Help with shuddering, mech can't figure out.

vibration at idle in gear? was that an original problem? the car is not moving?

 

check the transmission? last fluid change? filter change? Does it have any codes?

The vibration at idle in gear has always been there but not what I would normally consider unusual for an automatic, it has done it since I bought (~30,000 kms ago, currently at 195,000 kms). When shifted into neutral the vibration goes away completely, don’t recall if it is completely gone in reverse.

I had the fluid flushed a few months ago when I started working at figuring this out. They said the fluid was slightly dark but was clean. No codes have popped up since I’ve owned it. I need to find the work order to check on the filter.

The vibration at idle in gear has always been there but not what I would normally consider unusual for an automatic, it has done it since I bought (~30,000 kms ago, currently at 195,000 kms). When shifted into neutral the vibration goes away completely, don’t recall if it is completely gone in reverse.

 

I had the fluid flushed a few months ago when I started working at figuring this out. They said the fluid was slightly dark but was clean. No codes have popped up since I’ve owned it. I need to find the work order to check on the filter.

Yours is an auto? Boom, you've got aftermarket axles. I'm 100% certain that's the issue if this vibration occurs in gear while stopped. Put OEM axles on there wherever you've got aftermarket ones and your problem will go away.

I might be too confident in that, but I've driven plenty of Subarus and it's always obvious as hell when the owner cheaped out on putting an OEM axle in the car when the old one failed. The car just vibrates like crazy at a stop. You can't really tell a difference in manual cars, but the aftermarket axles also can't hold much upgraded power from what I understand.

The left cv was ordered from the dealer and the right was rebooted oem. I can’t really say if Subaru Canada is using third party axles in their remans but that is probably the best I can get. Subaru Canada doesn’t sell new axles anymore.

I did pick up a couple more oem axles today to get rebooted so hopefully that helps.

I also swapped maf sensors and that seemed to help and now it feels like purely mechanical but I need some more time to make sure before I pop for a new sensor.

I've heard from a former Subaru tech that I work with that he'd recommend replacing the MAF sensors in turbocharged Subarus around the time the car would be getting a timing belt because they become too erratic for a turbo car after years/gunk accumulate on there. The first part I replaced when I bought my car was the MAF sensor.

I bought this one for $106. Amazon says it isn't compatible, but it is wrong.

You may not need OEM axles just better quality reman's. My trusted mechanic will only use one brand of reman's. I have on issues with the reman's in my wagon. I have had issues but he knew how to fix it...

reman name?

Anybody know why my Amazon link for the MAF sensor opens the part on Ebay if I open it on my iPhone but opens the link I hyperlinked from Amazon if I link it from my desktop? Or am I going insane?

Uh...I hate to break it to you...jk, you’re probably not crazy but the link worked fine for me on iPhone and desktop/chrome.

Thanks Pleides, I was going to ask if anybody had a known good link to a denso maf on amazon.

https://www.amazon.com/gp/product/B007WMG8A0

I installed the new maf and it had no effect on the car. Not sure why the maf from the 2005 helped but I did swap the old maf from the 2007 into the 2005 and it certainly helped the 2005. I think the 2005 maf in the 2007 might have been a bit of a fluke or something.

It seems the 2005 maf had some low mass flow signal issues that were causing bucking in that car but perhaps worked well with the auto trans??? In the 2005, it was causing the actual throttle position to bounce between 5% and 20% (5-20-5-20-5 etc, no intermediate values) at low speeds so I assume the computer was seeing a spikey maf signal and trying to compensate with throttle position, which just caused surging.

Anyways, the 2007 goes in next week to replace the axles, ATF filter and balance the winter wheels/tires. Hopefully that's the end of it. My wife has decided she would rather deal with the devil she knows than the devil she doesn't so I guess we are keeping the car for a couple more years until work turns around for the both of us.

I think this will be my final update, unless I decide to keep this thread as a running log of maintenance and for any future issues.

Two rebooted OEM axles where installed, ATF fluid was drained (second of three planned drains [not power flushed]) and the wheels were balanced.

One wheel was bent slightly but they were able to balance it still.

I've driven the car a few times for short drives (<15 minutes each) but I've tried to get the shudder to occur and I am fairly confident it is gone.

This was quite the cascade of repairs and ultimately there were several different issues occurring at the same time, which greatly complicated diagnoses. Here is the summary of actual issues and other repairs that were done along the way:

Actual Issues (partial resolution with each replacement):

1: original front left split cv boot (replaced with reman from Subaru)

2: front O2 sensor (replaced with OEM from Subaru)

3: drive shaft u-joints and balancing (replaced with c-clipped joints, not staked joints)

4: reman front left cv axle from Subaru (replaced with rebooted OEM)

Other parts replaced (no change, or done in combination with above, so change is not clear)

5: rebooted OEM front right cv axle, done with 4

6: left rear axle from Subaru (no idea if reman or new)

7: transmission mount, done with 3

8: rear O2 sensor (OEM from Subaru)

9: MAF (Denso from link that Pleides provided, old MAF moved to my 2005)

10: 2x ATF fluid drains

11: ATF filter, done with 4 and 5

12: wheels balanced 2x (summer wheels)

13: wheels balanced 1x (winter wheels)

14: front and rear diffs serviced, with first ATF drain from 10

I guess the moral of the story is, as is for so many others with the 5EAT, don't use anything other than brand new OEM axles, rebooted OEM axles or perhaps high end reman axles like Raxles, and don't trust that Subaru has a supply of suitable quality axles.

Being in Canada, new OEM axles are not available from Subaru, and whatever they are selling is likely not a good option. Raxles and new OEM are quite expensive to get to Canada, coupled with COVID delays when the majority of the work was done. New OEM are well over $1000CAD for a set, shipped from Heuberger.

I now have two OEM axles on hand, one rebooted, one original with minimal leaking from inner boot, and one reman that Subaru sold me. My plan is to keep all three for future use, although I would only use the reman with an MT, if my measurements check out and it is not one of the many that were too long. If it turns out to be too long, then it will get scrapped, or I'll try to return it and either get my $300 back or a new axle.

Thanks to everybody for all the help, especially Max Capacity.

Now its time to get back to modding the 2005.

I suffer from the same vibration, and it's worse now that I'm back up to stock ride height again. I hardly notice during the spring and summer when I put my BC coilovers on.

My MT car is at 220k and the OEM axles are long gone. I think I might grab 2 oems from the junkyard for 40 bucks, fix them up and see what happens.

Oem units will be green right?