I've been calling around all day yesterday to (1) Twin Disc HQ, (2) field mechanics authorized for Twin Disc service
, and (3) fluid analysis labs. The upshot is: this level of lead is normal, in fact below average.
Some of these people said that lead does not even indicate clutch
wear. This contradicts what the report said. I could not completely follow the technical parts
of the conversation but my best summary is that this transmission
has no lead components and lead is produced as an oxide (?) due to normal operation of the transmission
, as was posted on this thread.
So, if anything, lead by itself is an indication that the transmission has been operated; high lead might be taken to mean the fluid has not been changed. This "lead = normal" situation may be specific to Twin Discs, a lab said they didn't see it elsewhere. Not sure how much weight to give any single
opened his file of past transmission fluid analyses for this transmission for me. Lead numbers were all around 100-120 for routine checks of normal Twin Disc transmissions of the same or similar model. A lab that I reached stated their rolling average for this transmission is 86, they would probably mark a value above 172 as "elevated" in another marine
transmission -- BUT they have a flag on their internal Twin Disc analysis instructions that says not to mark any level of lead as elevated. The oil
analysis tech said that they developed this policy after consulting with Twin Disc about the normal operation of the transmission. Twin Disc HQ said that they would consider a value over 300 as "abnormal."
Also I learned that it is hard to get busy, experienced mechanics to talk on the phone!
Compass790 I don't think any apologies are necessary the whole thread was very helpful to give my head
around the topic and give me what I needed to follow up on the phone
Thanks again for all of your help on this. We are not going to consider this an issue in negotiation with the seller. A lesson might be that I wish the surveyor
had used a different lab. If the lab had routine experience with marine
transmission fluid testing this value would never have been marked as "critical" and the last few days of my life would be different.