Catastrophic A/T failure

[1994SEV6]

So...I posted a pretty long version of this on another forum, but I want to keep this short today.

 

A little history:

130k on the truck.

Transmission swapped into truck at 120k miles. transmission had 48k miles on it.

Developed shift shock from 1st to 2nd about 2 weeks before this whole incident.

 

 

Ok, so I had shift shock. I changed the fluid, but of course, that didn't do anything.

My mom drove it, and the drain plug fell out.

She parked it in a parking lot. It only takes about 30 seconds for all the fluid to come out of the transmission. ~4quarts/litres/a gallon

She saw this massive fluid loss and drove it home anyway. The store was about 1/4 mile away from home.

There was still about 5 litres in the torque converter, lines, and cooler. some of this liquid came out while driving it, but the remainder came out while parked at home.

 

I went up and found the plug in rush hour traffic. No store had it, and it couldn't be bought online. I bought a gallon of ATF.

It took the whole gallon to fill up the transmission. I knew it had to be pumped to the TC and cooler. I started it up in park for about 15 seconds.

After being pumped through, the transmission was bone dry again.

I put another 2 quarts in.

It didn't even register on the dipstick.

I put another 2 quarts in and ran it for about a minute.

This put the total to 8 quarts. Advance Auto says my capacity is 8.4litres of fluid. I think that's about right.

 

 

I thought it was safe at this point to try to drive it. I put it in reverse and it worked fine. I thought I was in the clear.

I put it in drive and it raped me. I was idling inches at a time. Soooooo slow.

When I tried to accelerate, it was VERY sluggish. When I got up to about 20mph, it was fine. It felt normal.

I eventually concluded that when I put it in 'D', it is really in 3rd gear.

When I manually put it in 1, I am in second gear. When I put it in 2, I am in 3rd gear. When I put it in D, it is in 3rd gear only. I have no overdrive.

 

 

I have flipped the O/D switch on and off tons of times.

I tried the fail-safe mode reset method or whatever. It describes the process in the service manual.

It also mentions a "power mode indicator light" multiple times. I have no idea what this light is. IDK what "power mode" is. I have a little switch that says E-At on it, but it doesn't have a working light.

 

I pulled my passenger seat out to check the ECU. I think I may have reset the codes while trying to figure out how to use it, but it said 55

The transmission works great in 2nd and 3rd gear. No slipping, grinding, noises...etc.

I can drive it just fine, but I know that I will eventually burn up 2nd gear. That and I can't go above 45mph without blowing up the engine pretty much

 

 

Thanks for any help in advance. I don't really give a @!*% about this auto anymore. I bought a 5speed for a swap, but I still want to know what might be going on inside it.

[RJSquirrel]

Sorry to hear, but running your transmission out of fluid burned it up. No two ways about it. You'll need a new/rebuilt transmission, either a new auto, or a swapped-in manual. I can't speak to the "shift shock", but now it probably doesn't matter. You've got a big job or a big bill in front of you. Good luck.

[1994SEV6]

Sorry to hear, but running your transmission out of fluid burned it up. No two ways about it. You'll need a new/rebuilt transmission, either a new auto, or a swapped-in manual. I can't speak to the "shift shock", but now it probably doesn't matter. You've got a big job or a big bill in front of you. Good luck.

 

Right. I'm aware of the massive damage it caused. but my question is what happened?

 

Did my gears weld themselves together, or did a clutch pack disintegrate, or what happened?

[adamzan]

It probably burned up the clutches/bands/whatever they're called. Reverse was probably ok because she didn't drive home in reverse.

 

Sucks to hear.

[Towncivilian]

Man, that sucks. How did the drain plug manage to fall out?

[silverton]

best way to describe it, is without fluid in an automatic transmission, it's like holding the clutch of a manual halfway down while driving regularly. It burns up the clutch packs EXTREMELY fast.

 

Reverse works fine because it wasn't used. If you need an automatic transmission, source one out of an 01-03 NON-supercharged xterra. they are much more durable than the pathfinder and bolt in. only difference is the vent line, which with some extra vacuum line (might even be left on the trans?) you can hook it up to the vacuum T that's in the pathy.

[Precise1]

My mom drove it, and the drain plug fell out.

She parked it in a parking lot. It only takes about 30 seconds for all the fluid to come out of the transmission. ~4quarts/litres/a gallon

She saw this massive fluid loss and drove it home anyway. The store was about 1/4 mile away from home.

 

Thanks a lot Mom.

 

Sorry, but I hate people who do stupid crap like that...

 

B

[nunya]

Thanks a lot Mom.

 

Sorry, but I hate people who do stupid crap like that...

 

B

 

Not me, keeps me employed

 

All kidding aside it was basicly covered as to what happened by silverton (with apparently a good remedy/upgrade for you auto people)

[silverton]

also, being able to drive forward with the truck, should be used sparingly, it's only a matter of time (QUICK!) that forward just won't work at all. It still goes, but it goes slow because the clutches are slipping VERY badly.

[1994SEV6]

Thanks a lot Mom.

 

Sorry, but I hate people who do stupid crap like that...

 

B

 

 

yeah...it was completely ridiculous. She didn't take responsibility at all. She pulled that @!*% where she blames what she did on a pre-existing problem. "Oh, the transmission broke because it was shifting hard last week"

 

Going to put like 3 killswitches in when I swap the 5speed in

[nunya]

5 speed swap might be "kill switch" enough with today's driving population

[silverton]

To be honest, the harder a shift that a transmission does, the better. people like smooth shifting transmissions, but that's harder on the clutches, so they wear out quicker.

[sewebster]

To be honest, the harder a shift that a transmission does, the better. people like smooth shifting transmissions, but that's harder on the clutches, so they wear out quicker.

 

Presumably there's some trade off, slipping clutches/bands presumably reduces shock loading somewhere else? But maybe not too much since you've got the "give" in the torque converter too. How many autos actually end up dead because the clutches are worn out though? Seems to me they always die in some more heinous way.

[silverton]

Almost every single Pathfinder transmission dies because of slipping clutches. The reduced flow from a clogged cooler results in a loss of required line pressure. Almost like not having enough fluid in the transmission.

[sewebster]

Almost every single Pathfinder transmission dies because of slipping clutches. The reduced flow from a clogged cooler results in a loss of required line pressure. Almost like not having enough fluid in the transmission.

 

Ahh. Can't you just swap out the clutch packs then? Maybe too annoying.

[silverton]

Involves a full transmission rebuild. And if you talk to anyone who knows these transmissions, they will tell you rebuilding it in pointless. you're better off getting a transmission from an Xterra with as low of miles as you can find I paid 1000 for one from a shop with 40'ish thousand on it.

[1994SEV6]

To be honest, the harder a shift that a transmission does, the better. people like smooth shifting transmissions, but that's harder on the clutches, so they wear out quicker.

 

This is actually true. A friend of mine explained this to me. It's like a clutch on a Subaru STI. They put stupid high performance racing clutches in them, but people have no idea how to properly use them. The small Subaru engine has high RPMs and if you slowly let the clutch out, it just rapes the clutch pad. Also, the gears are more cone shaped so they bounce around a lot more. When they bounce and get shoved around, they get damaged much faster. The solution is to SLAM the clutch out. This seems bad for it, but with the racing clutch pad, and the design of the transmission, it's the only way to do it. But the down side is hard shifting and it will ruin your tires quite fast.

 

This same principal goes for all other transmissions, but the difference is that they can handle it to a degree.

 

Involves a full transmission rebuild. And if you talk to anyone who knows these transmissions, they will tell you rebuilding it in pointless. you're better off getting a transmission from an Xterra with as low of miles as you can find I paid 1000 for one from a shop with 40'ish thousand on it.

 

Yeah. I agree. It isn't very smart to do a rebuild unless you have a lot of time or money on your hands. If you are REALLY strapped for cash, but have plenty of time, then go for the rebuild.

For me, it wasn't worth it. Not even a longshot in any sense. My dad was really urging me to do a rebuild, but I don't have that kind of cash laying around. Besides that, I have no desire for an automatic, and it would probably brake again in 50k miles.

 

$1,000 seems a little steep. Especially if someone was parting it out or wrecked it. Actually, there was a guy local to me selling one of these for $250!! Auto trans with transfer case 21k miles. AHHHHHHH!!!! IF I had known they would fit!!

 

this is it http://washingtondc.craigslist.org/nva/pts/2679233188.html

he says it's out of a QX4, which is a Pathfinder, but you said Xterra. Does it specifically have to be Xterra?

Edited November 7, 2011 by 1994SEV6

[silverton]

That particular "pathfinder" uses the VQ35. It does indeed need to be out of an Xterra. "first" gen, between 01-04'ish. I got a VG33ER with transmission attached for 700$ with low miles. then I turned around and sold the engine for $500 Deals are out there! though, if I didn't wheel my truck, I would have probably swapped in a five speed.

Edited November 8, 2011 by silverton

[1994SEV6]

That particular "pathfinder" uses the VQ35. It does indeed need to be out of an Xterra. "first" gen, between 01-04'ish. I got a VG33ER with transmission attached for 700$ with low miles. then I turned around and sold the engine for $500 Deals are out there! though, if I didn't wheel my truck, I would have probably swapped in a five speed.

 

 

vg33er for ONLY $500!?!?!?!? wtf? You could have gotten a grand easy. Around here at least. Jerks around here want $600+ for a vg30e with 150k miles. Even pull-it-yourself junkyards want a minimum "$350 for any internal combustion engine".

 

the vg33e with the supercharger would fetch some bank. Especially with low miles. I'm not even a greedy person, but I wouldn't let the engine go for less than $900 and the trans would be another $600 in my pocket.

 

You like the automatics better for wheeling? I was reading a "good" (the only real one out there) thread on Nissan4wheelers and after putting the 5speed in, he said it was superior. 4lo in 1st gear just raped.

[nunya]

Auto versus 5 speed is one of those thugs that are "user preference". I'd actually 'think' about goeing auto if I could get my grimy hands on one of those Xterra transmissions. If that were the case I would have more donation parts though than just the transmission (if I get ahold of a totaled one)

[1994SEV6]

Auto versus 5 speed is one of those thugs that are "user preference". I'd actually 'think' about goeing auto if I could get my grimy hands on one of those Xterra transmissions. If that were the case I would have more donation parts though than just the transmission (if I get ahold of a totaled one)

 

are the Xterra ones really that good? Aren't they just the exact same transmission but without the overheating/self-destruction issue?

Personally, I think automatics were crap until like..last year.

[Kyle94]

are the Xterra ones really that good? Aren't they just the exact same transmission but without the overheating/self-destruction issue?

Personally, I think automatics were crap until like..last year.

yes they are WAY better. the internal are built stronger. and what really kills the stock wd21 auto is overheated caused by blocked stock trans cooler...

[nunya]

Their just 'better'. I'm not an auto person personally but I have thoughts about it when I'm either being lazy, hurt my leg/foot, or contemplate doing more work than I need to already do

[1994SEV6]

Hmm...well, I haven't put the 5speed in yet (damn you, procrastination). Is this auto from the Xterra an EXACT bolt-up? Is it externally identical? Does it wiring up the same? or are there more sensors and gizmos?

 

 

5 speed swap might be "kill switch" enough with today's driving population

 

Yeah that's for sure. I have a half filipino girlfriend. GOD is she horrible at driving. "Honey, the gas pedal means go, and the brake pedal means stop" She still can't get that crap straight. This is the original reason I wanted to by a 5speed truck LOL

 

but my mom...she think's she's some bad @$$ or something. She got some beater f150 when she was younger and it had a stick. So ever since then she thinks she's some master with a stick when she can't shift for her life. She can get it started, but after that she would just murder my clutch.

Edited November 10, 2011 by 1994SEV6

[Slartibartfast]

My understanding is that the Xterra trans is so similar, you can't tell it from the WD trans just looking at it. Plugs into the same computer, mounts the same, drives the same, just doesn't crap out as easily. Also the transfer case may be different, but that's just a bolt-on and you can swap cases from your old trans.