With gear "break in".....

**clg82** · 01-28-2009, 05:00 PM

Hey everyone I am going to get my 3.73 gears installed at the end of February and have to drive about 1 and a half to 2 hours away to get them installed. The guy that is installing them is very reputiable, but he is saying that I can drive straight home without stopping (for lunch maybe) and it won't harm the gears as long as i'm not flogging it......is this true will I be ok without stopping or will this be bad for the gears?~Chris

**bills98ta** · 01-28-2009, 05:54 PM

You'll be OK !!!

**bigrondownhiller** · 01-29-2009, 01:12 PM

Drive about 500 miles being easy on them and have them rechecked and have the gear oil changed.

**clg82** · 01-29-2009, 01:38 PM

Anyone else with any suggestions?

**Bottesini** · 01-29-2009, 02:32 PM

The way we broke in my 9" was to run it on stands getting up to idle in 4th gear. Then shut the car down with the clutch in and listen for any noise. Next we took it out for a short 5-10 mile drive, keeping it easy on the throttle. Looked for leaks and made sure the casing was not to hot (also on test drive listen for noise). Let the car sit for about an hour and then pounded on it.

**clg82** · 02-03-2009, 07:50 PM

anyone else with any suggestions or will i be ok to drive home?

**1TA LS1** · 02-03-2009, 09:00 PM

You'll be fine driving home. The only problem would be holding yourself back from driving it hard to try the new gears. Just baby it for about 250-500 miles and you'll be fine. That's what I did when I got 3.73. One of the best mods do date. Where are you getting the work done?

**JoshieDoom** · 02-03-2009, 10:19 PM

From what I have read you need to put some heat cycles on it before you beat on it, and when you stop let it cool all the way off.

**oldmanZ28** · 02-04-2009, 05:07 AM

drain/change the fluid,visual inspection of the drained fluid will tell a lot about what's going on in there.
Is it just the gears that are being changed or are you changing posi/differential too?

**clg82** · 02-04-2009, 07:55 AM

Originally Posted by oldmanZ28

drain/change the fluid,visual inspection of the drained fluid will tell a lot about what's going on in there.
Is it just the gears that are being changed or are you changing posi/differential too?

nope not changing the differential....just the shims bearing etc etc etc.

**stephen02ws6** · 02-04-2009, 08:01 AM

i would stop on the way home to let the gears cool down. that might help with keeping them from making noise.

**oldmanZ28** · 02-04-2009, 08:07 AM

visual examination of the drained fluid should then only show the gear break-in.Some gearsets are bronze phosfide coated to help break-in and there the fluid would show a 'bronzy' color,some are 'black/grey' coated with something to help break-in.Depending on the set you're using,initial drain should show some discolorization away from the normal transparent dark brown of the virgin fluid.
Only thing bad would be particles that are large enough to settle out quickly.

**Jays00ss** · 02-04-2009, 04:31 PM

for me I have always done a 3 step cool down. drive the car for 10-15 minutes, stop and let cool for at least an hour. do that 3 times. Then I take it easy for 500 miles varying my speed. Then I change my oil, then give her hell. Never had any "whining" issues when you properly break in your gears.