Hey all, So I've had some gear whine for a while now but it's started to get really loud. It starts around 35 or so and continues to a crescendo around 65 or so. If I let off of the throttle, the noise immediately stops (which leads me to assume that it's the gears). It sounds like it's either coming the entire car or the front right (could be middle though). I changed out the diffs and tcase fluid with heavier weight stuff and it had no effect. Is it the trans? I'm just looking for a way to make it stop. Thanks for the help all.
Loud gear whine, input needed
- Thread starter BGMachine
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Mine does it too. Its been suggested that replacing the front differential fixes the problem, which I am saving up for.
Cruiserdrew
On the way there
Even if you pull the drive shafts the front still turns.
You likely have a gear set or pinion bearing gone bad.
If it's the front, you could pull the drive shaft, pull the hub slugs, lock the center diff, and drive it. If the noise is gone, for sure it's your front diff and it needs to be rebuilt.
You likely have a gear set or pinion bearing gone bad.
If it's the front, you could pull the drive shaft, pull the hub slugs, lock the center diff, and drive it. If the noise is gone, for sure it's your front diff and it needs to be rebuilt.
- Thread starter
- #5
what are the hub slugs?
inkpot
SILVER Star
Drive flanges
The solid flange where manual locking hubs would be on other 4x4s.
Cruiserdrew
On the way there
You'd only be doing it for a brief test drive. Cover the hubs with a plastic bag and some tape to seal it up if you're worried. For sure, we've driven out of places just like that in rear wheel drive when the front diff is broken. It's the only way to isolate the front diff in an 80.
You want to know if it's front or rear, transfer case or transmission. To start narrowing it down, I'd start with the front diff.
I know some mechanics will mock up a piece of cardboard, put a couple bolts in to cover the hole.
- Thread starter
- #11
Hey all, so I have determined that the whine is definitely coming from the front diff. I used some accelerometers from work to find out which part of the trick was making the whine. The question I have for you guys now is: does anyone know where I can get a rebuild kit and gears just for the front axle? I can only find kits that do both. I know that it's probably better to do both, but I'm trying to not put a whole lot of money in the truck now. Thanks for the help.
inkpot
SILVER Star
I have run an 80 from Tuscon to Phoenix ( over 100 miles at hi way speeds) with no drive flanges and no covers. Bearings were still full of grease at end of trip and there was no grease on the wheels.
bloc
SILVER Star
I'd just find a used third member. Will likely be WAY cheaper/easier. I've actually thrown two away because I couldn't find buyers even with extremely low pricing.
Also, figure out why yours went bad. Leaking axles seals leading to low fluid levels is likely. if these things have good fluid kept in them they can go for a half million miles.
X2 on this.
I broke on the trail and tried making covers out of plastic. In the end, the plastic ripped off on one side, but the amount of grease and condition was the same on both sides.
- Thread starter
- #15
It was probably low fluid that did it. at one point, two of the steering arm studs on one of the knuckles broke which let out a bunch of diff fluid. I assume since I have the front locker that I need a third member with a space for the locker actuator?
bloc
SILVER Star
Yeah, you'll need a locked front diff which will be harder to find and most likely more expensive than if it were an open diff. The good thing is you can buy one with a bad actuator and move yours over.. might save you some cash. Make sure it's an 80 though.. the locking diff from a minitruck will physically bolt into the housing, but it isn't "high-pinion" like ours and will hit the relay rod and sway bar, and get your driveline angles out.
IIRC it changes the setup kit you need if you rebuild yours as well.. I think the actuator side carrier bearing is a different size than the other, or either on an open diff. Don't quote me on that though.
The problem you have is finding a used locking diff quickly.. assuming you need the truck on the road.
Just to be clear.. you removed the front driveshaft completely, engaged the CDL, and it was still making a lot of noise? that should drastically cut down on the loads on the front diff. If it got quiet doing this you should be able to drive that way until you get it fixed. Definitely put fluid in there though. And note that with CDL engaged you don't have ABS anymore.
IIRC it changes the setup kit you need if you rebuild yours as well.. I think the actuator side carrier bearing is a different size than the other, or either on an open diff. Don't quote me on that though.
The problem you have is finding a used locking diff quickly.. assuming you need the truck on the road.
Just to be clear.. you removed the front driveshaft completely, engaged the CDL, and it was still making a lot of noise? that should drastically cut down on the loads on the front diff. If it got quiet doing this you should be able to drive that way until you get it fixed. Definitely put fluid in there though. And note that with CDL engaged you don't have ABS anymore.
- Thread starter
- #17
I'm going to do the test today of removing the front driveshaft, locking the tcase, and removing the drive flanges to isolate the diff. I figure, if the noise is gone = it's the diff. if the noise is still there = probably the tcase or something else. A friend and I are starting to suspect the tcase since we put it in 4lo yesterday and it didn't make the whine. I'll post what I find later.
- Thread starter
- #18
Hey all.
So I opened up the diff and took it apart to see what was making the noise. I was looking for input from the gear gurus here. So the truck has 250,000mi on it and upon opening the third member, the bearings all look good. The gears looked ok as well. We measured the lash on the gear and it was .018". From what I found, that's waaaaay out of spec. Is that normal for it's age? Is this the source of my whine under load? Thanks for the help all.
Large pinion bearing
carrier bearing
ring gear
small pinion bearing
So I opened up the diff and took it apart to see what was making the noise. I was looking for input from the gear gurus here. So the truck has 250,000mi on it and upon opening the third member, the bearings all look good. The gears looked ok as well. We measured the lash on the gear and it was .018". From what I found, that's waaaaay out of spec. Is that normal for it's age? Is this the source of my whine under load? Thanks for the help all.
Large pinion bearing
carrier bearing
ring gear
small pinion bearing
I've been noticing a similar (or same) problem. It's quiet for the first 10-15 minutes of the day, then the whine starts when everything is warmed up and I'm giving it gas. It stops when I lift my foot off of the gas. I can't tell if the whine is front, center or rear until I can get it on stands with a helper to listen while I gas it (I'd bet on front or center) I'm watching this thread for info and answers.
I'm subscribed...trying to hold off as long as possible before I plunk down on a new front differential and axle. I've been living with the noise you all describe since I bought my 94, which was over 3 years ago.
