Vibration coming from 5EAT, possibly

[h6uy]

Hello all,

This is my first post even though I’ve been lurking the forum for a while. Gotta say some projects here are nothing short of amazing.

In my case I’m bringing a story of stress and money spending, hope you don’t mind! This is the story of my car and the issue that’s been driving me insane for the past year.

I am from Uruguay and own an ’09 Outback 3.0 5EAT (EU/JP spec).

This is my first Subaru which I bought used with ~112k miles (now at about 135k). Since getting the car I noticed a subtle vibration under some conditions, it was hard to pinpoint exactly when it happened at first, but it happened under load and mostly at low speeds, e.g. when driving up a hill at 25-30 mph.

I drive my car pretty hard so this issue soon became a bigger and more noticeable vibration, under the same conditions.

My mechanic suggested it could be u-joint related and I agreed, as I’ve had similar vibrations on BMWs with driveshaft issues. We took the driveshaft out and it clearly had already been serviced before (u-joints replaced and welded back in). Well I did the same thing and replaced u-joints again with my go-to driveshaft guy. According to him, these driveshafts are a POS because they’re not meant to be serviced. I agree with the sentiment.

Anyway, after installing the driveshaft again the vibration was still there. My mechanic said it could be the inner front cv joint (tripod joints). So I bought a new pair of those original from Subaru (green cup ones, just the inner joint). Mechanic put these in the car and it improved I would say about 90%. I could still feel some vibration when trying to replicate the issue, (go on a hill, drive slowly so that the car is in low revs and has to work its way up).

It wasn’t too bad at this point so I kept on driving (it’s my only car). Then with time the vibration started getting worse and worse and my mechanic couldn’t tell what the cause was (he’s not a Subaru specialist, nor has much time to troubleshoot the issue, really). So I took it to the Subaru dealership here in my country. They did sort of a quick check on the car, free of charge, and told me they though it was a combination of things (some bushings were going bad, plus they thought my driveshaft was bad). Got a quote on a new Subaru driveshaft and it was around 2500usd, which doesn’t make sense to me given the value of the car itself.

I then installed a new trans mount (old one was shot but not extremely bad) and various new bushings on front and rear as suggested by dealership. Of course that didn’t change anything.

So I bought an aftermarket driveshaft from RockAuto, brand name is “WJB”, final cost was about 550usd which seemed a lot more reasonable to me.

Went back to the Subaru dealership and they didn’t like the fact that I bought a non-original driveshaft, so they were a lot less helpful from this point on. They told me they would check the car if I brought it with the original driveshaft, and so I did. After a test drive, one of their theories was a bad torque converter. They plugged the car into a computer and told me from what they saw in the graphs, torque converter seemed fine. Driveshaft was bad so they asked me to take the non-original one and they’d install it. I took the new driveshaft to my driveshaft guy to make sure it was in good shape and balanced. Then took it back to the dealership, where they installed the driveshaft but didn’t even test drive the car (I’m guessing because it was a non-original part and they really didn’t want to mess with my car anymore). At this point I payed them and got out of there. I’m not rich by any means and can’t afford 2.5k in a driveshaft, which didn’t even seem like it was the problem anyway.

During this time (regardless of the driveshaft installed), the issue got significantly more noticeable when turning corners at low speed, no matter which way I was turning. I’ll upload a video of this where the noise can be heard. Yeah it was just vibration at first but now it's vibration with noise.

Fast forward to a couple weeks ago, after all that turmoil I decided to try and get new front axles. It seemed like the next logic step to me given the information I had. Thing is, Subaru axles would probably cost a fortune in my country (just the inner joints were 250usd each). So I went with the Cardone HD axles that are sold on RockAuto. I know, I’ve read many times that non-original axles are crap and you shouldn’t use them. But given the situation I’m not in a position to drop what I assume it’d be at least 1k usd on a pair of new Subaru axles. These aftermarket ones cost me about 150usd each delivered to my door. Plus, even if they are bad quality, I can live with that as long as they help me pinpoint the issue. If the issue was fixed but the axles broke after 30k miles then I’d eventually get original axles no problem.

Well wouldn’t you know, after I installed the new axles the car felt exactly the same. Vibration when turning is pretty bad now, which makes me not want to use the car unless really necessary. As another piece of information, the inner joints I took out (which had less than 20k miles and are Subaru original) already had some play in them (not the outer joints, those were fine). So whatever that vibration is, it's also causing my joints to go bad.

Now it all points to the transmission and more specifically, either front diff or center diff. This is of course what I gather from all I’ve been through and all the parts I’ve changed, plus the experiments I’ve done (like turning a corner in neutral at the same speed where I’d feel a vibration – shafts are moving but there’s no vibration then, which points to an issue inside the transmission).

A transmission issue is the worst case scenario for me, as finding someone who would fix a 5EAT in this country is very unlikely. So now I’m weighing my options and would love to hear thoughts from the experienced people here to see if my presumption is correct.

 

If this is trans issue, here’s the options I’m considering:

* Buying a used 5EAT and importing from some foreign country (there’s few 3rd gen Outbacks in my country and even less with the 3.0 so finding a working transmission here would be extremely hard). Risk is that I could be buying another bad transmission. My estimated cost for this is about ~3000usd for importing a used 5EAT from, say, Europe.

* Driving to Argentina and finding somebody who knows what they’re doing and rebuilds my transmission. Risk here is that I don’t know what they’ll find once they open it. Plus I’ll probably have to leave my car there for some time and figure out the whole logistics of it. Also the final cost is unknown.

* Opening the transmission, removing the center diff, welding the shafts like frank_ster (user from this forum) did, hope that fixes the issue and get stuck with a RWD car. Not ideal as I actually use and want the AWD, but if it works it might be the cheaper option to get the car running.

* Sell the car as it is now, with a much lower price than it should have and feel defeated.

 

If it’s not a trans issue, I really don’t know what it is.

 

All input and comments will be very much appreciated.

 

Hope everyone is having a great day, cheers!

Edited October 7, 2023 by h6uy

[h6uy]

Here's a video where you can hear the vibration while turning. I tried to replicate it in straight line at the end but pushed the throttle too much I guess. To me it sounds kind of like a bad driveshaft center carrier would, but that doesn't really add up.

 

 

Edited October 7, 2023 by h6uy