I have a Performabuilt 2 w/a PT4000, 3.73s, LS6 intake, lid. When I take off with the car in D or OD first gear is there just fine. When I put it to "1" when I'm going slowly (at a speed where it should go into 1) it doesn't down shift, and when I give it gas it acts like its in "N". If I put it in "1" from a stop it goes all the way up to redline like it should. I had it scanned at Advance Auto and no codes. Fluid level is good. I added little bits at a time to make sure it was good.

It was installed at the end of November, and I drove it to Wyoming and back, but up until a few weeks ago I rarely drove it (weather) so I haven't been able to drive it hard. I'm guessing it has 4000 miles on it now with 2500 being on the trip to WY and back. I took it back to the place where it was installed and they said they would look into it at no cost but I would like to see what the consensus is on here (especially from the Performabuilt guys).

Thanks.

 

Ok well I am little confused but, Now when you place the shifter in manual 1 the PCM will not allow the shift to occur or overun to ocur until some predetermined programed speed.Depending on your gear ratio this could be nearly at a stop. 373-410 gear would be and example.
As for first gear itself its the same in low 1 as in D and OD mechanically other than when you get slow enough the low/reverse clutch will come on for engine braking. Its not used in any other forward position and is not used to make first gear. It only comes on in manual low. Now if your in a low range to high for the low/reverse clutch to be on speed wise you would get a feeling similar to neutral at least until the engine catches up with the car. But unless I am miss understanding something it sounds like its doing what it should do. Contrary to popular belief unless you install a special 1-2 valve such as is used in the transgo kit. Even though you place the selector in manual low 1 the PCM is still in control of the 1-2 and 2-1 timing. GM did this to protect from being able to downshift into manual low one at a speed that could cause damage to the trans or engine.
But sounds like all is fine If you do have your guys look at it have them watch the data stream and see if first is being comanded since if its not even though your have the shifter in manual low it will not happen.
Give me a call if you have more questions. But since it shifts good in the D-OD positions and launching from a dead stop in manual low one I would say all is good.
Frank

 

When I had the stock trans/converter as well as stock trans/3400 Fuddle in it, it would down shift into 1 when going say 10, 15 mph (sometimes even briefly locking up the rear tires). Now it won't do it. Its not a problem with me as long as its not harming the trans. Also at low speeds should it shift as hard as it does?? If I'm on it hard it just shifts quickly and you don't even feel it. Again not an issue with me, as long the trans isn't being harmed.

Thanks, Frank.

 

The shifts will be quit firm particulary the 1-2 with the super servo used in the level 2. However if you have had any previous tuning done where they may have messed with the line presure. I would have that returned to stock settings I know alot of tuners will turn it up when tuning for a converter with a stock trans to make the shift feel better and this may have been done, We had a guy recently that found that had been done and once he returned those settings to stock while the shift remained quite firm it was much more palletable. The downshift timing may be different from your other trans as far as the PCM is concerned due to the different converter and any other mods you may have made including gear changes. It sounds like all is fine to me.
And of course you are allways welcome

 

Sweetness Frank, I can rest easy now. No there was no tuning done, I can't imagine the trans shop did that, but I will ask them. It had the gears in it before I had the trans installed (it actually had gears when I bought it, but I broke a pinion gear and had another of the same ratio installed before I got this trans).

Last year was a year of carnage. Broke the pinion gear, then exploded (literally) the tailshaft housing, and finally lost 3rd, 4th and reverse in the transmission.

So I kind of hit the panic button when this started.

 

Just relax we are right here when you need us But do hope this is a better year for you that was a rough spell sounds like.

 

Frank,

Just installed your lvl 1 tranny and about to either get a custom tune or the predator programmer for the main purpose of deleting the tm and running a cooler thermostat. From the above post your saying keep the line pressure/shift firmness at the stock settings?

 

Yes that is corrrect we have allready ajusted the line presure to be at max acceptable levels with the stock setting on line.