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so after some debating on whether or not to change my final drive i decided to change them to 4.10's. i bought the frpp 4.10's, motive bearing and install kit, and carbon t-lok rebuild kit from americanmuscle.com. I had my local shop install the gears because they had the proper tools from ford to get the spacing set right the first time (this is the same shop that did my cams). the install went smooth until we went to test drive the car. you could clearly hear that one of the bearing that were supplied in the kit trashed it self right away. i called americanmuscle and they directed me to motive who promptly directed me back to americanmuscle as motive is a wholesaler and did not want to discuss the issue with me. because amaericanmuscle said in there notes motive wanted customers to be directed to them for warranty issues they said they could only help me cover the cost of the parts and not any of the labor. for the shop to get the parts locally it costed 200 dollars with the synthetic lube, friction modifier, pinion seal, inner and outer pinion bearing, and inner and outer bearing races. the carrier bearings were fine. american muscle initially wanted to only refund me 80 dollars after sending them the invoice which was kinda a kick in the pants and i was eventually able to bring them up to 100. so after this is all said and done.

145 gears
75 motive rear end install kit and bearings
108 ford racing carbon t-lok rebuild
400 original install cost
200 replacement parts cost
400 second install cost
-100 from am refund

for a grand total of: 1,228 dollars

the car now has no rear end noise.

besides my frustrations with motive and americansmuscles policies the gears feel good. by no means does it feel like it was to high of a gear i 100% agree with people that say dont fear the gear. my cruising rpms did not go up much and with the cams it makes dead stop starts much easier and she gets out of the hole nicely. now i just need my bmr suspension stuff to get it to hook and a short throw to bang through those gears.
 

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Yikes sounds like a nightmare. I had a similar issue but mine shouldn't have happened, still kick my self for not having the right tools for the job the first time.

I did the gear install my self (with a helping hand to lif the rear) didn't have the proper tools didn't have a beam style inch lbs torque wrench to test the drag on the bearing. Apperently over torqued it 200 miles in, the outter pinion bearing ate it's self.

Ordered a torque wrench bought a new bearing and seal and fluid. Got it down to a 2 hour job now lol.

I feel that the 4.10s are not enough for my set up currently. My car beggs you to gun it in 1st or it wants to stall... Could also be the race tune from AM I use as a DD.

Now to fix my current issue and then get a SC kit. :)
 

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@05Nlstang - This sounds like a pretty unpleasant experience and I'm going to have someone reach out to Motive to see what the deal is. That would run me up the wall calling back and forth. Please shoot me a PM with your order number so I can take a look into this further.

Thanks in advance,

Alex
 

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For future reference, I only use Timken bearings.
 

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I feel your pain on the rear end nightmare. Feels like yesterday i broke my stock rear. I ended up buying a complete built unit for 1100 dollars. Swapped out my stockers, had the most insane gear noise. I think it was a shot bearing, shop claimed it was the lightened and polished 4.56 gears. Swapped those for 4.10s 800 dollars in parts and labor. Alls good till a few months later when the truetrac failed. Shop that built the rear originally put royal purple purple fluid in which is a big no-no for the truetrac. I bought a used rear out of a race car so basically was told to get ****ed. 950 dollars later for new differential and labor. 2 months later the axle seals fail. 350 dollars in parts and labor. Now a year after that, had to do the axle seals again but i did them myself. So now ive invested probably over 3k into a rear worth about 1600 dollars lol i should have just built the stock unit but live and learn i guess.
 

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I feel your pain on the rear end nightmare. Feels like yesterday i broke my stock rear. I ended up buying a complete built unit for 1100 dollars. Swapped out my stockers, had the most insane gear noise. I think it was a shot bearing, shop claimed it was the lightened and polished 4.56 gears. Swapped those for 4.10s 800 dollars in parts and labor. Alls good till a few months later when the truetrac failed. Shop that built the rear originally put royal purple purple fluid in which is a big no-no for the truetrac. I bought a used rear out of a race car so basically was told to get ****ed. 950 dollars later for new differential and labor. 2 months later the axle seals fail. 350 dollars in parts and labor. Now a year after that, had to do the axle seals again but i did them myself. So now ive invested probably over 3k into a rear worth about 1600 dollars lol i should have just built the stock unit but live and learn i guess.


That is why you need to pay with a credit card, so when they tell you your ****ed, you put a stop payment on the CC and lets see who is right. Meanwhile your money is in your pocket.
 

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Discussion Starter #13
For future reference, I only use Timken bearings.
thanks for the info. i will remember this for next time boss!

bigchriss197 i thought i had a rough time but i guess my stuff could break in a couple hundred miles and i will be following in your foot steps haha
 
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