Typerod

Hi all,

So I'll be picking up my Tahoe either today or tomorrow from the transmission shop where its getting its rear differential rebuilt. They are replacing the pinion gear and its pertinent bearings, the differential and its carrier bearings, the ring gear, both rear axle bearings and seals. And the right front axle seal which is slightly leaking. All parts that will be replaced are OEM GM, and the gearing with remain the same as what the car was built with.

So I asked the owner if there is a break in procedure, and he said no, just pretty much just drive it. BUT, when I googled, there is a lot of talk about there being a break in procedure, and the change the diff. fluid at a certain mileage soon after the rebuild.

From what I have read, there needs to be a proper heat cycling of the gears, so I would need to drive for a few miles stop and pull over and let it cool down, and to avoid highway driving (which would be impossible, b/c I need to get on the highway to get home much faster), and they say if highway travel is a must to not go over 55mph, another thread i read said don't go over 60 mph during the break-in period.

So can someone please confirm if there is a break-in period or do I just drive it? just and FYI, I don't go off roading in my Tahoe or tow.

Thanks in advance!

tech2

nope...they don't do that for new vehicles...why rebuilds.

Typerod

Thank you!!

cleveland63b

theres a lot of old timers and google mechanics that believe it absolutely has to be done but honestly the gears will "heat treat" themselves just driving anyway, never heard of known of a reason why you couldn't go interstate speeds right away if somethings wrong its more likely to fail on acceleration than cruise.


I build it, fill it and give it a normal test drive which is usually around 7 miles mostly highway and ship it.

Typerod

I picked up the car a few hours ago, and just drove it like as suggested. I asked a couple of other guys there and they said the same, just drive it. I love the no sound of whine or grinding, its awesome. They did a great job as far as I can tell. Both noises are gone. Too bad it cost me ~$3500, lol.

Thanks to everyone for their input!

in2pro

I would consider a blend of those ideas, do keep the speed reasonable 55-60mph, avoid hard takeoffs, do pull over and let it rest if driving for more than a hour at a time and I would consider changing the fluid after the first 500, but I do think old school
If nothing else, changing the fluid within 2500 miles would at least give you an idea of how it's doing and wearing and it's not costly...

Typerod

lol, on the way home, I was going anywhere from 60-80 mph, I just kept varying my speed. =) I just may change the fluid early, still debating, lol.