9" Rear end howling

[ForceFed70]

Long story short...I got screwed by a local shop that over-rates their abilities and doesn't stand behing their work.

So.. ever since my rear gear set and limited slip swap the ole 9" has been howling. It only makes noise under acceleration, and is most noticeable in 4th and 5th. When coasting or decelerating it makes no noise at all.

It's been doing this for about a year now. But before the T5 swap you didn't really hear it over the sound of the engine. But now cruising down the highway at 1700rpm's all you can hear is that damn howling.

It's time to fix this. Originally I took it into a shop because I knew rear end setups can be a little tricky so I wanted an "expert" to do it. This time I wonder if I might be better off doing the work myself.

So...given the symptoms (howling only on acceleration and only noticeable in 4th and 5th). Do you have any suggestions on where to start? Should I just find a different shop to take this to and hope they do a better job?

 

[CraigMBA]

Long story short...I got screwed by a local shop that over-rates their abilities and doesn't stand behing their work.

So.. ever since my rear gear set and limited slip swap the ole 9" has been howling. It only makes noise under acceleration, and is most noticeable in 4th and 5th. When coasting or decelerating it makes no noise at all.

It's been doing this for about a year now. But before the T5 swap you didn't really hear it over the sound of the engine. But now cruising down the highway at 1700rpm's all you can hear is that damn howling.

It's time to fix this. Originally I took it into a shop because I knew rear end setups can be a little tricky so I wanted an "expert" to do it. This time I wonder if I might be better off doing the work myself.

So...given the symptoms (howling only on acceleration and only noticeable in 4th and 5th). Do you have any suggestions on where to start? Should I just find a different shop to take this to and hope they do a better job?

Your problem is pretty simple. The pinion depth is wrong.

Depending on how long you drove it, you may have to replace the ring and pinion again because you got a pattern in it.

Rear end setups are really easy - but quite frightening if you've never done one before. I wouldn't try it myself if I'd not done one before.

 

[dennis112]

Pinion depth can make a difference and I would have that checked first. Also some gearsets are noisier than other. I prefer Ford/Motorcraft as they tend to be more quiet than the aftermarket varieties.

 

[rbohm]

not just pinion depth, but backlash can also cause a howling noise. one thing more, as you go lower(higher numerically) on the gear ratio, they become more sensitive to the settings, and have to be kept to closer tolerances than the higher gears.

 

[351carlo]

If everything was replaced, then yes the pinion depth was probably set wrong or the backlash was not set properly.

Either way, something was messed up. I was intimidated by setting up my own gears, but given the fact that I had the time, I took it on. After setting it up myself, I brought it down to a friend who is a tech for Ford. He and his boss checked it and it came out perfect.

I've only put about a hundred miles on the rear since my car's been off the road for a year now, but it was great. My reason for tearing the old one out was due to a whine on acceleration. But in my case the pinion bearing had worn, causing the depth to be off under acceleration. If that makes any sense.

 

[ratio411]

I had the same thing.
The guy swore he built a jillion rearends, but he screwed my Dana 60 all up.
I should have walked away when he asked where the crush sleeve was!
Anyone who knows Dana 60s knows that they do not have crush sleeves and use shims to set the pinion...
He broke my locker putting it together and just washed his hands of me when I complained the next day. I didn't know the locker was broke then though, and if I had, he would have denied it anyway.
I took the thing apart and it didn't have a shim one in the whole thing!
I asked Richmond how the locker broke, and they said the part that broke only gets broken by incorrect assembly.

The worst part is, once the gears are set wrong, they often howl no matter what after getting set properly.

If nothing has going south with them by now, I would probably just learn a lesson from it and put up with the noise until I am good and ready to start from scratch.

 

[ForceFed70]

Thanks for your input guys.

I AM going to fix this soon, I can't stand that damn noise any longer. I found a local shop that says all I need to do is pull out the carrier and bring it in and they will give it a try. Says they'll only need to bill me for a couple of hours but won't guarantee anything unless they are putting in a brand new gearset and can replace any bearings that they find "questionable". I think I'm going to give this a try and go from there....hope I don't need to buy a new gearset.

 

[bnickel]

it's worth a shot but you'll probably end up having to replace it. do yourself a favor and buy another chunk so you can learn the building process on it, just a junkyard core take it apart and put it back together several times, noting the pattern before you start and then try to get the pattern the same every time you put it back together. a good friend of mine that was an expert at setting up 9" rears learned this way. just get some shims and some gear paint and go to town

 

[Hack]

www.badshoeproductions.com
They sell a 9 inch rebuild video. I haven't done one yet, but the video was very detailed and I recommend it.

 

[351carlo]

I picked up my rebuild kit for 90 dollars shipped off eBay, with good bearings similar to those I used to carry when I worked at a parts store. The rear I bought came disassembled but with 4.11's. I took the old unit out and looked at how it was put together, then put the new unit back together.

A few hours of a local shop = a few hundred dollars. You can get entire center sections rebuilt online for 400-500 depending on the deal. So add up the labor costs they're going to charge, gears, rebuild kit and the fact that you're using your old center section and it might payoff to buy one already done.

If not, and you have a dial indicator, a good torque wrench and a micrometer, go to town! It just takes patience. If this 20 year old punk could do it when he was 18, you can get it done.

 

[gsxrken]

Do it yourself! I bought that video and after watching it, and buying one tool so I could measure case spread, I re-did my own and it is amazingly quiet. I used Richmond gears and rebuild kit and installed strange 31 spline axles and a truetrac diff at the same time. I enjoyed the video and it saved me a ton of money. Rears were the last uncharted territory for me, and I can say without question that if you've assembled an engine, you can CERTAINLY redo a Ford removable chunk.
http://www.youtube.com/watch?v=bSCUck4M6W4