Pinion Flange or U-Joints?

IllCobra

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So hopefully I can save some time and money by making this thread. I had a leaking pinion flange seal that I fixed, but after test driving the car I noticed a clunk noise that I can feel after letting off the gas and getting back on it. Strange thing about this is that it only does it in 5th and 6th gear...

How the heck can I tell if it's the Pinion Flange or U-Joint(s)? Is there something else it can be that I should also look into? I should note that I had a brand new Dorman kit that included the pinion seal, flange, and nut. This Dorman kit is a total waste of money! Neither the flange or seal fit and I didn't bother with the nut. I had to order a new Ford OEM seal and reused the old flange (nothing was wrong with the old flange I just wanted to replace it while I was there). The thing is, I hammered on the old flange to try and get the new flange to fit. Didn't work, obviously. Could this have damaged it? I feel that the symptoms I am hearing/feeling points to the u-joints, but hammering on the flange couldn't have been good?

Any help is appreciated.
 

P49Y-CY

fomocomofo
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i used the dorman kit too and noticed that the seal was not a very good fit (ended up using the ford part), but the dorman flange and nut fit fine for me.

i don't think it is a good idea to be hammering on that, it is better to pull the flange onto the pinion.
 

railroad

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The pinion flange sets the preload on the crush sleeve and pinion bearings. If you removed the pinion flange, it is necessary you tighten the flange to re establish the bearing preload.
Most will tell you, you cannot reuse a crush sleeve and ideally you would not.
The pinion should have no in and out movement after the correct preload.
The resistance to rotate the pinion shaft after correct preload is about 25 inch lbs.
This is without the drag of the ring gear, so you have about 1/4 of an inch or less to feel this resistance, without pulling the ring gear.
If you keep running the pinion loose, you will be buying a set of gears, ASAP.
Rear end lub can migrate out the spline of the pinion shaft and from under the nut.
A small amount of rtv on the spline and back of the nut will prevent this.
 

01yellercobra

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You'll have to get under the car and wiggle things. It'll be apparent pretty quickly what's loose. My guess is that by hammering on things you crushed the crush sleeve some more and have the wrong preload now.
 

IllCobra

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Dang, I was really hoping it was the u-joints. I feel like I got the pinion flange nut pretty close to what it was before I removed it originally, but I guess I might have messed with something when I was doing the hammering. I'll give things a check down there for sure and see what moves more than it should.
 

IllCobra

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i used the dorman kit too and noticed that the seal was not a very good fit (ended up using the ford part), but the dorman flange and nut fit fine for me.

i don't think it is a good idea to be hammering on that, it is better to pull the flange onto the pinion.
I guess it's hit or miss based on the reviews I've been reading after I tried installing the kit. In either case, I probably won't be buying Dorman again based on this and another bad experience. I did see that the flange read Made in China.
 

railroad

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Just get the slack out of the pinion gear, will not move in nor out.
Once you get the slack out, I would tighten it just under 1/4 of a turn on the pinion nut.
Probably nothing wrong with the flange.
Most do not change out the flange for a leaking seal, unless the mating surface has a groove worn in it or damaged.
You can clean up the seal mating area with a piece of sand paper or scotchbrite.
Just twist the flange back and forth in your fist, holding the sand paper against the metal.
 

hotcobra03

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I have always just got pinion flange from ford.

Cheap.

A file will help. Yoke should slide on by hand

These gears are known to clunk And whine

The front of diff poly mounts will inhance the noise also

The oem rubber mounts will soften also and cause this noise also.
 

railroad

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No place for a file on the yoke. The yokes are designed with a taper and will not fit on my hand, if correct. They should be drawn on with the pinion flange nut. It can be done with a pull handle, but most use an impact.
 

hotcobra03

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No place for a file on the yoke. The yokes are designed with a taper and will not fit on my hand, if correct. They should be drawn on with the pinion flange nut. It can be done with a pull handle, but most use an impact.
Try spicer. They made the part.

Plenty of information and it is not tapered
 

hotcobra03

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No place for a file on the yoke. The yokes are designed with a taper and will not fit on my hand, if correct. They should be drawn on with the pinion flange nut. It can be done with a pull handle, but most use an impact.
Try spicer. They made the part.

Plenty of information and it is not tapered
 

shurur

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Do you have the oem clutch packs type differential or maybe a Detroit True Track torque sense type differential?
 

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