Howl from rear end?

[Matt Weiser]

Hey all, I've got a pretty strong noise from the rear end at cruising speeds, I can only describe it as a continuous "howl." Mostly goes away if I let off the gas and coast, gets worse on accelleration. What could this be? Are we talking big $$$...?

BTW, it's a stock '86 TR G80 posi rear w/3.42 gears and @ 125k miles. I recently added fresh Mobil 1 gear oil and no change in the noise.

 

[Terbro]

Well, I know the howl is the tell-tale sign of an old (high miles) rear end. I had all the internals (posi, gears, and axles) replaced when I did mine. I'm not sure what actually causes the noise... either the gears or bearings, I would think.

 

[zam70]

Here's a little diagnoseing guide I got off of West Coast Differentials site:



Whirring noise only while decelerating at any or all speeds is most likely caused by bad pinion bearings or loose pinion bearing preload, and almost never by bad ring and pinion gears.

A howl or whine during acceleration over a small or large speed range is usually caused by worn ring and pinion gears or improper gear set up.

Rumbling or whirring at speeds over about 20 mph can be caused by worn carrier bearings. The noise may change while turning.

Regular clunking every few feet may indicate broken ring or pinion gears.

Banging or clunking only on corners can be caused by broken spider gears, lack of sufficient positraction lubrication, or worn positraction clutches.

Rumble while turning may indicate bad wheel bearings.

A steady vibration that increases with the vehicle’s speed can be caused by worn u-joints or an out of balance driveshaft.

Clunking only when starting to move or getting on and off the gas might be loose yokes, bad u-joints or worn transfer case or transmission parts

 

[STP]

Pinion is worn out, or not setup properly...

 

[Joe 1320]

Most likely a bad pinion bearing.

 

[xtremexnyc]

Whats a ballpark figure on the cost to have a shop correct this issue. Thanks

 

[Terbro]

This doesn't really answer your question directly, but when I got tired of the howl, I decided to replace everything. I.e., new ring and pinion gears, new Eaton posi, new axles (Tom's Axles) and all new bearings. ~$1,200, installed.

 

[xtremexnyc]

Thanks Terbo, I had a feeling it would be about that price more or less.

 

[GT MADNESS]

Rear End Noise

Hey gang,

I bought my GN with 109k on it with a posi rear end. I got a pretty decent price and love the car. Theres a loud noise coming from the rear thats been bugging me. As the car is going it sounds like the rear brakes are rubbing against the drum. Wondering if it had oil in the differential but it has. As the car is jacked up in the air and car in gear, I see that the drive shaft wobble a little up and down. Also the tranny has been rebuild, so dont really think is that. The faster I go the more it sounds. I'm thinking of replacing the axles and bearings, but dont think it will solve the problem. From ready you guys sounds it might be the pinion gears. : :



Thanks

 

[Joe 1320]

Costs are on average:

1. Ring and pinion $190
2. Posi carrier $400
3. Bearing and install kit (complete) $150
4. labor is roughly 5 hours @$60 per= $300
5. Lube and posi additive (synthetic) $50


Some parts depending on the source may be a little less or a little more. Careful shopping is a must.

 

[Crazi]

I used to have that growl as well. I had a leaky axle seal but didn't catch it until it started making noise. Well I fixed the seal and changed the fluid. No dice.

I ended up having to pull the diff and change the bearings. Luckily, that and the axle bearings where all the needed changing. No noise now.

 

[Matt Weiser]

Thanks for all the info. My wallet is already feeling a lot lighter! If it's a worn ring and pinion, is this something I can fix myself? Is it even worth it to save the ~$300 in labor that Joe 1320 listed, or is this best left to a pro? I know some special tools will be required, so that will eat into my $300 savings a bit. Any good how-to websites on this subject?

Thanks again!

 

[Joe 1320]

My advice is that a ring and pinion is a PITA that is best left for a shop set up to do just that. To properly set the pinion depth you will need a dial gauge with extensions, and to do it properly, a press to add/remove bearings. The pinion bearing needs to be pressed on and off a few times due to having to use shims. In short, it is one of those things that you'll be glad you paid a pro to do it.

 

[1ARUNEM]

GT MADNESS... It's your gearset... Been like that since i had the car.

I actually had a whole rear to go with the car but the person you bought it from did not want it at the time...