rear end noise

[tcjimmy]

2000 jimmy 4x4 auto. While in 2 wheel drive when when slowing down howling noise coming from rearend. where should I start looking

[old_master]

Howl or whine on deceleration only, usually indicates a problem with the ring and pinion gears.

[tcjimmy]

I've never messed with ring and pinion. Any estimates on what a garage would charge to replace?

[MT-2500]

Originally Posted by tcjimmy

I've never messed with ring and pinion. Any estimates on what a garage would charge to replace?

Proabley going to cost you a arm and a leg

And no way to tell to you open it up and check it out.

Here is a link that may help on diagnostic and parts.
http://www.differentials.com/install.html

Look under Tech info and then diagnosting problem.
Comes up like Old Master said.

Labor can run 8-12 hrs for a good complet rear end job.
If ring gear and pion noise I would figure ring gear and pion and all bearings and seals to start with and check spiders and case and positive traction stuff if you have on of them.

Add labor to you parts for a idea of what it might cost.

Or call your repair shop and ask them.

Let us know how it goes.

[Jimmmy]

tcjimmy, I have a similar problem also on my 2000 blazer 4wd. The rear end howl's or roars like crazy when I accelerate but is quite when decelerating. Thought it was the u joints on the drive shaft so I replaced them but still had the same issue.

I wonder how the ring and pinion move out of alignment over time? Could it be the pre load crush sleeve on the pinion getting weak over time?

I've only changed out the ring and pinion on mustangs and I know that takes a solid weekend to complete if I'm lucky! Alot of time consuming work as MT-2500 stated. Usually the shims on the pinion gear is a guess and check for me since I don't have the proper tool pinion depth tool.

I wonder if I drain the rear differential and use some lucas oil instead will it quite down some? I used the lucas oil on my front differential to swell up the seals because it was leaking and it worked.

[Rick Norwood]

Originally Posted by Jimmmy

I wonder how the ring and pinion move out of alignment over time? Could it be the pre load crush sleeve on the pinion getting weak over time?

The Ring and Pinion Gears are actually Bevel Gears. The Gear teeth are cut at an Angle (or a Bevel) to the shaft and transmit power at a 90° angle to the drive shaft, and out to the wheels.

When a tooth on the Pinion makes contact with a tooth on the ring gear, that contact point creates what is called a Bearing Pattern or a Wear Pattern on the teeth. See the link posted by MT2500. It describes this very well. You might notice that the gear teeth are actually curved to keep the teeth in contact with each other longer, increasing the size of the bearing pattern for longer wear.

Over time, the real (shaft) bearings wear, the teeth wear, backlash increases, the tooth hardness starts to deteriorate, the gear teeth bearing pattern goes bad (and I am sure a few other factors) and your rear end starts howling, slightly at first, then progressively worse. Pretty much like any other worn out bearing, and if you open the rear end up, you will find tiny metal flakes in the oil. Hauling or towing heavy loads can cause premature tooth wear.

Gear Teeth are hardened and ground to very close tolerances when they are made, and most companies prefer to keep their ring and pinion gears in matched sets to keep the bearing pattern as close to spec as possible. So don't be surprised if you are told that the Ring and Pinion Gears are only sold as a matched set. And My experience is, they ain't cheap.

The truth is, you should replace both gears at the same time to get the good bearing pattern back. Replacing one of the two gears probably won't eliminate the noise. And BTW, installation is touchy and critical.

As a possible alternative, I would price out an entire complete Rear End from a Wrecking Yard and R & R the entire unit. Some vehicles have a Differential Carrier or a "Pumpkin" while others have a solid housing from wheel to wheel.

Hope this helps.

[Jimmmy]

Any one know whats involved for swapping out the rear end? I have a 3.42 ring and pinion gear ratio. If I go to the junkyard what years are interchangeable?

I know I have to disconnect the d/s, brake lines, u clamps that hold the springs to the differential and probably some other things I'm forgetting.

[MT-2500]

Originally Posted by Jimmmy

Any one know whats involved for swapping out the rear end? I have a 3.42 ring and pinion gear ratio. If I go to the junkyard what years are interchangeable?

I know I have to disconnect the d/s, brake lines, u clamps that hold the springs to the differential and probably some other things I'm forgetting.

Best to start a New tread on yours.
Saves on hyjacking another persons post.

The bone yard should be able to help you on what years and makes and modles and ring gear size is interchangeable.

You can run into a lot of work on swap out.
Rusted u clamps and brake lines and bolts can be a problem.
Also getting a good rear from bone yard end is a hit and miss.
High mileage rear ends can have bad bearings and axels and ring gears and even bent axels and housings out of wrecked units.
What is bad on yours or why are wanting to swap it out.

What year make and model and ring gear size and 2-4 W and mileage do you have?

[Scrapper]

i'll say also ring and pinion gear or just plain bearing. if you take rear plate off hope the pin that holds pinion in i think it's 1/4 or 5/16th on the head of the pin.