Ian's Flatfender

[Flatfender]

Well I managed to drop my Dana 20 transfer case without having to take out the gearbox which saved a lot of time and effort - that NP 435 gearbox weighs a ton. Fortunately the cross member supports the adapter I made between gearbox and TC so it made it easy. The problem now is - I can't find the problem!
With a floor panel removed I was able to take the top off the gearbox to check it out and it all appears to be OK. No visible damage anywhere and the bearings feel perfect when you turn it over by hand. The TC rear output shaft, which is the only part under load in 2 wheel drive, also rotates smoothly. So where is my noisy vibration coming from? The only noticeable wear is on the output shaft splines for the sliding gear which engages 2WD, neutral or 4WD. The transmission expert in Hornsby reckons that is the cause of my problem but I am not convinced. I was going to swap my output shaft assembly with one from an old Dana 20 from Wooders today to eliminate it as a problem but I found it was worn more than mine when I pulled it apart. So do I buy a new shaft and sliding gear when it might not be the answer, or have any of you bright guys out there got any other suggestions Cheers - Ian W.