Shift From Park to Drive, Engines Revs Then Clunks Into Gear and Drags Forward Slowly

Hi There,
This forum is a treasure trove of info, it's awesome.
I've seen a few treads with similar things going on, but haven't really seen any follow up with definitive solutions. I use a reputable, local mechanic, unable to do repairs myself. No garage or proper tools. I apologize in advance for the length of this post, but I'm at loss here as to what this can be.

2001 Double Cab, 4WD, 3.4L V-shaped 5VZ-FE, VZN170L-PRPDKAB, Automatic, Currently has 227850+/- miles. New Hampshire.

Not sure what may be the cause, but here is a timeline to perhaps clue in or rule out possibilities.

---March 2022 Purchased the truck and have been working my way through the suggested maintenance things: LBJs, Timing Belt kit, rust repair, etc.
---Aug 2022 Heard a rotational chirp that would slow down when breaking.
---Early Sept 2022 Bed removed by a body shop for rust treatment and body work. They showed me the Load Sensing Proportioning Valve (LSPV) had a crack where it mounts to the frame. It was a clean crack(there was a lot of fluid film everywhere else) and I'm guessing maybe they pried against it when trying to remove the bed? No proof of that.
---Mid Sept 2022 Maintenance at the local mechanic on a few unrelated things(A/C compressor and evaporator, NH Oil Undercoating). They also installed some missing brake hardware to address the chirp and looked at the LSPV. They said the LSPV was rusted to all hell and the crack wasn't necessarily compromising its function. No leaking brake lines. Gave me a price for a new one (I asked for OEM) and we agreed to wait on it since it wasn't causing any problems.
---Early Oct 2022 Rear Diff and Transfer Case Fluids changed at Valvoline shop.
---Mid Oct 2022 Alignment/Rotate/Balance at Town Fair Tire.
***Late Nov 2022 The first time for this mysterious issue. Started the truck, warmed up for 10 minutes or so. I think it was cold outside, but not sure. Shifted from Park To Drive with foot on the brake. Foot off brake, the truck didn't creep forward as it usually does when letting off the brake. Gave it gas and the engine revved, but it was stuck and wouldn't move forward. Back into Park then tried Drive again. Same thing, but then finally clunked into gear and I could drive forward. Had to drive about an hour away that day and when I would come to a stop light and put on the brakes, they would kinda stick when I took my foot off to go forward. The transmission shifted fine the whole time I was driving and had never been an issue since I bought the truck. I think I kinda felt like the truck had a drag to it. It definitely didn't freely coast down hills and pick up speed by gravity, like something was holding the truck back. Set an appointment to have it checked when I get the oil change. It didn't do the start-up rev and clunk again for awhile.
--- Dec 5, 2022 At the local mechanic for oil change and to check the issue. He couldn't reproduce the issue. I never use the E-Brake, but he checked it and also rest of the brakes, cleaned, greased, whatever, wherever and made sure all was working fine. I asked about the transmission fearing for the worst and he didn't think that was it because it goes in reverse with no issue and shifts properly when driving. No codes or check engine lights.
Can't remember how many times the "Park to Drive rev and clunk into motion" occurred after that. Reported it to them and they said they'd look at it again when in the shop soon thereafter for the Trans and Front Diff fluid changes
---Dec 20, 2022 Had them do a Transmission drain/fill(NOT a flush) and Front Diff fluid change. There weren't any red flags with the transmission fluid and the truck still shifts fine when driving. They couldn't reproduce the issue again. The "Park to Drive rev and clunk into motion" happened again a few days later so I made the appointment for the LSPV since they figured that that may actually be the culprit after all.
---Jan 4, 2023 They replace the LSPV, bracket, small brake line and fittings. This seemed to work. I was psyched that we found the problem. No more "Park to Drive rev and clunk into motion", no dragging or slow to move from a stop light, gravity worked coasting downhill with no drag. Transmission shifts great. I thought we finally got it. Woo Hoo!
---Jan 17, 2023 Had them do the timing belt, thermostat, water pump kit, etc plus plugs and wires. Truck still driving great, no more "Park to Drive rev and clunk into motion". Nice!

---Feb 17, 2023 Damn it! "Park to Drive rev and clunk into motion" returns. This time I notice that it is cold out. This winter has seen lots of fluctuation in temperature. It's happened every day since and it's been cold outside. If I put the truck in reverse first thing, it moves fine. Only when going Park to Drive on the initial startup of the day. Once I've been driving it for awhile and park it, it doesn't do it on startup. I've only put less than 700 miles on the truck since this began.

Searching here and on YouTube, I'm guessing at moisture in the brake fluid? Maybe that's freezing? Or my rear wheel brake cylinders are getting stuck? I scheduled another appointment for them to change brake fluid and cylinders. They said they don't usually throw parts at things hoping to fix stuff and they've actually not charged me for several things here and there. Appointment is scheduled for next week, Feb 28.

What could it be??

 

... It's almost certainly a transmission issue and not a brake issue. Even with the e brake pinned, you can use the transmission in OD/D/2/L or R to move the truck.

In all of this, I see you have had one drain and fill done. That's great. I would call around and find a transmission shop in your area who are familiar with Toyota transmissions and describe to them your issue. They will most like suggest dropping the pan and filter and inspecting or replacing shift solenoids. As your issue is intermittent, it's likely fixable and not a larger issue.

 

Two things come to mind immediately...

1st is: Start using your parking brake. Every single time I put it into park, I apply the parking/brake. Helps to keep the rear brakes adjusted. I wonder if the 'drags forward slowly' could be an issue with improperly adjusted brakes (?). When were the shoes/drums last replaced? OE Shoes or aftermarket? Just because its a repair shop doesn't mean they know how to properly adjust the rear brakes on a 20+ year old truck.

2nd: When was the last time the carrier bearing and/or ujoints were inspected? last time the ujoints were greased? When worn this can lead to a pretty annoying 'clunk' when shifting.

upload a pic of the rear axle for us. Let's see this LSPV bracket they used... Try to capture the bracket and full axle views. See what we can see

 

^ also this

Just for clarity (cause I know @Area51Runner knows this already), applying the parking brake doesn't help adjust the rear brakes, outside of manually adjusting the star nut, it's the only way to adjust the rear brakes.

 

Actually - it all comes into play. Using the parking brake will help to keep everything from becoming a mess.





As for the parking brake lever and assembly -

 

@Andy01DblCabTacoma Thanks for this suggestion. Yesterday it was freezing here again. I started the truck, let it run for a minute or so and put into Drive with foot on the brake. Let foot off brake and the release and clunk was quicker than it has been. I pulled forward 10ft and put the brakes on and they kinda shuddered with a little skid before stopping. When I took my foot off the brake it rolled forward fine.
It's even colder today so I remote started it. I got a phone call so it ran for about 15mins. When I got in it, put it into Drive with foot on brake, let off brake and it rolled forward no problem. Took it for a ride. Shifts fine through the gears.

Maybe the Trans fluid is too cold in there and warming up the trucker a bit longer gets it moving? Would that effect the shift solenoid? But something is up with the brakes...

 

@Area51Runner I will start using the E-brake. Thanks.

U-Joints/Driveline inspected, greased in June.

Pics of LSPV (covered in oil undercoating) and the rear axle, best I could take today.



New England crusty.

 

Rust belt trucks hurt my eyes.

 

If you've never adjusted the rear brakes, maybe the wheel cylinders are maxed out or getting stuck . I think the brakes are just a red herring. If the engine revs and clunks into gear, the only thing that it can be is the transmission.

 

The struggle is real.

 

Scheduled to go in the shop Tues to look at brakes. Will head to a transmission shop soon thereafter.

 

My hands got dirty just scrolling the pictures.

 

@Andy01DblCabTacoma and @Area51Runner, Thanks for the suggestions. I had the rear wheel cylinders replaced and a brake fluid flush/bleed. They recommended if the problem persists then replace shoes, hardware and drums. The right rear brake has been sticking.
Truck has been coming out of Park no problem in all types of weather, rolls forward nicely when the foot comes off the brake pedal without giving any gas.

No issues with the transmission. Shifts through all gears seamlessly.

And, I’ve been setting the parking brake every time I park.

Thanks Again!