Subaru Legacy popping out of 4th gear

My son inherited my 2000 Subaru Legacy 5 speed station wagon 2 years ago. He lives in Los Angeles, CA. The car has approximately 140,000 miles and it started to pop out of 4th gear about 6 months ago. He took it to Subaru and they gave him an estimate of $1,800.00 to take apart the transmission and replace parts for the 3rd and 4th gears. He worries that they may need to replace the entire transmission. He got a second opinion from anoter mechanic and this mechanic suggested finding a used transmission and replacing the damaged transmission.

Should he take it to Subaru and hope it won’t cost more than $1,80000 or gamble on a used transmission from the local junk yard? He recently had the power steering pump replaced. Otherwise, it is a dependable car.

Drive it the way it is and don’t mess with the transmission…It’s a lose-lose deal…

The 1800 dollar price seems high unless they’re figuring in a 3/4 gearset replacement.
I’ve done a bunch of these and the problem is often due to a worn 3/4 shift fork and/or worn synchronizer hub and sleeve assembly. A 3/4 gearset is seldom necessary unless there has been some gear crunching going on.
Then again, the flat rate labor rates in his areas may be very high so that could be a contributing factor to the price tag.

Depending on the price, I’d be leaning towards a used transaxle.

Something to consider is this. The vast majority of times this problem is caused by the driver resting their hand on the gearshift lever. The lever multiplies the weight of the hand and forces the shift rail slightly off of its detent.
This in turn causes the fork to rub on the synchronizer sleeve which then wears the fork which then allows the synchro. sleeve to move back and forth. Hope that helps.