Rear end clunk in Valk CSC trike

[TXTrikeNewbie]

I just got a 99 Valk 1500 with a CSC trike conversion. Conversion done in 2006. When I decelerate anywhere 50-65 mph while changing lanes, I hear and feel a clunk. It almost feels like the differential switching torque, but may be something more.
Question to all you experienced Trikers, is there some rear end noise/feels that I should expect, or is this something I need to dig in deeper.

Any help is greatly appreciated.

[Nana]

Hey TX TrikeNewbie, welcome to TrikeTalk. I'm glad you found us here......there are a lot of knowledgeable owners on here, so I'm sure you'll get some good feedback.

[trike lady]

Check the universal joints, some have grease fittings. The sound only comes from those speed ranges and/or lane changes, does it happen at lower speeds and lane changes also?

[Gorilla]

welcome aboard txtrikernewbie u-joints are a good possibility

[CadtoChrome]

First thing I would check are your drive shaft joints and the connection points of the drive shaft to the rear end. There should not be any "clunking" going on when accelerating or decelerating.

Regards,
Chuck

[R J REEVES]

I have had 3 Valkyrie trikes. One was a 2000 Interstate and I put 307k on it with no problems at all except Alt. brushes and a set of Alt. bearings. All of mine were CSC and the only klunk I ever had was when the driveline needed service . (yoke) If its not the yoke I would say you have a problem in rearend. I now have a 2000 valk Interstate , this one is Blue and Silver and I put 27k on it since thanksgiving 2009. rjreeves@charter.net 931-247-4502

[1550vt]

The shaft drives simply employ a small automobile type differential and the same problems you would have in a rear drive automobile would be what you would look for in a shaft-drive trike. Like others have said above, u-joints and connection points in the shaft area is a good place to start, but if that is not the problem, there could be some excess slack in the ring and pinion gears in the diffy. Put it in gear and roll it fore-n-aft and see how much slack you have in the drive train or if you can detect that "clunk" when you roll it back and forth. Those little differentials are pretty bullet-proof...likely a joint or some connection at a joint.

You can do this in all the gears and see if the problem is evident in all of them. If it's just in a certain gear, could point to some slack in the tranny.

There could also be wheel bearing slack. I had one fail out in the middle of nowhere last year and the first thing I noticed before it became very obvious was a "clunk" back there somewhere. Jack both rear wheels off the ground and shake them to see if you can detect any slack at all. If you run a bad outer bearing very long....it will also destroy the inner bearing....then the repair becomes a big PITA.