Australian TE50 AU1 Member
Join Date: Jun 2001
Had the same problem with the TE, also talked to other TE owners and yep, they had the same problem, one bloke is on his second diff, still not satisfied.
First FTE changed the IRS axles, slight improvement, I went back and said still not satisfied, I want a new diff, they said not yet, try the new oil first. After new oil and seals were fitted the clunk went away and hasn't come back after 10,000kms. So fingers crossed, it has worked. This is such a common problem, all I get from FTE is it's the same diff as HSV, it's just the way they are. They are reluctant to talk about it in detail. Best of luck.