HS400 (Coleman UT400) Annoying Rattle-Fixed...

[cliffyk]

I have been meaning to write this up for some time. As delivered (in late October 2020) my 2020 UT400 had the expected number of loose "final assembly" nuts and bolts, but even after tightening down everything it still had an annoying metal-on-metal rattle--one f those that was quite audible but difficult to locate. it sounded like some chassis or suspension component but I could not pin it down. So, I took to carrying a large rubber mallet with me and stopping and banging on things when it really got to me.

Eventually I tracked it down to the rear uprights for the roll cage moving about on their mounting posts. The left and right rear cage posts slip onto forged steel hubs welded to the frame and were cross-bolted with some very pretty 10 mm dia. binding post type fasteners having an 8 mm threaded internal shank (the Service Manual says they should be torqued to 48 lbf·ft but when I tried all I got was a violent and quite loud "pop" as the head ripped off the female end):

Examine the torn apart section and it's obvious why it could not handle 48 lbf·ft.

Here's how it mounts, from the service manual; 

So, I replaced both binding bolts (pretty but not up to the task) with a plain ol' 10 x 1.25 x 50 mm class 10.9 bolts and self-locking nuts; and had at torquing it again--no problems, the cage upright squeezed up tight on the forged post and the rattle was gone making me a "happy 'UTVer'"...

Edited April 28, 2021 by cliffyk
typos (damned Parkinson's)