prophet@umcp-cs.UUCP (Dennis Gibbs) (10/11/84)
<> > However, to replace the oil, the only way to drain the old contents was to > unbolt about 20 bolts around the periphery of the housing, remove the > entire back panel and gasket, allow the oil to dump out, put on a new gasket > and replace the panel and bolts, and then refill with oil through the > "check-port". To me this is totally insane. Why on earth is there no > simple drain plug at the bottom of the housing? There is a very good reason for this. The reason is is that when changing the oil in a differential or transmission, the bottom of the pan (on a transmission anyway) should be inspected for signs of transmission or gear failure. Also, on most automatic transmissions, the filter should also be changed at periodic intervals. The only way to do this conveniently is to put the car on a lift. If there were a drain plug on the pan, do-it-yourselfers would probably just open the plug, drain the old oil out, replace the plug, and put the new oil in, thus totally forgetting to replace the filter or in- spect the bottom of the pan. Usually when inspecting the pan, there can be bits of worn gears, and sludge from oxidized oil, and other trash that were not picked up by the filter. It is always a good idea to clean this stuff out before putting fresh oil in. Also, if transmission failure is near, there are often tell-tale signs of stuff lying in the bottom of the pan. My Datsun has a drain plug on the bottom of the transmission pan (It is a five speed manual), but I always remove the plug and the pan when changing oil. Dennis -- Call-Me: Dennis Gibbs, Univ. of Md. Comp. Sci. Center. UUCP: {seismo,allegra,brl-bmd}!umcp-cs!prophet CSNet: prophet@umcp-cs BITNET: GIBBS@UMDB ARPA: prophet@Maryland
wmartin@brl-tgr.ARPA (Will Martin ) (10/12/84)
I can see that taking the opportunity to check for worn parts and cleaning out the housing during a fluid-change would be important, especially on a transmission. However, in the example I was using (differential on an off-road vehicle) the mechanic stated that you should check for water contamination and replace any contaminated oil EVERY TIME you run the vehicle through water. This could be every day, depending on how you use such a vehicle! So we are discussing a task which could easily be performed at much more frequent intervals than would justify removing the housing and checking for parts wear. In that case, I still am mystified as to why there is no drain-plug provided. Will Martin