Greetings. Have a recently rebuilt m410, it lost oil and was difficult changing gears and holding o/d. Refilled the box with redline Mtl. Works fine for 30 km or so and then trouble changing gear and holding O/D reappears, but no oil loss. Is this a pressure issue in the overdrive and if so how do I fix it? Or is it one for a specialist?

Just took the 164 out for a drive around the streets, went fine for 30 mins and then it became difficult to change gears. Must admit that I did not get a chance to try it in overdrive. Has it got something to do with oil temperature, or is this increased pressure in the box as the oil temp rises? Oh for the simpe pleasures of the m400!

I'm clueless. Maybe ODGuru has some ideas..
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George Downs Bartlesville, Oklahoma

Redline MTL may too light an oil to use on the M410.

I'm uncertain, and walrus3 may have the best answer, yet I believe the M410 seeks a 30W oil.

Did you run the M410 transmission for very long without fluid? Did you encounter any bearing gear noise? A beefy as the M410 roller and ball bearings are in the gear assemblies, they'll instantly begin to wear without being bathed in oil.

Redline MTL is like a 10W fluid and may be too light for the synchros to operate properly.

What Volvo model is this M410 in, anyhoo? P1800 or a 164 or ?

If you have one, the owner manual may indicate the correct oil type and weight (viscosity). Best to use a synthetic.

May want to remedy the cause of the leak.

walrus3?

Sorry and good luck.

cheer,

dud
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yet another puckless fryday nyght in slumkane, the toilet, wackington.

Thank you for your response. The box was not completely empty and there is not metal on metal sounds when driving. And for the first 30 km it is fine and then it becomes difficult to change gears. Also the redline Mtl is regularly quoted on the net as being a oil of choice for the box and when fine for the first 1500 Kim's until it leaked out. I also used it in a m400 for over 20,000 km in a 164 and it totally transformed the car into a driving pleasre. Hmmmm...

I'll try and find my Volvo OEM Green Factory Service Manual. That manual provides proper fluid specification.

What Volvo model is this M410 in, anyhoo? A 164, P1800, 140, Federation Alaska-Class battle cruiser, or something something?

Wait, lemme search here a bit using the HTML version of google search. (JavaScript blows. Why do I need an AJAX asynchronous web client while searching for kitties or proper M410 transmission fluid.

Searching with Google using the search string "Volvo M410 transmission fluid oil" (without quotes, of course).

Yeah, I thought so. That Redline MTL, while perhaps a quality synthetic, is WAY TOO THIN an oil for the mighty M410.

http://forums.swedespeed.com/showthread.php?136472-M41-versus-M410-transmission

My 1972 164 manual calls for SAE 30 or 20W-40 motor oil for the M410.

So, that means the synchros don't work well as the M410 synchros were meant for use with a heavier viscosity lubricant yielding the hydrostatic (correct term?) pressure required for proper synchro operation. You are also probably doing damage to all bearings in the transmission with the way too thin (or light oil). A 10W like Redline MTL is already way too thin at cold temps. Engage that Laycock D-type, and the Redline MTL encounter pressuures of around, say 500 PSI or so, to engage and maintain the planetary gear engagement for the over drive "upshift".

You may want to use a multi-viscosity oil like the 20W40. Yet use the very best synthetic. Perhaps Mobil 1?

I'm uncertain of Amsoil, anymore. I dunno what oil brand to suggest.

You may want to verify it in your Volvo OEM Green manual for your year and model or model range Volvo that is equipped with the M410. The M410 came in two incarnations, yet should both use the same lube.

Hope that helps.

cheers,

Suffering the Pot Vapors from the Apartment Below...
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... and I've spoken with them on how to exhale (what I call ventilate) externally to the building and downwind. They don't care. I do have to pass drug tests on occasion. I'd rather my clothes not smell like a Cheech and Chong movie, if the movies are equipped with smell-o-vision, when I go to work. Seems to me some WA-state residents are very entitled, even in the NE part of the state, in so-called conservative Spokan't Kounty. I dunno what is liberal or conservative in the USA. Probably what some may call considerate or inconsiderate of others.