Well I will try my best to share this experience which it was IMO
Ok first contact was with Troy support in canada who basically gave me the standard response
What lubricant should be used in the tiller transmission case?
In the past the rule was: For partial fill-ups (a few ounces or less) use SAE 140, SAE 85W-140 or SAE 80W-90 weight gear oil with an API rating of GL-4 or GL-5. For full replacement use SAE 140 or SAE 85W-140 gear oil with an API rating of GL-4 only.
We have also found that 80W-90 oil with an API rating of GL-1 is acceptable for both partial and full replacement of tiller gear oils.
I told them this was at least 15 year old and today it is impossible for me to find any gl-4 in canada plus why do you suppy your new machines with 85w140 gl5
They had no clue what I was talking about even after an escallation to a supervisor
So I said thank you I will call the US. Which was an issue for me since they will only talk to US customers. So my work around for that was to ask my brother for his cell phone and WV zip since he was here for xmas
First lady I spoke to was not 100% sure other than pretty much the same response I got in canada and said if you hold on I will transfer you to one of our sr. staff
The guy on the phone this time like me loved to talk troy tillers especially old ones and when I told him I was trying to fix an old u-haul model with the robin engine and hoped to buy a black horse it was like I hit a soft spot
Ok what he said was yes the new troy were coming with 85w140gl5 but syn
Most gl-5 made today are yellow metal safe and would be fine but be sure the gl5 used says that
I told him about the tillers I sold last year and was now worried that the lucus gl5 would damage them
He said I and the people would be dead before any significant break down would be experienced since it mainly will effect synchros,clutches and wet brakes none of which a troy tiller has
Also the tiller doesn't run fast enough or hot enough to really see any immediate break down but it could over many many years
He said if it was him overhauling that black horse he would source some gl4 somewhere since that machine has a chance of being around for another 40 years with a lot of non use
Also said the gl-1 people buy is not really a gl-1 any more since it is never tested now and most are just gl-4 which is fine
So I ended up ordering two gallons of crc sl24238 gl-4 for the u-haul and black horse and will keep using gl5 for the rest of the tillers
Why because it cost me $70.00 a gallon to get that gl-4 from the us
Not sure if I helped here or just made it more confusing
Cheers
Not to change the subject, but what did they have to say about the oil issue or do you have that in another thread?