Krik

iTrader: (4)

I wanted to put Royal Purple in my car (all fluids). I started with oil. Love it.

Next I went with diff fluid. Manufacturer specs call out 80/90w. RP doesn't make 80/90 but they do make 75/90. I pulled the diff cover off and cleaned everything up real nice. Put a new gasket on it and put the cover back on. Filled up the diff up to the plug hole and call it good. Now there is a noise...sounds like a pinion bearing to me, but pray its just a wheel (carrier?) bearing. Drain all my beautiful fluid out and remove the axels. Changed the bearings and seals (Timkin). New Gasket/new RP 75/90. Sound is still there...****. Take car to mechanic to have the pinion bearing replaced (timkin). He says the gears are real nice, minimal wear. He R and R the bearing and rebuilds the rearend. Refill diff with RP75/90 and new gasket again. Sound is STILL there. Seariously WTF is going on? Is 80/90 really that big of a difference? Does Synthetic just run louder?


Noise is most prevelent when letting off throttle at about 35-40mph. Sending out an SOS here guys, someone have any ideas?

Schwinny

Inspect the bearings in your wheels.

My dads SS did this about a year ago, It was wheel bearings.

Krik

iTrader: (4)

ALL of the bearings have been replaced, less than 40 miles on all of them.

J91

Go to a thicker Oil! I run Lucas 90/140, keeps it quiet...

Krik

iTrader: (4)

That doesn't sound like the correct "fix". Anyone else have a thought they want to throw out there?

J91

I f it's not your bearings or gears the differential is left, hard to tell w/o hearing it or driving it. Not many mechanics out there can get the lash right on GM 10 bolt 7.5's or 9 bolts. Sorry don't know what else to tell you? Is it howling loud or not that bad? When i had my stock gears and differential, they were noticeable but not bad at all, my 4:10's were never quiet, 3.73's not bad unless I use light oil...

jv9999

iTrader: (1)

Is this a 9 bolt rear? The wheel bearings can be noisy if the seals don't sit correctly (as they locate the bearings). As for RP... 95% marketing, 5% technology...

afremont

Maybe, but it's that 5% that makes all the difference. I've been running Royal Purple for years in my Sportster. It's the only synthetic oil that doesn't make the engine sound like it's coming apart inside (more than what is normal anyway). It also runs 20F cooler than HD dino oil. I've only noticed the marketing hype the past year or so, yet they've been around for a good while. If nothing else, at least they're honest..... it really is purple.

jv9999

iTrader: (1)

Whatever makes you feel better after spending $9/qt :-)

Krik

iTrader: (4)

Changed my gear oil back to 80w90 (Valvoline) with no change...scratch that sounds worse. Going to take it back to the mechanic on Monday. I am probably going to kick myself in the *** when it turns out to be something simple.

afremont

The bike only holds 3 and it's only about $7/qt, worth every penny. I tried several different synthetic (and blend) oils in my bike before RP, hated 'em all and kept switching back to HD dino oil. RP rocks.

My number one concern is oil temp on my air/oil cooled engine in houston, especially with the long traffic lights. The second big concern is what does the oil do when it gets to 260F. For allot of oils, especially non synthtics, it's not pretty at all.

jv9999

iTrader: (1)

Make sure the dust shield on the yoke isn't hitting. That's something simple that can sound like a bad bearing.

Krik

iTrader: (4)

For anyone keeping score, my ring and/or pinion was bad. Have no idea what was wrong with them, but i had them replaced and everythin is smooth as glass now.

mineddt

hey i have this noise going on in the back of my car for a while i thought it was my tires. did your sound like it was the brake drums scratching. just need to know so i can figure out my car. oh sorry i have a 91 firebird formula

Krik

iTrader: (4)

Sounded like a "whoomp whoomp whoomp ..." during deceleration.

I don't have a drum brake rearend so i'm not sure what noise yours making. Did you recently replace/repair anything?

ctsplicer

[quote=Krik;4275077]Sounded like a "whoomp whoomp whoomp ..." during deceleration.

]
I had that same noise.Turned out it was just peices of my ex wife wrapped around the driveshaft!

Krik

iTrader: (4)

[quote=ctsplicer;4275121]
That does happen

mineddt

Okay well after a month of not driving the car. i finally broke down and took it to a mech. i found it it was my front pinion bearing. the buddy i bought it from let it sit to long and i guess water got on the race and sat there and it ate a spot. and just chewed the whole bearing to crap. so since they where in there i had them replace all bearings and check backlash. now im good.

Krik

iTrader: (4)

Congratulations! Mind telling me what fluid you used?

mineddt

just what was called 80/90.

Krik

iTrader: (4)

I was wanting to know what brand, and synthetic or non (or a blend)?