Thanks, Gary, for the information on replacing the starter contacts. I think I may do it on my 95 LS400. I began to experience the same problem a few weeks ago. I took it into the dealer and they said they would replace the starter for about $1000.00 (I am in the USA).
You also may not know, but this was the subject of a National Highway Traffic Safety Administration (NHTSA) recall in 1998. See the NHTSA website at www.nhtsa.org, select Recalls and follow the links to Lexus, LS400. It applied to LS400s between 1995 and 1997. I am currently fighting with the dealer to get them to fix my starter for free, but they are refusing, saying that my VIN number is not included in the recall.
So, after reading your post Gary, I believe I can fix this myself.
Thanks