Has anybody used Spectro full syn tranny oil? For $20.00 a quart it better be some good sh*t. Says its specially made for 6 speed trannys.

 

I don't know what is special about it that makes it "for 6 speed transmissions". I have emailed them and they don't reply to that question. You will do just as well with Mobil1 75w90 from Autozone or Amsoil 75w110 Severe gear or Redline Shockproof Heavy 75w250 oe Royal Purple 75w90. All are cheaper and will do the same thing. You can even use Valvoline Syn Blend GL5 75w90 for $5 just don't run the dino oil past 15,000 miles. Some guy on here uses a farm brand 85w140 GL5 gear oil he gets for $1.50/qt. and changes it every 10,000 miles. As long as it says GL5 on the label you probably won't know much difference.

But if you ever find out why that oil is made for a 6 speed please let me know.

 

Thanks for the reply bro. I was just in Cleveland today. I live near Erie Pa.

 

Yes, it is some good sh*t. But after running HD Syn3 in the tranny any GL5 gear oil would be an improvement. That Spectro "sh*t" is SMOOTH though. I baught two quarts from BOB'S CYCLE SUPPLY for $38.97 including shipping. http://www.bobscycle.com/browse.cfm/4,97853.html

 

I've been running it for a little over 6000 miles now and I like it. Noticably smoother and quieter. Just checked it when I changed oil last week and it is as clean as the day I put it in.
I plan on staying with it.

 

I was thinking of sending a sample in to blackstone labs for analysis.

 

I've been running if for a few k and I don't know if it's the 75-140 weight or the brand but my shifting is alot smoother now. I was having problem finding neutral and since changing out the tranny fluid I haven't had a problem.

It didn't do much (if anything) for my 5th gear rattle.

I may try a cheaper 75-140 next change out. I also got mine from Bob's Cycle.

 

Put it in my Wife's 07 SG and my 07 Ultra !
Much quieter, smoother shifts and neutral easier to find.
Was using HD syn3
Rob .....

 

I would suspect it's because it's rated GL5. As you already seem to know, that's what's needed for helical cut gears used in the Harley Cruise Drive 6-speed. Labeling it 6-Speed oil differentiates it from GL1 rated oils which are fine in most applications for spur gears like Harley 5-Speeds. Buying the right stuff isn't easy for some people. You and I know GL5 is what you want, but most folks don't. Labeling it 6-Speed denotes it as the right stuff. By the way I got some of this stuff for $18.00 a qt. and really like how my tranny shifts. It might not be any better than other quality GL5 rated gear oils, but it really is good stuff.