Hum after rear-end gear change

While everyone loves to blame the mechanic... obviously the boat-person that built the gearset is an expert, I have found that some gearsets are just plain noisey.... Installation was performed using factory tools in accordance with factory procedures and to factory specs.... and the gears were noisy to some degree or another.... Another R&P, installed exactly the same way, might give no noise at all...

The important thing to remember is that your mechanic MAY be the cause of the noise... or he MAY be a victim of it..... There is no assurance that the gearset was perfectly machined. Without knowing your mechanic nor what he has for tools and/or skills.... there is no assurance that there is nothing amiss with the installation.

The noise itself.... how loud is the hum????? Is it coming from the gears???? (A dealer several miles away is having trouble with an 07 Mustang GT - noise on decel.... three new gearsets and two wheel to wheel assemblies and the noise is still there... ). My SuperCrew developed the dreaded "tip in" gear whine while it was still under warranty.... I never did have the time or shop space to have the concern addressed..... but it doesn't bother me because playing the radio at normal volume makes the noise disappear.... How objectionable is your noise....

Now... before some of you guys try to rip my lips off.... I have no idea of what any of you do for food..... But I dare you to tell me that you have never.,.... EVER said "that's good enough...".

To be honest, I can't recall ever having said "that's good enough", although I might have. I DO know that on many an ocassion I have said, 'screw this (or similar term)! I've had it/I need a break!' Even, 'ta hell with it'. :0)

snipped-for-privacy@m3g2000hsc.googlegroups.com...

Just an update....I picked up the car yesterday from the same mechanic who completely accepted to look into the situation after I contacted him about it.

The noise was loud enough that I could not drown it with the radio (I couldn't have a conversation without having to raise my voice at these speeds).

The mechanic has adjusted a few things and the noise is barely noticeable (you really have to listen for it) and is in my opinion "normal" (so far so good).

Like I said he is a great person and is an avid Mustang fan. He always goes above and beyond and this time around proved that once again.

Thank you for all of your advice. It has helped me understand things a little more and in the end my car is back in my driveway running well.

Regards, Marc

"88 Mustang GT Conv." wrote in news: snipped-for-privacy@c58g2000hsc.googlegroups.com:

I gotta ask - why the noise in the first place? If he test-drove it, he certainly would've heard what you described (the radio wouldn't even drown it out). If he didn't test drive it, then that's another story.

With mine, the more I drove it the louder and worse it got. Since the addition of the posi lube, it's been over a year with zero "noise". Sounds like the mechanic might, no matter how great a guy he is, have forgotten to add the correct lube, or similar.

I'd really have to have asked why he didn't catch it in the first place. And although the sounds like a good outcome, my rear end did not make a barely noticeable, "you gotta listen hard to hear it" noise when they installed the new rear, it made zero, just like the original. It just sounds like he's guessing at the adjustment.

Spike wrote in news: snipped-for-privacy@4ax.com:

@c58g2000hsc.googlegroups.com:

My experience has been that if the posi lube isn't added, things are still fairly "normal" until you make a turn. Then it's more of a chatter than a whine.

I still think the guy might not have adjusted them properly (not enough time?), then when he got it back he had to do it right. Guess we'll never really know...

SNIP

"Chatter" might be one way to describe it. Long ago and far away, there was a toy comprised of a string of squares held together with cloth bands. When you flipped the top one over, like dominos, the rest turned over with a CLACK CLKACK CLACK CLACK CLACK CLACK! Now, that's sorta what it sounded like. You're right, mostly during a turn with the left turn being far worse than the right, and when backing. Not what anyone, especially the owner wants to hear!

Spike wrote in news: snipped-for-privacy@4ax.com:

Yeah, I remember something like that but I'll be damned if I know what it was called. I'm not too far behind you in years...

That's for sure. My Dakota has a limited slip, and if I let it go too long w/o changing the fluid, the friction modifier loses some of its effectiveness and the rear starts chattering on turns like a bunch of chipmunks. First time I heard that I freaked, thinking the rear was exploding. A quick trip to the dealer and a fresh fluid change with new friction modifier made it as good as new.

It IS normal. Don?t listen to anyone that?s says different and to find a new mechanic. If you go to a beefier set up or different gear s, like racing gears, it will whine much louder. Try auto cross or drag ra cing with a differential and gears set up for that. It?s as loud as can be depending on the gear ratio. Especially in a coupe that doesn? ?t have very good sound dampening.