1999 Harley Evo Primary Oil
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Mobil vtwin 20w-50 and Harleys own synthetic 20W-50 are certified for use in the primary chain case. Most EVO engines spec formula+ in the chain case which I believe a virgin analysis showed it to be a 30 weight oil. Formula+ is only about $8 or so. I would just use that once a year. Of note, on Sportsters, the chain case shares a sump with the transmission.
I would also add do not use a GL-5 gear oil unless it specifically states it is "safe for yellow metals." Otherwise, the gear oil will attack the stator.
If you look up the comparative charts for engine oil and gear oil you will see a 20w50 engine oil is very comparable to a 75w90 gear oil.
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Harley specs they're formula+ oil for the evo primary. They do state to use an HDEO if formula+ isn't available, and then replace it with formula+ as soon as you can. A lot of guys run Rotella T5 in they're primary. I just run 20w50 engine oil in my 1995 evo. It has worked well for 20 years. I would never put GL4 or any gear oil in my primary.
I'm using Delo in my Twin Cam primary.
Based on feedback from riders, I've heard everything from engine oil - gear oil - ATF - HD spec formula oil. I switched out the primary oil to ATF... initially regular old DEXIII to flush and then Redline MTL. Shifting is smooth and finding neutral is more easier than before.
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Originally Posted By: Urshurak776
Mobil vtwin 20w-50 and Harleys own synthetic 20W-50 are certified for use in the primary chain case. Most EVO engines spec formula+ in the chain case which I believe a virgin analysis showed it to be a 30 weight oil. Formula+ is only about $8 or so. I would just use that once a year. Of note, on Sportsters, the chain case shares a sump with the transmission.
Thanks for the input ...Formula+ is the product for me.
Mobil vtwin 20w-50 and Harleys own synthetic 20W-50 are certified for use in the primary chain case. Most EVO engines spec formula+ in the chain case which I believe a virgin analysis showed it to be a 30 weight oil. Formula+ is only about $8 or so. I would just use that once a year. Of note, on Sportsters, the chain case shares a sump with the transmission.
Thanks for the input ...Formula+ is the product for me.
97 & been running 20w-50 no issues
Originally Posted By: g1212969
Originally Posted By: Urshurak776
Mobil vtwin 20w-50 and Harleys own synthetic 20W-50 are certified for use in the primary chain case. Most EVO engines spec formula+ in the chain case which I believe a virgin analysis showed it to be a 30 weight oil. Formula+ is only about $8 or so. I would just use that once a year. Of note, on Sportsters, the chain case shares a sump with the transmission.
Thanks for the input ...Formula+ is the product for me.
Any time
Originally Posted By: Urshurak776
Mobil vtwin 20w-50 and Harleys own synthetic 20W-50 are certified for use in the primary chain case. Most EVO engines spec formula+ in the chain case which I believe a virgin analysis showed it to be a 30 weight oil. Formula+ is only about $8 or so. I would just use that once a year. Of note, on Sportsters, the chain case shares a sump with the transmission.
Thanks for the input ...Formula+ is the product for me.
Any time
Originally Posted By: g1212969
Are there any issues with running a a conventional 20w50 car oil in a Harley primary?
I understand that this does not address your question, but I've yet to find anything that shifts as nice or makes neutral so sweet to find as Spectro Heavy Duty Primary Chaincase oil. It is application specific, not one fluid fits all.
Are there any issues with running a a conventional 20w50 car oil in a Harley primary?
I understand that this does not address your question, but I've yet to find anything that shifts as nice or makes neutral so sweet to find as Spectro Heavy Duty Primary Chaincase oil. It is application specific, not one fluid fits all.
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