1FST-Z

iTrader: (6)

Hey all,

I originally posted this in the gears & axles section, but thought I'd try to gather a few more opinions by posting in here as well. In a nutshell, my rear-end only howls (and LOUDLY) when giving it gas. That's it. On decel (no pressure on accelerator) it's quiet as can be. What is it that causes rear end noise only upon giving it gas? If I can learn what it is exactly that is causing this, then I'll know exactly what all I need to replace. It's my daily driver and an upgraded rear-end is not a financial option. Re-build the 10 bolt or nothing. So, any opinions as to the cause of this particular howl?

ghardester

Have you had any leaks? Pull the plug and drain the rear end fluid, see if you have any metal in there. It only costs a little time and a bottle or two of new fluid. You will need a small hand pump to re-fill the rear end. The parts store sells cheap plastic ones made to fit in the top of the bottle. Put the bottom plug back in, remove the plug on the side and fill it until fluid overflows out the side plug.

An examination of the rear end fluid and making sure it's full would be the first step. While you are under the car check to see if there is fluid spraying the under body of the car in the front of the rear end. The pinion seal there could be leaking.

1FST-Z

iTrader: (6)

ghardester:

The howling began after a track night. 5 passes and the noise started and has been getting louder by the week. During the week before the track night, a buddy and I changed the rear end fluid and tapped/welded a drain plug into the diff. cover for easy fluid changes in the future. Everything has held together leak-wise, she's topped off. No fluid trailing anywhere of any kind. I'm just stumped by the fact that the noise only occurs when the drivetrain is under load... shouldn't the rear constantly make noise all the time if she's on her way out?

ghardester

Hmm. That was my 2 cents. When the drive train is under load the drive shaft is pushing backwards into the rear end. Maybe look at the yolk and seal? I just had mine replaced and the part of the yolk that the seal presses on should have been firmly pressed on the yolk, but when taken off it just slipped off. Maybe you spun that part. It was a recent post so I will find it and post.

1FST-Z

iTrader: (6)

I appreciate your input ghardester. What were your car's symptoms when the yolk and seal assembly were spun?

ghardester

https://ls1tech.com/forums/gears-axl...al-2002-a.html

When I recently had my pinion seal replaced the shop thought it had a 2 piece seal because it all came off so easy. Turns out part of it should have stayed pressed on. You can see pictures of what it should look like and what mine looked like when removed.

Just a suggestion of where to look. Mine was NOT making any noise. I just had a little leak I wanted fixed. Don't buy parts on my account, I'm just adding a place to look at.

All Black SS

Thats incorrect. While under acceleration the pinion pushes out, thats why the inner pinion bearing is bigger.
Also you will know this if you ever seen a rear with a loose pinion nut, it's the exact opposite---when you coast the pinion pulls back and makes noise and can even hit the carrier, when you accelerate it pushes forward and gets quiet.

I replied to the other thread. I recommended draining the rear and the transmission, see where the metal is and you'll know.
I'd almost guarantee it's a transmission problem since it is a manual.

1FST-Z

iTrader: (6)

Time to get her up on ramps and do some investigating!

All Black SS

FYI you do have a two piece seal on a 2002 F-Body. The reason it's called a two piece is because it will not work without the part on the yoke. They have to be used as a pair.
The seal with the small ID is used for older models, or can be used if you remove the yoke seal.

To put it another way, you can install a new two piece seal on an older rear. One reason they went to a two piece design is so the yoke never gets a groove worn into it from the seal, also the larger ID of the housing seal will help it live longer.

1FST-Z

iTrader: (6)

So the opposite effect is what's causing my noise on acceleration?

All Black SS

For your sake I hope. You'd be lucky to find a pitted bearing. It would either be the bigger (inner) pinion bearing, or the drivers side carrier bearing.

If the rear checks out ok, it might be the transmission.
I've also had single teeth break off of trans gears and continued to run them hard, just odd noises.
But the trans output (or mainshaft) bearing going bad I've also had that happen and it would howl on acceleration and never any other time.

When I took that bearing out it was a ball bearing, I destroyed it to get it apart just so I could check it. It had pitting on the races. Never really found much metal in the trans from it.

1FST-Z

iTrader: (6)

Out of curiosity, what all is involved in this repair, assuming you are correct on your diagnosis?

Blacklightning744

iTrader: (7)

most likely ur rear pinion bearing is going bad or if the rearend was rebuilt, one of the races could not be seated correctly or the crush collar wasn't installed correctly. a good way 2 check this is to go under the car put both of your hands on the yoke and shake it up and down, if there is n e play, u have a bad bearing or the bearing races arent seated right, i had the exact same problem with my car.

the_merv

iTrader: (88)

I'm leaning toward a Bearing problem in the back there..

1FST-Z

iTrader: (6)

So is the consensus that I should just go 'head and rebuild the rear-end? Considering I'm nowhere near financial stability for a Moser...
Should I go 'head and replace the posi too... or just invest in a master re-build kit?

Blacklightning744

iTrader: (7)

well it depends on what u want to do and how much u want to spend i mean i spent $800 on a rebuild kit, posi diff, and gears thats it. axles cost about $400 more. but if ur tight for money i'd go ahead and invest in buying a rebuild kit, it'll run ya about $100- $130. heres my theory, if a bearing goes bad in the rearend, that causes friction, friction causes metal shavings, and metal shavings cause more bad bearings, and more bad bearings eventually add to damaged diffs, gears, etc. goodluck with whatever u decide

All Black SS

Depends on your skills, and money. You could just tear it apart and check everything. And put it back together if it checks out ok. Or replace everything and find out it's not the rear.

If you're comfortable just replacing whats bad then you can get out cheap.
One problem though is you can't check the inner races for pitting.
You can fully degrease one, squeeze rollers and turn the center to feel for it. I did that once and cut the cage off and sure enough it was ate up a bit.
I also found a pitted outer carrier bearing race (cup) when doing gears in my 2002 SS when it had 32,000 miles on it. So anything can go bad at any time.

SOMbitch

iTrader: (8)

I would look for a used one in decent shape after you rule out the tranny. No way Iwould spend good money on rebuilding a crappy 7.5 10 bolt. I have seen them in the $250 range. Then I would start saving for a 9"/ D60. You are throwing good money away to rebuild that thing if you have any fun with you car cause it WILL **** on you again

1FST-Z

iTrader: (6)

SOMbitch:

As far as ruling out the tranny goes... it seems that one popular opinion is the trans output bearing...how exactly do I "rule that out"... I mean when I have her up on ramps, how do I inspect that stuff... before opening up the differential and looking for broken teeth, etc?

Blacklightning744

iTrader: (7)

i highly doubt it, i mean as far as durability the rear end will go before the tranny output bear, as far as inspecting it, if its not leaking then its probably good, cuz when that bearing goes bad, it releases little metal shavings that would rupture the seal behind it. so if the seal isn't leaking its most likely good. also your symtoms of the problem point towards the rearend.


p.s. not to cut in sombitch, i was just compelled to answer, sry lol