Combines 1680 questions

I think the updates you are referring to were implemented in the 1992 production year.Except for the low engine RPM that was implemented with the 1666_1688 and was not in the 1644 due to the smaller engine displacement.

I think the long sieve 1680 showed up first in late 1990 or 1991. The oil bath unloader gear box showed up in 1991. The new hydraulic system showed up in 1992 production year. The reduced speed engine showed up in the 1666 and 1688 in 1993.

I had 1989 1680 that had the cummins in and that was the first year of production other wise prior machines had 466 IH in.

I have a '92 -1680. It has the slow speed Cummins. The dealer said it actually was a prototype 1688 as it came from the factory with all the updates previously mentioned along with the cross-flow fan. It also came with a factory Field Tracker. When I needed a separator drive belt this year I had to get the 1688 belt. It is a wider more HD belt then the regular 1680 belt. So far all the parts I've gotten were from a 1688 parts book. There are probably a couple of these machines around, if you can find them. I just bought it this past summer and have been very happy with it , other then all the small repairs I had to make due to it being a machine with 3900 hrs. lots of worn areas.

Both are very common. It's just another engineering blunder built in to sell parts. Definatly make sure you fix them both. The shaker drive will destroy seives and bushings if left go. The beater will explode right in the middle of harvest on a sunday when everyone is closed.

had both problems on 2188 definitly keep shaker parts tight to keep shaker from going to pieces ran beater for more than a season after this past harvest changed hubs and shaft and pully hub but found that the new beater hubs don't fit tight on the shaft, had 8 years on the original parts, good luck!

Removal is easy remove chaffer and seive. Remove: right bearing and pulley, left bearing, PUSH shaft through beater, lower down and out. Roll beater on the floor is it bentIJ or heavy on one side could be out of balance with dirt. Inspect shaker shaft bearings from inside (Hidden behind shaker arm on the outside) Nows the time to replace these bearings when you have the sieves out! What ENGINE rpm's you runningIJ High rpm's cause failure of the shaker in my opinion.