what fluid for transmission with a fluid drive?

[harmony]

Now I know I'll probably get scolded for a topic already covered, but the search engine here is pretty useless.  No matter which way I worded my search I got completely unrelated topics here.   I get better links to related topics on here from Google. 

Anyways the manual calls for SAE 10W oil for the transmission.  But is that motor oil or general purpose SAE 10W oil?  I couldn't find any 10W motor oil at the auto parts stores.  SAE 10W oil is pretty much crystal clear and the label says it's for low pressure hydraulic systems, or compressors.  Is that the stuff to use?  I've heard some guys use auto trans fluid.  I have a drip on the bottom of my trans which led me to check the level and sure enough it's low.  The drip looks reddish so maybe there is trans fluid in it now. I'll drain what is in there and start with fresh oil, once I know what to use. btw, I have a fluid drive. 

The other question is, it seems like the square plug on the side of the trans is the fill level and that plug is referred to as the fill plug.  So I'm guessing you run a tube in there from a funnel and keep going until it starts to come back out.  So my question is what is the large plug ( 1 1/8" ) just behind the trans solenoid?  I took it out and there is a long heavy spring under that plug that is under tension when the plug is in tight.  I mean it would make sense to fill from there. 

[greg g]

You neglected to tell us what transmission you have.  Since it is a Chrysler one would think it is the semi auto. But since it's the Windsor it might could have the manual three speed.

[harmony]

Sorry, I have a fluid drive coupler.  So in a sense  the transmission shifts gears using hydraulic pressure other than when shifting low to high.  Making me think that maybe the SAE 10W oil would be suitable.  But I remember back when 10W motor oil was available and it was the colour of motor oil just thinner. But then again, maybe they are completely different animals.

[MarcDeSoto]

I'm one of the guys who had a big thread on this subject.   You're right, you can't look up past threads very well here.   James did a long study and research on this question and came up with this product.  Mobil Light Circulating Oil ISO 32.  This product is difficult to look up.  I tried searching for it on Amazon and it gave many look alike Mobil oils, but NOT the right one.  I had to look up my order from Grainger's and use the product number to look it up on Amazon.  I saved a few bucks by driving 30 miles to the my local Grainger's, but even they had to order it.  You might well say that this is just 10W oil so why not put 10W motor oil in the fluid drive like you do in the semi auto transmission.  Well, because it won't work well.  This oil has anti-foaming agents to prevent  cativation in the fluid drive, which will cause the car to have poor acceleration and slipping.  It's because this oil is made for turbines that it works well in the fluid drive coupling.  It does not come in one gallon sizes, so you have to buy more than you  really need, which is just under two gallons.  

 

https://www.amazon.com/Mobil-DTE-Light-ISO-gal/dp/B07CSLKT1J/ref=pd_rhf_se_p_img_2?_encoding=UTF8&psc=1&refRID=HMVQFANK8D7F8CYKVMYX#descriptionAndDetails

[MarcDeSoto]

OK, I didn't read your question correctly, sorry.  The answer above is for the Fluid Drive unit, not the transmission.  The transmission uses 10W non detergent oil.  There is even a little sign on the fill plug that says that.  The manual says to not touch that square plug at the top with a spring.  The fill plug is below that.  Local auto stores probably don't carry 10W non detergent oil anymore.  But you can order it.  https://www.ebay.com/itm/Mystik-Non-Detergent-General-Purpose-Oil-SAE-10W-20W-or-30W-Case-of-12-1-Qts/163852887598?hash=item262664a62e:g:j40AAOSwj1BddOnb

[wagoneer]

I've been looking at lubriplate as a non-detergent 10W. Lubriplate seems to the have market for industrial oils an lubricants of all kind.

 

 

Has anyone tried lubriplate? 

https://www.lubriplate.com/Products/Fluid/Motor-Oil-Series/NON-DET-MOTOR-OIL-10W/NON-DET-MOTOR-OIL-10W/

 

 

 

 

 

 

 

With regards to the recirculating oil, @James_Douglas seminal comment quoted here many times

 https://p15-d24.com/topic/36209-fluid-drive/?tab=comments#comment-371508

 

I'm pretty sure there are also suitable alternatives nowadays that are recirculating fluids with similar properties to DTE. I have been eyeing a few recently. 

 

[Doug&Deb]

I have used AW32 hydraulic oil in my M6 trans with no problem. I drain and change the fluid every oil change. The other plug on the trans is to access the bolt for the shift fork I believe. I’m at work so no access to my service manual.

[harmony]

7 hours ago, MarcDeSoto said:

OK, I didn't read your question correctly, sorry.  The answer above is for the Fluid Drive unit, not the transmission.  The transmission uses 10W non detergent oil.  There is even a little sign on the fill plug that says that.  The manual says to not touch that square plug at the top with a spring.  The fill plug is below that.  Local auto stores probably don't carry 10W non detergent oil anymore.  But you can order it.  https://www.ebay.com/itm/Mystik-Non-Detergent-General-Purpose-Oil-SAE-10W-20W-or-30W-Case-of-12-1-Qts/163852887598?hash=item262664a62e:g:j40AAOSwj1BddOnb

Ok thanks, Yes we can get that general purpose 10W non detergent oil ( Castrol) at NAPA here in Canada. I just got a little confused and curious I suppose about the difference between the 10W motor oil back then and the general purpose non detergent 10W oil on the shelf these days. When I was a kid back in the 60's pumping gas I remember the individual grades and the 10W motor oil still had the honey colour of oil, just really thin.  The general purpose 10W non detergent oil I got at NAPA yesterday is actually clear as water. 

[harmony]

5 hours ago, wagoneer said:

I've been looking at lubriplate as a non-detergent 10W. Lubriplate seems to the have market for industrial oils an lubricants of all kind.

 

 

Has anyone tried lubriplate? 

https://www.lubriplate.com/Products/Fluid/Motor-Oil-Series/NON-DET-MOTOR-OIL-10W/NON-DET-MOTOR-OIL-10W/

 

 

 

 

 

 

 

With regards to the recirculating oil, @James_Douglas seminal comment quoted here many times

 https://p15-d24.com/topic/36209-fluid-drive/?tab=comments#comment-371508

 

I'm pretty sure there are also suitable alternatives nowadays that are recirculating fluids with similar properties to DTE. I have been eyeing a few recently. 

 

Thanks for that link, but as it was noted earlier in the thread, I'm talking about the transmission and not the coupler.

[harmony]

5 hours ago, wagoneer said:

I've been looking at lubriplate as a non-detergent 10W. Lubriplate seems to the have market for industrial oils an lubricants of all kind.

 

 

Has anyone tried lubriplate? 

https://www.lubriplate.com/Products/Fluid/Motor-Oil-Series/NON-DET-MOTOR-OIL-10W/NON-DET-MOTOR-OIL-10W/

 

 

 

 

 

 

 

With regards to the recirculating oil, @James_Douglas seminal comment quoted here many times

 https://p15-d24.com/topic/36209-fluid-drive/?tab=comments#comment-371508

 

I'm pretty sure there are also suitable alternatives nowadays that are recirculating fluids with similar properties to DTE. I have been eyeing a few recently. 

 

That's interesting that lubriplate calls it "motor" oil.  

[chrysler1941]

I also use ISO 32. 

I have easy access to ISO oils so I experimented.

Tried SAE 10W but gear shift is bit noisy. ISO 15 same noise as SAE10W 

This year will try ISO 46. It should be too thick but alright for a worn transmission.

[Dodgeb4ya]

A friend once  used 10/30.

Up-shifted way fast ...was slow to downshift.

He liked it for his beater 48 Chrysler club cpe.

 

[chrysler1941]

1 minute ago, Dodgeb4ya said:

A friend once  used 10/30.

Up-shifted way fast ...was slow to downshift.

He liked it for his beater 48 Chrysler club cpe.

 

Correct me if I'm wrong but aren't multigrade oil low number when "cold" and high number when "warm"? Transmission never get hot enough to change the grade to 30 ?

[chrysler1941]

Now that you mention it. I do recall it shifted faster with more "clunk" with the 10W oil

[harmony]

1 minute ago, chrysler1941 said:

Correct me if I'm wrong but aren't multigrade oil low number when "cold" and high number when "warm"? Transmission never get hot enough to change the grade to 30 ?

Interesting about the grades,,,,  When I was looking at all the selections available at NAPA. I thought ok, so why not go with 5W20.  It might balance out to 10W in a laymens way of thinking.

[harmony]

9 minutes ago, Dodgeb4ya said:

A friend once  used 10/30.

Up-shifted way fast ...was slow to downshift.

He liked it for his beater 48 Chrysler club cpe.

 

Any idea why that grade of oil would cause slow downshifting? I sort of understand what's going on in there with the shifting of gears depending on the oil pressure in the trans etc.  

[Dodgeb4ya]

Any oil  thicker than 10W will cause slower down shifting.

Idle speed must be close to 450-500.

Governor points must be wiped clean of oil too.

Over the past I have always bought by the case what local 10W oil was available.

Never an issue.

[48Dodger]

So.....I have Mobiltrans HD 10w.....that good for the gearbox w or w/o a Fluid Drive?

48D

[wagoneer]

I'm going to try this lubriplate non-detergent 10W in my transmission. I found a really good source that sells that individually, at a good price (almost as much per unit as would be if you buy the case of 12). Applied Industries. 

 

https://www.applied.com/c-brands/c-lubriplate/l0804-054/Motor-Oil/p/102105095

 

 

[James_Douglas]

Everyone should print this out and stick it on the garage wall...James

 

 

viscross.pdf

[wagoneer]

@James_Douglas are you suggesting that a 75W gear oil would work just as well in the m5 trans as a single weight 10w?

[James_Douglas]

SAE Engine oil weights ARE NOT the same as Gear Oil Weights. So a 75 weight gear oil is about a 15 weight motor oil as far as viscosity goes.

 

James

[T120]

Viscosity comparison chart, "W" designation is cold weather viscosity...

 

[wagoneer]

The transmission is a gear box , not a combustion engine , and primarily lubricates gears and flows through the hydraulic chambers. As far as the m5/m6 is concerned, viscosity is the primary mechanism for action in the trans. Probably being gear fluid also prevents break down and foaming or churn of the oil better than normal motor oil. A hypothesis would be that’s 75w single grade gear oil may be as good as 10w but also not since the 75w gear oil also matches up to higher viscosity motor oils.

 

[James_Douglas]

I have a pile of documentation from MOPAR Service Manuals, to Borg Warner Service Manuals, to 3rd party Service Manuals. In some cases I have them over a few decades.

 

If I go through them all, some state to use a particular motor oil and some say to use a particular gear oil. All in the same transmissions.

 

When one takes those recommendations and plots them onto one of the charts as above they all fall on, or near, the same horizontal line.

 

One thing to note. Viscosity IS NOT the same thing as Viscosity Index. Viscosity Index (VI) is the measure of how well any particular viscosity hold up to increased heat. This is important in things like the fluid coupling and to some extent to the engine. It is not terrible important in a manual transmission or rear-end as the oils do not get nearly as hot.

 

One of the things that the VP of Engineering told me at Gyrol was that in a fluid coupling the VI is very important and that the additives that increase VI do break down after 5 to 7 years. Even in the can of unused fluid.

 

Interestingly, my Borg Warner Service Manual for the overdrive in addition to stating the "Under no circumstances must a lubricant of the Hypoid Axel Type be used in an overdrive." also states that a, "Most satisfactory all-around lubricant for the overdrives is SAE No. 40 Engine Oil of a good grade. For extremely hard driving in hot climates, SAE No.50 may be used. Straight mineral oils of the transmission type, SAE No. 80 for all around use or No. 90 for hard driving in hot climates, will also be satisfactory."

 

Borg Warner made a lot of the internal parts for Chrysler for the 3 speed transmissions.

 

 

James