CHECK YOUR DIFFS...

rjgvt · February 14

When my truck arrived in January, I asked the sales guy if the the service department could check the front and rear diff levels during prep. He said, sure, no problem. When I picked up the truck, sales guy said it was all good.

Had an appointment today for an oil change at 1161 miles. Figured I’d burn one of “free” oil changes just after break in miles. Requested that they check the diffs since I did not see any paperwork when I got the truck. I requested no tire rotation due to low miles.

Service document stated that lube oil and filter service was performed. Also stated that they checked front and rear fluids, t-case fluid and trans fluid, all are in spec. Keep in mind that the diff fluid level should be 10mm below the fill hole opening. No problem found.

I’ve been running my tire pressures at 55 to 56psi when tires are cold. Tire pressures were at 60/70 psi after service. I waited a few hours after I got home and put them back to 55psi. Will have to request not to change the tire pressures next time!

bruceb58 · February 16

On 2/14/2024 at 1:29 PM, rjgvt said:

When my truck arrived in January, I asked the sales guy if the the service department could check the front and rear diff levels during prep. He said, sure, no problem. When I picked up the truck, sales guy said it was all good.

Had an appointment today for an oil change at 1161 miles. Figured I’d burn one of “free” oil changes just after break in miles. Requested that they check the diffs since I did not see any paperwork when I got the truck. I requested no tire rotation due to low miles.

Service document stated that lube oil and filter service was performed. Also stated that they checked front and rear fluids, t-case fluid and trans fluid, all are in spec. Keep in mind that the diff fluid level should be 10mm below the fill hole opening. No problem found.

I’ve been running my tire pressures at 55 to 56psi when tires are cold. Tire pressures were at 60/70 psi after service. I waited a few hours after I got home and put them back to 55psi. Will have to request not to change the tire pressures next time!

I thought the spec was 0 to 10mm which mean if it's level with the fill hole, it is also good.

rjgvt · February 16

The spec is 0 to 10mm, I wrote what was on the paperwork.

bruceb58 · February 16

9 hours ago, rjgvt said:

The spec is 0 to 10mm, I wrote what was on the paperwork.

OK...I thought you were implying that the correct level was ONLY 10mm down and not a range. Whenever I end up doing mine, I will fill level with the fill hole unless I buy the Banks cover in which I will fill to the middle of the sight glass on it.

elcamino · February 17

Don't know if it was said but some time ago I read service info that said the axle were lube filled at the axle plant, not the final assembly plant. I am sure they use means to cut costs such as filling to the minimum level and with lube from the lowest bidder. .

64BAwagon · February 17

American axle fills the units then ships them to GM. They are not checked during production unless there is an issue in validation/repair

Capt Bob · February 21

I checked my diff yesterday and it measured 25mm below the bottom of the fill so I ordered a quart of AC Delco juice to top it off. I’m now going to check the front and the transfer case. For all I know, my 2018 1500 might have been low. I never checked it till I did the first change at 25k. Still, I’m liking this truck a lot but it’s still early.

Capt Bob · February 24

Rear took a full quart to get it within the 10mm spec. Front took only a small amount but it was below spec.

I plan on a drain and fill at 5K. Is there any reason not to use 75W90 in both front and back rather than having two different specs. I still have two quarts of Redline 75W90 left and would like to use it up.