Today was the first day I have been on the highway in a few weeks, and as soon as I shifted into fifth I heard the dreaded noise, loud and clear. I think I can hear it just a tad in third as well, but it's almost imperceptible. It's been about a year since I drained the transmission and overfilled with Redline MTL, in the hopes of preventing this. :(

I've read through other posts, but I've got two questions for anyone who's gone through the same thing:

1) How long do I have before it grenades? I'm trying to find a replacement locally, but I don't know how long it'll be until I find one. I've been avoiding 5th gear, which I'm guessing will slow down the destruction a bit.

2) Is replacing (or repairing) the transmission the only thing I can do, or are there potential easier fixes, like a new bearing or something? I need to take a look and see if fluid leaked out and it ran dryer than it should. If this turns out to be the case will I be able to refill it and be OK?

Thanks as always everyone!

My '92 with the M47 started making noise around 225K. I got the car with 100K on it and had always overfilled the box, always used the recommended oil, and when I moved to AZ I started using MTL exclusively. Well, at just over 240K the trans locked up intermittently in stop-and-go traffic, and that was the end of the line. I should have kept the old box to do a post-mortem on it, but the indy Volvo shop I used concurred with my guess that some bearings failed, allowing a shaft to lock up an adjacent gear(not sure which shaft).

Just one data point for you.

If you keep it full you have quite a bit of time.When noise gets worse its time.I changed only the front bearing for the 5th gear shaft on my 87 m47 WITHOUT
taking out any parts from tranny(wish i would of documented procedure dont
remember details its not recommended procedure)It lasted over another 100,000km
till car was retired due to rust.It was always a sloppy tranny, would not do it again,but i now have many spares.An m46 may be easier to find,as long as it comes with driveshaft and od wiring its any easy swap. Good luck.
--
Rene

having had this on an 87 M47.

First on a 91 you should have the M47II...which was supposed to have "fixed" the problems. The refill hole is higher than the M47, and the 5th gear carrier bearing was redesigned to be tapered. Also the way the 5th Gear is mounted is different.

is you look at the PDF
TP30941-1 M46, M47, M47II and Overdrives.pdf
from this web page
http://www.volvowiringdiagrams.com/?dir=volvo/-%20Service%20Manuals
you will see how they are different.

When mine went it only made noise in 5th. There was no noise in 4th (direct drive) or 3rd...etc.

But the big thing that showed that my tranny was chewing itself to bits was the presence of metal...both brass particles (from the syncros) and steel shavings.

The steel was captured by the magnet on the drain plug. The brass you could see when the fluid was drained into a clean container.


If there is no alarming amt of metal in the fluid then, just refill normally with either Redline or that Volvo Fluid from TASCA...which costs just the same as Redline.

I change the fluid in my replacement M47 every 8 to 10K and use Redline, but then I just recently found out here on the BB about the Volvo Tranny Fluid which is supposed to be longer lasting.

You say 5th gear is whining ? The bearings make a whirring or sort of gritty rolling sound (krrrr...) when they go bad. Whines are usually the gears themselves.

The tranny in my '87 had noisy bearings when I got it. Draining the fluid produced some very glittery oil. Refilled it, drove it. Drain. Overfill. I change the tranny oil every 10,000 miles or so. It has been something like 30,000 miles and is still working fine.

If the car was in great shape, I would consider putting new bearings in it (~$450 from Volvo) and it looks like the fill plug could be moved up to an unused boss on the same side of the gearbox.

Otherwise drive it until it blows up and put in a Ford 5 speed.

Greg

I should have been clearer. It is more of a growling sound, similar to what I've heard on wheel bearings that are going out, but not quite the same. It's not like the whine that can be heard while driving in reverse (my understanding is that reverse gears in many cars have different teeth than the forward gears, and that's what makes this sound).

Anyway, I'm considering the possibility of a Ford T5 from a Mustang or something. Do you have any experience with this?

check your fluid level first
if you can fill a FULL 2 quarts of redline do so.

easiest way is to jack up the car on the left side it lists to the right.

start looking for a new box. not so easy to find anymore.
rebuilding is a waste of time and money. the bearings are costly and the box is inherently weak. IE: steel components housed in an aluminum case which will flex under load and stress

No one is specific when mentioning Redline for Volvo manual transmission on brickboard or on turbobricks. Truly frustrating. There is a difference between Redline MTL offerings.

In this thread, we see a comparison of the 100 degrees Celsius viscosity of the fluid from the Volvo MTF fluid:

Part Number 1161645
Part Name TRANSMISSION OIL
MSRP $23.95
Core $0.00
Save $9.36
Online Price $14.59

Please read this discussion for the 100 degrees Celsius viscosity

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2989981

The comment:

"Redline MTL (70w80) would also a good candidate w/a cSt of 10.6 [at fluid temp of 100 degrees Celsius]- right in the middle, and it's virtually sheer proof. Bet it will fit the bill, much like the Amsoil ATF."

The single Amsoil offering is somewhat too heavy, it seems, in viscosity.

http://www.amsoil.com/shop/by-product/transmission-fluid/manual/manual-transmission-and-transaxle-gear-lube-75w-90/?code=MTGQT-EA

Else, they sell you motor oil as manual transmission fluid.

So buy OEM or what Redline MTL 75W GL-4 version do you use?

So I'll kick off a thread asking what Redline MTL version of manual transmission fluid do you put in your M47 / M47 II?

How stupid for Volvo to print Type F everywhere like the owner manuals. Too thin for M47, yet offers the hydrostatic friction for the synchros operation while the ATF Type F additives eats at the brass in synchros.

Say NO to ATF Type F in that M47 / M47 II.

So what Redline MTL version do you use in your M47 / M47 II?

cheers,

Dud.

Try a fluid change using Volvo fluid and overfill the trans by raising the left side of the car as high as you safely can using jack stands. The extra fluid may prolong your trans.

I believe I have read accounts of the M47 whining quite a while before it gives up.

Make sure the fill port can be opened before draining.
Dan

I checked the fluid situation today, and it's still overfilled (and I didn't see any signs of a leak), and the fluid looked good. There's about 10,000 - 12,000 miles on it since I filled it with MTL, so that's not surprising.

I was hoping to find out that half the fluid had leaked out or something, and that I'd get lucky and refill and be good to go. Guess I'm not that lucky.

"fluid looked good"

from that, are you saying that there is no visible Metal in the fluid? And that you fully drained and inspected it in a clean pan...

if that is the case then I would look elsewhere on the drivetrain.

you are looking in the wrong place for the source of your noise.

if the tranny was the problem, you would see stuff in the fluid.

in my failure as it was happening, I changed the fluid every 2K and there was quite a bit of metal...very much metal in each change

PS

this went on for 15,000 miles
before I got the BiG noise in 5th gear

seems like we posted within the same minute

so you get the jist.. change the fluid...

avoid 5th if it sounds bad

got another 10K of town driving at least. mine was on the highway Balt to NYC

No, sorry, I only meant that I checked to see if it had lost a lot of fluid but removing the fill plug. The car was level, and plenty of fluid came out. It wasn't black and didn't smell bad, and there were no metal bits in it, but that's only from the bit that dripped out of the fill plug.

I guess I was still hoping that I'd just have lost fluid and filling it would be the answer and solve the problem.

I'm sure it's the transmission because the noise is only in fifth gear. I'm just going to have to find a replacement transmission. I do some driving for work, so I'm not really comfortable hoping that the transmission holds out and risking getting stranded.

If the weather is nice I'm going to try to fill/overfill this weekend.

Try a fluid change /or top up before giving up. Three weeks sitting and then the problem could be a slow leak. Old cars like old people....need plenty of fluids (also leak sometimes).
--
Patrick, '68 220 , '53 GMC 4104, '97 VW Transporter.

Hi,


I change my transmission oil every oil change. It’s really not that hard to pull the plugs out while you are waiting for the filter and engine to drain. I usually use 10W30 Mobil 1 in the M45 box. Works well.

Replacing a bearing is the same as rebuilding it.


Goatman