Just went to my local HD store to get the materials for a 5k service on my 2019 TGU and the parts person pointed me to a new HD product. It is reportedly "Tested-Certified" Harley-Davidson Heavy Synthetic Gear Oil for transmission and primary chaincase applications. It is intended for extreme temperature environments both hot and cold and is designed for "frequent two-up riding and heavy load riding applications". I know that the Primary and Transmission service intervals are deemed to be longer than I am using but I like changing those holes more frequently for possible smoother functioning and less wear and tear. Oil is cheap or at least used to be until I saw the $19.95 price tag for this "magical" full bodied lubricant. It appears that this new product that reportedly is not yet listed in Harley's catalogs might be pretty ideal for our heavy Tri Glides and even the Freewheelers. The only rub is that the list price on the product is $19.95/quart. This new product may quiet down the already reduced "clunking" of my 2019 tranny and make it quieter yet? Can't wait to complete the service and report back on it, if it seems to make much of a difference? With the Formula + in the two holes, I have not had one ounce of migration from the tranny in 5k miles. However, I suspect that this was the MOCO's answer to many of the heavier synthetic aftermarket products that they were loosing market share to (companies like Red Line Superlight Shockproof 75W-90, etc.). The critical factor for my personal use was that this is a totally approved/developed MOCO product and will not have one iota of impact on my current and HD ESP extended warranty. I casually understand the Magnuson–Moss Warranty Act but do not have the legal expertise or deep pockets to ever go down that road. With the history of some of us having experienced oil migration issues, I did not want to introduce any variables that could inadvertently invalidate my warranty should I ever experience that problem. One word of caution, the plastic bottle of the gear oil has much of the same shape and colors as the SYN 3 and this oil is NOT intended for the crankcase. I can see someone not paying attention and putting the wrong oil in the wrong hole ("Hey, my battery seems to have gotten weaker trying to crank my trike" <grin>).

 

I run it and it does help with smooth shifting. I only run it in the gear box I don't change it but every 10,000 miles. I run 20/50 syn in the primary.

 

Funny that Harley swears by this but I was at the Harley shop in Canada and mentioned it. Parts man said he has never heard of it so he looked it up. Came up on his Harley site that it was not available in Canada. If its so good why not Canada?

 

I’ve had a bad experience running synthetic in the primary. Screwed up my clutch, and had to replace it. Then used Formula+, and now issues after 30,000 miles.

As for synthetic in the tranny, I don’t see the need versus a good application specific gear lube.

 

I usually run Redline H-D Shockproof in my transmission(s) but SYN3 in my engine and primaries.

When I bought my '18 Tri-Glide last year I also purchased a dealer "Service Contract" which does not include synthetic fluids.
When I took my trike in for the 1,000 mile service I specified that I wanted SYN3 in the engine and primary and Redline in the transmission and that I would pay the difference in costs. Just looking at my invoice for that service and the cost was $ 46.87.

I think the heavier weight oil is much better for the tranny and the cost of it and the sythetics was worth the upgrade.

 

TriGeezer, Like all oil threads, all kinds of variables and controversies can arise. Harley states that the Heavy Synthetic Gear Oil is "Formulated to maintain the proper coefficient of friction for clutch operation..." The problem as I see it is that our clutches are considered wear items and so if the clutch goes out and it is due to the new oil, Harley isn't going to be replacing our clutches. I too have successfully used Formula + in my HD trannies and primary chaincases but trade them before I rack up the 30k mileage you are talking about. It may just be that some Harley clutch material suppliers vary the quality of their products and some clutches go early while I hear of others going 100k? I knew I was going down a "slippery slope" (pun intended) when I started this latest oil thread. I am willing to give the new product a try and see how it holds up. Here in Florida and trips I take out West, it gets hotter than hell sometimes (Gainesville, Florida set an all-time May record with a 102 degree day a couple of days ago) and this 114c.i. lump of an M8 engine has got to be running as hot as they get for Harleys when you consider it is in a heavy trike?

 

We're not supposed to tell, but we get a few laughs by porking Canadians. It's a U.S. thing. Sorry.

 

Interesting note-

When I did my 1000 mile on my 2019 TG, I noticed that the factory had used the gear oil in the transmission. However, they did not use it in the primary.

I already had my Redline Shockproof for the trans, so put it in. BUT, unlike previously, I did not notice any significant improvement when putting the Redline in the transmission. This, anecdotally, tells me that the HD gear oil is on par with the Redline, or, at least, much better than what they were using previously.

I used the Syn 3 in the primary. I may try the HD gear oil in the primary at the next change.

 

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Oh no, it's like deja vu all over again! I hated my Englilsh classes! Dr. Bob