Hey everyone, I'm having some problems with a new (to me) transmission.
The trans started life as a 130K unit out of a somewhat clean 2002 GP GT. I was swapping my transmission out because it had 230K on it, and a pretty bad 1-2 shift. My wife even complained about it. I pulled the 2002 (we'll say new transmission from here on out) trans apart and checked everything out, everything seemed fine...actually it was in REALLY good shape. I used the new trans's torque converter, since it was higher stall, lighter, and 100k+ less miles. I took some of my old clutches for input and 3rd, scraped off all the friction material, then smoothed it up with steel wool (just to be safe), and installed it on top of the top most friction. Then I took one of the 2nd clutch steels and added it in the 2nd clutch stack the same way. Other than that, I swapped over stuff from old transmission I had upgraded (right before pulling it).
I swapped over my gears, my HD diff, put in some hardened GXP chains, swapped over my channel plate\valve body, DIY shift kit (hardened 4th shaft, and 4th stack. The VB\Channel plate was reused because I had just bought it (used) off of this site, and it is re-manufactured with Sonnax upgrades:
Sonnax 4T65E Boost Valve and Sleeve Kit
Sonnax Performance Line Pressure Booster Kit
Sonnax TCC Apply Valve Sonnax TCC Relief Valve
Superior AFL Valve Kit
All shift solenoids were replaced
#2 & #3 oil feeds are opened up on the separator plate
An extra spring in the 4th Clutch Piston Feed
I also replaced the TCC PWM and EPC solenoids with new units I bought. In one of the many manuals\webpages I read during all this B.S. I was told to turn the EPC's adjustment screw 1\8th of a turn, so I did. I later read that this is pointless because the computer adapts to the increased line pressure...more on this in a minute.
First start up and drive was FANTASTIC. I loved it. The more I drove it, the harder the 1-2 shift got, and the more I could hear this clattering-type noise under heavy load. This happened with the old transmission as well, but I thought it was due to the transmission's age and mileage. Whatever it was carried over to this transmission. Another problem that carried over is a random RPM drop. This'll take some explaining, so I'll give this problem it's own paragraph.
It's not TCC oscillation to my knowledge, the oscillaltion was the entire reason I started working on the old transmission. It was repaired with the new VB and Channel plate, but the 1-2 shift problem arose. Still, the 1-2 shift on the new transmission is nothing compared to the old one. The best the old shifted is the worst that the new has shifted. Anyways, I live in a small town, so my average speed limit is 30 MPH. So naturally I do a lot of coasting, and the engine sits around 1,000 RPM while doing so. This random RPM drop happens and the engine drops to 500 RPM, and comes right back up to 1,000. I swear the PCM tries something, then says "Whoops" and puts it back. I've yet to have this happen in neutral...and I've tried...a LOT. This'll happen about once every 5 seconds, during that session of coasting. If I accelerate again or come to a stop, it might go away if I'm lucky. I've checked and swapped out my IAC, MAF, TPS, and O2 sensor. I monitor it all with Torque Pro and when the drop happens, nothing seems to trigger it. TPS is solid, MAF drops with the RPM just as the vacuum, and the IAC % doesn't change. On the HWY all is normal, except for the next problem, which will also get it's own paragraph.
The clattering sounds like chains, and is very similar, if not the same to the noise my old transmission made...although this is louder at times. Under load with somewhat low throttle, I'd say less than 50-60% you hear clattering from the driver side of the car. If I shift the car into neutral during this behavior, the noise goes away. I also think this noise is causing false KR. With my previous transmission I saw maybe 0.1* of KR driving to Springfield, on a regular basis. Today I drove to Springfield and I hit 3.5*. The alarm for Torque Pro went off and scared the **** out of the whole family, lol. The alarm is set at 3*, and we've never heard it before. This all happened during a high load\low throttle situation, which leads me to believe the transmission was making the noise.
The 1-2 shift problem is pretty straight forward, except for the fact it goes away when I reset TAP's, then slowly comes back. Today I reset TAP's in Springfield and it shifted GREAT, by the time I was back home it is back to being hard again. Nothing like the old transmission, but I don't think it's right. I'm thinking that when I reset TAP's the 1\8th turn I made on the EPC kicks in again, and that's why it shifts good. I'm on the verge of buying a Reptile tune for my car which has the increased line pressure in the tune, so the 1-2 shift issue might be repaired with that. The deciding factor on buying the Reptile tune is this damned transmission.
What do you guys think is going on and what should I do? Sorry the post is so long, I wanted to be as thorough as I could. Thanks for any input!!
