shudder when shifting to drive from standstill

Hello. I have a 2013 Tacoma automatic with the 6 cylinder 4.0 and 425K miles. Yesterday, I noticed a shudder when I shift from neutral to drive from a standstill.

The transmission fluid has been changed recently.

No codes.

Any ideas?

Thanks.

 

More information.

if I am on a level road, I can put the Tacoma in neutral without my foot on the brake without it moving. If I then move the transmission from neutral to drive, it shifts smoothly with no shuddering.

I can also shift from drive to neutral without shuddering.

Could this possibly mean that the problem is actually with the brakes or is something going on.

Thanks.

 

Let's keep it simple to start. Did it shudder before the fluid was changed? What kind of fluid was put back in? Who changed it - you, or some mechanic? At 425K miles has the fluid ever been changed before or is this the first time? If you changed it or if you have access to the old fluid, does it smell burnt?

 

Thanks for the help.

I changed the fluid myself using the service bulletin procedure. It was the Toyota WS transmission fluid. I don't recall the specific mileage when it was changed, but I don't think that the shudder has anything to do with that since there was some time separation. It was definitely not burnt, just a little darker.

I have subsequently checked the brake light switch. I saw somewhere that a malfunctioning brake light switch could display those symptoms. But it is working, so it is probably not that either.

Since the shudder started, I have also changed the brake pads. They were due, but the shudder is still there with the new brake pads, so that did not make a difference.

The shudder does not seem to be related to the transmission, as it only happens when I shift from neutral to drive with my foot on the brake. If I shift from neutral to drive without my foot on the break, it does not shudder.

 

If you're certain you properly fill the trans, look for vacuum leaks. Like the hose to the brake booster or the check valve.