Transmission?

I was cruising on the highway doing 70mph in 6th gear, when my car slowed down to 65mph on its own. I turned off the radio and the heat so I could listen for noises but I heard none. It got back up to 70mph and then it did it again. It almost felt like I tapped the brake lightly or maybe the fuel cut for a second. I coasted up to an exit off the highway. After stopping, I went to put it in gear to go again but it wouldnt shift. I let out the clutch and it moved even though the shifter was in neutral. I assume it was stuck in 2nd gear somehow because it was barely enough to get the car moving. I didnt drive it far probably 300ft into a gas station. I shut off the car and just got it towed to my shop so I can put it on the lift.
I am not 100% sure what is wrong with it yet but I know it is something internal. It could be a broken shift fork or maybe something else came loose or broke. All I know right now is that it is not the clutch or slave cylinder. I am going to pull the transmission out to see what is wrong. Does anyone know what could be wrong? Where is the best place to get parts? Any help is greatly appreciated.
The car has 84,500 miles on it.

tranny pull could be a little drastic. Pull off your shift boot and check all the shift linkage first. Linkage would explain the fact that is was in gear when it was in the neutral position, but not the fact that you lost power at 70. That sounds like MAS maybe or air/fuel starvation.

This is definetly a transmission problem. The first thing I checked was the linkage because it was the easiest thing to check first. It shifts and the linkage moves fine. It just is not engaging inside the transmission. It is never easy when something goes wrong. A loss of power is the only way I could describe the symptom but it doesnt have anything to do with the engine. I have no problem pulling the transmission. I work on cars a lot and this will give me a chance to replace other things and clean the engine bay a little. yay!!
But if anyone has any idea what could be wrong please help me out.

Seriously any input would be appreciated.

i had something similar happen, but i didn't lose power. i somehow got my transmission stuck in 1st gear and it wouldn't shift out. the shifter was in the neutral position, but it was stuck in 1st.

as it turned out, the shifter linkage that holds the shifter cables to the transmission came loose. i guess the bolts either weren't there (sounds stupid that i would forget to reinstall those bolts) or perhaps i installed the bolts incorrectly to hold the bracket down. basically, i just added some huge washers and re-tightened the bolts that held the linkage bracket. this fixed it.

if the linkage is loose (anywhere along the line), then when you shift, there will be so much flex and bend in the linkage that it won't engage the gears, but simply bend and flex.

I have also already checked that and it was a little loose but it wont go in any gear but 2nd and possibly 4th even though the shifter is not in that gear.

i'm havin a tranny problem as well under full throtle and speed shifting somtimes it dosent wont to go into gear.

that sux man. not leaking tranny fluid are ya? Anyways, keep us posted on what you find when you pull it. Good luck

ok, that's starting to sound like the problems I was having... if u are certain that the linkage is not the cause... 1st, I got a question, does the shifter move around like normal?... my linkage f'ed up one time.. .and the shifter wasn't moving freely like it used to...

after done with that... try to move in and out of gears... double clutch to move in and out of gears... it sounds like a problem I had after hitting a deer... Apparently the impact broke a synchroniser... and without double clutching... the gears would kick back sometimes, that broke the roll pin on the shift fork... the car would go into the gears (3-4) but it would take several times of trying back and forth between the two...
now with the car (I'm going to use this word, for lack of a better term) bucking... that tells me, the transmission was either starting to kick outta gear, or something was getting lodged in between the gears (my roll pin did... thankfully they are soft metal and sheer, no damage done to gears)...I'm leaning towards either a broken synchronizer/roll pin, or a shift fork... if the shift fork breaks, you will not get in and outta gears, but I've never experienced that first-hand... I have had a synchronizer break, that kept my Corolla stuck in 3rd gear... you couldn't shift whether the car was on or off...

I'm no expert at anything car-related... I know a little from experience and from what others tell me... so I'll be interested to see what you find...

I have also already checked that and it was a little loose but it wont go in any gear but 2nd and possibly 4th even though the shifter is not in that gear.

I jsut posted some thoughts, but I was reading back through... could u elaborate a little on this, I'm not understanding, does it go into 2nd and come out of it(just not other gears), and what do you mean by possibly 4th (if the shifter isn't in 4th gear's place, where is it at, Reverse?)

The linkage is fine I checked it at both ends. When I shift into a gear it doesnt lock into that gear. It almost feels like something is preventing it from doing that inside the tranny. Also, it happened while cruising down the highway I was not racing or driving fast at all. Then it started having trouble. When I put the shifter in neutral position it will move freely like normal side to side but it definetly is not in neutral. I is kind of like that with the other gears as well. It will feel like it is in a different gear but it is not. The only gear it doesnt seem like it will go in at all is first gear. My synchros are bad, they grind when shifting from first to second too fast. Maybe a synchronizer did break. That might explain why the linkage shifts and moves normal on top of the transmission but inside it doesnt switch gears.

The linkage is fine I checked it at both ends. When I shift into a gear it doesnt lock into that gear. It almost feels like something is preventing it from doing that inside the tranny. Also, it happened while cruising down the highway I was not racing or driving fast at all. Then it started having trouble. When I put the shifter in neutral position it will move freely like normal side to side but it definetly is not in neutral. I is kind of like that with the other gears as well. It will feel like it is in a different gear but it is not. The only gear it doesnt seem like it will go in at all is first gear. My synchros are bad, they grind when shifting from first to second too fast. Maybe a synchronizer did break. That might explain why the linkage shifts and moves normal on top of the transmission but inside it doesnt switch gears.
Huh, this puzzles me a little... I'm going to say some synchros are definitely bad (especially if they're grinding)... I'm also gonna say, there's prolly a broken fork, or some roll pins... there's a movement inside the transmission, which when u move the stick from side to side, selects which pushrod to move forward or backwards(engaging into the selected gear range 1-2, 3-4, or 5-r)... mine screwed up when I was putting my transmission back together... I lost reverse and 5th for a little while, went back and lined things up and regained use of all of my gears...

P.S.- My understanding and experience, when a synchro breaks (not just goes bad, but breaks) The stick will not move, and you will not be able to disengage the gear it broke in...that's what happened to my Corolla...

I finally got my car on the hoist. It took some manuevering because I didnt want to drive it and do more damage. I looked for signs of damage, rechecked the linkage and then for leaks. When I pulled the drain plug I found out there was probably a half cup of gear oil left in it. Now I am worried. The oil smells really bad, burnt smell to it kind of like a burnt clutch, the oil also had a silvery color to it like very fine metal shavings. The magnetic drain plug had some shavings on it but not more than it would normally have. I went ahead and drained the transfer case too but that was fine. There have never been signs of leaking and last time I checked it was a month ago. But the oil had to go somewhere. Maybe it needs new tranny seals.
Now I am wondering how much damage was done. I was driving on the highway for about six minutes until failure. Driving with the oil that low would cause a lot of heat and probably wasnt very good for my bearings either. The good thing is that as soon as it happened I stopped and have not drove it since, fearing further damage. I want to try filling it with gear oil and see if that will fix it. What kind and brand of gear oil should I use? The manual says GL-4 SAE 75W-90 for transmission and transfer case. The rear end is GL-5 85W-90, or 80W-90. Do you have to use the proper "GL" rating? Last time I looked into gear oil I had trouble finding GL-4, only GL-5.
What should I do now? Do you think I should still pull the transmission or do I have a shot of fixing it this way?

Wow, that is really low on oil... I can't really tell you how much damage that did... but driving it low for very long can cause catastrophic failure... I used Redline oils in my car... go to www.3sxperformance.com (http://www.3sxperformance.com) ... they sell a refill kit... if you don't wanna buy it from them, just take their suggestions... I have also heard of people using BG Syncroshift... I personally haven't had any experience with it though...

bg synchroshift (I & II), redline is good, i'm running Royal Purple.

stay away from Penzoil/GM Synchromesh

I pulled the transmission today. Things went pretty smoothly. Having a hoist and an engine crane helped a lot. The only trouble I had was with the passenger side driveshaft. I pryed on it and pryed, being careful not to damage anything, then finally after wiggling it around it popped out. I noticed that the end of the shaft with the splines was all pitted and slightly worn. I also noticed that the drivers side axle shaft is new so it must of been replaced recently. I am having it rebuilt. There are other things I am planning on doing while I have the transmission out. I will first clean the engine bay out and degrease everything. The transmission will be cleaned too before it goes back in. I am going to replace a ball joint, tie rod ends, oil pan gasket, rack and pinion boot seals, polish the intake plenum, replace fuel filter, replace plugs and wires and put in new gaskets.
I looked around for transmission oil and I ended up getting penzoil synchromesh. I heard it is good for the transmission. Someone said it is not good though so now I might look into it again. What should I use?

Should I not put in the synchromesh after the rebuild. I wouldnt want to damage anything new. I can take the penzoil back but what should I put in after the rebuild. I put some Lucas in the rear end because I heard that it works really good.

What kind of oil should I use? I dont want to screw it up after a fresh rebuild. I can take the penzoil back. I put Lucas 80/90 in the rear end.

i've heard from a bunch of 3si guys NOT to use penzoil synchromesh. however, i used it last year in my transmission, adn it worked fine, never had a problem.

when i dropped my transmission and put the LSD insert in, i then switched over to Royal Purple. but after draining the Penzoil Synchromesh, i didn't see any metal shavings, nothing to indicate that it was anyway inferior. i just thought i would follow the advice of very knowledgable people and use something other than the Penzoil synchromesh.

also, i as posted earlier, Redline gear oils are great, as well as BG Synchroshift I & II. you can find these at 3sxperformance.com.

I love the Redline oils... Expensive, but good stuff... ;)