Hi again. I'm beginning to get a bit frustrated with my car; I've now noticed that it seems to run noticeably louder in 5th gear. I did some investigation and have now read all about how the M47 is actually a crap transmission and will probably be cheaper to replace rather than repair. This is troubling as I thought I inspected EVERY possible major issue before I bought the car and now this creeps up. So what gives? I've read some things about Ford T5 swaps and finding used M47s at yards, but honestly I don't want to replace a crummy transmission with a crummy transmission. Has anyone else gone through this?

 

Well, yeah, M47 are known for a weak 5th... Repair will last a long time if quality parts are used (bearings are what makes for the noises) IF you find a shop (not a slam dunk proposition) that will do it right AND not at some astronomical cost. Don't know about Ford swaps...

These things do happen unfortunately--that's why the M46 is preferred and used in the turbo cars. Feel your pain...

 

If I avoid fifth gear can I prolong my transmission's life at all? My usual work route only takes me up to 50 mph on an average day anyway, so using 5th is kind of a rare occurrence (the occasional interstate/back road speeding)

 

Check the oil level, may be change it with some other alternative like/* Royal Purple? Generally, bearing noise doesn't indicate imminent failure--many can go on for 100k, even more. Better yet if you don't use 5th gear much. Don't sweat it, if it grenades, then deal with it but I bet nothing will happen for a long time.

 

I filled the M47 transmission in my wagon with BG Synchroshift over 100K miles ago. It's about $25 a quart....pricey stuff but worth every penny. It's a little thick on cold winter mornings, but won't break down like the thinner oils,and shifts very smoothly.I just can't imagine why Volvo spec'd. ATF for trans fluid, it overheats and breaks down very quickly.
Whatever oil you use,just make sure it's for transmissions as the additives in the oil allow the right amount of friction for the synchronizer blocking rings to "grab" the gear to slow it down to shift. Motor oils have too many anti -friction additives, that makes for hard and erratic shifting.

 

Busdude, I've also heard about overfilling the transmission when changing oil, do you have any experience with this? Thanks for your replies guys

 

You can't overfill a manual tranny. Go change the oil and you'll see why.

 

When I had mine apart in 2009 to replace the input shaft,I read that you can jack the driverside way up so that it will overfill. I tried it ,and determined that to get the car up high enough on the drivers side, it would be too dangerous...... you might get an extra half pint in. Not worth getting crunched.
If I remember correctly,Volvo cast 3 plug bosses (bumps) on the case at different heights,and drilled one. For example my trans. has the middle one drilled. There was some internet debate, that if the lower boss was factory drilled the fill level would be too low.This is where the idea to overfill came from. Just fill the transmission on the level with a good synthetic oil and you will be good.