96lt4c4

iTrader: (5)

is it quiet, and if so what gears do you have in it? I have had 3 ring and pinions in mine and they are all making noise. I just put my Yukon 3.75 back in and tried to set it back up this time running the backlash tighter and it is still signing to me. I am beginning to wonder if it is the case.

All the parts are brand new, I am about ready to take it to someone.

Kevin97ss

At what speed do they start making noise?

96lt4c4

iTrader: (5)

About 25 to 30 MPH. They just get louder from there. I can't figure out what I am doing wrong. Here is my last pattern. This is the Yukon 3.75.

I ran this gear before with about .010 lash to center the drive pattern up. This time I ran it at .005 to bring the drive down towards the toe. Same pinion depth as the first time I ran it, just tighter lash.

Oldsmobility85

iTrader: (1)

Bro are you absolutely sure it is coming from the rear???

Kevin97ss

The depth looks good but I would put backlash back around .008-.009.

25-30 sounds too low with a pattern like that, what is the breakaway and turning torque of the pinion? Sounds like it may be pinion bearing whine from excessive preload...

96lt4c4

iTrader: (5)

Yes it is coming from the rear. The pinion bearing preload is 20 inch pounds.

I know its the rear because the noise changes with different gears.

96lt4c4

iTrader: (5)

I had the lash at .010 and it made noise now it is at .005 to .006, which what is written on the ring gear.

Kevin97ss

20 in.lbs is high even for new bearings, could be the source of the noise.

96lt4c4

iTrader: (5)

Ok, what would you suggest. Its not to hard to pop out the pinion and loosen up the preload.

I was reading 25 to 30 on new in the Ford manual, the Yukon manaul says 15 new and 6 used. It just depends on where you look. My bearings are not new but do not have but maybe 100 miles on them.

96lt4c4

iTrader: (5)

The breakaway is 20 inch pounds then it drops. I didnt pay attention to what it was after it broke loose. I will check tomorrow.

Kevin97ss

At 100 miles I would aim for 8-10in.lbs in motion...should breakaway between 12-13

FWIW I've had bearings scream like a jet engine at 25in.lbs

96lt4c4

iTrader: (5)

Man, it would be nice if thats all it was. I will loosen them up. What about the carrier bearings. I have them pretty tight too, about the same 20 inch pounds. I use the end of an old axel with a nut welded to it to check them.

Kevin97ss

Carrier bearings can have a little more preload because they are bigger, 20 would be good for new. If they have the same 100 miles as the pinions then set it up for 13-15.

There is a formula to figure carrier preload: total torque - pinion torque x gear ratio = carrier preload

After reading some of your other post and re looking at your latest pattern I want to revise my suggestion on backlash to .006-.008

96lt4c4

iTrader: (5)

I found it! The pinion support has been moving. I pulled the pinion out and noticed a contact spot on the outer heel/face of the tooth on the ring gear. The support is aluminum so I have been installing it with washers under the bolts. I think the washers are too big and not laying flat. The outer edge of the washer is laying on a radius part of the support. I put 40 foot pounds on the bolts.

I was just thinking that maybe I should use the biigger bolt holes on my housing since it has them already there. I am paranoid about using the aluminum support no and thinking about getting an iron one. What do you think about the gear? Is it ruined or should I run it? If I set it back up like I had it then it shouldnt even get contact out where these spots are.











I put the pinion in a factory Ford support but it wont work with my yoke since it is for the Daytona style support.

Kevin97ss

The washers may have been a bit large but it looks like there is a 360 degree contact area under the head (black ring). My guess is the washer counter sunk itself and still had full contact.

The wear marks on the edge of the ring are concerning considering the pattern that was shown previous. Is it only on a cluster of ring teeth or every one?

96lt4c4

iTrader: (5)

It is on every tooth, on the ring gear and the pinion. Something has to be moving. When I pulled it out I checked the preload on the carrier and it was the same, it has not moved. The aluminum pinion support seems to fit loose in the housing compared to the original Ford. The Ford support is so tight that I had to pull it in with the bolts. I put the the aluminum support in a Ford center and it was even looser then in the Yukon housing. I just bought a Strange Nodular Iron support, ARP pinion studs, and a pinion bearing kit. The Strange support comes with Timken race's already in it, so I bought the Strange kit that comes with both bearings, a seal, a nut, and spacers. I may go ahead and get a new ring and pinion to start over fresh.

Oldsmobility85

iTrader: (1)

Whoah that looks wild. On a lighter note I put mine in gear for the first time on jackstands today. No noise that I could tell.

Took me a bit longer to get it together than I figured but I had to machine my wheels and rotors and I swapped to a bmr tq arm which took some time cause my car is tight.

Anyhow did putting the 9" in your car raise the rear any? Mine is sitting way up now.

96lt4c4

iTrader: (5)

No, still stock ride height. Did you use the stock brackets or did you buy some? When I cut mine off the 10 bolt I cut on the other side of the welds to make up for the larger tube. When my car is on the ground you cant even tell its been touched. Actually, I lowered my rear a little by removing the spring isolators and doing the heater hose mod so it sits level.

I was just sitting hear thinking about the OEM Ford gear that I pulled from that old truck, went out to the garage, and sure enough it has the same spots on it. They are nowhere near as bad as the yukon gear and are barley noticeable. I may be able to stick it back in there.

96lt4c4

iTrader: (5)

Check this out,

http://s105.photobucket.com/albums/m...=VIDEO0025.mp4

out with old in with the new

redtail2426

iTrader: (10)

i cant get the video to work??