The Daily Grind...ing noise

deminimis · 06-06-2008, 09:26 AM

So, when I take off from a stop, while turning, I get a grind-ish rubbing-ish noise front the front (gear sound). Its what i might expect if my hubs were locked in, but they aren't. My guess is when at close to full lock (turn), and under acceleration, the hub(s) is/are engaging. However, not an easy thing to check without getting run over. Anyone have a similar issue? I've checked for rubbing tires, etc., but the search yields nothing.

deminimis · 09-18-2008, 11:19 AM

Well, a whole lot of help you guys were on this one.

Since I orignially posted this, I've been trying to figure it out. Kept braking hubs, so switched to Dynalocs. The breaking hub problem cured, but still getting a grinding noise when taking off from a stop while making a hard turn. Decided the noise wasn't actually coming from the front, but the mid to rear part of the van (sounds can be tricky). Was thinking perhaps it was a U-Joint problem, but my U-Joints are as snug as a bug in a rug. Working backwards, I considered the issue coming from the driveshaft, but not enough play in the splined yoke to cause this. At lunch yesterday, I explained the problem with a professional mechanic buddy of mine. He immediately said I probably needed a differential additive for the limited slip rear end. Humm, the fluid was changed out in the vehicle's past as evidenced by the silicone on the diff cover. I just wonder if they failed to put in the additive? So, I ran out and picked up a 4 oz tube of Sta-Bil diff additive. Squeezed that magic stuff in last night and I have not been able to recreate the noise so far. It that was the problem, I hope the lack of an additive for who-knows-how-long, didn't cause any damage to the rear end. Diff fluild is good and clear, but definately had some metal (dust) on the magnetic plug (also had a large-ish circular metal sliver on the magnet, but it was the exact size of the plug's and bung's thread, so thinking (hoping) that was a sliver for the bung thread (very likely)). So, word to the wise, when changing your rear fluild, make sure you put the limited slip additive in there if needed. Some fluids have it, some don't.

scatter · 09-18-2008, 12:40 PM

Wouldn't that be great if it fixed the problem. Ya just gotta love the cheap and easy fixes. I doubt you did too much damage (if any) running it without the additive. The clutch plates are pretty tough. I'd run it for a while to make sure all the additive is mixed in and if you're not sure the limited slip is working you can always jack up one wheel with a floor jack, then start it up, put it in gear and SLOWLY add throttle and see if the rig moves or the raised wheel just spins. I think you'll be fine.

b and j · 09-18-2008, 01:22 PM

My 05 makes the same noise. You say it comes from the rear end dif ? It sure sounds like the front to me, just like yours, from a stop a hard turn either way I get a rubbing noise.
b & j

Danno · 09-18-2008, 02:02 PM

My van made the same noise this weekend while in 4X4 in the mountains. Sounded like a tire rubbing. At first I thought something broke. After looking all over and seeing no sign of anything broken, I kept driving. When making a hard right turn the noise would come back. Stopped again to check and still no sign of anything. Put the van back to 2wd and the noise has not come back. I have not had it in 4wd again to check if it is just a coincidence or not.

b and j · 09-18-2008, 02:10 PM

Mine makes the noise in 2 wheel drive on the road. Sounds like a front tire rubbing but its not. Maybe a brake pad?

deminimis · 09-18-2008, 02:43 PM

To whittle this down for others with noises. My grinding noise would happen in 2wd on pavement. It also sounded like it could be a tire rubbing on something, but no such rubbing is occurring. It sounded like it was coming from the front, but if I turned my head sideways to listen, then I could tell it wasn't the front (I suspect the sub floor transfers sounds from the back towards the front). Now, my mechanic buddy did have some bad news regarding rear ends. Heavy vehicles such as ours can be hard on the spider gears. So, in my case, if the additive is not the cure (won't really know for a while), then its into the diff for a new gear set most likely. Hopefully that's not in my future as I want to concentrate on shocks, amenities, and getting my old Bug resto project on its way (diesel is killing me because my Sporty is my daily driver). For those with noises, you can pick up diff additive at any parts store (heck, even our farm store had it). They all seem to work with dino lube or synthetics, but you best make sure unless you know what you have in your diff. Good luck and please let us know if any of you have sucess with this elusive gremlin.

**daveb** · 09-18-2008, 09:53 PM

Quote:

Originally Posted by deminimis

So, when I take off from a stop, while turning, I get a grind-ish rubbing-ish noise front the front (gear sound). Its what i might expect if my hubs were locked in, but they aren't. My guess is when at close to full lock (turn), and under acceleration, the hub(s) is/are engaging. However, not an easy thing to check without getting run over. Anyone have a similar issue? I've checked for rubbing tires, etc., but the search yields nothing.

Wow it almost sounds like the same problem I discussed with you. So far the fix SMB did with the hubs corrected it but I was feeling it in the steering wheel not hearing it. Seemed to happen on a sharp turn while climbing up and over a slight hill. I did have SMB change my diff fluids to syn stuff...so far so good.

deminimis · 09-19-2008, 10:54 AM

Hey Dave. How's it going? Yea, I started this thread back in June. Since then, the investigation took off in different directions. I've now logged three twenty-mile trips since the additive. I've gone out and tried to recreate the noise. I can't. With fingers crossed, it appears the additive is all that was needed. Makes me mad that I didn't figure this out on my own given the symptoms: Only while under power and only when making a sharp turn from a stop. A rear end with limited slip should have been the first thing I looked at given those clues, not the last.

deminimis · 10-27-2008, 05:06 PM

Was rummaging around Diesel Stop and discovered this rear end noise is not unheard of. There are others on that site with what appears to be the exact same rear end problem. The additive helped mine, but once good and warm, the noise continues (sort of a grinding/groaning noise when taking off from a stop while turning). One shop diagnosed another's van stating the limited slip clutches weren't operating correctly, but the shop felt fixing it was not worth the time (sort of live with it scenerio). Humm, just living with it is not something I really want to do. Guessing I might have to bite the bullet and actually have a driveline shop take a look at mine. If I have to have some rearend work done (no, not the Dr. with the elbow-high latex glove type of rear end work), I'll probably shell out for a mag-Hytec diff cover for some added capacity. While I'm at that, may as well go into the hole deeper and get a Mag-Hytec deep trans pan while I'm at it. Glad to be in a recession-proof job because this SMB (SOB) is getting expensive.