7080 - looking for advice

If the oil samples are fine, WHY would you want to open it up to do anything ??? The oil sampling is looking at things inside without doing so.

If you use the same oil analysis service, they are like your Doctor. They will tell you when something looks questionable. Main and rod bearing life is dependent on how many gallons per hour the engine uses (load), how frequent the oil and filters are changed and the quality of the oil and lastly clean air to breathe. If you've ever been around a poor old N-6 Gleaner with worn out helical bars and the boost gauge always at 20 psi for hrs on end, the rod bearings wear out much faster.

Thanks Dr, we are very religious on all filter and oil changes. 100-150 hours max. Annual oil samples and it’s always had A/C or Agco filters and Rotella 15w-40. Will keep an eye on samples for changes.   

Looking up info on the dampers, I’m 90% sure mine is original.   I found a thread on here discussing dampers on 8070s and replacing them with a vibratech damper for a 4-71 Detroit.   Would this be the same for the 7080?

https://www.allischalmers.com/forum/front-crank-dampener-for-a-8070_topic193124_page3.html

I’m curious. 8070 and 7080 have different part numbers. What was different on the originals 

A true story. I met this man in 1979 when he was about 60 years old. He was meticulous with his fleet of A-C equipment. He had a 68 or 69 series 2 D-21 that had a complete  7040 engine in it. The story goes when the D-21 was about 7 or 8 years old it had 1500 or so hours on it. In his ongoing efforts to be thee best A-C tractor caretaker that ever lived, he had his local mechanic drop the oil pan to "check" the rods and main bearings. The experienced mechanic did what was requested and reused the connecting rod bolts, of which there was an update to a better bolt at that time. The tractor ran about 20 hrs and pitched a rod right out thru the side of the block. So, the moral of the story is this......if there ain't a real good reason to be concerned, why set oneself up for a POSSIBLE failure ???  especially if you aren't skilled at doing such a thing !! If there was a real reason, that's different.

No advice on the bearings but that is about as sharp of a 7080 as I've ever seen.

I would imagine that tractor still has the 4-ring pistons and piston cooling is thru the main bearings. Only the very last few months of 1981 did any 7000 series engine get the newer pistons and piston cooling design.   When "brass" starts rising in the oil samples, that would indicate rod/main bearings are getting thin.

Edited by DrAllis - 04 Jan 2025 at 4:50pm

Duh, I was thinking 8070.....