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2004 4motion transmission replacement

11K views 16 replies 6 participants last post by  PZ 
#1 ·
Hello all.....I have a two part question I was hoping I could get some guidance on:

The background:
My wife was driving our 2004, 1.8T, 4motion down the highway. Saw smoke and pulled over. I was out of state so she had it towed to a "stealership" and they told her that they needed $6500 to replace the transmission. Once I got back, I had it towed to our house (where I have a barn with a car lift). Looks like the front pump seal (torque converter seal) is leaking. I drained the pan and got no metal but it found fairly black ATF. I was a mechanic many years ago and among other things, I rebuilt transmissions at a chevy dealer so I'm not totally afraid to tear into an auto trans but I have very little time.

Question 1:
I can't find any threads or videos on removing the 4motion transmission and I was hoping to get some advice. I can take out the trans the normal way, which seems the most logical or (big sheepish grin) would it be easier to drop the sub-frame (trans, engine, front end, etc)? I'm asking this because ...Please see question #2

Question 2:
Before I put the car on the rack, I tried the to see if it would go into gear (for a quick second only). It went into forward and reverse solidly with no hesitation. So, my thinking is....if it's not too difficult to R&R the trans, I could remove the trans and replace the front seal, flush the trans as best as possible and refill with new fluid and see if that will take care it. If that doesn't work then I would pull the trans again and rebuild or install a used trans.

Question 3:
Is this seal a common problem or is there another typical issue with the trans that makes it look like a front seal when in real life the trans is destroyed and I would be wasting my time trying to fix a front seal?

Thanks in advance for any input.....
 
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#9 ·
The trans is not overly difficult to remove, but it does take time as the axles, driveshaft and possibly the exhaust have to come out. It also weighs 300lbs, so you need a trans jack and engine support bar. You will have to lower but not remove the subframe. Removal gives a lot more room at the expense of adding time.

The front seal on the 4MO tends to fail (not that often), but more often on the V6, V8 and 2.7T models with this trans. This may be the 1st 1.8T bad TC seal I've seen.

I replaced the front seal on my son's transmission as a preventive mx item, I also put my low mileage rebuilt TC on his car. The V6 is much more difficult to pull the trans, the 1.8T has a lot more room.

As for your trans, see if the front bushing comes out with the TC. If it does, the front pump needs to be replaced. If the fluid was low enough, the bushing will spin and eventually seize to the TC. If the bushing is good, I would flush the fluid out (lines and everything) replace the seal and filter, refill and hope for the best.
 
#10 ·
PZ,
Thanks for the input. When you say lower the subframe, Im assuming you mean back out the main bolt (the back 2) until there are a few threads left or do you mean remove them and lower the back of the subframe down some?

So you are saying that in your experience with this trans, if the front seal is leaking but the TC bushing hasn't welded itself to the TC yet then you would flush, filter, new seal and reinstall?


Thanks,
Brian
 
#12 ·
The problem pretty much has to be the TC seal area, unless something broke, in which case you'd probably be aware of that. I had the torque converter's lockup clutch break on ours, or so said the guy who changed the transaxle. In that case, the was some pretty horrible scraping and dripping when the engine was running, and it had stalled the engine while cruising down the road.
 
#13 ·
I remove the rear subframe bolts and loosen the front, but I've only removed V6 4MO Tips transmissions and they suck compared to a 1.8T. I've done multiple 6sp 4mo trans and they are much easier than the Tip, even with a V6 or 2.7T.
 
#16 ·
Since the majority of the transmission is likely OK, he's probably looking at a new torque converter as the worst-case. If time is money, it will be a lot cheaper to pull the trans, R&R the torque converter, and bolt the trans back on, than all the work and parts required to make it a manual car.
 
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