Qblue92

I installed a 3.70 rear in my 60 about a year ago. Almost instantly it made gear whine on acceleration or steady pedal. I swapped it out for a good rear end today and realized that I may have used oil stabilizer with the 3.70 instead of gear oil. Would the wrong lubricant cause a lot of gear whine in the rear end?

vettsplit 63

wmf62

i'm gonna guess a 'positive maybe'. hypoid oils are specially formulated for gear service and I don't believe the lucas is anything more than a fancy STP.

hindsight being 20/20, putting the proper lube in before changing out the rear end would have told the tale..

wear patterns on the teeth of the removed rear end may give some insight

Bill

65tripleblack

That's too bad. Gear whine can be caused by wrong lube because there would not be enough fluid pressure to ensure that the ring/pinion are not contacting each other. The most common cause of gear whine is misalignment between ring/pinion. Take a look at this, and hopefully the gears can be sandblasted and re-used if they are not too badly blued/burned:

https://khkgears.net/new/gear_knowle...ear_noise.html

R66

Then again, I have put more than one aftermarket gear in and ended up with a whine even though it was set up with a pinion depth gauge, dial indicator, and blue checked. Using the correct gear lube and posi-additive. I have had better luck with used GM gears than aftermarket gears.
The Lucas Oil stabilizer appears to be physically identical to the STP of years gone by. I would guess it at 60 to 80 wt. rather than 30. It bearily flows out of the bottle until you heat it up.

wmf62

I can't say that I believe it....

https://lucasoil.com/faq

Q: Can I use Lucas Oil Stabilizer in anything else in my vehicle besides my engine?
A; Yes, In addition to being great for your engine, you can also mix it 25% / 75% in a manual transmission and 50% / 50% in the differential. Lucas Oil Stabilizer blends with any petroleum-based or synthetic oil, and is formulated for gasoline or diesel engines.

Bill

Qblue92

I didn't realize that that stabilizer junk might have been in my rear end until I was looking for more gear oil to put in my freshly installed 4.11 rear. The oil that I took out look pretty thin.
I never bought that stabilizer on purpose. I think I thought I was buying two bottles of 80 - 90 weight and grab the wrong thing maybe.
I wish I had noticed that bottle on the Shelf before I swap the rears. I would have tried just changing out the gear oil and hoping for the best.

Frankie the Fink

Thinner oil prob causes more noise to be transmitted; heavier lube may well dampen sounds....
Put the right stuff in it - a few bucks and 1/2 hours work and drive it a few hundred miles before panicking...
Everything could well be just fine.

Sometimes the bonehead gets away with something....

65GGvert

Sounds like he already swapped it out for a new one.

Frankie the Fink

Yes - I reread it.....the thinner oil could have made the original whine or the ring/pinion were not set up correctly....

rtruman

Qblue92

It was probably diluted with gear oil at least. But it was noisy. I'm gonna try n investigate the wear pattern on it.

449er

I'm surprised that the rear gear set survived for any length of time at all with the lubricant that you put in there

MikeM

MY opinion only. If the gear whine started immediately, the Lucas didn't cause your problem. The noise is caused by tooth misalignment.

Dan Hampton

Be glad it is a C1 and not a diff on a C2. You can swap, if need be, that rear end in about an hour. Not so with a C2. Good luck.

Qblue92

hour?? I'll pay your rate for that job.