ATX failure, what the **** went wrong?

[Huntervf]

On my way back from Kalamazoo Friday night, with the cruise set at 75, on the 93 ATX the transmission suddenly "went to neutral". I say it that way because that's exactly how it acted. The revs suddenly jumped up because the cruise was set, I hit the brake quickly to turn it off, and after that I had no gears. Not reverse, D, 2, 1, nothing.

I coasted off the highway into a gas station where I pulled codes and got a 452, vehicle speed sensor.

I unplugged the sensor with no change... any gear selected outside of park acts just like neutral, revs free, no hint of moving the car and I can push it just like in neutral.

A check of the fluid shows it's not burnt and in good condition, however it is WELL over full, even with the engine running and in neutral. 3000 miles ago when I checked the tranny fluid it registered in the normal full range on the stick, so apparently all of the fluid is sitting in the pan.

There are no leaks, no holes in the trans. The car makes no abnormal noises. I heard no noises prior to this happening, though my wife says she heard/felt a thud in the floor just before the revs spiked up.

I had no issues with the transmission prior to this. The only thing it did that I didn't like was a fairly hard 2-1 downshift if you were applying moderate brake pressure. Aside from that it was one of the nicer ATXs I've driven. It was also rebuilt 30,000 miles ago and has not been abused.

I need some expert opinions here because I'm already overbudget from Christmas, and I'm pretty much screwed if I in fact need a complete tranny rebuild. Please help me out SHOforum, I really need it right now

 

[voogru]

though my wife says she heard/felt a thud in the floor just before the revs spiked up.

Reminds me of when my ATX went boom, THUD. WHIIRRRRRRRRRR... mine also had same symptons, no movement, no wierd noises.

But, see and make sure both axles are ok, I hear that if an axle breaks you get no movement.

 

[Speedie13]

Yeah the axle thing was exactly what I was thinking too.
I had a 93 SLO that had an axle break. Same symptoms....revving, in what seemed like neutral, while it was in gear and had no other gears other than park. It was around $200 for parts and labor IIRC. Hope this helps.

 

[SeanMc]

Torque converter? When my trans went south, I was in 3rd gear, going 35mph, at 6500rpm. It was all the sudden too. Before that, it shifted slowly, but it was still pretty smooth. Then all the sudden, coming home from work, no matter the gas I gave it, it would rev, shift at an extremely high rpm, but the speed wouldn't be where it should have been at that rpm. Sorry for your loss .

 

[Huntervf]

Axles are fine.

There is no hint of movement from the car. Not in the least. Any gear. No noises either. Like I said, may as well be in neutral.

 

[NWGRN94MTX]

Axles are fine.

There is no hint of movement from the car. Not in the least. Any gear. No noises either. Like I said, may as well be in neutral.

Even in Park?

 

[Mr Anonymous]

Sounds like a broken pump shaft or blown planetaries.

 

[NeedAPartsCar]

That makes two of us. My diff pin blew as I was following Tim on the way to his house from the restaurant.

 

[somedude_001]

you my friend have expierenced the same failure I had on my second failure. I was at a dragstrip pulling up to the water box and I was flagged to pull into the box and my car was in neutral? just as you explained noting in any gear. i was puzzled??? I grabbed my tranny cooler with the car running after 5 min of sitting and it was cold. after tearing the transmission apart the female splines on the oil pump for the transmission had stripped out. these splines are about 1/2" in diameter so it is a small assembly and is driven directly by the torque converter.

failure symptoms: car acts like it is in neutral in any gear no jerks, clunks, or grinding.

to fix. remove transmission remove side pan on transmission remove oil pump cover and replace oil pump assembly. once the tranny is out it will take all of 10 min to fix, if this is infact your problem.

these splines are small and they do not make noise when stripped or warning of a failure. i never found the small shavings from them either when i tore the tranny apart.

to test the pump remove a tranny cooling line and start the car. fluid should shoot about 10 feet under pressure. (at idle)

A check of the fluid shows it's not burnt and in good condition, however it is WELL over full, even with the engine running and in neutral.

it is reading high because the fluid is not being pumped through the transmission

 

[Shoaz]

I think somedude_001 has the right idea, which Chris mentioned as well: Pump went blooie.

Dunno whether you can get at it without dropping the tranny.




Those MTX conversions aren't really that hard, ya know...

 

[kzoosho]

Thought it was the pump Cris thats the same thing that happened to me. i just said screw it . i went and bought a mtx and stripped my atx .

 

[firstgen89sho]

I have also seen the splines inside the torque converter strip as well

 

[Axianator]

Chris,

Like Alex and Javier, I also experienced similar symptoms when the factory tranny in my '95 ATX decided to eat it's forward planetary gearset at 135k miles in November '03 while I was gently leaving a four-way intersection at 2 AM. Consequently, I have to agree with Chris and Alex. My first guess would be on the pump shaft and/or pump assembly, followed by the planetary gearset.

Since this unit has been previously rebuilt, do you know what type of modifications were performed on the unit (TransGo, etc.)?

 

[St Louis SHO]

Id agree, pull the trans. If you need the splined shaft, I have a complete core I can pull parts out of for you. Just let me know what you find.

James

 

[93rev2sev]

Those MTX conversions aren't really that hard, ya know...

LOL I told him and Michelle that...when it was slowly creeping up onto the trailer.

 

[Porkchop]

Sounds like a broken pump shaft or blown planetaries.

DING DING DING!!!!

That happened to my car when my pump shaft decided to work better in 2 pieces.

replaced it and good as gold

 

[thecrew2999]

had those problems before.

its a atx and your wondering what the problem is ?

 

[SeanMc]

had those problems before.

its a atx and your wondering what the problem is ?

The problem is not the transmission, it's the smart ass comment like this that was posted. He is asking for help, not opinions.

Thank you. I'm here till Thursday.

 

[Huntervf]

Thanks for the input everyone

For those who experienced a pump failure, did you just replace the pump? My concern is twofold: 1. Any bits of failed pump making their way through the tranny and 2. any damage that may have occured when no fluid was in it.

Car will be going to the shop sometime this week. WTF... I didn't want to buy a house anyway.

had those problems before.

its a atx and your wondering what the problem is ?

You should just stop posting altogether. Seriously, just ****. I have no patience for shit like this.

 

[Mr Anonymous]

Thanks for the input everyone

For those who experienced a pump failure, did you just replace the pump? My concern is twofold: 1. Any bits of failed pump making their way through the tranny and 2. any damage that may have occured when no fluid was in it.

Car will be going to the shop sometime this week. WTF... I didn't want to buy a house anyway.

If it was just a break of the pump shaft, it can be done in the car by removing the valve body. Not easy, but for an experienced shop saves a couple hours over pulling the tranny. If the splines on the pump ground off at the valve body end or the little impellers in the pump failed, again it can be gotten to with the tranny in the car but as you suspect you're at a high risk for contamination.

Easiest way to test is for the shop to connect a pressure gauge to the port on the top of the valve body and start the car to see if the pump is pumping at all. If the pressure is good then you know the problem lies elsewhere in the tranny. No pressure indicates a pump problem, and then it becomes a matter of figuring out the cause and the cost/benefit of trying to diagnose and fix it in the car, or just pull the whole tranny.

Based on the nature of your failure being immediate, IIWM I'd suspect a broken pump shaft and take the chance that it can be done in the car. But, you're going to want to get the tranny shop's opinion as to the most cost-effective (and least painful) option will be for you.