Transmission problems?

[SageB82]

So I own a 2003 silverado that originally came with a 4.3,I converted it to a 5.3 out of 2004. The engine came with the harness and computer. I had both computers tuned and still have the same problem. At 80 mph I'm at 2900-3000 rpm. I'm not the brightest crayon in the box I know it should be around 2200 give or take a little. The transmission worked fine before the swap. I'm not sure if it's msybe the tune, harness, trans or tcc.

[Botlfed]

Make sure that its shifting into OD not just going from 1st to 3rd, could be your shift solenoids.

[farmtruc]

Check for dtc's.

[SageB82]

No DTC's, I feels like it shifts into all gears

[zebra]

converter locked?

[vortecyota]

How many up shifts do you feel? 3 up shifts = 4 gears. You may or may not feel the converter lock up. Once in high gear at light throttle tap the brake pedal without moving the throttle from part throttle and see if rpms increase a little. If they do, it is at least applying the converter clutch. If not, and you have all 4 gears, monitor brake switch status in scan data.

[SageB82]

The power wire for the TCC gets power and when you touch the brake it loses power, so I believe that's working correctly. Does anyone know the big difference between the V6 and V8 torque converter?

[Carazy]

The power wire for the TCC gets power and when you touch the brake it loses power, so I believe that's working correctly. Does anyone know the big difference between the V6 and V8 torque converter?

Do you have a scan tool to watch Data live? If so look in the transmission data for TCC Engage, TCC Duty % and TCC Slip RPM. Monitor those. When your TCC Engage is yes, the duty percentage should be up in percentage if not all the way to 99% and the TCC Slip RPM should be more than 10 at that time. This would answer if your TCC is working properly. Your 03 will be PWM (pulse width modulation) which means unlike the old lockup setups it is not like an on and off switch it gradually comes on. You can see all that through data.

The main difference between a 6 and 8 is mostly just the stall.

[kewljay223]

im not sure if this is any help but i thought id chime in... im not sure there is a problem because im running about the same RPM also.... But since nobody has mentioned that your RPM is "normal" or average, im a bit concerned now too. But there are plenty of factors that will determine your rpm/speed. i will list my setup so you have something to compare to and for others on here to see if its normal or not.

im running a lq9(doesnt matter what motor) with a 4l80e(stock geared), circle-D 2800 stall with lockup, stock gov-bomb rear with 3.73's, and 27" tall tires (295/30/20) that setup is putting me at 3k @ 80mph. i took a pic today on my way to work.


weather everything is working or not, im not 100% positive but im pretty sure it is. i have run a scan tool a while back to check for TCC lockup like CARAZY suggested and it shows that it is in fact locking and i know it is because i can feel it engage. it does so around 50mph. yours might be programed to engage/disengage sooner or later. i also have a shift kit so i can definately feel it shift through all the gears like it should. so like i said, im pretty sure everything is working.

Now something worth mentioning although it is not too significant is the OD gear ratio between the 60e and 80e is different. the 60e has .70 and the 80e has .75 Sux for me cuz the means higher rpm in overdrive. anyway, reason im bringing this up is you didnt mention what your setup is, but i assume since it came with the little motor, you have 60e. but idk if you swapped it to an 80 when you changed motors. also, you need to find out what your rear gearing is. there is a possibility you have steeper gearing in there to help the torque for that sixxer to get that truck moving.

As for the Converter, it doesnt matter what stall you have if it has lockup. as long as the lockup is working properly, and is engaged, there will be no slipage, assuming clutches arent worn of course....

You should confirm what gears are in the rear end and post it up along with tire size, type of trans your running, type of coverter, and weather or not your lockup is working properly. idk about anybody else reading this but i have a funny feeling this rpm is "normal" for at least you and i. opinions anyone?

[vortecyota]

Just thought of this, are you stating what rpm your gauge is showing or scan data? I'm guessing you're going by the gauge. If so, your tach out put parameter in the tune probably needs to be updated. I recently worked on an S10 with a 4.3-5.3 swap and at 2200rpm, the gauge indicated 3000. I played with the tach output parameters and got it within 100rpm at 3k.