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Discussion Starter #1
I just installed a set of 4.10 gears in my car everything is great except when im hauling it as soon as I hit overdrive now it has a vibration a really quick one and keeps going through over drive.I can feel it through the shifter.
Is it maybe the drive shaft wasnt installed in the same location,I know the yellow dots on the rear yoke are lined up but how do you line up the transmission yoke.
 

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The transmission yoke lines up only one way. the trouble you will have with the 410s is madd vibration at high speed. this is due to a few things. one is tire size. you need to step up your tire size if you havnt allready also you need to have them speed balanced at a race shop for high speed. 2nd, are you using the stock driveshaft? if you have aluminum you need to go have it checked for balance also and have it high speed balanced. 3rd, did you do the install on the gears or a shop? and how long after the install did you notice this vibration? the pinion nut could have backed off a little bit and is causing slack in the drivetrain and letting it vibrate. all these things i have done and it removed the vibration from mine. i got the vibration at around 150mph on mine. i hope this helps you some


Jerry
 

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Team Bullitt, if your install was done correctly and you are using an aluminum driveshaft with the yellow dots lined up then you should have no problem. No matter how few miles your car has always replace the pinion bearing and while your at it replace the carrier bearing. You have a 50/50 shot of having a problem 6, 12, 18 months down the road if you reuse the pinion bearing. A complete gear install kit with bearings goes for $65 bucks. If you are going to drop 4 bills to have gears changed then what is another $65 bucks to do it right. How did the installer adjust the backlash? By feel or by dial indicator? Some think they are smart enough to do it by feel. There are 4 important measurements...1) Pinion Depth, 2) Pinion Bearing Preload, 3. Backlash and 4) Carrier Bearing Preload...in this order. Screw it up and you have the problem you described. After setting the backlash how many times did the installer check the pattern with gear marking compound? If they did not check it at least 3 - 4 times no matter how many times they have done it before they are doing you no favors.

John
 

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Discussion Starter #4
I work at a ford dealer and me and a friend of mine who has been rebuilding rear ends for a very long time did it.
We did check with marking compound and it looked ok.
We put a measerment deal on there to find the right shim for the pinion bearing.
He checked backlash by hand and said it felt good.
I put a new bearing on the pinion but not the one on the small end.
I still have the stock driveshaft.
Should I go with the aluminum one?And where could I get one?Who makes it and maybe even a part # would help.

Anyway thanks for both you guys help it is much appriciated.

Chris
 

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Chris, not good..."checked backlash by hand". That's like flipping a coin and calling heads or tails. Chances are you are going to have problems down the road if you don't go back in. I would go for an aluminum drive shaft given some vibration at high speed is the nature of 4.10s. You can get it from www.fordspeed.com for $159. Did you add friction modifer?

John
 

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Did you remove the 'paperweight' from the rear differential.This was to reduce the NVH with the factory gears installed,and in most cases will cause a vibration with a gear change.hope this helps!
 

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Discussion Starter #7
Where exactly is this paperweight and what does it look like.
My car does fine at the track and all the way to red line in fourth without one bit of vibe until over drive hits and i put a load on the motor.
 

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two bolts hold it on from underneath, don't forget to take the bracket off from the top side.

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Mid Life Crisis #388



<font size=-1>[ This Message was edited by: Mid Life Crisis #388 on 2001-12-08 08:53 ]</font>
 

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Discussion Starter #9
Thanks ill try it and let you know what happens
 
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