05-10-2018, 12:17 AM | #1 |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
Poly diff bushings, vibration?
So, was reading about poly diff bushings and sometimes people hear more noise. I don’t see anything about feeling more vibration. Is there more vibration feel in some cases or just gear noise?
Long story short, swapped out my 3.91 geared factory diff, axles, and driveshaft with a lingenfelter 9.5” rear, matching axles, and driveshaft. Car was smooth before. Now around 75ish on up I feel a slight vibration. If it’s just a poly diff bushing thing I’m fine with it. I don’t mind. I just want to make sure it’s not a bigger issue. Any input from guys who’ve run poly diff bushings before? |
05-10-2018, 04:02 AM | #2 |
Angewendet Ingenieur
Drives: 14 Camaro ZL1 Join Date: Apr 2015
Location: USA
Posts: 401
|
Yes poly bushings can contribute to vibrations.
__________________
————
LQ9, Iron Block, Forged internals, 408CI, Jannetty custom cam, TS short block, Whipple, Hardened Jackshaft, PRC 260, 2X3 Dynatech Full Competition, HF Cats, CAI, NW 103, Chee, ID 1300, COPO Breather, MSD, Fore Dual Pump, ultratorque, E85, dual Meth, True Trac, 3:45, 1500hp axle-shafts, DSS CF, BMR, custom Pearl/Candy paint by Jaidah. |
05-10-2018, 07:51 AM | #3 |
GPI Sales Consultant
|
I did poly bushing in the diff when I did the 4.10's. I didn't pick up any vibrations at all. I do appreciate a little more noise doing tight parking lot speed turns - you can hear the LSD clutches. I also get a little gear noise rolling through 40 to 50 mph under real light loads. But other than that it's silent, and no vibration. I would suspect the driveshaft, not the rear. That 9.5 inch should be fun to hammer on! What gear did you go with?
__________________
GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph.
Got a question about a GPI product? Feel free to shoot me a message! |
05-10-2018, 08:17 AM | #4 |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
Went with the 4.10’s. Im looking forward to being able to play with it now lol. I’m curious if it’s the driveshaft too or not.
Those that have experienced vibration how much was it? Car is pretty smooth down low. At 80 it kinda feels like a massage chair on low lol |
05-10-2018, 11:18 AM | #5 |
Drives: Race Car Join Date: Sep 2009
Location: Seffner, FL
Posts: 6,226
|
No they don't.
the situation is that when you replace a soft Rubber Bushing at your diff with a Harder Material (Poly - it has to be high durameter to last or Delrin), there is less deflection of Noise & Vibration that comes from the Diff. The Bushings do not contribute, they transmit the NVH. |
05-10-2018, 11:42 AM | #6 | |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
Quote:
|
|
05-10-2018, 11:56 AM | #7 |
GPI Sales Consultant
|
You have a vibration from an out of balance component. Assuming it's the same tires and you didn't feel it before, it's probably the drive-train. The most likely component there is the driveshaft. The bushings don't cause it -it shouldn't vibrate. You notice it more because of the bushings, but they aren't at fault.
__________________
GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph.
Got a question about a GPI product? Feel free to shoot me a message! |
05-10-2018, 12:00 PM | #8 |
Drives: 2013 Camaro SS Turbo Join Date: Apr 2014
Location: South Florida
Posts: 1,525
|
No, what bmr is saying is the poly bushing itself does not vibrate but will transmit a vibration that the stock bushing might have absorbed and masked.
__________________
|
05-10-2018, 01:02 PM | #9 |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
|
05-10-2018, 02:12 PM | #10 |
Drives: 2013 Camaro SS Turbo Join Date: Apr 2014
Location: South Florida
Posts: 1,525
|
There should not be any noticeable vibration. Most common would be wheels and tires out of balance. Next step would be get the car on a lift to pinpoint the issue. If the driveshaft is two piece check the carrier bearing, if its a one piece contact a local driveshaft shop for balancing
__________________
|
05-10-2018, 05:12 PM | #11 | |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
Quote:
|
|
05-12-2018, 09:15 PM | #12 |
Drives: 2012 2SS 45TH Anniversary Join Date: Mar 2012
Location: Kentucky
Posts: 720
|
Op, get a good quality loud exhaust, the bushing noise will go away and all you will hear is the sweet sweet sound of unrestictive engine. Like me. 😊
__________________
PFADT stage 3 suspension kit, SW LTH, SW cat less retro exhaust, MGW short throw, 3.91 gears, MRR Z28 wheels, Roto Fab CAI, SLP underpully, 255cc ported heads, TSP 229/236 Cam, ZL1 pump, Street Slayer Twin Carbon clutch, ID850 injectors, Snow Stage III Meth kit
480whp/460wtq tuned by Dynosty |
05-12-2018, 11:25 PM | #13 | |
Drives: 2011 2ss convertible, 68 firebird Join Date: Aug 2016
Location: Athol ma
Posts: 142
|
Quote:
However it feels like I installed a massage chair on low at 80mph+ After talking with DSS I think I’m going to be ordering a one piece aluminum shaft this week and see if that solves my issue. The 6 week wait they quoted though for a custom shaft is going to be painful though. This setup is older so they don’t stock anything for it anymore... |
|
05-13-2018, 01:06 PM | #14 | |
|
Quote:
__________________
MODS 6.0 forged iron block, TH400, B&M shifter, DSS axles & driveshaft, Viking / BMR suspension, Full custom fuel system with cell, Twin 76mm teriyaki tornados on 24lbs.
https://www.instagram.com/whoopa_ss/ |
|
|
|
|
|