240 M47 Transmission Fluid Choices

OK so I've got a newb question here: looking to change the tranny fluid and wondering what the best choice is. As of now the car shifts great, feels like it's brand new. Bushings feel good, synchros are nice and tight, it was 25 degrees this morning and wasn't sticky in the slightest.

But! when it's hot and I mean hot (1.5 hours+ driving) it has trouble going into gear. It can be really bad. After a 3 hour trip a few weeks back it wouldn't shift into reverse or 1st. After 30 minutes sitting, all better.

I'm thinking a fluid change is in order and would like to know the collective opinion of throwing Redline MTL in these tranny's. I have an old 325iX that calls for ATF but loves MTL. I also have a 5sp Explorer that calls for ATF which hates MTL. (it likes pure Lucas Oil Stabilizer) Go figure.

I found this thread that was quite helpful though a little worrisome:

http://forums.turbobricks.com/showthread.php?t=232775&highlight=transmission+fluid

What say you men?

I use 10w40 motor oil, no problems hot or cold...
When my trans started to act up no fluid change would help so I swapped it.

williamtii said:

As of now the car shifts great, feels like it's brand new. Bushings feel good, synchros are nice and tight, it was 25 degrees this morning and wasn't sticky in the slightest.

But! when it's hot and I mean hot (1.5 hours+ driving) it has trouble going into gear. It can be really bad. After a 3 hour trip a few weeks back it wouldn't shift into reverse or 1st. After 30 minutes sitting, all better.


What say you men?

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DO NOT change the oil!
If the trans shifts good as you say the oil is fine. Unless you want to pony-up the $120/qt that Volvo charges for the extremely good MIL spec synthetic oil.

BT,DT, and every time I've had an M47 and changed the oil to MTL (currently running it in my '91 245) I regretted it as the MTL doesn't last longer than 50ki miles and doesn't shift as smooth as the orig oil. If you can get a look at the orig oil it should be clear and colorless. The only time it's reccommended is if it leaks out. If the drain plug shows a lot of metal, no new oil will change an already worn transmission. Trust me, when they say it is 'Lifetime' oil they mean it. That stuff is like gold in there compared to MTL. If I had to do it again, I would drain the orig oil and filter it and put it back in.

What you describe is a classic case of an M47 shifting with either a worn clutch or cable needing adjustment, or both. As the clutch gets older, the T/O bearing is engaged a bit, causing th4e input shaft to spin and the syncros not matching speeds, and as it gets hot the clutch disc spins more.
It could be worn transmission parts, but would check the clutch operation first.

For what it's worth, Redline MTL shifts alot better than ATF in my M47.

tjanson said:

For what it's worth, Redline MTL shifts alot better than ATF in my M47.

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Thats because ATF has detergents in it and MTL doesn't, and doesn't have the anti-foaming surfactants that ATF has which will eat the synchros. Motor oil would be just as poor for that reason. IIRC the ATF Type F that is reccommended for the M46 uses different surfactants and detergents than Dextron. When you say ATF there are many flavors.
In the manual trans a very pure oil is best like SAE 30 or the best non-detergent synthetic you can find.

Although I wish I'd seen a thread like this before I swapped my fluid, I have to say that although there was fresh ( less than 1000 miles )ATF in mine when I recently bought it (used, 150k,) some pretty balky shifting was cured by: 1st - adjusting the reverse lockout plate to allow enough (factory spec) clearance for getting easily into first, 2nd - switching to Redline MTL. I did the MTL first, and then it was pretty much just first gear that acted as though the syncros were GONE, but it was the simple adjustment that made everything work as it should. Since the OP mentions first gear as a problem spot, I'd suggest checking clearance on the manual stop/lockout, it's in the Bentley...

Just a thought, but have you checked the reverse detent plate to make sure it has the correct setting? The plastic reverse thingie on the shifter is plastic and wears over time and the wrong clearance can then make the shifter hard to get into the 1st to 5th selector slots, and it's frequently worse when the gearbox oil gets hot.

The bushings have to be ok in the shifter , and the reverse lock have to be adjusted correctly. Very often these cars will have a hard time shifting into 1 or 2 gear because of it. also make sure that the clutch have enough free play as already said. If something is malfunctioning inside the box , or it is noisy , no oil will really cure it anyway....Its only on US forums that fluid changes or flushing anything is considered a repair

I just changed out a hard-shifting-when-hot M47 for one I knew was good. I tried MTL, but the fluid that came out looked like clean MTL so it didn't make a difference. The clutch parts all seemed fine, but maybe that was the issue. I suspect the trans having not found any reason for the clutch to have been dragging.

I put in a spare '91 M47 and a new Sachs 740 Turbo clutch kit and my trans works great. Before I had to sit at lights with the trans in 1st. Now I can clutch-in and go right into 1st on demand.

When you pull back on the clutch fork (towards the back of the car), there should be 3-5mm play. If the clutch is adjusted properly, then suspect either a clutch or trans issue. I'm betting the fluid change won't help much.

Synthetic Type F ATF or Redline MTL works well. 30wt engine oil or non-syn Type F will work too. Don't use gear oil like what you'd put in the diff or an old trans...shouldn't be that heavy.

Damn. Loaded question. I believe I'll let things be then. I was not aware that a lifetime fluid was used. I'll have to buddy up to the Volvo tech I know and see if he can snag me some of that good stuff.

williamtii said:

Damn. Loaded question. I believe I'll let things be then. I was not aware that a lifetime fluid was used. I'll have to buddy up to the Volvo tech I know and see if he can snag me some of that good stuff.

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Go see Dan, or Dave at the dealership parts dept at exit 8 if you're set on changing the fluid. They've always done me right. Also, don't discount the good advice given you here in that a simple mechanical adjustment may yield you a better end result without laying out the coin.

I'm in Brookfield, work in Danbury, beer?

vvpete said:

DO NOT change the oil!
If the trans shifts good as you say the oil is fine. Unless you want to pony-up the $120/qt that Volvo charges for the extremely good MIL spec synthetic oil.

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Having owned so many 240's over the years I've gotten to experiment quit a bit and I have never found anything I really liked. MTL has been by far the best.

I'd like to try some of this magical oil you speak of. Part number?

I find it strange that the OWner's manual lists the 1st manual trans fluid/oil change at 1200 miles(if it's to never be changed) but then only inspections up to 60,000 miles. And it says nothing about a MIL spec oil in Owners Manual, only ATF Type F for manual trans.

Unless Volvo changed the type oil & told no one? And Type F has kept many M46's going strong for 200,000+_ miles. I think changing it more often will help either M46 or M47 IMHO. I change mine around every 10,000 miles

The first M47 I had I drained the trans fluid at 200k miles and thought as many say it would be plain-Jane ATF Type F but it was not, it was a clear colorless very thin fluid. I went to the local Volvo dealer and inquired about it and got this story.

Don't change it, we never do unless the trans leaks it out. In 17 years we've never change one M47. The fluid that Volvo puts in is a lifetime synthetic oil, that is put in at the factory after a break-in period (never mind the owners manual). Then the service manager went to the back got a small blue book with listings of specifications, and pointed to a line that gave the MIL-Spec numbers something like MIL-1927 from memory so don't quote me on that. He looked up the part number and said it was $22/quart and special order. I didn't heed his advice, drained it and put in MTL. BTW the plug is sealed at the facory, and if you find the plug easilly removed, and it has red oil in it someone has already drained the orig oil and replaced it. Now this was in 1999.
Fast forward to 2006 and my current '91 245. Same story, same clear fluid, 225k mi, same trip to the same dealer (I was prepared to spend $22/qt), and same service mgr said it was now $109/qt!

Anyway the orig oil is very good stuff, and if you decide to change it to another synthetic, go for it, as I did twice, but in hindsight, would have left it alone.

Sounds like someone is blowing smoke up your arse to me.

smoke

sounds like some expensive smoke.
my M-47 is very smooth with MTL
My friend was a volvo tech for 15 yrs in the 80s and 90s in boston and west palm beach and never heard of this fluid.
But im not saying this book with the magic fluid specs doesnt exist.
good luck

I found a footnote in both the 240 & 740 M46/M47 Greenbook Manuals.

It says, and I qoute:

In case of complaints use Volvo Thermal Oil, p/n1161243-3. Volvo thermal Oil should only be used for vehicles driven inareas where temperaures seldom drop below -10C(14F*)) or for high milage vehicles such as Taxis.

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Could this be the special Volvo clear colorless M47 trans oil ?

I've been using Wal-Mart's in house brand, Super Tech, in gallon jugs, because it works fine and is about as inexpensive as you will find.

Takes about 14 or so quarts when you power flush and refill.

Mr. V said:

I've been using Wal-Mart's in house brand, Super Tech, in gallon jugs, because it works fine and is about as inexpensive as you will find.

Takes about 14 or so quarts when you power flush and refill.

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power flushing your manual trans, eh?

Of course not.

Only automatic.

My bad.

Still, you can use Super Tech for manuals as well: I have.

For my daily driver though, I switched to Redline racing fluid, for Ford application, and the problems I had with rough, notchy shifting went away.