Gears & Axles - Break in motive 3.73 gears?

Ill be driving the car home 80 miles from the shop with new 3.73 motive gears. Mostly all highway. What is the way these need to be broken in? This will be a major PITA if I need to keep the mph low and stop a million times coming home to let them cool :bang:

What do you guys say?
:cheers:

Per the instructions, what you are planning on doing is exactly what they say not to do. At the very least stop once and let it cool. New gears get HOT.

Yeah, I would drive it ten miles or so stopping and going regularly throughout the trip. After the 10 miles, stop and get something to eat or something so the gear set can cool off a bit and do it again. Should be fine to do whatever after that. It really doesn't take much to break in new gears.

Well I made a 60 mile trip nonstop on the highway. Installer said he did a couple cycles after the install and I would be fine.

from what i researched when i did mine (and my friends 8.8), the initial heat cycle was the most important. Once you heat and cool down the first time, you can drive around without a problem, just no punishment. Honestly, I did some street launches after 200 miles and haven't had any issues, but i still wouldn't recommend it till after 500 just to be safe.

changing speeds every ten minutes helps things seat i was told. im still breaking in my 4.10s.

If you have to drive all highway, take every other on/off ramp so you will not have a constant load on the gears. This varies things a bit and I believe helps a lot. I even do this when I buy new cars! I also agree with one of the other posts. Drive about 10 minutes and get something to eat. Then I would drive another 30 minutes and repeat after an hour of cool down drive an hour and let it cool down and then you are home!

I believe in 3 heat cycles. I dont know if its right, but its always worked for me!

Joe

The bulider and tuner (which I trust) put 2 cyles on before I picked up the car.

1 Took the the car for a test drive for 10 miles up to 50mph...then let car sit at his shop maybe 15 min.
2 Drove car 60miles on highway then car sat for 2-3 hrs.
3 Drove car home on highway 30 miles then car sat 3 hrs.
4 Then that night took car out, drove 15 miles highway/street and let car sit 15 min. I did this (#4) 3 times before bringing the car home to sit over night.

Anyone see anything wrong with this? lol I have 200miles on the gears so far.

Nope, you're good man. Take it out and have fun now :P

;16543799']Nope, you're good man. Take it out and have fun now :P

Yea? Cant wait!

I took it for a 15 mile ride today on way to gym, let it cool for 45 min. Then took for another ride 15 miles and now ill let it cool maybe a couple hrs.
I was thinking on putting another 100 miles on or so today then letting it cool, and then having fun. Think im all set though huh? :D

id have it drained and refilled and you should be good.

I drove 2 heat cycles with low diff fluid. It had a very slight wine at 50. Now, even after a fluid change at 1000 miles, 5K miles later my gears are starting to get louder :(

Did a couple more cycles today and did some 1/2 and 3/4 throttle. I can hear the gears whining.

mine dont whine. i dont think thats good.

If you are hearing whining it is most definitely due to improper set up. Most likely, pinion depth is off just a touch. As long as the whine isn't unbearable, it won't hurt anything. if it were me, I would take it back to them and ask them to fix it. Before they even try, don't let them feed you the same BS as everyone else.. "Sometimes different manufacturers gears whine." That would be false lol.

Its not loud at all. On the highway I can hear it very little but on decel I hear it just a tiny bit more. You have to know what your listening for to actually hear it.

mine 4.10s dont whine. my 3.73s did and they fell apart.

Well no use crying over stuff I cant control...lets see how long they last before I get a 12 bolt or 9" aye? ha

Well no use crying over stuff I cant control...lets see how long they last before I get a 12 bolt or 9" aye? ha

normal driving itll last awhile. at least mine did. but it was a time bomb lol.

When I put 373's in my 98, they screamed until I got around 1k miles on them and the noise pretty much went away. Probably wasn't the smart thing to do to keep driving it, never had any problems though.

normal driving itll last awhile. at least mine did. but it was a time bomb lol.

Well we all know this car isnt driving miss daisy so f that junk lol


When I put 373's in my 98, they screamed until I got around 1k miles on them and the noise pretty much went away. Probably wasn't the smart thing to do to keep driving it, never had any problems though.

So what happened they ended up fine?

This is from Motive's website...24. Troubleshooting the correct problem will help the customer, installer and manufacturer. Remember, THERE
ARE ACCEPTABLE NOISE LEVELS which vary from manufacturer to manufacturer. Noise that may be
normal as per manufacturer, may be strange to a consumer unaware of acceptable noise. Explain
acceptable noise levels to your customer. If noise remains an issue, double check your tolerances for accuracy,
then call us for help.
25. Break in of gears is paramount to gear life. Initial run in should be at low speeds. This will enable gears to
run in without overheating

This too..Change the rearend fluid at 1000 miles. This is because during break-in, the gears and bearings will have
some material chip off or wear off, contaminating the fluid. Many chemicals used in heat treating or case
hardening are from the potassium nitrate family. This mixed with gear oil produces a number of corrosive
acids. These acids also break down the oil film, rendering the lubricant useless. Steel to steel contact then
happens leading to ultimate failure.

So what happened they ended up fine?

Yeah, never had a problem with them. Rebuilt the rear end and threw those in along with some other mods at 179k miles, haha. Didn't really break them in right or anything. Had to drive 60 miles round-trip to work 6 days a week, all mostly all highway, or at least 55 mph+.


My new TA has 273's in them so I'll have to upgrade the carrier when I put 373's or 410's in so I'll definitely keep more of an eye on it.

When I had my 10 bolt with 4.10s it was loud on decel, but was told its ok as long as its not all the time on or off the gas. About 5k mi of me driving the hell out of it it got noticably louder. We took it apart and found the pinion nut loose and the carrier bolts, how it didnt blow up I dont know. We reassembled it and the noise was barely there to our supprise. Two weeks later I went to the strip and 10-12 passes later it was a lot louder lol. I beat the snot out of the ten bolt and never blew up shockingly. When I pulled it apart to get the backing plates off for my 9 inch the shims started to back out spacing the carrier. Its one of the ten bolts your hear about surviving. Now my damn 9 inch whines more than the ten but found out last night Im way light on the preload and too much backlash. Im gona scrap the richmonds and get something quieter and start fresh this time. My guess is youll be fine, oh and the 10 bolt had motives.

My Motives are pretty damn loud. He set them up at .005? instead of .008? I think is what it was idk I remember 5 and 8. Anyway, I broke mine in perfect. It was 15 mins to work and part of it was stop and go traffic and part was a backroad at 45-55. So I drove to work, parked for four hours, went to lunch and went on a twenty min drive varying speed, then parked for four hours then went home. Easy money haha. They still whine like hell even after changing gear oil twice but there aren't any chipped teeth or pieces on the magnet so I guess they're ok. I did have it completely rebuilt when I put the gears in.

This is from Motive's website...24. Troubleshooting the correct problem will help the customer, installer and manufacturer. Remember, THERE
ARE ACCEPTABLE NOISE LEVELS which vary from manufacturer to manufacturer. Noise that may be
normal as per manufacturer, may be strange to a consumer unaware of acceptable noise. Explain
acceptable noise levels to your customer. If noise remains an issue, double check your tolerances for accuracy,
then call us for help.
25. Break in of gears is paramount to gear life. Initial run in should be at low speeds. This will enable gears to
run in without overheating

Yea see, some gear will make noise. Mine are around 55mph and not loud at all.


This too..Change the rearend fluid at 1000 miles. This is because during break-in, the gears and bearings will have
some material chip off or wear off, contaminating the fluid. Many chemicals used in heat treating or case
hardening are from the potassium nitrate family. This mixed with gear oil produces a number of corrosive
acids. These acids also break down the oil film, rendering the lubricant useless. Steel to steel contact then
happens leading to ultimate failure.

Is that from motive website? I planned on changing it at 500 miles but maybe ill do 1k instead.


Yeah, never had a problem with them. Rebuilt the rear end and threw those in along with some other mods at 179k miles, haha. Didn't really break them in right or anything. Had to drive 60 miles round-trip to work 6 days a week, all mostly all highway, or at least 55 mph+.


My new TA has 273's in them so I'll have to upgrade the carrier when I put 373's or 410's in so I'll definitely keep more of an eye on it.

Good to hear man. 179k :D :cheers:


When I had my 10 bolt with 4.10s it was loud on decel, but was told its ok as long as its not all the time on or off the gas. About 5k mi of me driving the hell out of it it got noticably louder. We took it apart and found the pinion nut loose and the carrier bolts, how it didnt blow up I dont know. We reassembled it and the noise was barely there to our supprise. Two weeks later I went to the strip and 10-12 passes later it was a lot louder lol. I beat the snot out of the ten bolt and never blew up shockingly. When I pulled it apart to get the backing plates off for my 9 inch the shims started to back out spacing the carrier. Its one of the ten bolts your hear about surviving. Now my damn 9 inch whines more than the ten but found out last night Im way light on the preload and too much backlash. Im gona scrap the richmonds and get something quieter and start fresh this time. My guess is youll be fine, oh and the 10 bolt had motives.


I think its fine to thanks for posting. BTW slowhawk just did my car h c i 3.73 :cheers:


My Motives are pretty damn loud. He set them up at .005? instead of .008? I think is what it was idk I remember 5 and 8. Anyway, I broke mine in perfect. It was 15 mins to work and part of it was stop and go traffic and part was a backroad at 45-55. So I drove to work, parked for four hours, went to lunch and went on a twenty min drive varying speed, then parked for four hours then went home. Easy money haha. They still whine like hell even after changing gear oil twice but there aren't any chipped teeth or pieces on the magnet so I guess they're ok. I did have it completely rebuilt when I put the gears in.

And your gears turned out fine :cheers: