[01-7700]

First snow, first time plowing snow and in 4WD since last winter. There is a ticking sound coming from the front when 4WD is engaged. Ticking is faster with speed - like 4 ticks / second at around 10 mph. I'm thinking u-joints on the front drive shaft but haven't wanted to lie down in wet to frozen slush to check it out yet. The u-joints on the front are original from 2001. It doesn't sound like bad half shafts. Do you think that's it?

 

[Lesblank]

Can you get it to click going from drive to reverse and back while sitting still, foot on brake? That would load and unload drive train. If it clicks when doing that it will probably be u joints. Oh, sorry about the snow, it was 80 degrees and sunny here today.

 

[01-7700]

It rained all day yesterday and there's a half inch of ice on everything. I'm still working from home so no bother there.

It doesn't clunk going from drive to reverse and back. It only starts clicking when moving ~10 mph or more. I didn't hear anything while plowing my driveway but first heard the noise while going next door to plow out the neighbor. It only clicks when 4WD is engaged.

I replaced the u-joints on the main shaft a couple of years ago (for the 3rd? time I think since owning).

 

[Lesblank]

If it’s not making noise when not moving and load put on drive train, doesn’t sound like joints. Unfortunately is sounds more like the actuator might not be engaging the hub all the way. It’s a pain, but other than jacking front end off ground and try to see where noise is actually coming from might be your only choice. Does it do it only in 4 wheel drive?

 

[01-7700]

Yes, only in 4WD - I will have to put it up on blocks to diagnose but the hub is a good guess. Thanks

 

[Lesblank]

There’s a vacuum actuator which engages 4 wheel drive which is prone to fail or line going to it. I think yours is set up that way. Being the what I call the heavy half ton you have I can’t remember.

 

[01-7700]

Great video thanks! Mine is set up the same way. Multiple failure modes, vacuum actuator, brittle plastic vacuum hoses, the left side hub is original and it's been having trouble reading the ABS tone ring for a couple of years. This narrows it down for me - I will put on my insulated jump suit and check it out this weekend.

 

[Lesblank]

Good luck and stay warm. If you want I could see about sending some of my weather your way for a few hours. Oh, I’m bad.

 

[01-7700]

Wow that looks nice! Very generous of you Les. You keep your weather and enjoy it. Our weather forecast calls for below freezing night and day for the next couple of weeks. Working outside is more difficult but coming back inside to a nice roaring woodstove makes it all worthwhile.

 

[Lesblank]

Have you had a chance to diagnose your noise yet. Hopefully it's something simple.

 

[01-7700]

Good morning Les ! Thanks, I hope so too. It snowed all day yesterday but didn't amount to much. Today is supposed to be warmer 34 with just a snow flurry. I'll start by jacking up the front to test front hub engagement then go from there.

 

[01-7700]

So I learned a lot about my 4wd today, but it still makes the noise. It doesn't appear to be an engagement issue. My truck has the actuator at the differential, not at the hubs, and it appears to be working fine. I had the truck up on blocks and all 4 wheels turning while I inspected underneath. Of course it wasn't making the ticking noise for me. When I put it back down on the ground the noise came back. The good news is it was slightly above freezing outside.

 

[Lesblank]

Is the ticking sound sound wheel speed or input drive shaft speed? That would narrow down you search some.

 

[01-7700]

Good point. I will measure it next time I drive.