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5w20 in Gyromatic?


mopar_earl

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Anyone have any luck running 5w20 engine oil in their gyromatic? I took mine apart today to clean and replace the gaskets and seal. It had all kinds of sluge. I'd like to run detergent oil but can't find any 10w detergent oil. Figured the closest detergent oil would be 5w20.

Thanks,

Earl

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The object of the detergent in oil is to attach to nasty stuff from the combustion process, and carry it to the filter to be trapped and held there.  Your transmission lacks both a filter and the combustion process.  I do not know what benefit there would be to running a detergent oil, or to use a variable viscosity fluid.  Can't imagine the source of the sludge unless some moisture had entered the transmission somehow over the years.  Clean it repair it and put the specified oil back in it.

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I presume that you are talking about the semi-automatic case, which has a tag saying add 10 weight oil only, and  not the fluid coupling. 

 

Someone said that the tractor-type hydraulic fluid is the same as 10 weight.  I hope they are are right.  I filled my M5 with it. 

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I see no issue running 5W-20.

I've used 20 weight too. Detergent non detergent use it. It's just a helical gear trans with a oil pump pushing a piston forward and letting the piston return.

I ran 30 weight in one too. That causes extreme fast upshifts and much slower downshifts.

I do run ND 10 weight though in all the customers cars and mine.

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I used hydraulic jack oil in mine. do not know the weight but it is a light oil and non foaming. easy to get and not too expensive. they make a zero weight oil now. that should work, it is a multi weight, o-20w or o-30w.   capt den 

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Thanks guys but I believe you guys missed my point. I want to use detergent oil to prevent sluge build up. I fully know the trans calls for 10w oil. My trans had thick nasty black sluge all up in the relief valve assembly, stainer and in the solenoid ball passage.

I have no issue with 10w oil other than its not detergent oil. I have a 2 gallon jug of 10w oil from tractor supply.

I use 10w-30 detergent oil in all my splash lube engines without issues. I'd have to look it up but I'm sure gear lube has detergents in it.

My truck uses auto trans fluid in the manual gear box and trans fluid is a very detergent fluid. So I'm not in agreement that you have to use nondetergent. I just was asking if anyone used 5w-20 in the trans and if it still shifted OK. My concern is its shifting, not the detergents.

Thanks,

Earl

Edited by mopar_earl
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I didn't miss the point. Put your 5W-20 in it.

It will work fine. BUT.....

The book says as does the trans tag.... use only 10W

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I didn't miss the point. Put your 5W-20 in it.

It will work fine. BUT.....

The book says as does the trans tag.... use only 10W

Yes I know that lol but I can't find 10w detergent oil. Happen to know where I can find any??

Book calls for 30w oil in the engine but I run 10w30. Rear axle calls for 80w oil but i run 80w-90.

Earl

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I don't want to get into legal trouble saying to use 5W-20!!!

So I'm also letting others know what is 100% by the book.

I break the rules all the time seeing what I can get away with so I can learn other avenues and possibly better ways to service and repair these old MoPars.

Dump three pints of 5W-20 in that M-5 and let us know how it works!

Bob

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Add some "Oxydol" to non detergent oils. Cleans like you cannot believe.

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In the old days, mechanics would run kerosene mixed with 10wt in the tranny for a short run (say 20-30 miles) to flush out the system.

Then re-fill with 10wt non-detergent. I believe I read this in a Gus' Garage story a long time ago as well.

Kero is the old school detergent. I believe it's in my service manual.

Earl

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There is a strainer in the M-6 trans. An Oil flush won't clean it out. You have to remove it to clean it.

Shown is an M-5 trans filter but similar.

post-302-0-30445200-1441073208_thumb.jpg

post-302-0-98535500-1441073309_thumb.jpg

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There is a strainer in the M-6 trans. An Oil flush won't clean it out. You have to remove it to clean it.

Shown is an M-5 trans filter but similar.

Yep, pulled the strainer and cleaned it. Was really bad. No idea how the pump drew fluid. No metal or such. Just black pudding like sludge.

My rear axle fluid was black thick and sticky like tar. Definitely could ofvran kero in that! Lots of brake clean. Had to clean the axle tubes with a pipe and rags like cleaning a gun barrel. I could easily tell they werent detergent fluids lol

Earl

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