'98 Regal - Odd Transmission Issue - 4T65E-HD

[tekkdrone]

Hello all, I'm new to AF as a poster though I've gleaned many a useful bit of information from the forums over the past couple of years. I finally bit the bullet and registered when all the searching in the world couldn't turn up the answers I was looking for

I'm having some difficulty with my 1998 Regal GS's transmission.
(GM L67+4T65E-HD Powertrain) here's all the information i've come up with so far:

1) There are no DTC's set, and there are none pending.

2) D4 (OD) and Manual 3 do nothing from a stop. (Like sitting in Neutral)

3) Manual 1 and Manual 2 engage, but it feels as though max line pressure is commanded.

4) Park and Reverse engage normally.

The odd part (to me anyway, not so much to a trans tech):
If I begin driving in Manual 2, I can feel a light shudder at the start, but as I speed up, it shifts into 2nd, and I can upshift to D4 and the transmission shifts as it should, first on to D3, then D4. If I come to a stop, it's like being in Neutral again...

Any advice, any suggestions, and any ideas are welcome and much appreciated.

[HotZ28]

This could be something as simple as a gear selector switch (range switch) located on the outside (driver back side) of the transaxle, or it could be internal problems. Unfortunately, you will need to check the trans functions with a trans capable scanner to tell what is really going on. We could only speculate here, as to what may be causing this!
BTW, Welcome to AF!

[BNaylor]

It is always helpful to post the mileage and when the last tranny service was performed. Mainly when the ATF and screen filter were replaced.

I too hate speculating but it sounds like an internal mechanical problem to me. What does it do if you never put it into overdrive - 4th. Run a test by leaving it in D3 only and see if it ever drops to neutral.

[tekkdrone]

Originally Posted by bnaylor

It is always helpful to post the mileage and when the last tranny service was performed. Mainly when the ATF and screen filter were replaced.

I too hate speculating but it sounds like an internal mechanical problem to me. What does it do if you never put it into overdrive - 4th. Run a test by leaving it in D3 only and see if it ever drops to neutral.

Aye, the mileage is about 135K, I purchased it used recently and was still in the process of taking care of the previous owner's maintenance shortcomings... The trans filter and fluid's last change are a complete mystery though they were due to be done this coming weekend. I'll run the test you suggested also bnaylor, and I'm looking at the internal differences between OD1 and Manual 1 in the unit repair manual's flow diagrams. I've edited my first post to better reflect the conditions encountered.

Thank you for your quick replies

Edit: When starting in manual 2-1st gear then upshifting to manual 3, reaching 3rd and then slowing down results in loss of drive. Bnaylor, I suspect it's going to be internal, I'm just hoping it's on the accumulator side and not the valve body. It doesn't fit the PCS or TCC Apply failure descriptions that I've come accross so one can hope...

[tekkdrone]

Dropping the pan almost immediately revealed the issue, sadly enough... Sitting in the pan was the first inch of the forward band, including the lip that contacts the forward servo.