Advice on rear end whine

[Hollowdweller]

Gonna try to keep it short. Car had 181k hard miles on it when I got it. I could tell the car’d been beat on pretty hard. I had 3.73 gears put in about a year ago (didn’t know it had 3.55’s, thought 3.27’s like my 2002) but the rear end set outta the car for that year, no driving. Had a very reputable shop install the gears but after 50yrs they’re closed. Got the car uppin runnin now and I hear a pretty loud whining out of the back. I’m not 100% sure it’s the gears but 2 other people told me they’re pretty sure that’s what it is. Had a buddy come run a contact pattern on the ring gear today and he said it looks like it’s setup in a “ competition pattern”..? He also told me that he thinks my diff/ trac loc (not sure what it’s called) is shot. Said there’s a lot of play in it. I took some vids hoping you could see the pin kinda moving around and it looks like the gears in the housing are kinda loose. I dunno, I have no clue if it’s supposed to have some play in it. When I take my foot off the gas the whine goes away. I’ve taken a few rear ends apart, all 8.8’s, know my way around them “ok” I guess but never setup a set of gears in one. I can easily replace the trac loc if that’s what it is. Hoping someone watches the vid and says YES YOUR TRAC LOC IS SHOT. Hoping to get a new FRPP one, swap it out, and all be good….hoping lol. Thanks for any advice

 

[Hollowdweller]

In the 2nd vid im trying to show that top gear kinda moving around. Looks like it back n forth alittle

 

[whitmanink]

i just did 410 in my car,, im gonna throw the axle up today hopefully,
but your gear pattern is off alot,,
the backlash seems loose as well,
as much as the trac loc is the easy route ,,
it seems like you need to re shim the backlash and reshim to move the pinion away from the ring gear

 

[whitmanink]

the spyder gear movement is a little loose but under load it wouldnt be

 

[GriffX]

My guess is that if you adjust the backlash and the pattern you're ok. The spider gears do not whine, I remember you can buy them separately. If you have no whine under deceleration the pinion set-up should be ok.

 

[JC SSP]

At 181k I would suggest you repack the clutch packs inside the carrier.

 

[86GT351]

At 181k I would suggest you repack the clutch packs inside the carrier.

This will help eliminate some of the gear movement as well.

 

[Hollowdweller]

Yeah I thought the gear pattern was off a lot too. There was no paint at the heel. Went ahead and ordered a new diff/trac loc. Gonna slap it in Sat hopefully and run a new pattern. Gonna watch a few vids and see what adjustments I can make. I’m thinking it needs to go more to the drivers side/left….but have no clue lol

 

[GriffX]

it needs to go more to the drivers side/left….but have no clue lol

Read the Ford pdf, it is excellent (except that it uses the color coded shims, we don't have).

 

[Hollowdweller]

Can I reuse my ring gear bolts?

 

[86GT351]

Can I reuse my ring gear bolts?

Technically they are TTY but they can be reused. Clan them on a wire wheel and a drop of lock tite

 

[Hollowdweller]

I tried to do another contact pattern before tearing it apart. I loaded the teeth up pretty good (2 coats), let it dry for a few mins, spun the tires several times, and nothing really. Didn’t seem like it made contact at all.This pic has about 20 revolutions on it.

So I thought maybe I wasn’t supposed to let it dry so long. Tried a quicker job and got this.

A little better but I can’t really see anything. Seems easy, apply paint, spin wheels…am I doing something wrong?

 

[lwarrior1016]

Try to hold the ring gear with one hand while turning the pinion with the other. It creates drag on the gears and gives a better read.

 

[Hollowdweller]

Try to hold the ring gear with one hand while turning the pinion with the other. It creates drag on the gears and gives a better read.

That was a workout lol!!

 

[Hollowdweller]

I mean, I have no idea but it looks like the pinion gear needs to come back and the ring gear needs to go toward the passenger side…?

 

[Hollowdweller]

Had the neighbor spin the tires so I could hold more pressure

 

[Midlife Crises]

Those patterns are not “clean” enough to read clearly. Do not turn the wheels! Hold tension on the carrier with your hand or a bar and turn the pinion. That will show the heaviest contact spot on the tooth. My guess is you need to add a couple thousandths to the shim under the pinion. It looks like the pattern is wiping on the crown of the tooth and is heavy on the toe on the drive side and on the heal on the coast side.

 

[Hollowdweller]

Those patterns are not “clean” enough to read clearly. Do not turn the wheels! Hold tension on the carrier with your hand or a bar and turn the pinion. That will show the heaviest contact spot on the tooth. My guess is you need to add a couple thousandths to the shim under the pinion. It looks like the pattern is wiping on the crown of the tooth and is heavy on the toe on the drive side and on the heal on the coast side.

Awesome, that’s it!!! I kept thinking “man there’s something your doing wrong”. I can see how turning from the pinion would change everything!! Love this forum

 

[whitmanink]

pinion depth is too low (more pinion spacers.. thicker one) and shims must be added to move the carrier ring

 

[lenko]

Look at my post # 18 here: https://www.s197forum.com/threads/gear-pattern.151455/#post-2577142