Driveline whine at 55-60 mph

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Driveshaft grrrr

After owning and working on numerous 80 series over the years, Ive found that the driveshafts are very sensitive. If you go over 3" lift you run the risk of needing a double cardan driveshaft. One would assume that the driveshaft is ok as a quick look will tell you that the angle is not very severe. The noise that you get is more of a grrr on the float, at coast or light acceleration. A double cardan shaft is generally the fix. The font is shorter and is more likely to experience this issue with a smaller lift (IE J Springs). A quick way to check is to lock the center diff and pull the front shaft. If the noise is gone, than its the driveshaft. Now, adding to the equation is if you do a gear change form 4.10 to say 4.88, the driveshaft speed is increased. This means that the driveline "grrrr" will be experienced at a lower speed, it could have been there prior to the gear change but was likely at a higher speed than normally traveled, and drowned out by other road noises / harmonics. I've had many people mention this over the years after doing a gear change as logic would tell you that the whatever mod you last made caused the problem, when in fact its a mod you made that amplified or changed the dynamic of an existing issue that was unaddressed. So before pointing fingers at the diff or the diff installer, look into your driveshafts. The same goes for the rear shaft, usually 4"+ lift height. Many people run with it if it's not too severe, but I'm very picky when it comes to driveline issues. Sure some aftermarket gears out there are noisy, but it will generally be a mild howl, usually around 40-50mph. The "grrr" that you can play with on/off throttle is more likely driveshaft. It's not really a "Vibration" like most would expect from a driveshaft issue, it really is a "grr", and could easily be mistaken for a Transfercase or differential issue, if I hadn't heard it a gazillion times and fixed numerous trucks with the same condition (including several of my own). I'm guessing those of you experiencing this have stock single joint shafts?
 
Last edited:
OK...you can throw that therory out the window (and I trust your opinion) because I've had this grrrr/wine on stock gears and now on 5:29's with front and rear DC shafts with a 4" lift. I'm leaning towards the rear transfer case bearing. I'll be changing it soon because my seal is leaking. Just my opinion.
 
They're so friggin' finicky, one diagnoses doesn't fit all, so offering for others to deduce.

Had refreshed shafts in with no vibrations, period, zilch, nada, on OE gears/OE output bearings.

Regear diffs to 5.29s and refresh TC and the same shafts that previously (108k babied LX on OE gears and output bearings) worked, vibrate so badly you'd think the wheels were square.

The driveline angles are the culprit, with the rear much easier to address with link lengths.

The front is a different animal, I'm finding, BUT have been running an ancient version of the Slee spec'd front DC shaft (loaner that returns today, unfortunately) which is too short by ~1 1/2", vibration free.

Can't say if the new bearings have anything to do with it, or not, but prior to the regear and refresh, a lengthened, balanced, new u joint drive shaft rode perfect. After diff/TC work, doesn't work, at all.
 
sizzle, wondering if you ever got it fixed. i've found that whine with a vibration between throttle and off at a specific higher speed means your backlash should be checked.
 
I haven't had a chance to pull my front draft shaft yet. I was gonna do it one weekend, but couldn't make the noise happen, so no point in trying to fix something that ain't there.

It's back now and i've narrowed it down to when i lift off the throttle between 55 and 60 mph. But since it came back life and weather have not cooperated with me being able to pull the shaft.

I did recently grease my u-joints and noticed play in one of the rear u-joints. So u-joints and balancing are definitely in the future. I only have a 2.5" lift and not planning to go higher, so i'm sticking with the stock shafts.

Thanks to everyone for the input. As soon as i get time i'll drop some shafts and report back.
 
Solved my vib/shaking of truck :
-purchased used rear upper control arms adjustable..fr Mr Ali...great price thanks again !
-installed upper arms .. (thx Ryan of disturbed industries ) ....the sound of what I thought was gear noise gone completley gone ....but still have vib/shake
-took front DC shaft out ....vib 90% gone ...
-purchased string ..protracter set..rum...set rear angle ...looked at front angles changed out 5 degree casister plates for 3.5/4 ...caster measurment was around + 4 ....prior to changing of plates
Put oem shaft back in smooth as glass but some grrr no shaking ..
-brought dc back to shop that put together ....said nothing wrong ....talked s to district manager of shop ..he pulled truck in measured angles ...he took apart checked all out again and re phased it ...noticed weights changed on shaft ...put it in and no vibes shakes nor grrrrr's....knock on wood !!!!fingers crossed ... Man its nice to have no vibes shakes or grrrr's
 
I developed a small seep at the front pinion. No drips, just enough to make the area a little moist. I decided to check the fluid level in the diff and it was maybe half full.

There is no way i've lost that much fluid since the axle was re-geared and rebuilt. That thick stuff would be everywhere! Knuckle seals are dry. Most not have been filled all the way by the mechanic. I wouldn't think i'd have to check the fluid level after getting it serviced. Go figure.

Well i filled it, drained it and refilled it. There were a couple of small shavings, but nothing that would give concern. I also extended the diff breathers and modified the value to make it two-way since there was a definite vacuum when i loosened the fill plug.

Drove it and no whine. I'm not holding my breath becuase the noise has come and gone before, but that could have been the issue. I'll drive it more next weekend and going a long trip over new years. Should have some definitive results by then. But if you have the whine, first check your fluid levels! (Duh!)
 
After a couple weeks of driving, I'd say the whine is mostly gone. It's still there, but down to a level now that i would consider normal for a 20 year old, lifted truck. I'm also running slightly thicker diff oil, which also might help.

Now I'm getting more of the grrrr's inbetween throttle on/off. Before, it was just between 55-60 mph. Now it's happening at anything above 55. I know at least one u-joint needs replacing, so i'll start there and work my way through the others to see if that's the culprit. From everything i've read, the u-joints are most suspect.
 
Can't say with certainty, yet, but this should (on paper) be the cure-all for any and all driveline vibes, regardless of caster, pinion angle, or any other front drive shaft related vibration.



image-342183738.webp


Will know Saturday, definitively, if it works in mine.
image-342183738.webp
 
Since my front pinion was leaking after a full axle rebuild and gear swap, i took it back to Mudrak, and explained my symptoms. After getting it back, here is some new info that might help someone:

There was a groove on my pinion flange that was causing the small leak. Mudrak fixed this for free with a used part he had on hand. It seemed to do the trick.

The grrrrs were caused by worn drive flanges on the front hubs. He swapped those out and no more grrrs at speed.

He checked my u-joints and, though one has a little play in it, he didn’t think they needed replacing.

Now that I have driven it for a few weeks, the grrrrrrrrrs are gone. Also, this fixed a small clunk I got when taking off sometimes (felt like one of my rear storage drawers wasn’t latched and was sliding and bumping the tail gate when I accelerated, but they were locked). I though that was unrelated to this, but might not have been.

I still get a pretty significant whine, but only exactly at 60 mph when feathering the throttle. I almost have to try and make it happen. Maybe this is just the harmonic frequency of my cruiser. :steer: Overall, it is runny pretty good now, so I’ll live and let live, but report back if I can cure this, or it gets worse. Thanks, all! :cheers:
 
Delancy said:
Can't say with certainty, yet, but this should (on paper) be the cure-all for any and all driveline vibes, regardless of caster, pinion angle, or any other front drive shaft related vibration.



View attachment 714661


Will know Saturday, definitively, if it works in mine.
Click to expand...

Is that a double-double DC shaft? Out of curiosity where did you get it?
 
High Angle. Not for the faint of heart, and certainly not for all front DS issues. It's not a cure all for the common angles, but was successful for mine.

Unsolicited recommendation would be to discuss with Ben Swain at Slee. They've successfully outfitted a front, too.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom