Reverse to Drive Delay - Different issue? (2006 TRD Sport 4x4)

Apologies in advance if this has been covered. I searched and didn't see the same problem, although there's quite a few ways to title it. Here's some details:

Truck:
2006 Tacoma TRD Sport. 4 door long bed. 4x4
155,000 miles. No prior transmission service.

Delay going from reverse to drive.
3-4 second delay
Happens cold and hot, hill or no hill.
No consistency as far as how often, but becoming more frequent
Delay time has been consistent.
This is not the gas pedal delay. I shift into drive and just wait for the transmission to "click" into drive. The transmission is in neutral or disengaged, (car will roll if its on a hill) as I wait for it to engage.
1-20-17 Update: I've had 2 situations where my truck wouldn't start until I moved the shift handle around.

What I've done:
I brought my truck in to be checked at our local independent transmission shop. Tech said I was low about 1/2 quart of fluid. They added it for $5 total charge. They did say they drove it to get to the correct temperature. No signs of a leak. No issues all summer.
Issue came back a few weeks ago. Went back to the shop. They said the fluid level was correct. Next they would "drop" the transmission to inspect it and change the fluid. Estimate $600.

Any advice here? I have guesses but they're just guesses.

Thanks in advance.

 

Is a burnt smell present that seems to be coming from the transmission? When the delay occurs does it feel like a "slip"? I'm not sure why they would want to drop the transmission. Are they wanting to inspect the gears or just perform a fluid change?

EDIT: Realized they're wanting to inspect. $600 isn't a bad price though for all of the work they're going to have to perform.

 

Thanks for the reply.

1 - No burnt smell that I can detect. I would hope the shop would recognize it if there was.
2 - Slip: I don't believe so. It's just a delay. But is slightly more aggressive? when it does engage into drive. When the delay doesn't happen, it shift normally / smoothly.
3 - Dropping the transmission: They said they want to inspect it, get a visual and change the fluid.

 

Hmmmm, do you by chance switch gears while moving? When you're reversing would switch into drive before coming to a complete stop? I know this will add wear considering the transmission is acting as a brake.

 

No. I never hit drive when still rolling back. I'm pretty light footed overall.

 

clutch be draggin
valves be draggin
accumulator delays

tranny needs to be dropped, opened, inspected

I would test-kit the atf for presence of coolant first and foremost

 

You're way past due for the fluid change. Get that done with a bottle of Lubeguard added and report back.

 

I left a message with my closest Toyota dealer, (Auburn, CA) to see if they do drain or flush. Their answer passed through the receptionist: "We never recommend changing the world standard AT fluid". A tech is calling me back to follow up

My question:

Is there any official Toyota literature that says to change the fluid sometime in the life of a Tacoma with WS? I can't find anything besides personal opinion, with maybe 75% saying it needs to be changed at some point.

 

I have an '05 TRD sport and have been having issues with mine lately similar to yours. I also notice on the dash that the lights for D or R or N don't light up right away when this happens. Could there be some sort of electrical/computer issue going on?

 

interesting. I'll see if it's similar with my truck in a few hours.

 

No connection with the indicator light for D / N / R

But for the second time in a last 3 months, my truck wouldn't start until I moved the shift handle around.

Anyone have any thoughts on a possible connection between delayed R to D and shift handle?

 

Resurrecting my thread. It's been about a year since I was having this problem. I've added 15k miles in the last 10 months. Just started again during the last 3 weeks. Maybe once out of every 10 shifts. If it does it once, it happens a little more frequently. I also did a trip to AZ from Nor Cal and it didn't happen at all during the drive. Consistency doesn't appear to exist?

Changes: It's been a little colder and raining lately, (going down into the 30's). It was down around zero in AZ, and it didn't happen at all. If anything is consistent, it's just been a higher moisture content.

I brought my truck into a local Toyota guy here in town. He's not a transmission shop but is focused on Toyotas. He said it could be a "lifter pump" in the transmission. He noted he's never seen something like this "all of a sudden" fail, but possibly worsen as time goes on.

Any comments on a lifter pump and if it makes sense?