Topic: Help me find the cause of this RF1A Double Transfer Case Spline/Bearing Wear

[GRM]

Recently, I have noticed increase bearing noise. This past weekend I tore down the transfer case, and found damage to the caged needle bearing, the adapter coupler, and the input to the 4.7 transfer case gears. It looks like all three of these components will have to be replaced.

My truck is an 86 mini truck, with a 22re/w56/2.28/4.7 on 35's with 5.29 gears in the axles.

This adapter was installed in February of 2009, and has seen 6000 miles put on it. Most of these miles have been driving on LA freeways, one wheeling trip a month, along with drives up and down California. This vehicle is driven regularly, and has not been used hard, or abused.

A few notes on the problem:
•Transfer Case torn down due to leak, and a caged needle bearing noise
•Upon disassembly wear was found on the splined coupler, rear case input shaft, and caged needle bearing
•Transfer Case always had enough oil in it
•Vehicle still drove when disassembled (500 miles the day before tear down)
•Splined on the 4.7 gears are in a 'V' Shape
•Caged Needle Bearings are Worn, but still work.

The attached pictures should help illustrate the issue. Please let me know if there is anything else I can provide to help in this investigation.

Thanks for your help

[Cheesemaker]

Is that rust? 
Was it new from Marlin when you installed it?  Cause we've had guys come on and pregnant dog about a MC-0? failing.  And later we find out that it was second hand used. 
Best thing to do, is to call the shop in the morning, and they can help ya out better than us trying to solve the issue from the pictures. 

[GRM [OP]]

I should have mentioned... niether of these are marlin parts. I posted here because of how many smart mini truckpeople are on here.

I'm trying to isolate the issue so that I feel justified in buying new marlin parts vs replacing parts