We recently received a JD 670B from another area within our department so we actually have a grader (we currently have a Galion 503 L). They say the damper drive? is out. I haven't been into a grader before and was wondering if this would cause the problems we are having. It started smoking in the rear of the engine around the transfer case to the trans and smelled of rubber burning. This is all per the old operator. We went to pick it up and it has no hyd functions, brakes, or movement in any gear. My questions are: What does the damper drive actually drive? Should I have hyd functions for the blade, steering, etc. if it is out? What does the pump that connects to the crankshaft do? Would the trans charge pump have anything to do with it? The motor sounds great and is pretty clean to have 7700 hrs on the machine. They recently had all new bushings, wear pads, cutting edges, and other wear parts replaced about 6 months ago and just got a new CAT 14M. I have ordered a service manual from Deere that should be here end of the week, but I was just wanting to shoot some ideas out there as to why it is doing this. I have been told 2 different things from 2 deere dealers as to what the damper drive does. One said I would loose everything and one said I shouldn't. Who knows? Maybe someone else has had experience with these. We are more than capable of doing it, I just wanted to make sure we were headed in the right direction. Thanks Dustin
The damper is like a clutch, it drives everything behind the engine, including the transmission charge pump. The hydraulic pump on the front of the crankshaft needs the charge pressure from the transmission to operate, so you won't have anything without the damper. This is a fair guess based on the way other Deeres work. Have you tried removing the starter to see what you can see in there with a mirror or what you can pull out with a vacuum cleaner hose?
Not yet. I am the manager of a wildlife management area and have a set budget that rolls over July 1. We are looking into trying to find the funds to repair it now. The damper drive alone is $1800 from Deere. It makes sense that it had to have charge pressure to work, I just haven't been into a grader before, neither has my crew. We can spit an ag tractor in no time and have it back together pretty quick. We have also done a lot of transmission/final drive work on D6Ds and a lot of 450/550 Gs. This can't be that hard once we get it in the shop. Just waiting to get a new to us D6d out of our shop so we can pull this monster in. We don't have room to tear into it and leave it in the shop for a while. Overall its a great looking grader. I went and ran it a few months ago before the damper drive went out. They would have fixed it if Cat wouldn't have delivered their new grader when they did. I would have been in great shape then! Thanks for the info.
You have more experience than I do. Wait and see if any of the Left Coast guys have anything to offer. Just because the damper is broken doesn't mean the transmission is good:beatsme
The damper drive is basically a clutch type connection between the engine and transfer drive to the transmission components. Once you get it tore down you may be able to find a local clutch shop that can rebuild the clutch disc and pressure plate that make up the damper. Should be able to pull the engine and tear it down fairly quick, once the cowling and fuel tank are removed, the engine and radiator can be removed as a module. The front of the engine sits on two large guide dowels and has to slide forward to disengage from the transfer case. You might also check the apply lever in the cab and be sure its not partially applied or stuck, it resembles a park brake beside the seat on a 570, best I can remember its about the same on the 670. Be aware that you could have more serious issues, but its hard to tell if there are tranny issues if that damper disc is burnt up. You may want to check around for a plate and disc set before you pay $1900 bucks for one also. I just did a quick search and found the disc for $350.00 and the pressure plate for $350.00 as well.
Found he money to fix it. We tore it down and the damper drive is out. It is a rubber type, basically a splined metal piece vulcanized to a plate that was bolted to the flywheel. It also ruined the shielded pilot bearing. We bought a service manual from Deere. It wasn't bad really. Take the hood, back cowling/fuel tank, and lower guard off, drain some hyd oil, then unbolt the transfer drive. The TM had a shop built stand to bolt to the engine since the transfer drive holds that end of the engine up. All in all took us about 2 hours to tear down with 2 guys while I fabbed the brackets. Could be done with a gantry crane and a motor hoist. As long as the engine gets support. We are waiting parts and putting new seals in the clutch pack and a new SEALED pilot bearing. It reminds me off a boat prop where the rubber is the weak link. Now I know why Deere recommends changing these around 3000 hours. Much easier to do in a shop. We had to hookna D6D to the front to pick it up and put it in the shop. Hard to load and put it in the shop if it doesn't move!