Oil?'s

[mtnrgr]

Not sure

 

[rusty ol ranger]

Oil is oil man.

Valvoline is good. Just dont run ya know, supertech or something.

Id still run motorcraft in the motor, but thats just me.

 

[Craig0320]

My buddy stopped using supertech at his shop because he started random vehicles developing lifter rattle right after changing the oil. He swapped to havoline and hasn't had a problem since.

 

[Ranger850]

With every brand of oil having many different formulas to choose from, you should be able to use all the same brand of fluids. But like Rusty said oil is oil, man.

 

[4x4junkie]

If seals were all replaced when the engine was rebuilt (seems they should've been... isn't that part of what a rebuild is about?), then there's no need to use "maximum life" or "high-mileage" type oils. I don't even use them in my 250K+ mile 2.9L and it burns nothing beyond what is normal (maybe a quart in 20K miles, if I were to leave it in there that long). No leaks anywhere either other than a little seepage around the valve cover gaskets (normal 2.9L crap lol).

IMO, high-mileage oils may even be detrimental... Such oils have an additive that purposely swells the seals to make them not leak as much, but I've seen more than just a couple reports (unconfirmed of course) that an engine started leaking from multiple areas it never leaked from before after switching to regular oil from high-mileage stuff (likely due to seals now shrinking in the absence of the additive). So once you use it, it's possible you may be committed to it.


Also be aware that "Mercon" ATF no longer exists branded as such, it is now called "Dex/Merc" fluid. Reason for the name variation, some years back Ford pulled licensing for the name "Mercon" and began to insist that Mercon V fluid was a compatible replacement. However I've seen it cause permanent shifting difficulties in manual transmissions (I assume this is for a M5OD), I suspect because it's too slippery for the synchros to function correctly. So make sure whatever you get uses the old Dexron III/Mercon formula (it'll say on the bottle "Suitable for all Dexron III & Mercon applications" or something similar).

Hope that helps.

 

[black_demon69]

If seals were all replaced when the engine was rebuilt (seems they should've been... isn't that part of what a rebuild is about?), then there's no need to use "maximum life" or "high-mileage" type oils. I don't even use them in my 250K+ mile 2.9L and it burns nothing beyond what is normal (maybe a quart in 20K miles, if I were to leave it in there that long). No leaks anywhere either other than a little seepage around the valve cover gaskets (normal 2.9L crap lol).

IMO, high-mileage oils may even be detrimental... Such oils have an additive that purposely swells the seals to make them not leak as much, but I've seen more than just a couple reports (unconfirmed of course) that an engine started leaking from multiple areas it never leaked from before after switching to regular oil from high-mileage stuff (likely due to seals now shrinking in the absence of the additive). So once you use it, it's possible you may be committed to it.


Also be aware that "Mercon" ATF no longer exists branded as such, it is now called "Dex/Merc" fluid. Reason for the name variation, some years back Ford pulled licensing for the name "Mercon" and began to insist that Mercon V fluid was a compatible replacement. However I've seen it cause permanent shifting difficulties in manual transmissions (I assume this is for a M5OD), I suspect because it's too slippery for the synchros to function correctly. So make sure whatever you get uses the old Dexron III/Mercon formula (it'll say on the bottle "Suitable for all Dexron III & Mercon applications" or something similar).

Hope that helps.

I have been Running dex/mercy with about 1/3 Lucas oil treatment in my m5od and it has never shifted better. Prior if I accelerated a little hard I would get a slight grind when changing gears. Added the Lucas and that problem is no problem now.



My point is that manual transmissions are more forgiving on fluid type then automatic transmissions.



In fact I have been told that you can run 30weight motor oil as long as it is non detergent. This is from a transmission shop.

 

[4x4junkie]

I have been Running dex/mercy with about 1/3 Lucas oil treatment in my m5od and it has never shifted better. Prior if I accelerated a little hard I would get a slight grind when changing gears. Added the Lucas and that problem is no problem now.

Dex/Merc fluid is fine (that is what I'm saying to use). It's formula is what the M5OD calls for.
0W-30 synthetic engine oils have also been reported to work well in the M5OD also (no personal experience).

"Mercon V" is the one I've seen causing issues. Not everyone reports problems using it, though I have to wonder if that could be some combination of different brands affecting it differently, possibly along with differences in people's tolerance of the issue (it doesn't prevent shifting the trans, but can make the shifts less smooth, and also difficulty getting it into gear at a stoplight, like as if the clutch doesn't fully disengage, but after a few seconds of putting pressure on the stick (or going to another gear then coming back), it'll drop right in).

There's enough reports out there (and well as my own experience too) that I won't touch the stuff for any manual trans. I've not seen or heard of it causing issues in automatics, so I've no opinion either way on using Mercon V in the A4LD for example.