6 speed manual drone or bearing noise in only 4th and 6th gear

Hello guys searched the forum with no luck seeing if anyone has any experiences with a droning or bearing noise in only 4th and 6th gear. Like literally through it into 5rh at 70mph and it stops instantly or down shifting into 4th or upshifting in 6th it instantly comes back? Any thoughts. Im 95% sure it's coming from the trans. Any help thanks!

 

when was the last time the manual transmission fluid was changed? My old subaru did something similar to this.....had a leak in the gearbox (so the fluid was low) and 5th gear droned, then eventually 4th, then 3rd......

 

Do you downshift from higher speeds often and how many miles on the truck?

 

I just did the clutch and since it was closed I didnt. One owner vehicle I purchase at 165k. I'm at 205k could prop use a flush!

 

Yes I do down shift alot. Not so much since i did my breaks recently. Just put a clutch in. She has 206k I do alot of fwy miles and not easy on her so I'd say yes I down shift often

 

Change trans oil first, if still there consider the URD quill mod. There’s a design flaw with our 6 speeds trans housing: the quill is casted into the housing itself and the clutch throw out bearing slides over this quill. Over time it eats into the housing. Don’t forget to grease the bearing too.

 

Really think the throughout bearing would make a noise in one gear but not the other? I did grease the bearing but with only with the small package included in the clutch kit. Going to change the fluid and get back. Ya the throughout bearing was the reason I did the recent clutch replacment.

 

Maybe not but loads on different gears can be strange.

 

Wow OP. I got a bad feeling about this one.

The 6-speed only holds a meager 1.9 qts., has no internal filter, and has no internal magnet, save a tiny, weak one on the drain plug. The 6-speed also tends to run hot. I certainly hope it has not gone more than 200k miles on the original fill. The noise common to 4th and 6th would not be unusual because both share the same rail.

I was inside a newish 6-speed with totally ruined rear bearings due to a lot of swarf present and the thing had less than 6,800 miles. Fluke? Perhaps, but my first thought when seeing the insides was that the transmission just begs for an early flush of gear oil and frequent changes thereafter.

 

Ya I'm thinking it may be internal as well. I'll do a tranny flush instantly after work today. At worst I figure I'll need a full rebuild in my near future. I know the vehicle was extremely well maintained before I purchased so hopfully I can save her. I do notice it only when I'm full throttle as well.

 

Unfortunately, it's probably bad bearings in the transmission- not the T/O bearing or anything cheap or easy.