mopower440
Well-Known Member
Doing the ring and pinion swap on my 8 3/4 (first time doing a gear swap). How does the pattern look?
741 case 8 3/4 progress
- Thread starter mopower440
- Start date
Looks like the pinion could be a couple thousandths deeper but, I would bet it will be fine where you have it now.
Mike
I aggre the pinion needs to go deeper. I'd try .005". If you look at the toe of the tooth on the drive side you will see the pattern has a point at the top of the tooth. That point should be further towards the root and be located in the center of the tooth from the root to the top.
Doug
Doug
mopower440
Well-Known Member
That looks pretty close. Still a touch shallow but not much. Maybe .002-.003"
Doug
Doug
mopower440
Well-Known Member
Well, Im a dumbass. Got this all back together today and it whines..Mowing season is here and i have no more time to mess with it right now. Come winter i will send it to someone on here who can do it right for me or just find another chunk. Pisses me off as it was a GOOD unit before i messed with it. I drove it around and it works fine but shouldnt be noisy. So pissed at myself for spending all this oney on tools and parts when i should have just got another chunk with the gear ratio i was after.
Did you add the additional shim I suggested? Was this a new gear? Even then sometimes they’re still noisy. Of all the stuff I do (and I do everything myself) rear gear set up is the worst. The most work, and the greatest chance of disappointment.
Doug
Doug
mopower440
Well-Known Member
No, i had already got it back in the car when i saw your response..not sure i trust it now..
I have a gear set that I installed in my diesel.....Dana 70 which my setup indicator doesn't fit. Had to measure the bearing caps and saddles to make sure they were equal. They were off by .005 so had to take that into account. Got the new gears in and the pattern looked acceptable. It's quiet up and down but has a very slight whine between 55 and 65 and nowhere else. No one on here knew what to do about it except for one which only said, "it ain't set up right". Asked him which way would he go with it and crickets. Used a wide base depth mic to measure to the face of the pinion and it was within spec.
Anyways, with gears coming from all over the world, who knows how they are going to act. In 1990 I bought a new Dakota for our business and it had a slight hum and not a whine. Dealer said it's not bad enough to worry about. Got 100k miles on that thing with no gear issues before the oldest daughter totaled out.
Another thing on new diffs....the radius on the bearing fits is different than factory and well, shims are made with a larger ID which can also be a hassle to work with. Need to stick them in place with some light grease.
Just because it’s a little noisy won’t cause a failure.
Doug
Right, but a factory vehicle won't pass muster if a rear end makes noise, unless they will get louder and louder. I did my truck several years ago and the gears are not any louder but, haven't put that many miles on it either.
- Local time
- 1:42 PM
- Joined
- Mar 10, 2010
- Messages
- 32,930
- Reaction score
- 61,595
- Location
- Hanover, Pennslyvania
What brand ring and pinion did you use?
Lots of new gear sets will whine these days. Aftermarket gear sets aren't lapped in like they used to do. The auto manufacturers are more than likely using sets that are lapped in. This is the reason you'll see a coating on the gears we get today. It's to help with break in. Sometimes they will become quieter as time goes by.
Do the break-in procedure and change the lube around 500 miles. Give them a chance.
Lots of new gear sets will whine these days. Aftermarket gear sets aren't lapped in like they used to do. The auto manufacturers are more than likely using sets that are lapped in. This is the reason you'll see a coating on the gears we get today. It's to help with break in. Sometimes they will become quieter as time goes by.
Do the break-in procedure and change the lube around 500 miles. Give them a chance.
A friend works with reared lubricants for an oil company. All he does is Ford stuff. They can now even mix and match ring and pinions.
Doug
Doug
33 IMP
Well-Known Member
- Local time
- 10:42 AM
- Joined
- Dec 21, 2017
- Messages
- 15,266
- Reaction score
- 26,294
- Location
- taxifornia,soon 2b Arizona.
Agree with above comments.
I had a friend who owned a rearend shop (passed away. )
He said some of the gear sets being made are gonna make noise, the quality is just not there.
He also said that if a gear set whines due to poor setup (NOT reflecting on the o.p.!!) they are gonna whine forever, no matter how or how many times they are re-setup.
He successfully set up a couple used gearsets for me, and warned against using synthetic gear lube.
I had a friend who owned a rearend shop (passed away. )
He said some of the gear sets being made are gonna make noise, the quality is just not there.
He also said that if a gear set whines due to poor setup (NOT reflecting on the o.p.!!) they are gonna whine forever, no matter how or how many times they are re-setup.
He successfully set up a couple used gearsets for me, and warned against using synthetic gear lube.
Years ago I got a 3.91 3rd member from a truck that had been in a junk yard for many years. It was there long enough for the gear oil to leave the ring gear and rust. The bottom was still in oil and was fine. Took them to work and cleaned them then bead blasted them. Talked to one of the techs and he said that there was still plenty of surface metal on them. I put them back together and they ran fine for many years after. The tech also said not to run synthetic lube.
Similar threads
