Rough Shifting Chevy

First thing to do is have it scanned for codes. Some codes will cause the tranny to raise the line pressure to max when they set. This increase in pressure will often be felt as hard shifts.

-- Old Crow "Yol Bolson!" '82 FLTC-P "Miss Pearl" '95 YJ Rio Grande BS#133, SENS, TOMKAT, MAMBM

Though I can't specifically answer about your car, I can tell you that Chevy's 4L60E trans has this same problem due to a design flaw with the valve body. Transgo makes a rebuild/shift kit that fixes this problem, if it is caught in time. One of the check ball seats gets worn to the point it becomes slightly larger then the ball, allowing it to sit in the hole and not come out. The kit replaces this with a larger ball and addresses other issues.

Depending on the tranny in your Imp, you may have a similar problem. Hope this helps a little bit.

This is probably related to the Pressure Control valve. Either its sticking or the computer is detecting slippage. Sometimes cold weather causes these valves to stick if they sit a little while.

Here's a possible related TSB: _____________________________________________________ Slips, Harsh Upshift or Garage Shifts, Launch Shudders, Flares, Erratic Shifts and Intermittent Concerns, DTC P1811 or P0748 Set (Replace Pressure Control Solenoid Valve Assembly) #00-07-30-002B - (07/19/2002)

2000-2002 Chevrolet Impala

Cause

The above condition may be due to any one of the following which may affect line pressure output:

• Sediment inside the pressure control (PC) solenoid valve, causing the PC solenoid valve to mechanically bind.

• Sediment in the valve body, causing the torque signal regulator valve to stick.

• Incorrect transaxle oil level. _____________________________________________________

(Now watch out for Snoman. If he see's your thread he might confuse your

4l65e with a Powerglide.)

haha oops I mean 4t65e.

So, it sounds like the 4t65e and the 4l60e have the same problem

I was going to post on the pressure control solenoid:

Just to add on your post, these solenoid valves have the tendency for the coil to break down: (wear and short internally) under the higher temperatures that are generated by the slippage.

So I would use a scanner and look at the rpm and output shaft speed in third gear. This is how the leakage and non operation is found.

Basically:

That's why they went to the 4L65 and the 4T65 due to some mediocre upgrades.

So, will a 4L65E bolt in place of a 4L60E? Would it even be worth the swap?

I'm sure it will:

The updates are electrical, and the two issues in the valve body. But, the

4L65E fits the LS series small blocks, I don't know if they have the same bolt pattern, or a dual bolt pattern.

I've yet to rebuild a 4L65E, but the valve bodies are visually different.

Hmm, maybe I should ask the tranny expert of 1870, Snofraud and see what he has to say about this? LOL

Thanks for the info though, I'll keep that in mind if I keep the Silvy much longer then I plan too. Right now, it hard shifts a little, but I know the transgo kit will correct the problem and that is something that I can install myself.

I highly recommend the Trans-Go kit,

I especially recommend you >> I'm sure it will: