gyouska

I replaced my gears about 3 or 4 months ago to 4.10s. I set the backlash pretty close. They had a little whine at first but i realized my preload was not itght enough. after tightening the pinion a bit the noise came to a minimum only when i let off the gas. after some weeks the noise went away. now it has been a few months and just this week i have noticed a pretty noticeable whine at about 35 miles an hour when deccelerating. what could this be the cause of?

mjr46

your install is fubar.........did you use a new crush collar?? also did you set preload on the bearing (old) 8-16 inch lbs new bearing 16-28 inch lbs.........if you didn't do such, there in lies a lot of the problem, also did you run the pattern afterwards to check tooth contact??

dawson1112

http://search.yahoo.com/r/_ylt=A0oG7...htM-4209-8.pdf

Here is a link to the Ford racing 8.8 ring and pinion installation instructions.
You must follow instructions in this tech sheet. If you don't have the correct tools and gauges to measure with do not attempt a gear install. You can not guess at this.

gyouska

i used a new collar i went to rear end shop they pressed on the bearing with the correct shim that they have in their cheat sheet. i checked the mesh and it said it was acceptable. I cant remember the backlash measurement but i think it was 1 number too tight but peeps told me that as long as it was close they would be find its all about the mesh thats whats important. the backlash was within range. the preload got ****ed up and i just had to tweak it till there was no sound then it was good for all this time. my question is what is causing this sound all the sudden? is it a bearing going bad or too loose of a preload something of that nature at this point i dont care what caused it. it probably was my preload but i just want to know what i need to fix.

dawson1112

Howling or whining of the ring gear and pinion is due to an incorrect gear pattern, gear damage or incorrect bearing preload.

Are you sure what you are experiencing is not chuckle?

Info directly from the ford service manual.

Chuckle that occurs on the coast driving phase is usually caused by excessive clearance between the differential gear hub and the differential case bore.

Damage to a gear tooth on the coast side can cause a noise identical to a chuckle. A very small tooth nick or ridge on the edge of a tooth can cause the noise.

Clean the gear tooth nick or ridge with a small grinding wheel. If the damaged area is larger than 3.2 mm (1/8 inch), install a new gearset.

To check the ring gear and pinion, remove as much lubricant as possible from the gears with clean solvent. Wipe the gears dry or blow them dry with compressed air. Look for scored or damaged teeth. Also look for cracks or other damage.

If either gear is scored or damaged badly, install a new ring gear and pinion.

If metal has broken loose, the axle housing must be cleaned to remove particles that will cause damage. At this time, any other new parts in the axle housing must also be installed, if necessary.

dawson1112

The only thing I can suggest is to pull it all apart .
Really is no way for any one to tell you exactly what the problem could be with out hearing it seeing it and checking the mesh pattern.
Redo the installation with the correct specs.
If the back lash was .001 out of spec , you should have removed .002 from one side and added .002 to the other side. Don't listen to peeps that say its close enough.