Maybe this is a stupid question guys but i am not a mechanic anyway. My question is, i just had 4.56 Precision gears installed on my Mark LT 4X4 truck 2 days ago and i read a lot of things about break-in period like this from Precision Gears website:



1. Insure that the axle has been filled to the correct level with
proper hypoid lubricant before driving the vehicle.
The oil rating must be GL5 or higher.

2. Bring the axle to normal operating temperature by driving the
vehicle (unloaded) for approximately 15 to 20 miles. Do not
run full throttle accelerations or create any shock loads.

3. Let the axle assembly cool completely.

4. For the next 200 miles of operation, drive gently, without any
heavy loads.

5. If trailer towing is intended, an additional cycle of 200 to 300
miles of break-in is required without the trailer. This is important!
To properly break-in a new gear set, a minimum of 500 miles of
driving is essential before towing.

Ok, here is the question, if my truck is a 4X4, do i have to engage the 4X4 traction in order to break in the front gears too or it doens not make sense. Thnaks a lot guys.

 

no you do not need to engage 4x4, your ring and pinion in the front are spinning they just arent getting any input(power) from the transfer, you should be fine i recomend a 500 mile mixed driving no long trip break in with a fliud change at 500 miles when i do gears, good luck

 

-Joe

edit: Just realized it was a MarkLT, not a 150.... ignore my initial post....

You'll need to manually engage the front hubs, and that means connecting the vacuum lines that lock them in to a vacuum source. I don't know where the control solenoid is for them offhand.... need to do some reading first.

-Joe

Second edit:

Just found this in the service manual:
So, if I'm reading this correctly, the IWEs are vacuum-RELEASE, spring-lock. Simply disconnecting the vacuum line to the solenoid, un-plugging it, or disconnecting and capping the vacuum lines on the IWEs should engage the front axle and get the gears spinning without locking the vehicle in 4wd (which you should never do on dry pavement).

That's my best suggestion at this point.

-Joe

 

GIJoeCam
Senior Member Join Date: Jan 2000
Location: Along Lake Erie
Vehicle: 2000 Ford F-150
Posts: 1,682


-Joe

edit: Just realized it was a MarkLT, not a 150.... ignore my initial post....

You'll need to manually engage the front hubs, and that means connecting the vacuum lines that lock them in to a vacuum source. I don't know where the control solenoid is for them offhand.... need to do some reading first.

-Joe

Second edit:

Just found this in the service manual:

Quote:
Pinpoint Test K: The Front Axle Does Not Engage/Disengage Correctly/Makes Noise In 2H Under Heavy Throttle

Normal Operation
In 2WD, the 4WD control module (PCM) supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front axle). In 4WD, the 4WD control module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the hubs engaged. Systematically check the necessary inputs and outputs at the 4WD control module (PCM), internal components of the transfer case, mode select switch, IWE components and drive axles.





So, if I'm reading this correctly, the IWEs are vacuum-RELEASE, spring-lock. Simply disconnecting the vacuum line to the solenoid, un-plugging it, or disconnecting and capping the vacuum lines on the IWEs should engage the front axle and get the gears spinning without locking the vehicle in 4wd (which you should never do on dry pavement).

That's my best suggestion at this point.

-Joe







Why your opinion is a lot different than what BIGTRUCK 311 wrote down.
He said that i don't have to do anything special to break in the front ring and pinion, he said "just drive the vehicule normally and the front axle will spin the ring and pinion automatically without the truck being in 4X4.

 

I believe he is incorrect. As far as I know, the information I posted from the service manual is correct. With the transfer case disengaged and the hubs unlocked, what is going to cause the gears to spin? They won't spin on their own and, therefore, cannot break in.

He is incorrect even for his own specific model of truck. In his truck, when in 2wd, the center axle disconnect breaks the passenger side axle shaft. The Front driveshaft, pinion, and ring gear stop turning, and the spider gears start differentiating 100%. There is nothing to drive the front axle even in his truck.

The Integrated Wheel Ends in your truck completely disconnect the wheels from the differential. With no wheels connected and the transfer case disengaged, what's going to drive the front gear-set?

I'm no expert, by any means, but am I missing something?

-Joe

 

i will get back to this have to call a supplier at presision gear, get bact to you tomarow, i got alot to say

 

I have my 4.10 gears and eaton e locker ready to go in the front of my truck. I don't plan on breaking them in. I don't see much point in it since you only use the gears in 4wd. When you get a truck new you don't break in the front gears.

 

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What did you find out? I'm kinda curious to what you all have to say, as I've been doing alot of research on the front end of these things lately. Kinda curious as to what to believe or not.

 

what they told me was that unless it will be used for very long times in 4x4 (IE baya) that nothing more than the recomended break in for the rear was needed, the front does not need any modification to break in and that normal mixed driving and fluid change at the recomended interval of the gear manufactuer was all that would be needed

 

How's it going to break in if it's not turning? And what's the recommended break-in for the rear?

 

it will break in when you use 4x4, but this is not that often and usualy for short periods of time, that is why you will not need any extra break in for the front unless you are going long distances in 4x4 (IE baya type activities) and each gear manufactuer recomended break in is alittle diffrent some recomend 250 miles mixed driving with no towing and full throttle runs some recomend 500 miles then a lube change, i recomend a 500 mile mixed driving no extended highway trips and no towing untill 500 miles than a fluid change and then gears will be properly broke in, but if in doubt call the manufatuer of the ring and pinion set and follow their break in instructions