breaking in gears

[beerthirty]

How long do I have to drive soft on my new gears? I just got them put in today, and hoe do I break in the gears in my 44 do I have to drive around in the dirt in 4wd for a while or can I just start wheeling with them? I also got a detroit in the rear and I have a little vibration is this normal. Thanks for your help guys

 

[Mr Joe]

I run the gears for 20 miles, then let them cool. Then I run 50 miles and let them cool. The next couple trips I continue to run easy, letting them cool after 100 miles. You're golden after 500 miles. The fronts, I always take it easy during the first couple wheeling trips.

You could feel a little vibration when installing lower gear sets. The vibration you feel could have been there all along. The pinion is spinning faster then before at the same vehicle speed. If it vibrates too bad, try unbolting the driveshaft and reinstalling it after turning it 180*.

 

[beerthirty]

thank you i will try that. I went for 3.50 to 4.88s so your probably right.

 

[beerthirty]

Do you think i can go wheeling this weekend? I want to try out my new set up. I got 4.88s a detroit in the rear and a aussie in the front, I also got 37's. I want to see the differance from my 3.50s open diffs and 33s. I should be great I cant wait ;D ;D ;D

 

[Nobody]

For front end applications, just wheel it.

 

[rednck21]

as stated above...the key to breaking in gears is several heat and cool cycles...it actually hardens the metals. as for the front...when i break in front gears, ill put it in 4hi with the hubs UNLOCKED and drive around no faster than 45-50mph. that should create a little heat in the front

 

[73stallion]

ditto on the heat and cool routine. we got a card with the 4.11's on jones' bronco and it says run 15, cool 15, run 15, cool 15.

do you have a twin stick? you could always run the rear axle in neutral and cycle the front axle in front wheel drive.

 

[beerthirty]

thats a great idea. Im getting twin stick in a week, and thats what im gonna do. Thanks

 

[Wes harden]

break in question

Do the gears need to be loaded ie humping the truck around. couldn't you build
enough heat letting them be driven by the engine on jack stands ?
just a thought beats diving around in circles and can be monitored for noise and exesive heat.
Wes

 

[Mr Joe]

Do the gears need to be loaded ie humping the truck around. couldn't you build
enough heat letting them be driven by the engine on jack stands ?
just a thought beats diving around in circles and can be monitored for noise and exesive heat.
Wes

Often, I run it on the stands for the first 15-20 miles. This helps with the break-in and you can check for odd noises ;D

 

[SaddleUp]

Keep in mind when you break them in the key is for them to wear the right pattern "BEFORE" they get hot. That is the reason for the cooling time. If you get them too hot right away then they do not have a chance to wear the pattern into them before the gears harden. The reason you do not want to work them hard during the break in period is because they will deflect some under hard use which could wear the pattern in at the wrong spot. The deflection on the front will be even greater than the rear for two reasons. First is that the Ford 9" pinion has an extra bearing that helps prevent the deflection. The second (Unless you run a HP Frontend) is that the front gears drive on the coast side of the gears instead of the drive side. The same is true for a HP 9" used on the rear. I.E. A High Pinion 9" used in the rear also drives on the coast side of the gears.

 

[BabyBlue69]

We would run our race car on jackstands while holding the brakes to break in new gearsets. Check the differential occasionally and when it gets warm to the touch let it cool and then do it again.

 

[supermottl]

I will be wheeling with my new gears up front this weekend. I don't plan on doing anything tremendously hard, so I'm sure I will be fine. Prolly won't need 4WD with the detroit in the back..

 

[sprinksbeme]

when I had mine done the shop had me lock the front hubs and while driving around in 2WD just to get some wear on them before wheeling them hard. Don't Know if right or wrong but made sense.

 

[Merlin76]

I had my gears REM finished. It is supposed to reduce or eliminate "break-in" time. It was a bit pricey, but from what I have heard, it's worth it.... The only article I could find that sorta explains it was here...

http://www.taylor-race.com/isotropic.cfm

We'll see if it really makes a difference once I am running again.

 

[SaddleUp]

when I had mine done the shop had me lock the front hubs and while driving around in 2WD just to get some wear on them before wheeling them hard. Don't Know if right or wrong but made sense.

If you lock the hubs in then you wear the pattern in on the coast side rather than the drive side. I would alternate between locking in the transfer case and the hubs during the initial break in to wear the pattern on both sides.