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Bearing questions


Dolzell

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I own an '02 legacy gt and just paid it off last year after putting an engine in it. Been a really great car but the other night I was leaving a friend's house and didn't have the radio on or anything and I heard a roaring noise. It went away when I pushed the clutch in so I made the mistake of assuming it was the throw out bearing. When I got to work (in a shop) I pulled my trans and replaced the throw out bearing. It was still doing it when I left so today I pulled it in and had someone in it to drive it in the air. Its loudest through the stethoscope at the bear on the tail of the transmission where there rear driveshaft goes in.

I've called a transmission shop in the area and they said it's internal and the trans has to be disassembled to change it. Then quoted around $3000. Does this sound correct?

Also, I just took on payments for a new motorcycle which put a lien on the car so can't afford that much to fix it so would it be possible to remove the rear drive shaft and cap it to make the car fwd? And would this have any long term damages?

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I think he was saying it's cheaper to find a used transmission to replace your current one.

 

Noises can be tricky to diagnose over the internet. It is possible your problem is just in the tailpiece of the transmission, that contains the transfer gears. This can be removed and rebuilt without having to remove the entire transmission. Hard to be sure, though.

 

There is also a bearing that supports the driveshaft than can go bad. Typically, this makes a different sort of noise, though. More of a thudding sound.

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I know what you mean. I work in an automotive shop and have people call wanting us to diagnose over the phone. The best information I can give is what I've figured out so far. It will only do it under load. I couldn't get it to make the noise with the car in the air on the rack. If I go above 4k rpm there is a loud metal on metal squeal. When I put the mechanics stethoscope to the front axel inputs, center of the transmission, and at the very end where the rear drive shaft goes in, the very tail end was the loudest sounding like a pitted wheel bearing.

I have never taken apart a transmission but the tail shaft doesn't look too complicated. Would it be fairly straightforward to replace or should I take it out and take it to a trans shop?

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There are a few common problems, but it's going to be hard to know without taking things apart a little.

 

For example, does it sound like this (center diff bearing noise) (ignore terrible music at end of video :) ):

 

There are some other things that can go wrong in the tailpiece. For instance, a snap ring can pop off and the center diff will come apart. The center diff has to be replaced as a unit and costs several hundred dollars as a new part.

 

Here is a long video that goes through the process of removing the tailpiece and replacing some of the bearings:

 

Depending on where the problem is, it's probably going to be a lot cheaper to just swap a used transmission in. You can do that DIY if you have a secure way to lift the car and a transmission jack.

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From what I could hear in that first video that's my noise. It's hard to tell for sure with the white noise but when described as very prominent in low gears and low speed that identical to my issue with exception that you don't hear it much in fifth.

I've done some searching and it seems I can buy just the differential assembly. Is this what you would recommend?

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It's hard to know what's needed at this point. You might want to drain the trans oil and see if you get any metal fragments that might help diagnose.

 

If the center diff itself were bad, you would probably have a different set of symptoms involving noise on tight turns. From what you have said it sounds like a bearing going out. That would require replacing the failed part(s) but you won't know till you open it up.

 

A used transmission from a recycler might cost around $500-900, based on prices I've seen.

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Yeah, all I have for sure right now is all the noise is in the end of the transmission. The front part where the front axles go in is quite. That's all I have. And unfortunately I don't have a spare vehicle to use while I tear this one down to locate the issue. So, I guess my only bet is to sell some stuff to get a transmission and hope it doesn't have issues haha.

Is this a really common issue? My trans has around 220k on it

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You can buy from a recycler that will give you a warranty, some will give six months, some 30 days, some are just "as is".

 

You could try opening up your current transmission, but it's just hard to know in advance what will have to be done to fix it.

 

It seems to be common to develop noises at higher mileages, the factory recommends replacing the trans oil every 30K miles, a lot of people don't do that. Then there are people putting down more power due to upgrades, that can bring some issues.

 

On the center diff, there is an fairly common issue that happens because people don't know they are supposed to run the exact same size tires on all wheels. If they try running different sizes, this can strain the center diff and damage it. I don't think that is your issue, though, that usually results in a problem where the car binds in turns and causes a knocking noise.

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I haven't had any issues with binding and I've always made sure my tire size was the same and the tread depth was similar. I would love for it to just be the differential because I've found those new for a good price but I get what you're saying about needing to get into it. Noise echoing in the case and down the shaft and all that.

It's had that high pitch squeal in high rpm for a while. I just thought it was the clutch release bearing but I replaced that when this roaring started. I suppose that squeal may be related.

Probably won't help but it doesn't hurt to try but I recorded the sound with my phone on my knee next to the center console.

 

https://youtu.be/0sueoJGpbZU

 

It sounds louder in the video than I think it does in the car but my heads not next to the shifter either haha. I'm going in on my day off tomorrow to drain the trans and see if there's metal in it. But it's definitely a wallowed out bearing noise. Like a roar and a rattle together. That's why I was hoping it was the bearing on the tail end ��

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I checked it after replacing the clutch release bearing. It was on the mark and a little darker than sap from a tree. Some ran out of the tail shaft when pulling the transmission and it was darker. More brown. I didn't really see anything alarming.
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Found the culprit. Transfer shaft front bearing pitted like crazy. Unfortunately the bearings that came with the ebay transfer unit are different in the bearings are bigger but the outer races are thinner so everything still fits. Only problem is that bearing that's bad, the new bearing didn't come with an outer race. Smh

 

YkrFyzv.jpg

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