Transmission won't shift after DIY Transmission service

i know from experience when i did a trans filter on a ram... didn't have the filter fully seated in.. put pan in. fill it to spec.... and. nothing literally wouldn't do a thing. just like you have here

 

Ok.

 

This happened multiple times in the years I've worked there. Customer gets hit with a big repair bill after the warranty is up or some other circumstance and Lexus helps them out with paying for the majority of the repair under "goodwill".

 

Overtightened filter bolts will jam up the valving in the vale body creating a " no move condition " .
Interested to know if the OP was checking the fluid in park with the engine running ?
If you check the fluid with the truck off , it will show way way overfilled .
Need the engine running in order for the transmission pump to turn and charge the vale body with high pressure fluids
Those are my 2 best guesses

 

This is why I'll probably never change my fluid, heard this story too many times...

Well, if you can take these "floating substances" out, why can't you put something back in??

 

Update: thanks for all the responses. I think the winner is that the friction material was holding it together. The old oil was completely black.

I wasn't ready to give up on the transmission, so I bought a friction modifier at AutoZone as a hail Mary. Added a little more fluid and let it run for a few minutes. Tried to change the gear and...I have gear changes! I've driven about 20 miles now and it seems to be acting normal. I am probably on borrowed time but for now it's running and driving.

If anyone else is unfortunate to destroy your tranny in attempts to take care of your truck, I recommend trying that. The modifier was Lucas brand but I'm sure there are others out there.

 

How do you know that the fix wasn't from just adding a "little more fluid"?

 

Thank you .

 

Friction modifiers of this sort will only begin to function after the transmission gets very hot like a good solid highway trip or some stop and go traffic for at least 150 miles .

 

Dr. Z I suppose it could have. I added 2 quarts more than what I thought it would take with no effect. Once I added the friction modifier I only added maybe 1/8 quart to wash that additive down through the filler. If that little can make the difference between it not working at all to functioning normally I suppose it could be that. I personally didn't think it was likely.

Gearcruncher I was not aware, I'll take it on a trip and see if I notice a difference afterwards. It's still hitting some gears pretty hard.

 

You may be correct that the friction modifiers did something. I've just never heard of this situation of draining all the friction material out when you do a fluid change. It seems unbelievable, but I have an open mind and I'm going to search for other instances of this happening. I'm no expert in how automatic transmissions work.

 

Throw some Lubeguard at your transmission . That should help with the harsh shifting
https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/

 

OP just curious as to how your pan magnets looked, were they coated in sludge or shavings? I have did two drain and refills myself, but didnt touch the pan or filter... bought my taco with about 205k, fluid was very dark brown safe to say it had been well overdue for a change... However after hearing all the horror stories i decided not to touch the pan or filter since it still shifts smoothly.
My only thing is when i go into R it takes about 2 sec or so for it to engage but going right into D there is usually a "clunk" into gear.. It is a immediate clunk, no time what so ever to engage. Ive adjusted the kickdown cable on the tb but i still usually get a clunk into D every time...

 

Austins they were covered in sludge. I actually used a little bit of solvent to clean them and the pan. It needed it. Again at the time was thinking I was doing it a favor. Neither before or after this did it ever have delays like you're talking about. Certainly no 'clunk' into drive. After this experience I certainly don't suggest doing a service on it. Maybe there is an additive that would help? No expert by any means but I am glad at least that I changed the gasket for the pan. It was going to start leaking at some point, completely rotten.

 

Sounds like it was pretty neglected. Mine shifts smooth even with the dirty fluid it did. I noticed the clunk I spoke of really is only noticeable when it’s cold and the rpms are higher. Pretty sure it’s just the drivetrain or something. Maybe yours Will hold on awhile.

 

I'd like to know as well.

 

Before adding the friction modifiers an interesting test would have been to remove one of the oil cooler hoses going to the lower radiator to see if ATF was being pumped/circulated.

My thinking is the transmission doesn't have an sort of built in electrical pump to circulate the ATF. The spinning of the engine spins the torque converter and this motion of the torque converter is what the transmission uses to generate ATF pressure to circulate it to wherever it goes in the transmission. The torque converter doesn't rely on friction when the car is not moving. It only relies on having ATF in it.

What I'm getting at is if the theory of the friction material being drained out caused the transmission not to go into gear in spite of the proper fluid level, then the torque converter should still spin and ATF would circulate out of the cooler hoses. If ATF didn't flow from the cooler hose then the torque converter probably didn't have enough ATF in it.

(Maybe I'm completely wrong about this, haha)

 

Thought I would give an update to this issue. A year later and the transmission is still running strong. It's a daily driver so we've put another 10k miles or so on it. I've since added a tranny cooler. I'm assuming that if it was ruined it would have died by now? Some mechanics said that I only bought a few hundred miles before it would start slipping and eventually stop working.

 

I bought a ford van with a bad trans years ago. It would slip on the highway and shudder when shifting. Did a flush using the BG machine and used snake oil and friction modifiers when I refilled it. Paid $400 for that 1 ton van, had a trans sitting on the shop floor if needs be, but I ended up towing my race car with that 'crappy' transmission for 40,000 miles. *Sometimes* you get lucky with the snake oil. My particular snake oil of choice is a cocktail of Trans X along with some of the thicker-than-cold-honey Lucas friction modifiers.

 

Exactly! I guess I did. I've never heard of Trans X, I may look into it if I start having problems again and see if it works in our A340's.