This is topic How to Break in New Gears in forum Tech Talk at Northern California Ford Owners  .


To visit this topic, use this URL:
https://californiafords.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=004622

---

Posted by blue88lx (Member # 2970) on :
 
Tomorrow morning Im getting my 3.73s installed in Santa Clara. What is the correct way I should go about breaking them in. Im racing at Sacramento Saturday night so I want to get 500 miles on them the correct way!
 

---

Posted by 91sleeper (Member # 779) on :
 
The heating and cooling process is what is important not miles themselves. To heat up the gears and then slowly cool tempers and strenthens the gears. Basically drive around come home sit for 2 hours, then go drive around again do that a few times (3-4) and you will be good to go.

I had my gears installed saturday morning and was racing on them that night.

Have fun with them
 

---

Posted by 91sleeper (Member # 779) on :
 
I notice you have an AOD, go with 3.73's NOT 3.55's.

3.55's will make you feel but 3.73's will make you feel

Trust me

Oh and for your next mod get a good set of Drag radials either Nitto or BFG and get a torque converter that stalls no lower than 3,000 rpm's

[ June 30, 2003, 04:39 PM: Message edited by: 91sleeper ]
 

---

Posted by 91sleeper (Member # 779) on :
 
dbl post.

[ June 30, 2003, 04:38 PM: Message edited by: 91sleeper ]
 

---

Posted by Blown GR40 Mystic (Member # 476) on :
 

quote:

---

Originally posted by 91sleeper:
I notice you have an AOD, go with 3.73's NOT 3.55's.

3.55's will make you feel but 3.73's will make you feel

Trust me

---

quote:

---

Originally posted by Blown GR40 Mystic:

quote:

---

Originally posted by 91sleeper:
I notice you have an AOD, go with 3.73's NOT 3.55's.

3.55's will make you feel but 3.73's will make you feel

Trust me

---

isnt that what he said?

---

quote:

---

Originally posted by blue88lx:
I got 3.73s! You said, "drive around". How long should I before letting them cool?

---

I'd say 20min. Doesn't take long for them to heat up. Make sure you give like an hour or two for them to cool off though.
 

---

Posted by PeNiNsula302 (Member # 1061) on :
 
blue88-- have you ran @ the track before? If so what times? Also what tires will you be on sat. night? We might be a good run
 

---

Posted by RioredGT (Member # 2300) on :
 
How funny, I just finished breaking mine in
I take it you're going down to Rearend Specialties?? I can summarize what the paper that they gave me for breaking in the gears says.
Basically for the first 100 miles you can only drive it 15-20 miles at a time and cannot drive it over 50mph. You have to stop and let the differential cool for 30 minutes after every one of these short 20 mile trips. They stress that you go easy on them. For the next 400 miles you you have to keep your speed at 65mph and under, still taking it easy on them. And that's pretty much it.
You don't know how happy I was to finally hit the 500 miles, now I don't have to drive around like a grandma. Have fun
 

---

Posted by RioredGT (Member # 2300) on :
 
Sorry double post......

[ June 30, 2003, 10:01 PM: Message edited by: RioredGT ]
 

---

Posted by Black94 5.0 (Member # 655) on :
 
Its funny, I had Rearend Specialties put in two gear sets and both made a whining noise...I made sure I followed the break-in instructions too!!!..

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

I would make sure to change the fliud after a few hundred miles just to get the metal shavings out from the gears breaking in...
 

---

Posted by y2kgt01 (Member # 1257) on :
 
if they were installed right u dont need to break gears in
 

---

Posted by 50PrNcEsSGT (Member # 2308) on :
 
When I got mine installed he told me to drive it around try not to go on the freeway I think once u hit a certian mph they start to spark n e ways drive it around on the streets for awhile then after about 500 miles I would change all the fluids this is what I was told to do and did and mine have been fine so far. Good luck
 

---

Posted by 91sleeper (Member # 779) on :
 

quote:

---

Originally posted by Black94 5.0:
Its funny, I had Rearend Specialties put in two gear sets and both made a whining noise...I made sure I followed the break-in instructions too!!!..

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

I would make sure to change the fliud after a few hundred miles just to get the metal shavings out from the gears breaking in...

---

quote:

---

Originally posted by y2kgt01:
if they were installed right u dont need to break gears in

---

Don't know about that, if you don't do many heat up and cool down periods your gears will not become tempered and they will be weak. Go run slics at the track and well see if you break some teeth off.
 

---

Posted by MR GO FAST (Member # 2088) on :
 

quote:

---

Originally posted by Black94 5.0:
Its funny, I had Rearend Specialties put in two gear sets and both made a whining noise...I made sure I followed the break-in instructions too!!!..

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

I would make sure to change the fliud after a few hundred miles just to get the metal shavings out from the gears breaking in...

---

quote:

---

Originally posted by MR GO FAST:

quote:

---

Originally posted by Black94 5.0:
Its funny, I had Rearend Specialties put in two gear sets and both made a whining noise...I made sure I followed the break-in instructions too!!!..

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

I would make sure to change the fliud after a few hundred miles just to get the metal shavings out from the gears breaking in...

---

What place did you take it to?

---

It says in his post rear end specialties.
 

---

Posted by MR GO FAST (Member # 2088) on :
 

quote:

---

Originally posted by Black94 5.0:

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

---

 

---

Posted by Black94 5.0 (Member # 655) on :
 

quote:

---

Originally posted by MR GO FAST:

quote:

---

Originally posted by Black94 5.0:
Its funny, I had Rearend Specialties put in two gear sets and both made a whining noise...I made sure I followed the break-in instructions too!!!..

The next place I had install my (current) gears told me I could drive it "however I fuckin wanted"!!...The owner of the shop even drove with me on the freeway to make sure that they didnt whine...I havent had any problems and they dont whine at all...

I would make sure to change the fliud after a few hundred miles just to get the metal shavings out from the gears breaking in...

---

What place did you take it to?

---

I took it to Bay Area Specialties in Fremont....Sal, that USED to own the shop had a couple of 10 second cars...He also had a 9 second Willy's pro-street blown big block that he drove to work every day.. I figured this guy knew what he was doin....
 

---

Posted by st5150 (Member # 51) on :
 
Here is something to ponder about gear break-in:

Why doesn't Ford tell you to do any special break-ins when you buy a new Mustang?
 

---