Manual Tranny, Grinding/Scraping whine when shifting into, and driving in 5th gear

subaru
legacy

#1

The car is a 2007 Subaru Legacy 2.5i 5MT with 122000 miles. I had a new clutch put in about 31000 miles ago.

The problem is what I can best describe as a grinding, metallic sounding whine that occurs the instant I push in the clutch while in 4th to shift into 5th. The noise continues while driving along in 5th gear as well. Apart from that, the car runs smoothly and shifts properly.

Initially, I checked the transmission fluid when the engine was hot and saw that the fluid was at the low mark, so I emptied the all the fluid and filled it with new 75w90 like the manual reccomended.

So obviously the fluid change didnt help, hence why i’m here. If anyone can diagnose what my problem might be from these symptoms that would be of great help. I’m taking the car back to where the clutch was done to get it looked at tomorrow.


#2

Likely bad bearing in trans.


#3

What would cause a bearing to fail? And is continuing to drive the car hurting anything?


#4

Agree, likely bad bearing in the transmission. Not sure why the noise occurs in 4th when the clutch is pressed. That seems a little strange if a bearing related to 5th is going bad.


#5

Perhaps having driven it for an extended period of time with a low level of trans oil is the source of the problem.


#6

Can it be caused by abuse as well?


#7

If you are not the first owner, then it is entirely possible that the previous owner(s) liked to do speed shifting, and/or that they ignored transmission maintenance.


#8

Ive driven it the entire time since the clutch was replaced and I drive it like an old lady.

Im hoping I can blame this on the tech that did the clutch job…


#9

I’d table that thought. The tech didn’t have to open the transmission to do the clutch job so its unlikely he did anything to affect this. That said, a good look at the shift linkage is in order just to make sure.

Bearings wear out. Just a fact of life. Maybe 122,000 miles is a bit early but 91,000 miles to replace a clutch is too. It happens. Yes, this can cause loads of other problems IF that is the problem and IF you ignore it. The noise is caused by little hard metal bits being torn off the bearing. Those bits enter the oil and may find their way to other, perfectly fine bearings that will be damaged by them. So get it into the mechanic for a look-see.


#10

I left out that the engine was replaced at the same time as the clutch (yes, I have a lemon). Would he still not have opened the trans?

I also had to take it back once already for a “defective” throw out bearing…


#11

“I checked the transmission fluid when the engine was hot and saw that the fluid was at the low mark.” I’m not familiar with Subaru M/Ts. Do they have a dip stick?


#12

Yes they do


#13

A “lemon” is a new car that has unrepairable defects.
You have a 7 year old vehicle with over 100k miles, and it appears from the following that you are not the first owner:

I think that you are dealing with the result of previous owner(s) who abused the car by the way that they drove it and the way that they failed to maintain it.


#14

Make sure the gear oil for the manual transmission is actually GL-5. I use Red Line 75w90 NS. If the gear oil is too slippery it can damage the syncros. Not all 75w90 is alike. The rear differential can use the slicker stuff, but not the transmission.


#15

Now I’m curious. U bought it for avg retail 3 yrs ago? Than the motor and trans failed? At same time? So u replaced both? maybe the motor died and u got a deal on motor/trans from wrecked car?


#16

Likely you have a worn/damaged bearing, agree to the rest of the advise here in the thread…

Let me give you a piece of advise on “what’s after it is repaired”.

I used to have 2003 Outback and 2007 Impreza, both with manual transmissions, and Subaru is not exactly a top-performer about their manual transmissions, since they have to crumple too much stuff into such a small box, so… it is quite picky on type of oil you use, even for correct 73W90 GL-5 standard stuff.

You can read long&length email threads on Subaru-lovers-forumns, I will only tell that from what you can get from the chain stores, Valvolyne Synthetic was the one people agreed as “usable” and it worked great for me when I was initially puzzled about “hey, I’ve drained/filled with SOME new oil and and shifts WORSE now???”, then I refilled with Valvolyne and it shifted great after that

good luck!


#17

Jdmere - The oil was Mobil-1, is that acceptable?

Cavell - I didnt replace the trans, just the clutch. And was a brand new motor.

Andriy - I never said I had problems shifting… its the noise that is the issue.


#18

yes, Subaru has a dilemma in their manual transmission:

  • for differential, oil has to be slick
  • for synchros, oil has to have some positive traction for good shifts

I used Valvoline with good results, Red Line was mentioned as good one too from what I recall, it was that local store did not have it and I was lazy to do any online ordering :slight_smile:


#19

one of first replies mentioned “you have a bad bearing”, I second that diagnosis

I can suggest you some “Snake Oil” type of product, which worked well for me before:

If your grinding noise is NOT yet like a “catastrophic” one, it might help

I had great success with XADO restoring compression in worn engines before, used this particular transmission additive for “humming” rear differential in my first '96 Subaru Legacy with 126K miles - it made it quiet in around 200 miles.

Still, it can help, but only in that “borderline” case if it is not worn catastrophically, as in that case you better think proper repair.


#20

I’ve read on Subaru forums that Mobil 1 is not good for the transmission and can cause problems. It is OK for the rear differential, though.