Gear lube change

[tallpaul]

How many miles should I put on my new 4.10's before I change the fluid? How many miles before they are broken in? I was thinking at least 1K miles. Any recommendations on which fluid to use? I have about 650 miles on the gears.

[ImpalaSlayer]

How many miles should I put on my new 4.10's before I change the fluid? How many miles before they are broken in? I was thinking at least 1K miles. Any recommendations on which fluid to use? I have about 650 miles on the gears.

they are plenty broken in, go beat the crap out of it. id say change the fluid when ever.

[rayjay]

Royal Purple gear oil.

[Zack]

Gears dont require break-in, LOL

[ImpalaSlayer]

Gears dont require break-in, LOL

amen dude. i dont get where this comes from

[Zack]

amen dude. i dont get where this comes from

It comes from people believing pure idiots.

Just like your transmission needs to break in after a rebuild, :laugh:

[FordNut]

I'd change it after about 50k.

[Zack]

I'd change it after about 50k.

^^^^Good advice.
The gears arent gonna shed metal if they were set up properly

[FordNut]

And that's probably about the time it will need to come apart for new clutches.

[babbage]

amen dude. i dont get where this comes from
Break in with dyno oil - go easy for first 500 miles - especially with 4.10's Then change to a quality synthetic like Royal Purple, AMSOIL, or Redline.

I don't agree. Here is a quote from an owner of a ring and pinon manufacturer. How can you argue with logic?


In most stock vehicles with stock tires there is seldom a risk of a burned gear set. For those of us who modify and use our trucks, there many situations that can contribute to burned gear syndrome. Motorhomes, towing, tall tires, and high numeric gear ratios (4.10 & up) can all generate a lot of heat and cause the gear oil to break down. The greatest damage to a new gear set results when it has been run for ten minutes or more during the first 500 miles and the oil is very hot. Any heavy use or overloading while the oil is extremely hot will cause it to break down and allow irreversible damage to the ring & pinion. In order to make them run cooler and quieter, new gears are lapped at the factory. However, they are not lapped under the same pressures that driving creates. The loads generated while driving, force any microscopic high spots on the gear teeth back into the surface of the metal. This is called "work hardening". Work hardening is similar to forging in the way that it compresses the metal molecules into a very compact and hard formation. This can only be accomplished if the metal surfaces are lubricated and the gear temperature stays cool enough that the molecular structure does not change. If the temperature of the metal gets hot enough to change the molecular structure, it will soften the surface instead of hardening it. This may seen like a balancing act but it all happens easily & passively as long as the oil keeps the gear cool while it is breaking in. Some of the synthetic oils on the market today can help a gear set live longer. I’ve had great success with Red Line ®, Torco ®, and Richmond Gear ® synthetic gear oils. These oils will continue to lubricate at temperatures where many crude oils break down.
Even with synthetic oils, I still recommend the following procedure for breaking in a new gear set: After driving the first 15 to 20 miles it is best to stop and let the differential cool before proceeding. Keep the vehicle at speeds below 60 mph for the first 100 miles. I also recommend putting at least 500 miles on the new gear set before heavy use or towing. During the first 45 miles of towing it helps to go about 15 miles at a time before stopping to let the differential cool for 15 minutes before continuing. This is necessary because not all of the gear tooth is making contact until it is heavily loaded. When towing, the teeth flex to contact completely, and cause the previously unloaded portion of the teeth to touch and work harden. All of this may seem like paranoia, but it is very easy to damage the ring & pinion by overloading before the teeth are broken in. If you take it easy on a new ring & pinion and keep it full of high quality oil, it should last a lot longer.

[RF Overlord]

After 650 miles, they're broken in already.

If you replaced the gears just for the upgrade...IOW there was nothing else wrong, like bad axles...then you don't need to change the gear lube again. If you're really set on doing it, then use Motorcraft 75W-140 synthetic. That's what Ford supplies in the axle TSB kit.

[babbage]

After 650 miles, they're broken in already.

If you replaced the gears just for the upgrade...IOW there was nothing else wrong, like bad axles...then you don't need to change the gear lube again. If you're really set on doing it, then use Motorcraft 75W-140 synthetic. That's what Ford supplies in the axle TSB kit.

Wrong. Gear oil should be changed after first 500 break in miles - there is metal particulate in the fluid. Don't take my word for it -- I'd suggest you call Motive Gear or Richmond or even Ford Racing they will tell you all he same thing: Brake them in with dyno oil, take it easy for 500 miles, then change the diff oil.

[FordNut]

When the Ford dealer changed mine out they said there was no need to change the oil as in "break-in". But if you got money to waste, go right ahead.

[RF Overlord]

babbage, you do know that many Ford vehicles come with 75W-140 synthetic gear lube from the factory, right?. If it was so crucial to break them in with dino oil, why would Ford not do that?

[ImpalaSlayer]

babbage, you do know that many Ford vehicles come with 75W-140 synthetic gear lube from the factory, right?. If it was so crucial to break them in with dino oil, why would Ford not do that?
exactly. plus im sure there isnt a 500 mile maintenance note for the rear end.

[babbage]

3:55 are different than 4:10

[babbage]

babbage, you do know that many Ford vehicles come with 75W-140 synthetic gear lube from the factory, right?. If it was so crucial to break them in with dino oil, why would Ford not do that?
Factory assemblies are done with robotics plus factory cars do not usually come with do 4:10s do they??

Call ANY aftermarket gear manufacturer and ask them if there is a process to break the gears in. there is! I double dare you to ask them why... you MAY be able to get by without doing it -- but this site is visited by people who love thier cars and would rather do it right.

AMSOIL says dont use their gear oil until the gears are broken in. ask yourself why that is...They do not even make gears. Motive gear states they get way more gear failures by customers who started out with full synth.

The above are facts not opinon.

[ImpalaSlayer]

Factory assemblies are done with robotics plus factory cars do not usually come with do 4:10s do they??

Call ANY aftermarket gear manufacturer and ask them if there is a process to break the gears in. there is! I double dare you to ask them why... you MAY be able to get by without doing it -- but this site is visited by people who love thier cars and would rather do it right.

AMSOIL says dont use their gear oil until the gears are broken in. ask yourself why that is...They do not even make gears. Motive gear states they get way more gear failures by customers who started out with full synth.

The above are facts not opinon.

all im saying is when i had mine done by a guy who has prolly done thousand and he filled it up with synthetic RP fluid. how does synthetic fluid cause a gear to fail? its 2 metal gears, not the most complicated thing in the world.

[fastblackmerc]

Factory assemblies are done with robotics plus factory cars do not usually come with do 4:10s do they??

Call ANY aftermarket gear manufacturer and ask them if there is a process to break the gears in. there is! I double dare you to ask them why... you MAY be able to get by without doing it -- but this site is visited by people who love thier cars and would rather do it right.

AMSOIL says dont use their gear oil until the gears are broken in. ask yourself why that is...They do not even make gears. Motive gear states they get way more gear failures by customers who started out with full synth.

The above are facts not opinon.

Well I call B.S.

This is a fact...............

I had my FRP 4.10's installed at 15K with Redline 75w140 oil and no friction modifier. Now I have 67k on the car and there is no, I repeat no noise from the rear. The only break in I did was no burnouts and no constant speed for the 1st 500 miles.

[Phrog_gunner]

When at all possible, I do my best to not believe what "THEY" say (no offense to The Stig, or fastblackmerc) and whenever possible use the opportunity to educate myself with original sources. I even posted links for your viewing pleasure.

While I did find MANY websites that pretty much had the exact same procedure (Drive for about 10 miles and then let the gears cool down and then take it easy on ring and pinion for the first 300 miles), NONE of the manufacturers had this in their instructions.

Ford Racing Parts:

http://www.fordracingparts.com/download/instructionsheets/FordInstShtRing-And-Pinion.pdf

Richmond Gear:

http://www.richmondgear.com/01instructions.html

Richmond Gear Recommends Full Synthetic gear lube on installation.



I found some Motive Gear Instructions that were almost word for word to the above two links but I didn't post it because it was "second hand".

The last step in both above original sources was to fill with fluid to the proper level and mentioned NOTHING about a "break in" procedure or changing the fluid.

[babbage]

The FRPP document above is stale it said to use EP85-90. It is a generic document that does not take into account 4:10 ratios.

I actually called Motive and asked them if there was a break in procedure for their 8.8 gear sets. Again they said to use dyno oil, as it lets the gears get hotter and will properly compound and harden them during initial break in for the first 500, then to change it out with synthetic which will help keep the heat and friction down once they are broken in - this is the best way to deal with higher numerical gear sets.

Jim you *can* do it the way you did - I but it isn't the *best* possible way. Plus you leave the metal particulate in the fluid for 67K+ Which is another benefit/reason to use the dino gear oil for break-in.

[fastblackmerc]

The FRPP document above is stale it said to use EP85-90. It is a generic document that does not take into account 4:10 ratios.

I actually called Motive and asked them if there was a break in procedure for their 8.8 gear sets. Again they said to use dyno oil, as it lets the gears get hotter and will properly compound and harden them during initial break in for the first 500, then to change it out with synthetic which will help keep the heat and friction down once they are broken in - this is the best way to deal with higher numerical gear sets.

Jim you *can* do it the way you did - I but it isn't the *best* possible way. Plus you leave the metal particulate in the fluid for 67K+ Which is another benefit/reason to use the dino gear oil for break-in.
I actually changed the oil at 45k.

[Midnight]

...........

[Marauderjack]

Funny how some just have to argue about "feel good" service requirements!!!:shake:

The damn gears don't know they are 4.10's or 3.55's and the fill plug magnet will pick up any ferrous metal particles that may 'wear' off!!:beer:

Most manufactures don't recommend changing the rear end fluid for 100K miles......do what makes you happy...it's YOUR CAR!!:D

[babbage]

Funny how some just have to argue about "feel good" service requirements!!!:shake:

The damn gears don't know they are 4.10's or 3.55's


Brand new 4.10 gears shouldn't be driven at 80Mph for constant hours on end.
You can however drive factory 3.55 gears at 80 for constant hours on end.

:argue:

[FordNut]

Brand new 4.10 gears shouldn't be driven at 80Mph for constant hours on end.
You can however drive factory 3.55 gears at 80 for constant hours on end.

:argue:

Why???????

[Marauderjack]

WHY x 2!!!!!:confused:

[babbage]

Why???????

The gears will overheat. Instead of compacting and being hardened the metal will instead weaken and could strip or fail if they get too hot.


Here is one example: http://www.precisiongear.com/pgtechbreak.htm

There are thousands of such examples on the net by most gear manufacturers.

[babbage]

BREAK IN
A new ring and pinion installation, especially a high numeric ratio with new bearings, can cause an excessive heat buildup in the rear end and cause softening of the gear teeth and bearings if a break in is not performed.
Street vehicles should be driven at normal street driving speed for approximately 10 miles, then stop and let cool for 30 minutes. Do this 2 to 3 times. Towing vehicles need approximately 200-300 miles of normal street driving before being used for towing.
On circle track race cars make approximately 6 to 8 laps at slow speed, then let cool for 30 minutes. Make 6 to 8 more laps at slow speed, then 2 to 3 laps at full speed, the let cool again for 30 minutes.
Drag cars need only an initial run-in since they are driven short distances and heat is not normally a problem with proper lube and backlash allowance.
NOTE: If after the above break in is performed, overheating of the rear end is suspected, repeat the final portion of the break in procedures.


http://www.richmondgear.com/01instructions.html

[babbage]

http://www.differentials.com/install.html

Gear Oil, Additive and Break-In

Use a gasket or 100% silicone to seal the cover or third member to the housing. Use only high quality name brand gear oil and fill the differential until the oil spills out the plug hole. Positraction carriers require anti-friction additive.
All new gear sets require a break-in period to prevent damage from overheating. After driving the first 15 or 20 miles you must let the differential cool for 30-40 minutes before proceeding. Drive 500 easy miles before towing. Tow for very short distances (less than 15 miles) and let the differential cool before continuing during the first 45 towing miles. Change the gear oil after the first 500 miles. This will remove any metal particles or phosphorus coating that has come from the new gear set.

ANY OVERLOADING OR OVERHEATING CAN CAUSE THE GEAR OIL TO BREAKDOWN AND THE RING & PINION CAN FAIL.

[babbage]

Great info here and pictures.
http://www.explorerforum.com/forums/showthread.php?t=144780


The Break-In Period
This is the most crucial part of the gear install.

Gears have to be broken in properly or they will fail within the first 500 miles of installation. Most gear sets fail because people neglect that they need to break in the gears.

It’s pretty easy. Drive for no more then 10-30 minutes at a time. Make sure you give your differential adequate time to cool after driving (at least an hour).

Drive normally. You should be alright gassing the petal a little bit, just put any extreme stress on the differential until the 500 break-in period has expired.

Make sure you set your Trip meter after your install, so you know when the 500 mile mark comes. When it does, change the gear oil. You should take notice of any metal shavings and debris in the gear oil. If anything seems a bit excessive then closely examine the (with gear marking compound) gears and make sure they are meshing properly. You never know, you might have gotten some debris in the shims and gotten a false preload setting?

[fastblackmerc]

Great info here and pictures.
http://www.explorerforum.com/forums/showthread.php?t=144780


The Break-In Period
This is the most crucial part of the gear install.

Gears have to be broken in properly or they will fail within the first 500 miles of installation. Most gear sets fail because people neglect that they need to break in the gears.

It’s pretty easy. Drive for no more then 10-30 minutes at a time. Make sure you give your differential adequate time to cool after driving (at least an hour).

Drive normally. You should be alright gassing the petal a little bit, just put any extreme stress on the differential until the 500 break-in period has expired.

Make sure you set your Trip meter after your install, so you know when the 500 mile mark comes. When it does, change the gear oil. You should take notice of any metal shavings and debris in the gear oil. If anything seems a bit excessive then closely examine the (with gear marking compound) gears and make sure they are meshing properly. You never know, you might have gotten some debris in the shims and gotten a false preload setting?

OK, so did anyone do that on their new car?

I think not.

I drained my rear end oil after many more than 500 miles and there were NO metal shavings r debris on the oil or in the case or on the magnet.

In your other post you refer to numerically high gears...... so if I have 3.23's 3.55's are numerically higher yet you state in yet another post that 3.55 gears didn't need to be broken in.

I just think you need to be easy on any new gears during the first 300 - 500 miles and use a quality oil either synthetic (preferred) or dino.

[Marauderjack]

CYA for the manufacturer!!:rolleyes:

Just how hot do you think they get under severe load with synthetic gear lube???:confused:

[FordNut]

Never had a gear problem, never done a break-in lube change, never done a "take it easy for 500 miles". Been through numerous gear changes on both 8.8 and 9" Ford rear ends with no problems. I'll continue to do it my way, you can throw away perfectly good lubricant if you want to.

[Marauderjack]

Sintered metal gears are manufactured to exact tolerances and then heat treated to harden them to around 30 Rockwell hardness (I just read that) which is pretty darn hard!!:beer:

When we rebuilt my rear end at 177K miles the gears still showed the machine marks (though shiny) and met OEM tolerances....at 214K miles still quiet and doing well!!:bows:

To each his own but I don't buy the argument that 4.10's generate more heat unless you do burnouts long enough to set your tires on FIRE??:eek: Even then I don't think you will ever get hot enough to degrade the lubricant!!:shake:

I'm done with this one!!!;)