I've been having a howling noise under load at around 40 mph, I locked the CDL in HI with both the front and rear drive shaft still on and the howling was gone. Could this be the VC, I have a 94 Land Cruiser
VISCOUS COUPLER?
- Thread starter BrettFriebel
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only way to find out is lift one tire off the ground and see if you can turn it in both directions, if you can't your VC is toast.
Don't think that the vc does anything until wheel slip. Are all tires the same size? Try removing shaft and see what it does.
- Thread starter
- #4
Tires are all the same size, I have the CDL locked in HI with the front driveshaft out right now and the noise is still absent. Howling is only present with CDL unlocked. Does it matter if I lift a front or rear tire to try and turn it?
Nope any four of them should turn, with a little effort by hand if off the ground but if you'll have to put the front DS back in first. If the VC is toast you wont be able to turn the tire at all, no matter what one you take off the ground or how hard you try.
Obviously you'll need the trans in N and chalk it so it won't roll on you.
I got my info here when I did mine https://forum.ih8mud.com/threads/tu...ous-coupler-photos.124794/page-7#post-9166327
If you delete the VC get the allen plugs from Beno for the drain an fill holes.
To clarify the VC only locks the center diff temporarily if the rear or front DS is spinning faster than the other so you can get some power to the axle that has traction albeit the wheel with the least resistance.
Obviously you'll need the trans in N and chalk it so it won't roll on you.
I got my info here when I did mine https://forum.ih8mud.com/threads/tu...ous-coupler-photos.124794/page-7#post-9166327
If you delete the VC get the allen plugs from Beno for the drain an fill holes.
To clarify the VC only locks the center diff temporarily if the rear or front DS is spinning faster than the other so you can get some power to the axle that has traction albeit the wheel with the least resistance.
So when you unlock the center diff is your front driveshaft still removed? That would explain the howling.
- Thread starter
- #7
I haven't tried that, I only unlock the center diff once I out the front driveshaft back in and that's when I'm getting the howling.
- Thread starter
- #8
While I'm turning the wheel, should the driveshaft rotate as well?
ElPolloBlanco
SILVER Star
My VC was Effed when I got my first 80 a few years ago. The drive line would bind up pulling into a parking spot or flipping a u-turn. You could feel it in the wheel and hear chirping and the truck would need input from the gas to make the turn. I pulled it out and never looked back. Smooth turns and never had any problems without it.
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I seriously doubt it's the VC, everyone that I have seen failed was locked, so would act the same CDL locked or unlocked. Sounds like something in the front drive, diff fluid good, knuckle grease at the proper level, u-joints tight and greased?
- Thread starter
- #11
Knuckle grease is good, front driveshaft u joints are good because I just replaced both of them, replaced both front wheel bearings. I also changed the front and rear diff fluids and the transfer case fluid. There is also no signs of any leakage from the knuckles, pinion seal, or transfer case.
front output shaft bearing maybe?
Pt kit (welded or solid viscous) and some free wheeling front hubs will fix it all.
I went PT after yanking the VC, got the lokka spool found superwinch hubs off ebay new for $60, then found ASIN hubs on mud for and and never looked back.
CruiseOrlando
Conveniently Enhanced
So the noise started happening after you did all this work?
- Thread starter
- #16
Noise was present before all that work.
OffGridOverland
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- How are your driveshaft and axle angles?
- What suspension are you using?
- Are your coil springs shot?
- How are your bushings?
- over greased driveshafts?
Are your axles centered in the frame rails like they should be?
I had some noise and vibration. After replacing all the wheel bearings, I later figured out that my coil springs where toast, and my shocks with it. Which lowered the 80 almost totally onto the bump stops. And this moved the axles and pushed everything off center.
The shop that replaced my wheel bearings would have never figured that out. Since they always lifted my truck up and let the suspension hang.
Last edited:
- Thread starter
- #18
It has a stock suspension for now, and the only reason I'm thinking VC is because the howl is gone when I lock the center diff even with both drive shafts installed. But I'll have to get under it and check out all the things you listed.
- Thread starter
- #19
Maybe I'll just take the VC out and see if the howling goes away
It sounds like something in the tcase for sure with the howling going away with the cdl switched pushed. Nothing else changes other than that... I would pull or swap the vc and go from there. Seems like the most obvious choice to me.
