4.10 install nightmare, going with 3.73's, would like your input on...

[marksman14]

This I believe is one of my first posts here, I have spent more time on mustangforums.com and have chronicled the events there, but I would LOVE the input from the local guys since I have to obviously use a shop close by for the installation....

Details about what happened with my 2007 Mustang GT 5spd:

Last year I had a speed shop in xxxxxxxx (not going to post who, but they are a sponsor here which is how I found out about them) install a 4.10 ring and pinion. From the MINUTE I got the car up to 40mph, I could tell something was wrong. I noticed a low pitched hum/vibration coming from the rear end. Now, its not terribly loud, but I notice it. I paid specific attention to the noises coming from my car prior to the install to ensure that I knew about everything going on back there.

The noise is noticable at 40 mph, and then around 60mph. Undetectable under 40, and over 65 or so. I complete the three heat cycles as per their break-in procedure, and the noise is still there. No better or worse, still the same.

I call the shop, and bring it back in. They rotate my driveshaft 180 degrees, and the noise for whatever reason seems to dampen SLIGHTLY, but it is still there. Not as bad at the lower speeds, but near 60 its still there.

They claim there is NOTHING wrong with the car or the install. However...they replaced no bearings, and used standard fluid. I have heard mixed reports on these potentially being problems, but the car went in with 11k miles on the clock. The tech explained his procedure on the pinion bearing, and that was that. Seemed reasonable at the time, but long story short, they would not open it up and take a look, since they claimed they couldn't hear the noise.

Now, I set the car up for winter, and get back in it this weekend. I'm driving it, and just happy to be in the mustang. The noise isn't that bad I'm thinking, so I take it out on the highway and give it some gas. Anyways, I'm ok with it until I get the differential heated up, and then at 60mph, the noise gets louder. Can't detect a change in the noise at 40 with it heated, but at 60 its now more noticable.

So...lets recap/specify certain details-

1- Noise detected after FRPP 4.10 install- speed shop flips driveshaft, has minimal effect
2- Speed shop claims they cannot hear the noise, tells me "sorry, nothing we can do" even after reusing all bearings and using standard gear oil.
3- Noise worsens as differential heats up
4- Noise is low pitch. Almost like a resonating vibration (IE, at certain wavelengths, the vibration is audible)
5- The noise increases in a linear fashion- As speed increases, the audible pitch increases. IE, at 60mph, it is slightly louder and higher pitched than at 40.
6- The noise occurs regardless of engine/trans activity. I can shut the motor off and put the clutch in and as long as the rear wheels are spinning, the noise is present.
7- I'm absolutely pissed and it makes driving the car a pain in my ass.


So, logic tells me that all signs point to the ring and pinion. I understand 4.10 gear sets can occasionally produce noise, but this ain't right. So, I am having the ****er completely redone.

1- Getting a FRPP 3.73 gears- is M4209F373 the right product number? I'm ordering from http://www.latemodelrestoration.com/iwwida.pvx?;item?item_no=M4209F373%20%20%20%20%20%201&comp=LRS are these the RIGHT GEARS? I know FRPP has motive make some of their gears, and I want the GOOD FRPP ones...
2- I am having a different shop do the installation (no ****)
3- I am going to use an install kit, but I'm not sure which one I should use- input?
4- Should I have OEM 75w140 synthetic put in there, or royal purple? Do both still require the use of the additive?

Essentially I would like to know if I have my bases covered for the new gears. I want to make sure that my part numbers are the ones I need, I get the right install kit, and use the right fluid/additive. I want this ****er to be flawless when I am done, and that is that.

Lastly- One of the shops I have contacted said that there is a minor possiblity that the differential itself may have been warped from the heat caused by the ring and pinion...and its possible that there may truly be a problem with the current install beyond "well, sometimes gears make noise". Have any of you heard of this happening, and if so, where the hell can I get a new differential for under 500 bucks?

THANKS FOR YOUR TIME GUYS, I just need some reassurance from you guys that I'm on the right track. I already have about 600 bucks into the ass end of my vehicle and it chapps my ass to know that I have to spend another 6-700, but I really want this car to be the type of quality it should be and not sound like a worn down high milage car that was beat on.

LASTLY AND POSSIBLE THE MOST IMPORTANT- WHO should I have do this installation? DID racing and Deans Performance are both close enough to avoid hassles...recommendations?

Scott

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[Bigturbonotch]

it is not the gear it is the way the gear was installed. You have too much backlash.....most likely.

 

[marksman14]

Is that a common problem, or atleast one that is easily adjusted?

Sorry, admittedly I am completely ignorant when it comes to this stuff.

Thanks
Scott

 

[Bigturbonotch]

the problem is with whoever installed it wrong...they did it wrong.....your probably going to need new gears since the wear pattern probably screwed up the gears you have in there now. take it to someone who knows what they are doing an you will be OK. Speed inc or deans, you cant go wrong with either. Good luck:biggthump

 

[marksman14]

Unfortunately the shop I took it to is "reputable"...and they still left me high and dry by claiming they couldn't hear the noise. Whether or not this is true, I don't know...but theres not much I can do about it now other than never go back there. When I took the car back, the man who did the install looked baffled, and kept claiming it was a "textbook install". He seemed sympathetic to my cause, but said he couldn't hear anything and that was all there was to it...and if I really wanted him to open it back up again, they would charge me to look at it.

So long story short, they hung me out to dry and that was that. They were completely unwilling to help beyond what they did despite me and plenty of other people who rode in the vehicle confirming the noise.

Since the gears probably took a set, I will just go ahead and replace them rather than risk paying money to have them adjusted, only to find out they make more noise now than before...that would be my luck lol.

Thanks again
Scott

 

[SVTLSC]

Either like mike said backlash, basically any shop can do it. It is just shimming the the gear on both sides to make the pinion and ring gear mesh together right, im guessing that the ring gear is too far from the pinion. Or it could be the preload on the pinion bearing was set with an impact gun instead of a torquewrench. You can check to see if is still too tight by getting an old fashioned torquwrench (works best but can use a new style one) one with a beam and needle and find out how much torque should be needed to start turning and to continue turning the pinion. If you need any help shoot me a pm, i have done several rearend rebuilds at the shop i work at.

 

[blownstang]

Take it to Hans at Dean's Performance. He has worked on most of the guys cars on this forum, including mine, and I have never heard one bad review about any of his work. He rebuilt my entire rearend, welded the axle tubes and torque boxes, and installed a few suspension components. Definitley give 4.10's another shot. 3.73's are just not going to cut it in your car. My rearend has a slight whine between 35 and 45. I'm the only one that notices it because I know what i'm listening for. Passengers don't notice it, or they think it's the exhaust. It's definitely not a big deal. Hans even said the right when I picked it up that there is a slight whine in 5th gear around 45mph. I get most of my parts from buyfordracing.com or americanmuscle.com.

 

[SVTLSC]

Take it to Hans at Dean's Performance. He has worked on most of the guys cars on this forum, including mine, and I have never heard one bad review about any of his work. He rebuilt my entire rearend, welded the axle tubes and torque boxes, and installed a few suspension components. Definitley give 4.10's another shot. 3.73's are just not going to cut it in your car. My rearend has a slight whine between 35 and 45. I'm the only one that notices it because I know what i'm listening for. Passengers don't notice it, or they think it's the exhaust. It's definitely not a big deal. Hans even said the right when I picked it up that there is a slight whine in 5th gear around 45mph. I get most of my parts from buyfordracing.com or americanmuscle.com.

that noise is ok, when adjusted for drag racing you want the gears closer which will make them whine

 

[Bigturbonotch]

for racing your going to want a tighter backlash, but only by a thousand or two....well see how my install goes in a few weeks lolol

 

[SVTLSC]

for racing your going to want a tighter backlash, but only by a thousand or two....well see how my install goes in a few weeks lolol

that what i said man

 

[Flyn]

In my experiences, gear noise meant premature gear failure. I have had noise 3 times over the years and each time the gear failed within a year or two. The quiet gears I have had lasted much longer.

 

[Flyn]

It started making noise then failed a year or two later, and the noise was indicative??????

Anything can happen in a year or two, especially in a car that gets driven alot and raced.

My cars have always been road cars with little drag strip time. Maybe one or two times at the track each year. Gears that I had installed that didn't whine always have lasted the life of the car.

Plus, only one of the gears made it 2 years. The other 2 failed in less than one month and less than one year respectively.

 

[marksman14]

Biggest problem is that I've never heard this noise before, and given my limited experience, I cannot tell if its ok or not. I figure its probably just the nature of 4.10's, but it really sounds bad after the thing heats up at 60mph. If it didn't do that, I'd probably just leave it and be done with it...but I can't figure its a good thing.

Since they used standard fluid, would upgrading to royal purple or ford synthetic possibly help quiet them up a bit? If anyone is near the Barrington area I sure wouldn't mind taking them for a ride to help me figure out if this thing is ok.

Thanks again for your help guys, very much appreciated.

 

[blownstang]

Biggest problem is that I've never heard this noise before, and given my limited experience, I cannot tell if its ok or not. I figure its probably just the nature of 4.10's, but it really sounds bad after the thing heats up at 60mph. If it didn't do that, I'd probably just leave it and be done with it...but I can't figure its a good thing.

Since they used standard fluid, would upgrading to royal purple or ford synthetic possibly help quiet them up a bit? If anyone is near the Barrington area I sure wouldn't mind taking them for a ride to help me figure out if this thing is ok.

Thanks again for your help guys, very much appreciated.

Barrington.... hmmm.... that's pretty close to Schaumburg I suppose.

It's definitely not the nature of the gears. Something was messed up during install. I've got Royal Purple in mine. If using the ford gear oil you need to add friction modifier. If its got friction modifier in it, I doubt changing the oil to Royal Purple or a different brand will make a difference. Get a new set of 4.10's and an install kit. Your are most likely worn in already so there is no way to fix them.

 

[IZZy]

4.10's installed correctly dont make noise, sounds like an installation problem, using regular oil shouldnt be the problem either

 

[rdsnake]

deans performance for gear install...

 

[Logan@DeansPerformance]

deans performance for gear install...

+1, i took m,y trans am to a place called KOMET motorsports, started whining after a week and it was fucking TERRIBLE actually one of the reasons i traded the car in for a cobra.

 

[Egreen99]

had mine done at speed inc last year no issues also had them done via a private guy working out of his garage in my old 88GT and had no issues with him either. good luck and I would not go with 3.73s, 4.10s or bust for a modular motor. Had 3.73 in my 99gt and wish I went with a higher gear.

 

[marksman14]

I'm definitey intrigued by some of the geographical deductions that have taken place thus far...

I'm going with 3.73's because I've heard of less noise related issues with them, and to be honest, I'm not taking this thing to the strip. I'd like to also be able to take it on a road trip without driving myself and my girlfriend nuts...so I figure 3.73's are the way to go. Not to mention going FI in the future is becoming more of a legitimate possibility, so the 3.73's might make more sense. Either way, I had 3.31's in there from the factory, so it will still move quicker than it did when I started this ordeal.


I am setup with Dean's Performance on the 28th of this month. He seems to have plenty of wrench hours on S197's and their differentials.

He has all the parts I need on hand, and its going to do it right for me. I've heard of no complaints about the work he has done from anyone especially in regards to gears. I've heard multiple stories of him re-doing other people's gears too because they had issues with other installers, and he has come through every time. After doing some research on the guys who did the original hack job, I've come to find out that alot of people have had problems with not only gear installs, but other jobs they've done too. Wish I would have known earlier. Either way, I'm still going to give them a chance to make it right and reimburse my money. Deans said they would check the original install and see if the problem can be identified, so it will be interesting to see what he finds. He said there is a possiblity he could fix the current issue which would save me the money of the new gears, but to be honest....I don't think its worth the risk. I'd rather spend the money and get new parts in there so that there is NO chance of noise.

Is there anyone out there that has something bad to say about him? Cause I know I sure haven't found anything.

Just out of curiosity, do any of the shops around here offer a no-noise garauntee on gears? I know some do, but I haven't found anyone around here that does.

 

[cobra maniac]

Speed did my 4:10s on my 01 cobra and its def. the way to go. even with a blower which i have as well. I was considering 3:73 but glad i didnt.. They are a excellent shop. My .02

 

[SVT SPEED 04]

We did this gear in Scott's GT and have no problem stating we did so since everytime it has been here there was no noise.

Scott you are being a bit ridiculous here IMO.

-you were hung out to dry?

-hack job?

-many problems with our work?

come on man!

We did not replace bearing because the car was brand new and didn't need them. The FRPP gears come with a minor install kit and most of the time it's all that's used.

The car does not have std. fluid as you stated either..synthetic was used with friction modifier.

The 2 times you noted noise Dan and I drove the car + had a 3rd tech go for a ride & we heard nothing. We rotated the shaft at your request as you noted to see if that would help, but we heard no difference since we heard no noise to begin with. The comment you made to me washey I'm that guy that could hear a cell phone ring over a car on the dyno in the back of the shop...so maybe you have supersonic hearing and hear something we don't ???? that makes us hacks?

you noted you took friends for rides without mentioning any of these issues of noise you hear with the gear and they instantly noticed the noise ..bullshit!

We would have no problem resolving and issue if there was one to be resolved.

This is not the first gear install we have done on an 8.8...keep in mind the same tech that did yours does all our gears as well as his on in his TT 1000+ rwhp Cobra which has 8.8. I had him install a used gear in my 89 Coupe and it makes no noise.

has something changed since the last time you were in? is there more so called noise now? if so we would be glad to look at it.

I'm not afraid to say we have had issues with things here and there over the years. This is expected when modifications are done to cars & if a shop claims they have had no issues it BS. The thing that has got us far and kept us in business for 10 years now is we stand behind our work ( when and if there are issues ).

There are a lot of people here the know me on a personal level and know I would never try to do anyone wrong. I like to work closely with my customers and make sure they are always taken care of and pleased with their visit.

We just have not seen or heard anything wrong with your gear service to see re-installing it and I'm sorry.

I'm done and will not go back and forth on this matter.

 

[FirstWorldProblems]

My old 4.10 made a little noise, the pinion bearing (i think) slid loosely right onto the shaft when it was supposed to require being pressed, even with a new bearing it still did it so I just dealt with a little hum, IDGAF.

Stop bitching, speed inc. didn't mess it up.

If you want a car that makes zero noise don't buy a mustang:biggthump

 

[Bob_Kurgan]

backlash has almost nothing to do with noise in a rear end gear. Gear noise is something that is created by poor patterns.. Thats why you see gear noise on accel and gear noise on decel... If the pattern is not nearly centered on both accel and decel, you will exhibit noise. I set my gears up tight on my race car and set the pattern SUPER DEEP on the accel side since i make close to 1400hp. I dont care if it makes noise on decel though.

Dan has done gears for my street car in the past when i was too lazy to do them. I have never had an issue with his work. I know that speed inc are not hacks and do give a shit about their customers. I know that this has bugged Larry from the beginning because he has talked to me about it. He, along with his techs, dont hear any noise.

 

[03GEETEE]

My rearend was proffesionally straightened, welded, then stuffed with ford 4:10s (used from the last install) rebuilt Ford Tracloc, and Moser 31s but a Ford Tech at Sutton. It fell right in the window of acceptable backlash, preload was good and the pattern near perfect. My car with not having as much insulation and sound deadener makes it easy to hear the rear of the car. On decell @ 50-55MPH my car will whine ever so slightly, does that mean its not installed right....NO. The tech did it by the book and thats what you go by. I would have no problems right now going to any track and side stepping the clutch at 6K from a dead stop....the rear end would be FINE....with or without a slight decel whine.

Speed Inc has done work for me as recent as a month ago and it was flawless. Car was better then when I dropped it off so I know that Dan (tech on my car) knows his shit.
If it aint broke dont fix it, if you arent ready for a little change in the car DONT MODIFY IT.

JTR

 

[IZZy]

Im glad we heard the other side of the story, sounds like they have been as helpful as they can be