Rear end problem help

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MoparMark91

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So guys I need help, I had purchased a new sure grip 8 3/4 rear end pumpkin from quick performance(i think) through eBay in September. Well just finally got to installing it. Well I went to take it out today and noticed some things in not happy about.

1st one is I am hearing a howling when I decelerate around 40mph

2nd one is I'm getting like a clunking when I turn?


What could this be? Did they not set up my pumpkin properly or does it have to wear in? I'm at a complete loss on this and not happy as I spent a pretty penny on it
 
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Did you add the friction modifier?

Cass at Dr diff said to add the friction modifier directly to the friction disks during assy.
 
Did you add the friction modifier?

Cass at Dr diff said to add the friction modifier directly to the friction disks during assy.
Yeah I added it but not directly to the disks but would that be causing my issues?
 
Don't know. There are folks here who will know. I was just covering the 1 thing I knew to ask:rolleyes:
 
Howling on deceleration can be a loose pinion bearing ! In that case you will need to have the pre load on the pinion bearings readjusted ! Friction Modifer will fix the clunking noise ! You just need to drive it ! Go to a school parking lot and do some figure 8 with it! The clunking is the friction clutch’s grabbing and letting lose again! Once the modifer gets on the clutches good that will stop !
 
The noise on decel is "something" changing the pinion gear angle, OR the pinion gear is set at the incorrect depth. As mentioned, check the pinion yoke nut. If it's tight, chances are good the pinion gear is set incorrectly. As for the clunking, IF it's a limited slip type (you didn't specify, so we don't know) and you did not add friction modifier, that could be your problem. Clutch type or cone type both need that to help keep operation smooth and quiet.
 
Howling on deceleration can be a loose pinion bearing ! In that case you will need to have the pre load on the pinion bearings readjusted ! Friction Modifer will fix the clunking noise ! You just need to drive it ! Go to a school parking lot and do some figure 8 with it! The clunking is the friction clutch’s grabbing and letting lose again! Once the modifer gets on the clutches good that will stop !
So if I just give the pinion but a little more preload the howling night go away? Okay I just was starting to thinking I'm going to have to take it all apart or send it back. Thank you for the info. My buddy said they're is also a chance the howling will go away once things are worn in?
 
take it out and check backlash, sounds like you got too much somewhere, probably the side adjusters..move the gear closer if you got crazy ring gear lash. may have to remark the gear pattern. Rob says your pinion...it may not be deep enough. supposed to give it 500 miles and then change the fluids per Dr. Diff. Id take it out ASAP and find the issue. If the pattern is centered and the lash is in spec, it may indeed be break in noises. Never broke in a new set of gears but if the factory didnt either, there would be a lot of complaining new car customers!
 
The noise on decel is "something" changing the pinion gear angle, OR the pinion gear is set at the incorrect depth. As mentioned, check the pinion yoke nut. If it's tight, chances are good the pinion gear is set incorrectly. As for the clunking, IF it's a limited slip type (you didn't specify, so we don't know) and you did not add friction modifier, that could be your problem. Clutch type or cone type both need that to help keep operation smooth and quiet.

Hey old timer ! How you Sir ? Did you see the post I posted about /6 cars ! Read that if you would Sir ! Then you can respond !
 
Hey old timer ! How you Sir ? Did you see the post I posted about /6 cars ! Read that if you would Sir ! Then you can respond !

I'm ok I guess. Lemmie go read it again. I scanned over it.
 
So if I just give the pinion but a little more preload the howling night go away? Okay I just was starting to thinking I'm going to have to take it all apart or send it back. Thank you for the info. My buddy said they're is also a chance the howling will go away once things are worn in?

Just up and grab the yoke ! Then see if the yoke moves back in fourth or side to side ! If the pinion is lose , it will cause all these things that you are being told ! If the pinion is loose that’s going to change the backlash settings ! Because the pinion is moving back and fourth on the ring gear ! If your pinion has a crush sleeve you probably will be able to tighten the nut and crush the sleeve more ! If it has shims for the pre load you will have to reshim for your pinion bearing pre load ! But do check the pinion nut for tightness also !
 
Even thought it has been a while, contact the builder BEFORE you do anything. 1 tweak of a nut might void any warrantee you might have
 
So I have contacted the builder but still no response but it's only been about 8 hours of me knowing.

I'm curious if to know if when I called the day after I ordered to ask them to change the yoke I wonder if they changed it but used the same crush sleeve making more okay?

Everything felt tight when I installed it but I will say it did feel hard to spin the axle?

The howling would do it for like the first couple passes up and down the road then would get quieter

It's a clutch sure grip 3.73
 
Do you have adjustable axle bearings?
Yes I and I loosened them a little thinking maybe they were to tight but didn't change kinda of set it by feel since I couldn't get the dial indicator out but did normal steps to set it
 
Just wanted to eliminate that a possible clunk. Rear end noise at that speed is usually ring and pinion engagement. They can be noisy on acceleration or deceleration or both. The pumpkin needs to come out, readjust ring and pinion (or replace) and re-check pinion. Crush sleeves are only supposed to be used once even though we all have broken that rule.
 
Yes, an incorrect pinion contact will create howling and whirring noises. If you do remove the pumpkin, brush some Permatex Prussian Blue on the pinion gear to take the guesswork out of the equation and actually see the pinion/ring gear pattern.
Screenshot_20201123-043505_Google.jpg

You will see for yourself exactly where the pinion is contacting the ring gear before you start chasing your tail. This basic chart may help.
Gearing Contact Patterns
 
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Yes, an incorrect pinion contact will create howling and whirring noises. If you do remove the pumpkin, brush on some Permatex Prussian Blue to take the guesswork out of the equation and actually see the pinion/ring gear pattern.
View attachment 1715635445
You will see for yourself exactly where the pinion is contacting the ring gear before you start chasing your tail. This basic chart may help.
Gearing Contact Patterns
Even if it's not howling all the time? Only when I let off gas around 40 I hear it
 
Even if it's not howling all the time? Only when I let off gas around 40 I hear it

Yes. You've been told several times. We cannot help that it's not the answer you want to hear. SOMETHING has caused the pinion gear depth to change......that is unless it's been making the noise the whole time, then it was set up incorrectly. Either way the pinion gear depth is not right. What it's due TO you will not know unless you start investigating.
 
What are the last three digits on your chuck ? 489 ? 742 ? 489 has the crush sleeve . Others have shims.
 
Yep.
Its the last adjustment process to ensure proper pinion to ring gear adjustment when you rebuild a rear, especially if you replace the pinion bearing. Can't just tourque down the pinion and hope it works.
If its just slapped together, you may hear whirring, and howling. These noises are harmonic, caused by improper pinion depth, and hi speed revolutions.
That is why it is adjustable.
Paint the blue on the pinion, spin it around and see where the blue ends up on the ring gear.
Then dial the pinion nut, in or out by tightening or loosening. Wipe down the ring gear and check contact again as needed. There are many charts or tutorials depicting adjustment procedures. If you have a crush sleeve type, and need the pinion to move "out", you will need a new crush sleeve so the pinion remains tight and doesn't slap.
If you have shims, remove or add shims accordingly to maintain proper pinion depth.
Joe
 
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Send it back. It should not howl at all. Clunking around turns could be several issues. But the howl means premature wear and something is wrong. All the rears I installed and they howled didn't last very long.
 
So i was confused about who i got it from i thought it was the same shop but i bought it off a ebay store name nine inch nodular. Im guessing he does a lot of ford 9 inch as well but doesnt have a single bad revieew and all good reviews since 2005 so im waiting for a reply on what to do since right now im dead in the water and got to waiti till wenesday to remove the pumkin.
 
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