Does this make sense?

[wood4heat]

Originally Posted by TwinTurbo

Have you crawled under and looked at the transmission? I put one in my truck that came out of a friends, that had been rebuilt, it had a tag on it from the company and I was then able to call them and find out what they do in a typical rebuild. Just a thought.

Not closely, I'll give it a good look over the weekend.

Originally Posted by cleatus12r

wood4heat, what is your PCM code? Longshot270 had some really great information there, but as far as the 4R100 is concerned it is a little off....

Under normal acceleration, the TCC is commanded to apply in 3rd gear at some point (Depending on PCM code, which is why I asked for it).

If you can truly FEEL the 1-2 and 2-3 upshifts under normal acceleration, it's likely you have something done to the transmission. Typically, with stock programming and a stock transmission, the 1-2 and 2-3 upshifts SLIDE into gear and you really don't notice much of an RPM change.

I'll look for the PCM code as well. You can definentely feel the 1-2 and 2-3 shifts under normal driving, the next shift slides in as you described.

[ToMang07]

I have a little bit of a hard shift from 1-2 only from a dead stop, but I'm pretty sure it's just the TC locking, the tranny shifts VERY smooth the rest of the time, tons of power and no slip.

[wood4heat]

So I crawled under the truck yesterday evening and spent 20 min wiping away road grime but didn't find a tag or any identifier left by whoever rebuilt the trans. I also looked for the PCM code and had no luck there either. It was a long day and I didn't have the energy to pull the pcm.

I don't need the code to order a chip do I?

Also since my 1-2 and 2-3 shifts are solid would it be possible or even recommended to leave them alone and firm up the 3-4 shift with the chip?

At this point I'm wondering if I should just leave the trans tuning alone and do a valve body later. At least then I would know what I had.

[ToMang07]

Originally Posted by wood4heat

So I crawled under the truck yesterday evening and spent 20 min wiping away road grime but didn't find a tag or any identifier left by whoever rebuilt the trans. I also looked for the PCM code and had no luck there either. It was a long day and I didn't have the energy to pull the pcm.

I don't need the code to order a chip do I?

Also since my 1-2 and 2-3 shifts are solid would it be possible or even recommended to leave them alone and firm up the 3-4 shift with the chip?

At this point I'm wondering if I should just leave the trans tuning alone and do a valve body later. At least then I would know what I had.

Yes, you do need the code. All you need to pull the PCM is a 7mm and a 10mm socket. Remove the 10mm harness from behind the fire-wall, (under the master cylinder) then remove the 2-7m bolts holding the black box that secures the PCM.

Turn it to the right and remove.... reverse to re-install.

The Code should be on the plastic cover where the chip will go, and on the end of the PCM that plugs into the harness.

And from my experiance... DO NOT use the black box to re-mount the PCM... mine was turning the chip causing random shut-offs and no-start. Removed the box.... no more problems.

[907DAVE]

One thing I do with mine is to remove the box and use that small grounding tab (on the lower 7MM bolt) to keep the PCM up against the firewall. This also acts as a case ground for the PCM.......whether its necessary or not - I could not tell you.

[ToMang07]

Originally Posted by 907DAVE

One thing I do with mine is to remove the box and use that small grounding tab (on the lower 7MM bolt) to keep the PCM up against the firewall. This also acts as a case ground for the PCM.......whether its necessary or not - I could not tell you.

I fashoned a little "Z" shaped brackt... attached a rubber runner on the PCM mount and a rubber "arm" on the bracket....and used the lower screw on the stock mounting bracket as well. I think I will go get a pic... could come in useful!...

[ToMang07]

[cleatus12r]

Originally Posted by 907DAVE

One thing I do with mine is to remove the box and use that small grounding tab (on the lower 7MM bolt) to keep the PCM up against the firewall. This also acts as a case ground for the PCM.......whether its necessary or not - I could not tell you.

You go a lot further than I do.

The 2000 PCM is flopping around; only being held in place by the wiring harness. The PCM in the 1995 is resting between the underhood fuse box and brake master cylinder.

[907DAVE]

I did this mainly so I can get the connector back into the PCM without any assistance, and seems to work well.