Did I ruin my transmission

Hello, long time user but first time posting to the forum, proud owner of a 2001 TRd limited 4x4 Tundra with Auto Transmission, 143,000 miles,

So here’s the dumb decision I made

Had rear end of the truck in the air, wheels and drum off both wheels, I was trying to diagnose a sticking brake issue. When the drums came off on Pass side the whole inner assembly was “wet” looked more like grease to me, I checked the Diff bleeder and it was totally crusted with dirt, no good so I cleaned it up and also cleaned the brake assembly on both sides with soapy water and brake cleaner, the shoes look pretty good shape, I was going to change them anyway but I’m thinking the sticking was coming from the brake dust grease goop combo. So decided to start the truck up in the air and put it into drive and when the wheels where spinning I gently stoped one wheel and listened no change i noise on either end (did both sides) I shifted into R and back and forth and it shifted smooth like it always had. Then for some reason I decided to go form N to P… and that’s when a loud grinding noise happens and the wheels came to a halt, I just shut the truck off cuz I was terrified of what I was hearing. And now I’m pretty certain I’ve ruined my transmission, I’m hoping someone can give me some direction on why that happened and maybe some more info on how fucked i am. Thank you

 

@shifty`

 

Well, it sounds like like you your parking pawl was grinding as it tried to engage a moving gear. What you heard was it skipping off gear teeth, as its supposed to do if you try to engage it on a moving gear. Once it slowed the gear down enough, it popped into place and stopped everything.

You may or may not be okay....the parking pawl can take a certain amount of abuse, as even though you are never supposed to go engage Park while moving, people do it all the time. Most likely, you just ground a little metal off it and it's fine. Don't go it again.

That being said, you can break the parking pawl off if you grind it hard enough. You just have to test the truck out, but you're probably fine.

Now, with that out of the way, you probably need to replace your outer axle seal. Most people replace both inner and outer seals and the bearings when they do the job, but this is a lot harder and if its just a blowout from a clogged breather, its not a big deal to just replace the seal and move on with life.

Check out the sticky thread on first gen Tundra Brakes when putting your brakes back together. Replacing a leaking seal was how I figured out the rear brakes are tricker than most people realize.

 

Going from neutral to park, the transmission will try to engage the parking pawl which is a small steel rod that engages the drum inside the transmission, preventing it from turning. If the transmissions is spinning, it will often make a ratcheting sound until it slows enough to engage.

It can do a lot of damage to a few parts, or simply make a very loud pop that can be quite disconcerting. The pawl essential wedges between the case and the drum, so those three items are susceptible to damage. It can bend or break the pawl, crack the case or the casting that pawl engages, or mess up the drum.

If, while in park with the engine off, you can try to rotate the tail shaft back and forth but it’s not allowed to spin, that’s a good thing. If your try to spin it back and forth and you hear crunching, that’s not a good thing. You can try draining the fluid to check for debris, or drop the pan and visually inspect the pawl and associated parts. That would be the course of action I would recommend.

 

Your probably ok. Put it in park and start the engine. Is the parking pawl holding the truck from rolling? If so hold the brake and try each gear listening for grinding sounds. If none, slowly roll a few feet in each gear again listening for noises. If none, go for a drive start slowly and if no adverse symptoms increase speed to road speed. If everything checks you should be ok

 

I'll add, if it does seem okay, anytime you park on an incline in the future, make sure to use the parking brake and turn the wheels in such a way that the truck will roll towards the nearest stopping point just in case it should ever let go. Last thing you want is to have a total disaster over a park pawl.

 

When my girlfriend was younger she was offroad in her dad's 2000 tundra. A brake line broke and she shoved it in park, it rolled down a hill like that. Park still works to this day if that gives you any sense of hope.

 

Just wanted to thank y’all, the parking holds great and I’ve pretty much always used my ebrake cuz I live on a hill, so everting checks out, apologies for the panic again thank you for the advice!

 

I did this myself once, but it wasn't a grind noise, it was a metal on metal repeating banging sound which was the parking pawl as the driveshaft was rotating to a stop. Checked that I could still engage park on a hill without any slop going into or coming out of park so it appears I was fine but the wheels were originally engaged at a very low speed, like under 10 mph.