Technical New pictures Post 29 with yellow compound...Noisy 9"

SEE Post #29 for new pictures using Yellow compound.

I have been on here the last month or so asking question about Heat, Bearings, Installing and etc. I am posting this because others that have read the previous threads won't read them again.

This is a new rebuilt by a well known builder in the Midwest. It has been noisy since day one. We are trying to work out the problem.

I pulled it and wanted you to hear how it sounds.
Can someone tell me which pictures are the Drive Side and the Coast Side?

1. Click on Attachment below that says download all attachments.
2. Go to bottom of screen and click on Open/wait for it to load.
3. Double Click on IMG_0699.
4. Turn up your volume
OR.....Go to Squirrel's post because he put it on youtube!!!

 

drive is the "flat" side, coast is the "angled" side. Think about which way the pinion gear is pushing on the ring gear when the driveshaft is turning the direction that makes the car move forward.

Can't really see how the gears are mating without some marking grease on them!

The noise does not sound like it's a pattern problem...those noises change a lot when you let off the gas, push on the gas, etc, and they sound more like "singing". The noise you have sounds more like a bearing problem, it's more of a growl.

 

How do I do marking grease and where do I buy it? Thanks for your input.

 

I don't know where to find it locally, aside from a shop that works on them.....I have a couple little containers that were included with rear end bearing and shim kits.

http://www.summitracing.com/parts/mgr-gmc1

 

Ok......Great!!!! What do I have to do to R&P and how do I use it?

 

White lubriplate will show something [not the best] available at a parts store..Or bluing paste [http://www.mcmaster.com/#bluing-paste/=101f62s] at a industrial supply store [better], used to use white lead, red lead....I would say that the pinion is too deep from what I can see but I would remove the pinion retainer [can't hurt as is o ring and shim] and see/feel what the preload is..I'd bet too much...Were the gears new or used? Did you happen to check lash?

 

They are brand new Motive 3:00 gears in an open 9" Carrier. They also used New Timken Bearings.

 

I cant hear see/hear the video, but what about the axles? New bearings on the axles? Did they get checked for straightness?

 

You must follow the instructions exactly like I stated in my first post. It will open and you can hear the noisy 3rd member.

New bearings at install. Axles worked fine with the old 3rd member with no noise.

 

here's the video on youtube, in case you dont want to download a .zip file

 

Thanks Squirrel..........I don't go on youtube and don't know anything about it or how I would post future videos.
The noise you are hearing is all rear-end noise. My car has Dyamat Extreme and you can barely hear the car running.

I ordered the gear marking compound and it will be here later this week. What do I need to do with the R&P? I'm thinking wash it down with Brake Kleen. Then I guess I just brush it on. Do I go all around the ring gear both the drive side and the coast side with the compound?

 

That is brutal. The pattern looks to low on the toe of the ring. And why do the gears look like they have sparkly metal all over them?

 

only need to do a few teeth to see what's going on, usually.

 

Your pinion is definitely too low. Take a few thousandths shims out then paint about six ring gear teeth and rotate the pinion until it marks the ring gear paint. You want the pattern roughly in the middle of the tooth mesh. Now hold the u-joint yoke still and rock the ring gear back and forth to check tooth backlash. You need about .008-.010 backlash.
Set the preload on the pinion bearings by putting the pinion carrier in a vice and turn the u-joint yoke nut. You want about 20 inch pounds to turn the nut. If you replaced the pinion and carrier bearings and the clearences are correct the noise is in the wheel bearings or u-joints.

 

I will have the yellow gear compound in a couple of days. When I put a pry bar (made of plastic) against the back of the ring gear and carrier and apply pressure.....there is no movement at all. Is this normal?

If it is normal, why apply pressure when running the gears around with the compound? I don't see how it would have any effect on the yellow pattern.

 

Not an expert but when setting up gears in the past it doesn`t take but a few miles to wear the pattern in and then the gears are forever noisy. You can improve it but it may be too late.
Those teeth look very rough.

 

You need to apply a fair amount of force to the R & P to make it mark the patterns correctly (especially on a used set) so for example you need to try holding the ring gear from turning while turning the pinion.

 

I don't understand why you're fooling w/it , can you not send it back ???
dave

 

NO PRY BAR....piece of wood wedge between the OD of the RING gear and the case so that when you turn the pinion there is resistance....

 

Yes....I am going to send it back. I want to document, with pictures and save for my records, the gear pattern before I send it.

Now I understand why I'm to put pressure against the R&P according to Russco's post.

Hey Seb......Thanks for the heads up on the block of wood and the need for resistance. I'll post pictures when I get the gear pattern with yellow compound for your thoughts.

Thanks to everyone for your input!!!!

 

That pinion looks like its set mighty deep

 

If you grab the yoke can you fill any side to side movement?

 

This is not mine but it sounds exactly like it.

 

Let me put just a little info on here. A friend of mine had a 9 in built a few years ago buy the local 9in guru. My friend had bought new gears,i'm not going to mention who's but the rear had a bad whine in it. i felt bad because i had recommended the guy to build it . At the shades of the past show the vendor of the gear set was there,so we asked about the whine. He told him the gear set was cut for heavy duty/race duty and that yeah ,they probably would have a whine in them because of the way they were cut. He (The vendor) said that when they set up a rear for the street that they would try to find some used gears to use. Not sure if the manufacturer you mentioned makes gears for racing applications but that might be part of the problem. I'm sure some folks are not going to agree with this but that is what they told was the problem. My friend found a used set of same ratio, had them put in ,no more whine.

 

I have heard that reason, not really buying it..I originally thought the OP's noise was from pinion bearings too tight never thinking that they could be loose after a hundred plus ft lbs of torque for the pre load set up with a crush sleeve and 200#'s with a solid spacer! But stuff does happen; I did early on suggest removal of pinion retainer and checking preload...Here is video of 9" rebuild...

 

I was told buy one vendor that they only use OE gears in closed cars to help with gear noise.
Another vendor told me that the more expensive gear sets cost more and stand a better chance of being quiet because they were lapped in for a longer time.

 

I bought a bargain 9 inch for my 55 Customline that howled like a banshee. Turned out to be a hairline crack in the carrier at the rear pinion bearing cup housing. Very hard to see. Who sez 9 inchers are indestructible?

 

seb fontana: Thanks for posting that great video.

 

Your welcome..If you can find a Ford repair manual for a early 70's vehicle it will be even better; in the video he does some extra proceedures that are not necessary especially when using a crush sleeve and setting carrier bearing preload but he is close enough to understand..

 

These are new pictures with Yellow Gear Compound. Tell me what you think of the setup from the builder.

Top picture is Coast....Bottom picture is Drive. You can see that the Coast Side is way at the bottom of the Toe. The Drive Side is located towards the bottom of the Toe also.