ss_454

iTrader: (2)

I have a RPM built level 5 4L70E trans in my Trailblazer SS with about 17k miles on it, has been flawless never had a problem and my SS is now making 450RWHP. I have a huge cooler with a gauge never gets above 180* even on the hottest days and i run a FTI SRL3600 billet converter. The other day I was out and I always drive in 3rd unless on the Highway above 60mph. Well I was accelerating up a ramp and started gettin into it and when it normally kicks back it just freewheeled and hit the rev limiter I let off as soon as this happened and when I did it slammed back into gear or something ? I pulled over and looked it over best I could checked fluid was perfect ? drove it the rest of the day without a glitch till later that night it did it again and after this time it stopped wanting to shift into 3rd every time to take off from a start and I also notice the converter stopped locking. I tried manually shifting and it seemed fine ? I don't know alot about transmissions just the basics so let me know what you think ? maybe I am missing something ? I am going to take it out and send it back to RPM if I don't find anything obvious wrong....

performabuilt

iTrader: (25)

I am a little lost on when you say does not want to shift to third you mean just wont shift or neutrals on the 2-3 ? When you say it shifts good manually do you mean you can get all 4 gears and last have you checked it for codes?
Try to describe what it does and does not do taking off normally in the OD position.

ss_454

iTrader: (2)

Ok, It does not do it every time, if I take off normally in OD position it will shift fine from 1 to 2 and then just stays in 2 will not shift to 3rd and other times it will shift fine all the way to OD. If I accelerate hard shifting manual or just leaving in OD it will get to about 4000 in 2nd and then freewheels until I let off then it will slam into 3rd. I have not been driving it in to limit any damage ? if I shift manual all gears work , but after driving for 2-3 miles it will unlock and not lockup again till I stop and shut it off at restart it also it will slip in and out like a surge, but if I pull over shut it off and start right back up it is fine for 2-3 miles again. I just scanned it and got code PO700. Also it is 2wd not the AWD model. I noticed tonight the stall seems to be lower than normal or tighter like something is dragging in the trans. it's hard to explain the feeling. One thing I have noticed last couple months before all this started, my part throttle shift from 1st to 2nd has became progressively harder at lite throttle.
One last thing I installed the FTI converter about a month ago and drove it about 200 break in miles very easy stop and go, should I have done a trans service again after the converter break in period ?

performabuilt

iTrader: (25)

The PO700 code is just telling you there is a code in the TCM you need a different scanner if yours cannot accesss it

ss_454

iTrader: (2)

my scanner is just the basic OBD2/Canbus I cannot pull the code from the TCM with it ? I bought the scanner because dealers around here are a joke $100 just to pull the code ?

performabuilt

iTrader: (25)

No that scanner cannot pull a transcode you will have to see a shop or a tuner to get it

lt1pwr1

iTrader: (1)

Yep, you'll need a scanner that can read the TCM. Do you have an Orielly Auto near you? They loan out (for free) some nicer scanners that read different modules and I"m sure the more expensive one can read your TCM.

I have a fairly cheap scanner from Harbor Freight that can even read a TCM,. Your's must be the very basic version.

Jeremy@RPMTransmissions

iTrader: (12)

ss_454 I am going to shoot you a PM. Let me know when you ordered the trans. We had a small run of defective bands. Unfortunitely we have had 4 of them fail recently with very similar symptoms as you are discribing. Let me know and we will get this fixed for you asap.

Thank you,
Jeremy

ss_454

iTrader: (2)

Thanks Jeremy pm replied, the code is po741 converter lockup slippage or stuck off ? I did not get any codes until I was almost home and the trans. was really struggling. I am not driving it and the next chance I get I'm gonna get it on the lift and drop the trans out and send it out.....when I moved it I noticed alot of pump whine and that the speedometer was moving in park if you rev it up ? I drained a little fluid out and it's not good, it's not burnt but it has alot of metal in it. I recently installed a FTI 3600 converter and it was working great I am just wondering if it broke ? it's hard to tell in stop and go driving ,but it seemed the converter was stalling lower ? I could normally jump on the throttle and flash the converter from a roll to 38-4000 and I noticed it was feeling tighter and only going 3200-3400 and at the end of the night felt like something dragging in the driveline about a mile from home ? transmission still has all gears , but I noticed just in the short time it ran to move it and scan it with my Mac tools scanner it got 180* idling it has never got that hot even racing on a 100* day. I disconnected the cooler lines to check for a blockage and all was good there. I just ordered a new cooler and lines I am not taking a chance with these.....

WRT

Sounds like you burned up the 3-4 clutches or blew the snap ring out of the input drum. I don't see how a "defective" band would affect 3rd gear??