rear end vibration after braking rear right axel

[Rock-It Man]

Originally Posted by sixty9fordkiller

do dss driveshafts even have guibos?

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Originally Posted by LHRxDeadx

well looked under the car to find almost all the bolts loose on the driveshaft. i just used the dss bolts that came pre locktied but i guess it wasnt enough. got new bolts and used the red locktie and vibration got significantly less but still a there over 80mph not as bad tho.

I looked at DSS site; they have several drive shafts.

But if OP has been driving around with loose bolts, there may be damage that needs to be addressed. Or it may be that driveshaft is poorly made, unbalanced, and the resulting vibration is what caused bolts to back out.

Either way, I would be talking to DSS at this point.

[LHRxDeadx]

vibration was prior to dss driveshaft i bought it thinking my stock one was giving out or a bushing was worn. being that my car is 720 whp i know i was pushing that driveshaft.

ive looked at everything under the car and everything seems fine and just today the vibration came back under hard acceleration and like it has been before once i hit 80mph it begins to vibrate

[jonathanmoguel]

nvh is caused by a rotating vibrating force. it flows like this engine , trans , propshaft, diff pinion gear, axles, hubs, wheels, and tires. also check engine mounts , trans mounts.

im having the same issue . i replaced the slave cylinder and when i put everything back togehter it would vibrate at 4000-5000 rpm after going 40 mph.

but i felt it coming towards the front dash or by the transmission. it was hard to pinpoint since the exhaust is loud.

also check you exhaust. vibration is transmitted through the exhaust as well. or heat shields.

i found a toe rod in the left rear to be loose so i tightened it and it significantly reduced the vibration. there is still some but it dosent happen when i apply a load/ acceleration like before. will check drive shaft too . i do remember that it got split in two since its a two piece shaft. i might have placed it one tooth off . but i will see soon when i look under again. the car is in the body shop so it will be several weeks.

[LHRxDeadx]

well got my tires road force balanced new break pads and resurface the rotors they said they where a bit warped on of the rear ones and i was hoping that was my issue but nope!
what the hell is it????

i will list everything ive put new since the vibration started when one axel snapped
Slave cilinder
clutch
driveline
rebuilt dss axels
new brake pads all around
resurfaced rototrs
road forced balanced tires twise now

everything is tight under there ive chacked every bolt and nut there is and marked them and still cant find the damn issue. I ve taken the car up to 155 hoping something just brakes finally lol

either way ive got ls fest in two days i havent slept for 3 days now getting the car ready and im giving up...

[Rock-It Man]

As already suggested, if the problem starts with hard acceleration, maybe the engine and transmission mounts are just overpowered by your high output engine.

[sixty9fordkiller]

i still think the driveshaft is out of balance

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[sixty9fordkiller]

any updates?

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[LHRxDeadx]

got a new driveshaft went carbon this time new rotors new brakes new engine mount and trans mount. I attended LS fest west and went hard on the car for 4 days and nothing broke vibration still there.
ive done 2 road course events near home and vibration got worse i can feel in in my ass on every gear now.

I have done everything you could ever imagine car has 50k miles im going to be pulling the rear end mid july and see if anything is wrong in there

[jonathanmoguel]

probably the differential i saw mine that the bushings are torn. going to drop diff and change them . also saw my DSS axle boots are torn going to replace those too. i saw that hendrix engineering sell offset bushings for the diff. my car is lowered, sitting on eibach multi pro r2 coilovers so the drop is about 2 inches.. will post here if issue is gone. definitely seeing this issue more common now i have a friend who has a similar issue too.

[LHRxDeadx]

Originally Posted by jonathanmoguel

probably the differential i saw mine that the bushings are torn. going to drop diff and change them . also saw my DSS axle boots are torn going to replace those too. i saw that hendrix engineering sell offset bushings for the diff. my car is lowered, sitting on eibach multi pro r2 coilovers so the drop is about 2 inches.. will post here if issue is gone. definitely seeing this issue more common now i have a friend who has a similar issue too.

mines lowered one inch i haven't really messed with it to much ive got 4 track events and a hand full of drag strip passes nothing has broke yet lol

[LHRxDeadx]

Well a month later few more drag passes nothing has broke vibration still present.

[hammdo]

On mine, I replaced all bushings when I decided to track. I don’t drag anymore but, I would ck the stock knuckle bushings right away — those have been known to cause a vibration. Jack up the rear, grab the tire and rock up/down — should have no play. Any play, take the tire off and inspect the knuckle then the hub.

After that I would ck the diff bushings, cradle, trans mount, engine, trailing arm bushings, upper control arm bushings, and shock tower bushings.

-Don

[JerTM]

Have you had the the runout checked on the rear diff pinion flange?

[Rock-It Man]

Originally Posted by hammdo

On mine, I replaced all bushings when I decided to track. I don’t drag anymore but, I would ck the stock knuckle bushings right away — those have been known to cause a vibration. Jack up the rear, grab the tire and rock up/down — should have no play. Any play, take the tire off and inspect the knuckle then the hub.

After that I would ck the diff bushings, cradle, trans mount, engine, trailing arm bushings, upper control arm bushings, and shock tower bushings.

-Don