15W-40 in 4-Speed Manual Transmission? - Page 2 - PeachParts Mercedes-Benz Forum

JHZR2 · #16 07-02-2011, 01:15 PM

Quote:

Originally Posted by scottmcphee

Rotella is designed to suspend diesel soot. How much of this do you have in your tranny?

The add pack dispersants are acceptable for putting into a transmission specified for motor oil. That is not a consideration.

However there are chemistries that are more suitable for transmission use, particularly with the synchronizer materials, and yellow metals.

Remember that the API gear oil and motor oil numbers are not the same. A 15w-40 motor oil is similar viscosity to a 75w-90 gear oil.

junqueyardjim · #17 07-02-2011, 01:16 PM

I would recommend that you use it. Originally I think they used ATF, but that has changed a lot in 30 years. I would drain and refill the transmission with it, and I bet it will shift like a dream. Maybe just a little more resistance for a mile or so if it is very cold.

nategodin · #18 07-02-2011, 01:24 PM

Quote:

Originally Posted by JHZR2

Not really. The HDEO add packs are fine and compatible, and the slight cold flow viscosity change (there will be none at operating temperature) should make no difference other than when it is less than 0F.

Huh, good to know, should be fine for summer use, thanks!

nategodin · #19 07-02-2011, 01:27 PM

Quote:

Originally Posted by junqueyardjim

I would recommend that you use it. Originally I think they used ATF, but that has changed a lot in 30 years. I would drain and refill the transmission with it, and I bet it will shift like a dream. Maybe just a little more resistance for a mile or so if it is very cold.

Thanks, what do you use in your 4 speed?

junqueyardjim · #20 07-02-2011, 03:15 PM

Nate - I didn't change the oil yet, will do that shortly and will probably use Mobil 1 10/40. I think it is really a great lubericant.

junqueyardjim · #21 07-02-2011, 03:17 PM

Nate - I am using that in the differential also, have had it in there for three years I think.

JHZR2 · #22 07-02-2011, 03:24 PM

M1 10w-40 isn't the right spec for the crankcase... There are better products for the engine. Same for the transmission. And if you're putting m1 10w-40 in the diff, wow, just wow...

junqueyardjim · #23 07-02-2011, 03:32 PM

How do you know it is isn't the right stuff. Isn't right for the Crankcase, common give me a break. What do you use it for, on your pancakes! Anyway, I'd listen to you until you say" no good for crankcase". What rock do you live under? Here I thought it was the best in all the world for the crankcase!

JHZR2 · #24 07-02-2011, 03:54 PM

Time to learn about oil, friend. The add packs in M1 10w-40 (which is a high mileage oil, BTW, not that there is anything wrong with that), do not carry recent diesel specs, which would be superior for soot detergency and dispersancy, something that is important in a 616/617.

If going syn and M1, get the correct product -turbo diesel truck 5w-40, which carries recent API diesel specs, a decent level of Zn/P adds, and is designed for EGR equipped turbodiesel engines.

Nobody said M1 isn't great lube (for engines, transmissions and diffs), you just need to be informed enough to use the right product for the job.

Now, back on MTs, I believe M1 75w-90 gear oil carries an API MT-1 spec, which MAY mean that it is yellow metal (transmission) safe. API GL -5 lubes, like standard diff lube is not Correct for MTs, but GL-4 and/or MT-1 should be. If applicable, the benefit would be that the same fluid could be used for the MT and diff...

Important to understand specs and applications...

t walgamuth · #25 07-03-2011, 06:25 AM

I always start with whatever the book recommends for my trannies, but after a couple of hundred thousand miles sometimes with the wear I will go to something a little heavier. I believe I have rotella in one of my high mileage stick mb trannies.

One of my trannies has been acting up a little but I think it is due to misalignment of the shift levers and rods. These trannies are very sensitive to shift rod alignment and will graunch if they are not aligned correctly.

Older trannies back in the fifties and sixties used gear oil. When the emphasis started being fuel ecomony they started specifying 10w30 motor oil in some of them, then ATF. What is needed in a brand new machine may be diffrent than what is needed after it has done two or three hundred thousand miles.

Now about puttting things in the oil sump of the motor, it is a different story. Using the wrong thing there can cause real trouble, but using a little crankcase oil in your tranny won't hurt anything.

Also if you just want to use it no reason not to put in a quart along with your modern synthetic, just don't overfill it.

So I agree with Jim on the tranny. I don't think I would use it in my diff though!

junqueyardjim · #26 07-03-2011, 09:45 AM

well, I have a tag on the differential and that will tell the tale. It has been in there for a number of years because that is the diff that came out of my 85 300D. And it is very quiet and smooth and I made two trips with it from Indy to DC. Mostly with my old Mercedes I don't get much out of town. But I am confused now as to what is in there, and I will have to crawl under neath to verify. But I am "pretty" sure it is a very heavy "SAE" label of MOBIL 1, maybe 20W 50.

leathermang · #27 07-03-2011, 09:56 AM

If the military specs on the two items are the same you could feel safe using it... otherwise... how much does this gallon of Rotella Cost ? You would take a chance on it being the wrong thing for your transmission based on not wanting to ' waste ' a gallon of oil which is not specified for your trans.... I am not following this ' logic '....
Third members typically use lubricant specified ' hypoid gear oil ' ...
I use Redling MTF based on what our local MOD and Engineer and long time MB owner suggested.... ( JimSmith )....
There was a time when Chrysler changed from normal old style oil to ATF type viscosity... called ' new process 'gears where if you used the old style oil you could actually cause a fire in the transmission...
It is YOUR Transmission... feel free to be the Guinea Pig .... but for the cost of one gallon of oil ? When that oil could be used lots of legit places ?

JHZR2 · #28 07-03-2011, 10:51 AM

Quote:

Originally Posted by junqueyardjim

well, I have a tag on the differential and that will tell the tale. It has been in there for a number of years because that is the diff that came out of my 85 300D. And it is very quiet and smooth and I made two trips with it from Indy to DC. Mostly with my old Mercedes I don't get much out of town. But I am confused now as to what is in there, and I will have to crawl under neath to verify. But I am "pretty" sure it is a very heavy "SAE" label of MOBIL 1, maybe 20W 50.

Motor oil does NOT belong in a differential, period.

JHZR2 · #29 07-03-2011, 11:08 AM

Quote:

Originally Posted by leathermang

Third members typically use lubricant specified ' hypoid gear oil ' ...
I use Redling MTF based on what our local MOD and Engineer and long time MB owner suggested.... ( JimSmith )....
There was a time when Chrysler changed from normal old style oil to ATF type viscosity... called ' new process 'gears where if you used the old style oil you could actually cause a fire in the transmission...
It is YOUR Transmission... feel free to be the Guinea Pig .... but for the cost of one gallon of oil ? When that oil could be used lots of legit places ?

For manual transmissions, current MTL GL4 viscosites are:

1. ATF Series - Type; 6.5 to 8.5 cSt (Equivalent ATF viscosity; Note: ATF additive package is weak compared to most GL 4's)
2. Synchromesh Series -Type; 9.3 - 9.5 cSt (such as Amsoils MTF, Texaco's MTL, Pennzoil's Synchromesh, GM and Chrysler's Synchromesh)
3. 75W85 Series-Type; 9.8 to 11.5 cSt ( Redline's MTL, RP's Synchromax LT, Nissan's MTL, Honda MTL, Castrol Syntorq LT)
4. 75W90 Series-Type; 12.8 to 14.5 cSt (Amsoil's MTG, Redline's MT-90).

MTL specific lubes we're developed for manual tranny's and transaxles, and not for differentials or industrial gear boxes. A differential lube may not kill your tranny, but it is not the optimum lube for it. A diffy 75W90 (GL5) usually has a higher viscosity than does an mtl in the same advertized weight.

Many if not most GL5 fluids rated for differentials may also be rated as MT-1. Some manufacturers, such as Amsoil®, state the following:

“Recommended for use in differentials, manual transmissions and other gear applications requiring any of the following specifications: API GL-5, MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037), Mack GO-J, or the differential (hypoid) gear oil specifications from all domestic and foreign manufacturers such as GM, Ford and Daimler Chrysler. Can also be used in axles where an API GL-4 lubricant is recommended.”

This MT-1 rating refers to use in heavy duty truck transmissions, and as such, does NOT necessarily mean that this fluid will function properly in a light truck or car synchromesh transmission.

ATF fluids contain a specific additive package for Automatic Transmissions, and not for manual transmissions. Most ATF specifications for use in mtl's, IMHO, were to improve cold weather shifting, and not to improve wear.

Look at the VOA's for clean ATF fluids and compare to clean MTL analysis for example. There is a big difference in the AW/EP additive levels between the two.

ATF's contain AW's, whereas mtl's and differential lubes contain
both AW's and EP agents.

The motor oil doesn't have the EP and AW additives that you would like in there.

Amortize the $6-8.00 over the years of projected use of the car, and just go and get the correct fluid.

Some good reading is in this thread, start with Doug Hillary's post up top and go forward/backward from there, paying special attention to MolaKule's commentary too:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=518833

That's all I hopefully have to say about that. Beyond that, it is your transmission/diff, feel free to damage its operation as you like.