High pitch whine above 40mph...

[merlot566jka]

I've recently started to use my deuce for a daily driver while my corvette is in the shop getting paint. I havent even had the deuce for a month!

Anyways, when I get up to about 40mph, in 4th or 5th gear, I get a high pitched screaming whine that will make your ears ring. It is significantly quieter when the truck is cold. It gets louder with speed, and the pitch (frequency) increases accordingly.
When I push in the clutch, the noise goes away. It is not coming from the engine (obviously).
If I ease off of the throttle, I can quiet the noise, but the second any load is put on the truck, the noise returns.
To me the noise sounds like gears meshing with out fluid or extremely high speed gears. But where is it coming from?

Where do I start to look?

I thought maybe the differentials would be a good place to start,but what am I looking for? How do I check the play in the gears without tearing it all apart?

I thought about the trans, but since it does it in both 4th and 5th I dont really think its the transmission. I could be wrong.

My next thought is fluids... Maybe a lack of or the incorrect fluids were used. I am sure I can find the right stuff at NAPA to refill the diffs and trans. Anyone have specific part numbers/brands that worked for you?

Any help would be greatly appreciated, I want to nip this in the bud before it nips my wallet!

Thanks!
Jonathan Anderson

 

[TexAndy]

I don't know, but I'm having the exact same issue.

 

[ryker725]

GL-1 gear oil is available at most auto part stores.

Check for proper fluid levels first.. Tranny, T-Case and Diffs... Remove the plug shown, add oil until it over flows and reinstall the plug..

 

[Jimma]

My 68 Kaiser Jeep is doing the same exact thing as well. Hope we get some answers.

 

[Jimma]

Napa near me sells GL-1 in gallons jugs for about 9.50 each. Dont bother with Advanced and some of the others. They want to sell something they claim will work but in quarts for about $7.99 a quart.

 

[TexAndy]

I think it's got to be something related to power transmission (differential, t-case, transmission) because at least in my case, the noise happens when your foot is on the gas (at or above 40 mph) and goes away when you take your foot off the gas.

If it was the wheel bearings, I would think the sound would happen regardless of whether power was being transmitted or not.

 

[merlot566jka]

Tex,
I agree completely. I dont think its wheel bearings, far too noisy and the wrong kind of noise. And as you have wrote, it stops when my foot is off the throttle.

Jimma,
Thanks! I will get a few gallons today and tackle the diffs.

This seems like a common problem. I wonder if M35Tom has seen this? I know he does a lot with the transmissions.

 

[porkysplace]

GL-1 gear oil is available at most auto part stores.

Check for proper fluid levels first.. Tranny, T-Case and Diffs... Remove the plug shown, add oil until it over flows and reinstall the plug..

Don't fill the tranny till it comes out , keep it down about 1 inch from filler hole
or gear oil will come out around the imput shaft as there is no seal . If you over fill the tranny youwill end up with a oiled clutch.There have been several threads on this .

 

[wcolt45]

Mine was doing the same thing and i adjusted the clutch,no more noise!!

 

[porkysplace]

Kind of sounds like the throw out bearing.

 

[FormerNewMVGuy]

Had a friend who had a whine in 4 th - 5th, turns out the trans had very little lube in it.

 

[merlot566jka]

Porky, Yup I read those, I will heed that advice! Thanks

WColt, Can you elaborate? what on the clutch needed to be adjusted?

Porky, Wouldnt that make noise in every gear and only when the clutch is dis-engaged ?
(pedal pushed down)

Former, The seller of this Deuce removed the winch and PTO from this truck, I wonder if some fluid was lost and not replaced?

Thanks folks, Keep the suggestions rolling in!

 

[paulfarber]

Its gear noise. Spur gears are the noisiest type of mesh and proper lube levels will help.

But its simply a wear issue.

The bearings (or bushings if there are any, I don't know) are worn and allow the gears to vibrate, they travel to the case which amplifies them. Noise is created by *something* vibrating. That movement is the additional slack cause be shaft, bearing or bushing wear.

A throwout bearing will whine in all gears, not just 4th/5th.

Its most likely a transmission issue.

Shady tree mechanics will throw in a mystery goo like 'Marvel Mystery oil' to thicken the oil and dampen the vibrations... but at some point you are rebuilding / replacing the transmission

My 66 M35 whines really good in 4th/5th above 40-45 under load... coasting or downhill nothing. So I have a clutch (simply worn out) and transmission rebuild/replace in the somewhat distant future.

 

[merlot566jka]

Ttt

 

[mcmullag]

Mr. Shadetree writes....

Dear Merlot person:
I had a similar issue in a former 1971 deuce I owned. I changed the fluids in all three axles, and the trans and the transfer case and I added a quart of Lucas gear oil in each of the above-mentioned units along with the wallyworld MT-1 gear oil. It done got a lot quieter, yessir.
I did the same thing when I brought home my new-to-me '87 AM General GL-win as seen below and this has caused; a quieter ride, reduced ringing in the ear, fewer skidmarks at laundry time, cessation of consistent post-nasal drip and I no longer limp due to the reduced hip pain.
g-dawg mulligan
working today for a better tomorrow

 

[armadillofz1]

i put a new tranny in mine, still same noise.

 

[mcmullag]

great for;home, office, farm and home....

This was the same '87 truck before adding Lucas gear oil (oh, and re-painting it and putting on new tires), true fact.

 

[merlot566jka]

An update:

I changed the trasn fluid to Royal Purple 85w-90 (i think cant remember off the top of my head about the viscosity)
It made no difference in sound or shift feel. Wasted $98 on fluid. I have used this stuff in my corvette and noticed signifcant difference in shift feel, mileage and noise reduction. Not so in the deuce.

I changed the transfercase fluid to Rotela 15w-40 with 1.5 qts of Lucas oil stabilizer. Took the harshness out of the sound, but the sound is still there, less pronounced, but still there. The sound only happens with a load on the transmission. This could be diffs, and I am going to change that fluid soon.

All of the fluid that came out was still good, no metal in it, not foamy, and still smelled like crap. (vs burnt crap)

 

[hdmax]

I just found this thread, and was thinking the same thing, but thought I'd read though it before posting. But I think you are right.

Kind of sounds like the throw out bearing.

 

[hdmax]

I tend to agree with this, however the deuce is so loud, that it may not be heard until the truck settles into 4th/5th gear.

A throwout bearing will whine in all gears, not just 4th/5th.

Its most likely a transmission issue.