Black02Z71

Well I rebuilt my transmission last weekend, I spent 24-25 hours on it and I didn't feel like talking about it after I was done, so I waited till now.

The worst part and only hard part was getting the trans out of the truck, I don't know maybe I'm just spoiled by using a hoist at work all day, I hate working off a creaper.
I wish they would go back to the old style bellhousing, with the cover plate, its a pain undoing the TC bolts through the starter hole, and headers don't help ether. I broke the wires off the oil level sensor, from fighting with the starter (I just let it hang by the wires).

I installed these parts

- torque drive kit - hardened input shaft, drum, sun shell, low roller clutch inner race
- 5 pinion planets
- Z pak 3-4 clutch
- double caged 29 element sprage
- Alto master kit
- Corvette servo
- Transgo shift kit
- aluminium accumulator pistons
- high output pump slide spring
- Raybestos pro series band

I learned that 2002 4L60E do have the 13 vane pump, and they have a torrienton bearing between the reaction carrier shaft, and the sun shell. They use to have a plastic thrust washer there.

I also learned that a weekend is not enough time to remove, rebuilt, add over $2000 in parts, reinstall, and still feel good about the build. I would have liked to take my time with it, but its my only vehicle, so its fix it or not go to work.

Shift feel - 0 TM

The shifts are a lot firmer now, 1-2 is hard, 2-3 is firm, 3-4 stock. I left the 1-2 accumulator all stock, no washers, and it's still to hard. I am currently trying to tweak the pressure to soft part throttle shifts. At wot the shifts are quick and firm, 2-3 is much improved. 2-3 at lighter throttle still has that 2 step feel, but at wot it feels more like one event.

gonzo 6.2

iTrader: (8)

On a your other post i questioned about the 13 vain already being there.What did you drill the 2nd feed hole to?Did you end up using both band spacer?Does your custom PCM tune have the trans main line pressures raised?

Black02Z71

I drilled the 2nd feed hole to .093", and I used one band spacer.

As for the PCM the force motor table is stock, and I have set desired shift table back to stock, and put -4 on the 1-2 upshift table in the lower torque range.

Mr. Sandog

What is the issue with the hard 1-2 shift? Is it a programming issue? Or is this the result of the normal Transgo/shift kit install? This issue has me concerned and wondering about my own pending install.

I don't think a hard shift is a good shift. I used to think that barking 1-2 was good, but not anymore. I believe that quick+firm shifts are desired, but all that hard shifts do is subject hard parts to undue stress.

Please keep us posted on how this works out.

Black02Z71

I have the same belief, hard shifts = broken parts.

The 1-2 isn't tire barking just a lot harder then I'd like. At wot its quick and firm, its the 25-50% tp range that is hard (it feels like someone drove into the back of the truck).

What I don't understand is how the pcm calculates the input shaft rpm, because are no speed sensors in the transmission that I have seen.

My theory is at lighter throttle the rpm is not dropping at the shifts, do to the looser TC. This then causes the pcm to set shift time errors and add line pressure to shorten the shift time.

My shift times are 1.5-1.7 sec range at low rpm, and 0.1-0.2 sec at higher rpm. Also shift time errors read 5.5-6 sec at lower rpm.

gonzo 6.2

iTrader: (8)

My 1-2 shift at 25%-50% throttle is to harsh with the transgo.I then took out the 1 accumulator washer all that did was make a less clean 1-2 shift.Then I made the 2nd feed hole smaller .082 I think.Still harsh.So next was to remove the vette servo and running the OE.Still to much bang.I know my problem is with the Ed Wright

tune.I have Edit I need to just get a 02 PCM and fix it using Edit.

Mr. Sandog

Pressure turned up too high?

gonzo 6.2

iTrader: (8)

I think with OE trans setting and raise the shift points mine will be spot on. i can then put back in the vette servo

KySilverado

iTrader: (7)

I've been able to tune mine down a bit. Much improved but still very firm part throttle 1-2 shift. We have about the same setup except I did install one shim in the 1-2 accum. I tuned the transmission->a4 shift properties->1-2upshift pressure modifier by trans temp table. Here is what it looks like.

-28 -29 -31 -32 -32 -15 -10 -5 0 0 0 0 0 1 2 5 6
-27 -28 -31 -32 -32 -15 -10 -5 0 0 0 0 0 2 4 6 7
-25 -26 -30 -33 -33 -15 -10 -5 0 0 0 0 1 2 5 7 8
7 6 1 -4 -4 0 0 0 0 0 0 0 2 3 6 8 9
10 8 2 -6 -6 0 0 0 0 0 0 0 2 4 7 9 10

I've also taken the shift times up in the lower rpm range and took the base pressure back to stock from raised that came with the radix tune.

Black02Z71

I adjusted the 1-2 table by -10 in the lower torque range, that made a big difference. I think if I pull a little more it will be close to stock. I've even been thinking of adding a little TM just at low torque.