Nicholas Fluhart

Here’s a nice machine I recently sold. This one was owned by a logger and was also used to do some dozer contracting.

1987 John Deere 850B Bulldozer

I actually sold two of these. The first one was a parts dozer, a 1986 model, and this one was a 1987 model which was a good running machine. The 850 is large enough to do substantial work. The guy who owned this one also has a late model Caterpillar D6N and he indicated the old 850 would actually out-perform the Cat in some situations. The 850B utilizes a 6 cylinder turbo charged John Deere diesel engine producing 165 hp. The operating weight is just shy of 40,000 lbs. Check out all the specs here.

Now lets see it in action! I took a short video clip to demonstrate how it operates.

As indicated in the video, the hydrostatic drive enables easy and swift operation. The engine is also very powerful. Below I’ve posted a couple of pics of an 850B engine. It’s the engine from the ’86 parts dozer after it was just rebuilt.

The winch on this machine is a 60,000 lbs Hyster with 1 inch diameter cable. It was installed to winch out log skidders when they got stuck in the mud.

60,000 lbs Hyster Winch

How about some pros and cons? Well, I’m by no means an 850B expert, so this is solely from the information I’ve gotten from operators who have used and/or owned these machines. It’s funny that one of the main pro’s is also considered by some to be the major con, and that is the hydrostatic drive. This drive system is much smoother than a powershift system and eliminates the need for steering clutches and steering brakes. It also allows for dual-path operation which means the tracks can turn in opposite direction from each other making it turn 360° in one spot, great for working in tight areas. The main drawback of the system however, is that apparently it is prone to failure after about 10,000 hours of service, or so they say, at which time the hydrostat units require rebuilding or replacing which is a very costly procedure. For this reason, the 850 has earned a bad name in certain circles of the construction industry. Aside from that, they appear to be very good, solid machines. If you’re setup to do repairs yourself you can definitely save a lot of money, but it’s a major undertaking nonetheless. Alternatively, if you buy one that’s just had the hydrostat units rebuilt or replaced (like the one I sold), you’ve got a good machine with lots of service life.