Post 4.56 Gear Install Observations/Questions
11-08-2014, 07:08 PM
#11
Senior Member
If there is whine on decel only and not accel or coast then that means the pinion is set too deep. Sounds like they did not properly measure and setup the gears. I install average of 2 set of gears a week. Some guys set the pinion based off pattern, some actually measure pinion depth and set according to ford specs. There is numbers etched into the face of the pinion that will be used in this process. I use the measure process as that is the best way to know 100% it is accurate. All manufactures use this method also. It is recommended that after 500-1000 miles to flush the differential and install new fluid to flush out the old break in oil and what metal shavings appear after break in. A small amount of "glitter" as i call it is normal to see after a new set of gears have been installed. I would definately take it back and have them take a look at it. Depending on how bad the whine is, they may be able to re shim the pinion and reset the backlash and you will be good to go. But dont be surprised of they end up needing to install a new set of gears.
Last edited by Blackpony; 11-08-2014 at 07:12 PM.
The following users liked this post:
jonbar87 (11-08-2014)
11-08-2014, 07:21 PM
#12
Senior Member
Thread Starter
If there is whine on decel only and not accel or coast then that means the pinion is set too deep. Sounds like they did not properly measure and setup the gears. I install average of 2 set of gears a week. Some guys set the pinion based off pattern, some actually measure pinion depth and set according to ford specs. There is numbers etched into the face of the pinion that will be used in this process. I use the measure process as that is the best way to know 100% it is accurate. All manufactures use this method also. It is recommended that after 500-1000 miles to flush the differential and install new fluid to flush out the old break in oil and what metal shavings appear after break in. A small amount of "glitter" as i call it is normal to see after a new set of gears have been installed. I would definately take it back and have them take a look at it. Depending on how bad the whine is, they may be able to re shim the pinion and reset the backlash and you will be good to go. But dont be surprised of they end up needing to install a new set of gears.
11-08-2014, 11:43 PM
#13
Senior Member
Ehh the second picture doesnt cause concern, but a fluid change and flush would be recommended. Inspect the fluid carefully when draining to see how much sparkle there is.
11-10-2014, 10:44 AM
#14
Senior Member
Thread Starter
Got this from Chase Perry, the owner of the ECGS. Normally I wouldn't trust someone telling me this as the consumer who already paid the bill, but he's known for his honestly so I'll take his word:
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
11-10-2014, 10:52 AM
#15
Senior Member
Got this from Chase Perry, the owner of the ECGS. Normally I wouldn't trust someone telling me this as the consumer who already paid the bill, but he's known for his honestly so I'll take his word:
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
11-10-2014, 10:55 AM
#16
Senior Member
Thread Starter
12-09-2014, 01:05 AM
#17
Got this from Chase Perry, the owner of the ECGS. Normally I wouldn't trust someone telling me this as the consumer who already paid the bill, but he's known for his honestly so I'll take his word:
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
"The diff is currently filled to the factory level. The mag tech will allow more fluid to be held, Don’t go above the second line though as it will be overfilled and shoot for the lower line it changes pretty quick. Your temps are excellent for a new diff on a long ride like that . Diff fluid does not break down/ change properties until 280 degrees The lucas we use advertise much hire number than that in excess of the 325. The metal on the stick is normal it’s a strong magnet and will pick it up from anywhere in the housing. The decel whine is gear whine and is normal with a 9.75 diff with aftermarket gears they are highly susceptible to noise even with an OE gear it is just the nature of the diff. The noise should not change. IE it was their immediately after regear and I it will not go away or get worse. If the noise was to change get worse then it would be a concern. Thanks, Chase
From:
Sent: Saturday, November 08, 2014 2:29 PM
Good afternoon,
I checked the dipstick this morning and there were some shavings which I expected (see attached photo).
Also, there is a noticeable whine during deceleration. It's only during deceleration; it sounds fine during acceleration. Is this normal? I have followed all the break in procedures and even measured the diff temps with my infrared thermometer. The hottest I saw them was 180 degrees which was the first time I pulled over after driving for 30 minutes (I pulled over just south of Raleigh). The second time I measured them in Sanford they were 140 degrees.
Lastly, the fluid level was barely on the dipstick (see attached photo). Not sure how visible it is in the picture, but the fluid was only about 1/4 of an inch up the dipstick. Is there a reason the tech did not fill it up to the full mark? Or is it not necessary to fill the fluid up to the full mark with these Mag-Hytec diff covers? If it is necessary, I think I'll add some fluid because I would hate to run it low.
Thanks.
I have this setup...4.56 and 9.75.....Yukon gears....I have the decel whine too....and was told the same thing by the guy that did it who was a friend that has setup gears as long as I can remember...Im use to it now soo it doesnt bother me anymore.....Ive pulled a tandem axle landscape trailer for over 20000 miles with the gears...no problems.. + Doesn't bother me
Last edited by DaughtryLc; 12-09-2014 at 01:14 AM.
The following users liked this post:
jonbar87 (12-09-2014)
12-09-2014, 09:04 AM
#18
Senior Member
Thread Starter
I have this setup...4.56 and 9.75.....Yukon gears....I have the decel whine too....and was told the same thing by the guy that did it who was a friend that has setup gears as long as I can remember...Im use to it now soo it doesnt bother me anymore.....Ive pulled a tandem axle landscape trailer for over 20000 miles with the gears...no problems.. + Doesn't bother me
12-09-2014, 09:17 AM
#19
Snow Engineer
Thanks for the info! My whine is starting to go away as well. Now that I've passed the break in period and changed the fluid, I've gotten on it pretty hard and nothing has locked up (yet) so hopefully it's ok. I've heard a lot of people say these gears have a whine so I'm not too concerned. Thanks again for the vote of confidence.
Thanks!
12-09-2014, 11:32 AM
#20
Senior Member
Thread Starter
