Noise, vibration at high speed after gear install.

[96snake1]

Installed 4.30s now have vibration and buzzing at about 75mph....kept the stock driveshaft. Would an aluminum driveshaft take care of it?

 

[cobralvr01]

Did you make sure the backlash is correct? I'm pretty sure what you're experiencing is coming from the diff. so an aluminum driveshaft would just make the buzzing louder as it transfers sound better than steel. If a shop did it, take it back as soon as possible and make them redo it. If you did it, you need to go through it again and make sure everything is within spec. I had the same issue after putting in 4.10's. The backlash drifted off from spec.

 

[96snake1]

Forgot to mention it only happens in 5th gear and starts at about 2600 rpm and it goes away if i depress the clutch or if I take it out of gear. Ive taken it to over 80 in 4th and no noise or vibration. Im gona double check backlash and preload. I got under the car with trans in neutral and e-brake on and gave the drive shaft a turn. Has a little less than half inch of movement, and from what i heard that should be within specs. I think my throwout bearing might be going out but i dont l know if that would cause vibration.

 

[Alegend123]

I know it sounds insane but I had a similar issue and was going to tear the rear end apart but had to get a clutch done first because of a bad throw out bearing... believe it or not now that clutch is done I don't have what I thought to be a rear end problem... mine would "whine" on and off the gas only in 5th but went quiet when clutch peddle depressed now with new clutch the whine is gone

 

[96snake1]

I know it sounds insane but I had a similar issue and was going to tear the rear end apart but had to get a clutch done first because of a bad throw out bearing... believe it or not now that clutch is done I don't have what I thought to be a rear end problem... mine would "whine" on and off the gas only in 5th but went quiet when clutch peddle depressed now with new clutch the whine is gone

That seems pretty damn identical to my issue. Did you feel vibration through the shifter as well?...im thinking that issue might have been there before the gears, but now that the rotation speed changed throughtout the rpm range i can feel it at cruising speeds. I have to replace the throwout anyway so will inspect everything else

 

[96snake1]

Did you make sure the backlash is correct? I'm pretty sure what you're experiencing is coming from the diff. so an aluminum driveshaft would just make the buzzing louder as it transfers sound better than steel. If a shop did it, take it back as soon as possible and make them redo it. If you did it, you need to go through it again and make sure everything is within spec. I had the same issue after putting in 4.10's. The backlash drifted off from spec.

Forgot to mention it only happens in 5th gear and starts at about 2600 rpm and it goes away if i depress the clutch or if I take it out of gear. Ive taken it to over 80 in 4th and no noise or vibration. Im gona double check backlash and preload. I got under the car with trans in neutral and e-brake on and gave the drive shaft a turn. Has a little less than half inch of movement, and from what i heard that should be within specs. I think my throwout bearing might be going out but i dont l know if that would cause vibration

 

[Alegend123]

Yeah I could feel a light "thumping" feeling in the shifter... it also had a "knocking" sound when idleing in neutral if you put yourhead near the shifter like it was banging around

 

[Alegend123]

My throw out bearing was trashed when removed all is well now... if you can afford it I highly recommend a light weight flywheel I did a fidanza flywheel andclutch kit the flywheel made a huge difference in acceleration in my opinion it revs super fast now

 

[96snake1]

Yeah I could feel a light "thumping" feeling in the shifter... it also had a "knocking" sound when idleing in neutral if you put yourhead near the shifter like it was banging around

Yup, sounds similar if not identical to mine. I would think gears or driveshaft issues would vibrate in all gears, not just 5th...hopefully when i replace my clutch it takes care of it.

 

[96snake1]

My throw out bearing was trashed when removed all is well now... if you can afford it I highly recommend a light weight flywheel I did a fidanza flywheel andclutch kit the flywheel made a huge difference in acceleration in my opinion it revs super fast now

How did the pilot bearing look?? Did you replace it? ...thanks ill take a look at that, cant spend alot of money on it right now though. Glad its not my daily so i can save up to get it done right.

 

[Alegend123]

I bought the fidanza kit... it comes with the aluminum rebuildable lightweight flywheel,pilot bearing,puck style clutch disc, pressure plate and throw out bearing all for $600... I just had mine installed 50 miles ago so I'm not sure about longevity just yet but like you it's not my daily driver either... I've got a lightning,ole lady's Toyota, and company truck as well

 

[96snake1]

I bought the fidanza kit... it comes with the aluminum rebuildable lightweight flywheel,pilot bearing,puck style clutch disc, pressure plate and throw out bearing all for $600... I just had mine installed 50 miles ago so I'm not sure about longevity just yet but like you it's not my daily driver either... I've got a lightning,ole lady's Toyota, and company truck as well

Thats not a bad price at all for all that....i drive a 4runner as my daily as well, cant go wrong with a Yota daily. Just sold my 72 Fastback...what year lightning? I want to get my hands on one of those if not a Termi.

 

[Alegend123]

The lightning is a 2002 she needs some work on interior and body but the motor pulls like a raped ape.. I pulled on a termi the other day he didn't want none lol.. I'd love to have a termi but their like $20k.... the supercharged 5.4 lightning will do just fine.. I got it in trade so I'm happy as hell with it

 

[96snake1]

Update!! After opening up my diff and re-checking backlash and pattern everything was good in the diff. Pinion angle also passed.... transmission inspected and passed....noticed my driveshaft had a slight wobble visible only at low speed (15mph) but didnt cause a vibe at that speed. Decided to pull the trigger on a JEGS performance HD aluminum driveshaft and voila! Vibration gone...havent gone over 100 yet but it doesnt vibe at all.

 

[96GT226410]

Glad you got it figured out and thanks for posting your findings.