Gears Making Noise, Only 180 Miles after install!

[Al Guapo]

I have a 2011 GT, manual.


So exactly 1 week ago today I had a local "mustang specialist" install a KB blower and gears.

Last night I was just cruising on the highway at 55MPH and all of the sudden
the rear starts making a howling noise. It gets louder when I lift off of the throttle and most of the noise goes away when I hold a steady speed or put the car in neutral. I smell burnt rear end oil. There's a little oil splashed on the part exhaust that runs by the pumpkin.

I have stock O.E.M. tires.

For the moment I'm refraining from naming the shop in hopes that they'll right their wrong.

I purchased all of the rear end parts from them. Parts, labor and tax cost me about $800.

I haven't called the shop yet because this happened last night and they're still not open this morning.

So my questions to you guys are...

1) Should the shop do all the repairs with no money out of my pocket?

2) How would you go about dealing with this?

Thanks for reading.

 

[nbk13nw]

I had mine gutted and rebuilt along with some other work at a shop. Within a week a squealing started but only when it was cold. I took it back several times and it would not act up when they had it. Fast forward to 6 months later and the howling started. Took it back to them again. Gears were trashed. They replace the gears and also found the pinion seal was bad. No charge. So yeah. No gears should make any noise if done properly. So they should make it right.

Sent from my SM-G925V using Tapatalk

 

[mrt2you]

when you installed the gears.
did you have them install a crush sleeve or a solid spacer?

 

[Al Guapo]

I had mine gutted and rebuilt along with some other work at a shop. Within a week a squealing started but only when it was cold. I took it back several times and it would not act up when they had it. Fast forward to 6 months later and the howling started. Took it back to them again. Gears were trashed. They replace the gears and also found the pinion seal was bad. No charge. So yeah. No gears should make any noise if done properly. So they should make it right.

Sent from my SM-G925V using Tapatalk

Glad it worked out for you. Thanks for sharing.

when you installed the gears.
did you have them install a crush sleeve or a solid spacer?

No because I don't know about those things. I'm not a mechanic so I told them to do what they think needs to be done. I left it to the "professionals" to handle it. I even bought the parts from them so that the finger pointing wouldn't begin. I've been there before. Thanks.

 

[Marble]

$800 is on the high side. IMO

You should be able to drop it off and tell them to fix it with no cost.

 

[BruceH]

I've had a crush sleeve decide to crush a little more after going to the track. The result was a whole lot of gear noise on the way home. A solid spacer is the way to go.

Did you put any high loads on the setup and did you try to put a few heat cycles on the gears prior to putting a big load on them? Are you sure it's a gear noise and not a bearing?

I ask because aftermarket gears aren't lapped as finely as factory gears. This is why FRPP gear sets cost about 1/3 the cost of factory gears purchased from a dealer. Aftermarket gears will lap themselves in (self machine) during break in. While they are going through this process you will notice a whole lot of heat on the rear end cover for the first few heat cycles. It takes about three complete heat and cool sessions, at least that's what I've noticed anytime I've had gears changed out.

Noisy gears suck imo. The only options are to change them out or go with a louder exhaust.

 

[skaarlaj]

I noticed when doing my gear install a while back, that after fitting the bearing over the pinion just using heat on the bearing, that after it was cool there was still a very small gap between the shim, and bearing shoulder, and had to press it on just a bit further. I wonder if people that use the "heat method" sometimes don't check to see if the bearing is still tight against the shim after it has cooled back down. Either way, I hope your gears are OK and can be fixed easily.

 

[Al Guapo]

I've had a crush sleeve decide to crush a little more after going to the track. The result was a whole lot of gear noise on the way home. A solid spacer is the way to go.

Did you put any high loads on the setup and did you try to put a few heat cycles on the gears prior to putting a big load on them? Are you sure it's a gear noise and not a bearing?

I ask because aftermarket gears aren't lapped as finely as factory gears. This is why FRPP gear sets cost about 1/3 the cost of factory gears purchased from a dealer. Aftermarket gears will lap themselves in (self machine) during break in. While they are going through this process you will notice a whole lot of heat on the rear end cover for the first few heat cycles. It takes about three complete heat and cool sessions, at least that's what I've noticed anytime I've had gears changed out.

Noisy gears suck imo. The only options are to change them out or go with a louder exhaust.

My friend said that it may have been a crush sleeve too but we won't know until they open it up.

High loads? Maybe. Here's what happened... The blower and gears were installed at the same time. Car was dyno tuned and they made about 20 pulls because the KB tune was not satisfactory. Power was falling off after 6k. So after doing some email tag with KB for revised tunes the tuner decided to tune it himself and we finally came to a 550RWHP on a mustang dyno with an average A/F ratio of 11.4. So I don't know if this answers your question but my assumption is that after installation the gears went straight to the dyno . We also put a tire on the car for the dyno pulls.

I noticed when doing my gear install a while back, that after fitting the bearing over the pinion just using heat on the bearing, that after it was cool there was still a very small gap between the shim, and bearing shoulder, and had to press it on just a bit further. I wonder if people that use the "heat method" sometimes don't check to see if the bearing is still tight against the shim after it has cooled back down. Either way, I hope your gears are OK and can be fixed easily.

I don't know but yes, I also hope that the gears are ok. Regardless they're standing behind their work which means a lot. As of now they haven't lost my business because people make mistakes. Only hassle is taking the train 65 miles to go pick it up. Thanks.

 

[skaarlaj]

When you get that car back on the road, let us know how you're liking that blower!!

 

[Al Guapo]

When you get that car back on the road, let us know how you're liking that blower!!

Haha, I can tell you right now... it was the funest 180 miles I've ever driven.

It MPH hard with the 3.31s and because it's so quiet (stock exhaust) that it's deceptive. I'm sure in time that I'll catch a lot of cars off guard.