05slpGT

So... i have had motive 4.10s in my car for a while now, they had a little bit of whine and it never really bothered me that bad. This weekend i had my BMR upper and lower control arms installed! i was very happy. I was driving around for a few miles and then i got to a stop light and decided to try them out and see how well they work. Well they work so well(or something went completely wrong) that when i launched on my crappy nittos my car shot forward and then i heard a big popping noise from the rear end. i was litterally 200 feet from my house so i drove home and didnt worry about it. When i later left to go pick up the GF, i was on the highway and i noticed the gears were whining intensly and some weird nasty noise from the rear end, i was realllllllly worried. After i picked her up she also noticed it was really loud. So next morning i took it to my friends shop and watched as he ripped apart the rear end. When it came to lower pinion bearing, it was crushed and right when he touched it the bearing fell apart and all the little things in it fell out. He also checked the ****ty 2 piece driveshaft that ford decided would be GREAT for the new mustang.... and the bushing was pushed out of place, we fixed all of these things. So it seems like i got so much traction that my driveshaft slammed into the pinion bearing destroying the bearing and messing up the driveshaft bushing (or whatever the hell it is). So i watched him sham the gears and reinstall and we test drove it. The gears now whine very loud when accelerating and letting off the gas, but not when crusing, also very bad when turning. The noises that sounded very bad and nasty are no longer there but now we dont know what to do bc it is still loud as hell. (Note that the guy who did this drove me around in his stang that has motives and it was very quiet compared to my car. So i really dont know what to do. I did buy the car used ayear agoand im thinking about taking it to ford saying something is wrong and if they mention the gears arent ford then im going to tell them they came with the car. Not sure if itll work though. Anyone have any ideas. I really want to switch to some ford racing or richmond gears but i dont wanna spend the money when i already bought these gears like 4 months ago. Anyone heard of this!?!?!? what do i do!!!!!

Argonaut

Wow, that really blows. You have my condolences.

Question - are the UCA and LCAs you had installed adjustable items? Are you sure their length is the same as stock? Do you have relocation brackets? The reason I'm asking is because of pinion angle. In other words if the install caused the pinion angle to be way off then that could potentially be the cause of your problem. Not sure...just trying to think thru it.

I don't think you should assume the gear whine is only because the gears are made by Motive. As you probably know, Motive makes most of the FRPP gears (although I don't know if they are exactly the same). I have heard this gear whine story again and again. It is all too common for 4.10 gears. It seems that every rear end tends to have its own personality and the exact same settings on one car will cause whine on another. I would wager (a small amount) you could get the Motives to stop whining with further adjustments. In my case (FRPP 4.10s) it took my installer 4 times (pulling the diff apart) to get them to stop.

Good luck.

05slpGT

Non adjustable, should be the same length, car isnt lowered. i guess i can keep trying to get them adjusted but i dont see it stopping... ill try to decide what to do. i really wanna just take it to ford and bs them and try to get them to warranty (with my plan above) and try pay them the difference to put in some FRPP 3.73 or 3.90

marcuskeeler

Your problem is weird, it's almost like you jumped a tooth on the pinion, which is almost impossible to do unless a bearing collapses.

I know a lot of you guys swear by low ratio rear end gears, but honestly they frighten the bejesus out of me. I've had noisy gears before in other cars and from trying to get them fixed i know how hard it is to get a good installer who does a good job time and time again. I've even heard about so called 'good guys' who install them using nothing more than a torque wrench. No preload checks, nothing [:@]

From all the problems lamented over on this site, I reckon gear related woes are the most common.

It doesn't help you right now, but simply put, gears are just about the last things Irecommend anyone touch, especially on a DD. Despite what others might say, they just aren't good for DD's anyway, quite the opposite - bad gas mileage, increased rpm at cruise speed, snappy 1st gear.
A track car, Yes.

NyFordTech

Thats why the FRPP gears are more money no whine... my .02 cents

05slpGT

yea i either wanna go back to stock or if at all possible go to FRPP. i just dont have the money right now :-/ unless u wanna donate

Simon1

If I were you I would bite the bullet and by a completely new diff and gears and have a reputable shop take care of it.

I wouldn't be surprised if the diff in there now is so damaged it will ever sound correct or work properly. First week in March I'm gettingnew locker and gears installed by a shop that said they will do it right the first time and if something isn't right, they will fix it until it's correct.

Good Luck

Bluestar

If this car came with 3.73's from the Factory, there would be a lot less guys doing gear changes.

blk07gt

not exactly sure what to tell you here rob but
i would go for the ford bs attempt since we arent inthe wealthiest situation here
then if that doesnt work i would say get the frpp 3.73s just cuz i wouldnt go as far as 4.10s onyour DD
just what i would do, or if i were YOU id place some $$$ down on the fights since you know youre stuff lol

05slpGT

1. yeah i think i might try to BS ford... mickey doesnt think itll work but i think its worth a shot, im good at this kinda stuff
2. man, i missed the last 2 payperview fights... i dont even know about this next one, henderson and silva are both beasts, but silva seems to be in his prime right now... and hes from brazil that gives him an 80% chance to win the fight lol.