I got a couple of old trenchers real cheap and fixed them up. One is a Davis T78 and the other is a Davis Task Force 300. both use the Wisconsin twin cylinder engines such as the THD and TJD. Not sure how old they are. I have a couple of questions.
1.) some trencher teeth were missing so I cut some teeth off a spare chain that came with the units and bolted them on. I recently lost a couple of them probably due to not using elastic stop nuts in that high vibration environment, and need to bolt a couple more on. The teeth are of the cupped variety. I noticed they seem to have a varying degree of cupping throughout the chain and some teeth are put on with spacers, some are not. There are also two shoes with a flat piece of steel at about a 45 degree angle to the line of travel. Does anybody know the ins and outs of trencher teeth design? It looks like the flat shoes scoop the dirt up, the front edges of the cupped teeth do the cutting, and the cupping of the teeth throws the dirt to the windrow on the sides where the spoil augers flatten the peak and keep the windrow from caving back down the trench. Should I try to replace the missing teeth with ones that will preserve the tapering of the cupping or will just any tooth from the spare chain will do? 2.The roller chain on the T78 has a lot of the rollers missing, cracked, and/or paper thin. I have been using it for maybe 50 hours or so since rebuild in intermittent service around the farm and not for making a living. Will the chain prematurely wear if the rollers are missing? 3.) Anybody info about these two particular trenchers would be appreciated (manuals, parts etc.), especially the Task Force 300, as the gearbox in the unit will not shift into the travelling gear any more and it takes forever to get it around the jobsite.- posted
19 years ago