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All Black Everything!
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Discussion Starter #1
Ok so I have a lifted 2007 NNBS which I swapped out the gears to 4.88s. Did the break in for 2 weeks was just driving normal with the speedometer off by like 15-20mph, topping out at around 70-75ish. So I just went to San Antonio driving almost hitting top speed on the speedo but really going slower, I went to get a Blackbear tune, all went well the speedo was fixed and everything but once we were done and on my way back to Houston I notice that once I hit 70mph my truck starts vibrating really bad, i give it a little gas and it gets even worse so i had to drive back under 70mph which rode normal as long as stayed at 65mph, anyone know what might be the problem??
 

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have your tires rebalanced and alignment checked. if those dont work then start checking elsewhere.
 

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All Black Everything!
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Discussion Starter #5
well I just got an alignment like a month ago so that shouldn't be it, I should check the tires but I doubt that is it, The noise from the vibration is coiming from down the middle of my truck. I got the gears installed at Pyle Bros Performance Differentials in Baytown Should I take it back to them?
 

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i would do that.
 

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All Black Everything!
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Discussion Starter #8
Well i guess ill take it to them asap, Hopefully they can solve the problem
 

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All Black Everything!
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116 Posts
Discussion Starter #9
Well i Just came back from taking it to Pyle Bros Performance Differentials and they said It was from the 4.88 gears I put on my 35's spinning the driveshaft too much? They said once I put the 37's which will go on soon it should fix it. Does that make sense?
 

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I don't have a truck
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Well i Just came back from taking it to Pyle Bros Performance Differentials and they said It was from the 4.88 gears I put on my 35's spinning the driveshaft too much? They said once I put the 37's which will go on soon it should fix it. Does that make sense?
No.
 

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All Black Everything!
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116 Posts
Discussion Starter #11
Yea that didnt make any sense to me either, he took it for a test drive too and said if it was the pinion angle it would be vibrating most of the time but it only does it when it starts hitting 70mph, I guess ill have to take check out a shop that works with driveshafts now
 

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In memoriam...
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maybe the driveshaft wasn't indexed when it was reinstalled, and is now 180* out of phase.

Always put marks on the shaft and pinion flange to ensure they are reinstalled exactly as they were removed. Otherwise, an imbalance can occur.
 

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maybe the driveshaft wasn't indexed when it was reinstalled, and is now 180* out of phase.

Always put marks on the shaft and pinion flange to ensure they are reinstalled exactly as they were removed. Otherwise, an imbalance can occur.

That there is a very smart man :shake:
 

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Bad Luck is all i got.
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Id move the back tires to the front and see if there is a change. If not then flip the driveshaft 180*. Best of luck
 

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Rotate your tires and see if the vibration goes away or develops at a different speed. If either happen, you know at least one tire is out of balance.
 

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All Black Everything!
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Discussion Starter #16
Well after checking the driveshaft turns out I had a dent on it, dont know how it got there but it never gave me any issues with the old gears, I took it to a shop and rebuilt me a new one for $500 with new U-joints. Hoping this would finally fix the problem which it kinda did from when i first drove it off from the shop on friday. so saturday i decided to take a road trip since i thought it was fixed. Well as soon as i hit the highway i start getting the vibration again but it was reduced by like 40%, so i jus slow down to like 65mph and said fuck it ill jus drive it like this all the way, well as soon as i hit the first town heading west on i10 from houston, a friend following me says im leaking something...looked under the truck and everything was covered in some kind of fluid. I drove it to the closest gas station and as soon as i pulled up my trans temp was reading 210 degrees and i started seeing smoke comin from my hood. looked under the truck again and saw the problem. dont know much but i guess where the d-shaft connects with the yoke? to the transmission or t-case there a seal that came off and leaked out all the transmission oil and noticed I can move my d-shaft up and down like it has a little play to it i dont think thats normal. drove it to park it at a safe spot to take a look at it better my gears started slipping bad and couldnt drive it....had to call a wrecker and take it back to Houston, what a trip huh? Any1 know how the hell this happened? I know ima have to go back to the shop to bitch at them but wanted to see if anybody knew anything about this...sorry for the long post
 

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All Black Everything!
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Discussion Starter #17
Oh and does the transmission usually start slipping on gears when it loses most of the fluid or did I just fuck up my transmission?
 

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I am just guessing but the transmission works off of fluid pressure and if you are low on fluid it will not get the correct pressure and not operate right.
 

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All Black Everything!
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Discussion Starter #19
yea that makes sense and hopefully I didnt fuck anything else up i had to run the transmission at 226* just to get to the gas station
 

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yea that makes sense and hopefully I didnt fuck anything else up i had to run the transmission at 226* just to get to the gas station
Damn..hope you get it back right soon.
 
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