and you arent abusing it, then you shouldnt really be having any problems.

people have ran up to 15 lbs boost on daily drivers on that trans and still running....


and if the built transmission was blown, then you should have found out WHY and had them fix the issue.

well ive been boosted for over a year now on my daily driver. I used to beat on it alot, so far no real problems, the trans slips when shifting from 1-2, but thats easily fixed with the shiftplus turned on, and it only shifts when im in boost. If im not in boost it doesnt slip.


2006 Black Cobalt SS Supercharged G85
13.91@102.77

also youve bought 2 used transmissions for really cheap, ever hear the saying you get what you pay for?


2006 Black Cobalt SS Supercharged G85
13.91@102.77

the second trans had the yank converter in it along with 4t45e clutch packs and the newest pump design for our application. The old one used to have a washer from what I was told on the pump shaft and that use to cause problems with the pump. << THIS trans is still in the car and I have no time to dive into it again when the only real thing that made a difference was the torque converter which I think caused the problems in the first place.. So therefore instead of paying someone to redo or even diagnose the problem on the other one which would cost several hundred, WHY not take a chance on one for a few hundred shipped ??? Theres your answer as to why . and as far as the sang goes You Get What You Pay For < Your right. A cheap azz piece of crap 4t40e < these trans' are crap man. Not made for big power.

Yours is slipping too huh? lol and your claiming that I don't know what I am talking about it seems like. Up the boost and watch what happens to your allready slipping trans. It may not slip with the shift kit on but that doesn't mean that the damage isn't allready done to it. On my first post I said that anybody putting down even close to 200 whp is having slipping , banging, humming, grinding, crazy shifting, you name it. Don't defend the auto trans please because I did not beat on my car and I can't get a break as far as these things go. So cut me some slack. lol


<img src="http://img.photobucket.com/albums/v292/dragmyz24/shoppedcav2.jpg">
01 Z24 Turbo with a snail shaped power improver.

I changed my profile for you since I didn't have a good built trans I guess.


<img src="http://img.photobucket.com/albums/v292/dragmyz24/shoppedcav2.jpg">
01 Z24 Turbo with a snail shaped power improver.

I will defend the auto tranny. I have a boosted 2.4 auto. 96, orginal tranny, boost has been to 10-13psi at times. No problems. I know the car was putting over 200 at the wheels. the only tranny related issue was the flex plate ripped. It has a custom flexplate now. Then it pulled the bolts for the flexplate out. upgraded those and all had been good, until spun a rod bearing. Still on stock converter. Plan to upgrade that. I know at some point the tranny will go. I know of many people in the mid to low 13's on stock tranny's on juice or boost.

dragracemyz24, put a tampon in or something. . .
when i watch people run over 300HP through the trans and its still fine, im not worried about it. Yeah my trans slips 1-2 when the shift kit isnt on, but i believe its more so caused by the shiftkit than anything else. Ive noticed something. If ive had my shiftkit on for a while and turn it off, the car slips alot worse than if i had, had it turned off for a while. I believe that the whole fact that its a piggy back sorta way is whats really messing with it. I think the computer sees the increased line pressure and assumes that is the normal pressure, so when the shiftplus is off, it doesnt supply enough line pressure. But then after a lil bit i can feel the line pressure build up, and the shifts are fine.

I honestly think the tuning software will eliminate all my problems.


2006 Black Cobalt SS Supercharged G85
13.91@102.77

without the shiftplus on, you're getting the true condition of your trans. its slipping. raising line psi will only work for so long. run the shiftplus on continuously and sooner or later it will begin to slip.

see i dont believe that. Like i said, i can feel the transmission slip alot more when the shiftplus has been on for a while and i turn it off, then if it has been off for awhile. One of the reasons piggy back systems arent that great for our cars is because the computers are really tempremental. They like to do things there way only. I feel more than confident that my slipping is only caused because the computer thinks the line pressure is higher than what it really is. Because how come my trans doesnt slip any anyother time? I doesnt slip going into gears P->D, it doesnt slip while in gear or any other time.


2006 Black Cobalt SS Supercharged G85
13.91@102.77

ok, the shiftplus raises your line pressure. and when yours is on the trans doesnt slip, correct? now when you turn the shift plus off the trans slips, right? raising line pressure in a slipping automatic will usually stop the slipping, if i lower the line pressure back down to factory specs it will slip again. now on todays automatics the computer can compensate for slip with adaptive learning, but it will only go so far. slips in trannys are progressive, they always get worse to the point of no movement. your trans has input and output speed sensors that give feedback to the computer. its only programmed so far. if this still makes no sense than consider this, if i take a brand new cavalier with 1 mile on it and install the shiftplus and turn it on, the trans will shift quicker and harder, i turn it off the trans shifts like it did from the factory with no slip. the transition from hi line pressure to factory line pressure is instantaneous. there is no slow transformation. the computer will compensate for the slip by raising line pressure a bit. but it does that because there is wear in the trans, be it a leaking seal or a worn clutch pack. the wear will continue untill the computer can no longer compensate for it because its out of parameter, and the trans will slip continuously. this may take 10000 more miles it may take 1000 miles. but you need to realize that its happening. how long it lasts depends on how you treat it from here on. leave the shiftplus on it may help.

well then how come like i said if i have had the shiftplus on for a while, then turn it off the trans slips almost constantly. Like a low RPM 1-2 will slip. But if i have had the shiftplus off for a while 1-2 is nice and firm? Something elsei noticed yesterday as well. I was doing about 30MPH and punched it with the shiftplus off. At that speed the trans would downshift to first, and while going at WOT the trans shifted perfectly to 2nd. Again with no shiftplus on.


2006 Black Cobalt SS Supercharged G85
13.91@102.77

because once again, your computer has adaptive learning. its raising line pressure to compensate for the slip when you turn the shiftplus off. get the sucker hot and try some Wot upshifts and see what it does. as i've said before you dont need the shiftplus, have a trans shop turn up your EPC solenoid, it does the same thing.

I have been beating the @!#$ out of my original 4t40e for about 5 years no with no real problems yet.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

^^ i want your trans jeremy . It seems to be one of a kind.


<img src="http://img.photobucket.com/albums/v292/dragmyz24/shoppedcav2.jpg">
01 Z24 Turbo with a snail shaped power improver.

how much would it cost to have a trans shop do that?


2006 Black Cobalt SS Supercharged G85
13.91@102.77

the side cover needs to be removed which is kind of a pain in the ass. my shop does it when we update valve bodies, or during a rebuild on a performance car, its no more effort than twisting the EPC solenoid screw in 1/8 of a turn at most.( too much adjustment and the sunshell will break. ) the cost of just tweeking the EPC is anyones guess. coupled witha trans service maybe 250 bucks at most.

My old non '96 with the Shiftplus on the highest setting started shifting softer and softer, turned it off, and holy slippage!

I solved the problem ASAP though, and bought a 5 speed.

upgrade your internal bands and clutches, so that when you do up the pressure, the quality of em will no deteriorate...

also especially the boosted people.... keep an eye on your transmission temps.... most prob have no clue on what it is on avg, and heat is the biggest killer of transmissions....

the stock radiator is crap when it comes to upgraded transmissions.

once you start venturing over 200 degrees, you start oxidating parts internally....



you guys have A/F guages, boost guages, and oil pressure guages, but no trans temp guages.....

in my view it would suck to spend a 2000$ or more on boost, 200$ on other guages.... and not have a 50-60$ trans temp guage to where it costs you another 1-2000$ for a rebuild or a new transmission ......


if you dont know the temp and you trans is slipping chances are thats part your problems..

^^ thanks for the advise. I will do that for sure.



01 Z24 Turbo

hey i learned the hard way man.... my temps were FAR above 217 at times, turns to find out, thats how i burned fluid in under 23,000 miles...

found out the temps, then added a cooler and things were fine.........

until i upgraded the stock transmission..... now i was up in temps again.....so i have a new trans cooler to add, along with the new Griffin radiator...

it was Eric (JDM cav) from pacesetter than clued me in on operating temp vs running temp... try and keep it as cool as possible, especially if you get on the gas, you;re gonna reach operating temp no prob... so keep it as cool as possible.

luckily i havent ran into any real problems yet, but it was good someone clued me in before i did run into probs that were potentially there. that i am thankful for.

Dirty Muffins (Event) wrote:upgrade your internal bands and clutches, so that when you do up the pressure, the quality of em will no deteriorate...

also especially the boosted people.... keep an eye on your transmission temps.... most prob have no clue on what it is on avg, and heat is the biggest killer of transmissions....

the stock radiator is crap when it comes to upgraded transmissions.

once you start venturing over 200 degrees, you start oxidating parts internally....



you guys have A/F guages, boost guages, and oil pressure guages, but no trans temp guages.....

in my view it would suck to spend a 2000$ or more on boost, 200$ on other guages.... and not have a 50-60$ trans temp guage to where it costs you another 1-2000$ for a rebuild or a new transmission ......


if you dont know the temp and you trans is slipping chances are thats part your problems..

Plan in our project car, is to use Matt Teske old dash and we currently have 3 gauges on the pillar, and 3 more will be in front of the passenger. Oil pressure, Oil Temp, and Tranny temp.
stock 96 4 speed tranny, except the flex plate. No problems. Also has the B&M shiftplus. We notice no slipping after using it and then turning it off.


H&H Motorsports
Jacksonville, Fl

not to be a pain or jack the thread, but where would i be able to pick up a tranny temp gauge? i'm boosting soon and i didn't even think of tranny operating temp.


Blown.