Scheduled Maintenance

[mc7719]

Hey-

I know what most of you will say.. "Your owners manual is your friend" and the such.. And true it covers the maintenance intervals. HOWEVER, I can't seem to find a scheduled maintenance interval for the rear and front differentials? The transfer case, transmission, etc., is listed.. but not the axles. It does list what kind of lubricant/oil to use (Front: 80W90 axle lubr., Rear: 75W90 Synth axle lubr.).. but not when to change it...

 

What do you guys that are in the know, recommend? I'm coming up to my 50000mi/80000km interval.

[tanked_darren]

Do it when you do your transmission. Transmission severe duty is 80,000kms in the owners manual.

 

My haynes manual (which matches my owners manual in servicing it lists) states it should be done at 160,000kms but its so cheap to do might as well do it at 80,000kms

Haynes manual suggests 50,000kms for transmission and 100,000kms for rear-end.

 

I found some metal in mine. Glad I did it at 80,000kms with my transmission.

 

I will now do both at 40,000kms intervals.

 

Some guys on here do it every year, IMO thats over-kill.

 

Look here for other discussion on this:

http://www.gm-trucks.com/forums/index.php?...le+fluid+change

[mc7719]

thank you!

I DID try searching for a few phrases but didn't come up with that thread.

[Z45]

If you plan to keep the truck a long time its a good idea to change both the front and rear differentials out at about 5,000 miles give or take a few thousand. Lots of heat and wear is generated in the first few hundred miles of use and its just common sense to replace the low bidder oem fluids with high quality synthetics. I prefer AMSOIL Severe Gear 75W-90 and have used it for years. Of course you are free to use what ever but in my opinion you should base your decision on whats the best gear lube to use and not what costs the least.

[Jay69]

If you plan to keep the truck a long time its a good idea to change both the front and rear differentials out at about 5,000 miles give or take a few thousand. Lots of heat and wear is generated in the first few hundred miles of use and its just common sense to replace the low bidder oem fluids with high quality synthetics. I prefer AMSOIL Severe Gear 75W-90 and have used it for years. Of course you are free to use what ever but in my opinion you should base your decision on whats the best gear lube to use and not what costs the least.

 

+1, very good advice.

 

As I have said in the past the rear axels seem to be a week link in the 1/2tons. That is if you are towing and/or loading it down anyway! In my last 2 Suburbans (1990 and 1994) I replaced the rear axels and outer bearings in both of them. Not sure if the our 2011 is the same or not but I'm planing on more rearend oil and inspections.

[ChevyTech77]

Correct, there are no listed service intervals because the every year or 15,000 mile interval that use to be used, was deamed overkill but some of the general public. Plus the now factory fill use of synthetics has pushed that up some but GM deems these axles to be now maintence free. That is why there is no listed service interval.

 

For what it's worth, I still change mine every year. My truck is usually only used for towing things around though and

it is dunked in the lake a few times a year too.

 

I recommend nothing over 30,000 miles to my customers. Especialy if the rear axle has a locking or limited slip diff.

[Ryan00TJ]

We have work trucks that have never had the OEM fluid changed and a few are nearing 200K miles. We've neve encountered a problem yet. That being said, I changed my OEM fluid at 3K miles and replaced with M1 Synthetic. I plan to change them at 50K mile intervals which should be somewhat overkill with Syn fluid and no water contamination or overheating.

[mc7719]

At the 50000mi intervals (listed for transmission service for severe use) I'll just have everything done: both axles, transm, and transfer case.. and keep that up. Better to be safe than sorry

Thanks for all the replies.

[DwayneJ]

If you plan to keep the truck a long time its a good idea to change both the front and rear differentials out at about 5,000 miles give or take a few thousand. Lots of heat and wear is generated in the first few hundred miles of use and its just common sense to replace the low bidder oem fluids with high quality synthetics. I prefer AMSOIL Severe Gear 75W-90 and have used it for years. Of course you are free to use what ever but in my opinion you should base your decision on whats the best gear lube to use and not what costs the least.

 

+1, very good advice.

 

As I have said in the past the rear axels seem to be a week link in the 1/2tons. That is if you are towing and/or loading it down anyway! In my last 2 Suburbans (1990 and 1994) I replaced the rear axels and outer bearings in both of them. Not sure if the our 2011 is the same or not but I'm planing on more rearend oil and inspections.

 

 

There was a time at least during the mid 90s when GM omitted the lube slots in the 8.5" cover gasket this caused a lot of outer axle bearing failures and corrisponding ruined axle shafts. The slots allow oil slung by the ring gear to hit the cover and get pushed out to the axle tubes, when they decided to stop putting those slots in the gasket for a few years axle bearing failures went up though I think the just quietly started putting the slots in again and never truely admitted the mistake.

[tanked_darren]

At the 50000mi intervals (listed for transmission service for severe use) I'll just have everything done: both axles, transm, and transfer case.. and keep that up. Better to be safe than sorry

Thanks for all the replies.

+1

[Jay69]

If you plan to keep the truck a long time its a good idea to change both the front and rear differentials out at about 5,000 miles give or take a few thousand. Lots of heat and wear is generated in the first few hundred miles of use and its just common sense to replace the low bidder oem fluids with high quality synthetics. I prefer AMSOIL Severe Gear 75W-90 and have used it for years. Of course you are free to use what ever but in my opinion you should base your decision on whats the best gear lube to use and not what costs the least.

 

+1, very good advice.

 

As I have said in the past the rear axels seem to be a week link in the 1/2tons. That is if you are towing and/or loading it down anyway! In my last 2 Suburbans (1990 and 1994) I replaced the rear axels and outer bearings in both of them. Not sure if the our 2011 is the same or not but I'm planing on more rearend oil and inspections.

 

 

There was a time at least during the mid 90s when GM omitted the lube slots in the 8.5" cover gasket this caused a lot of outer axle bearing failures and corrisponding ruined axle shafts. The slots allow oil slung by the ring gear to hit the cover and get pushed out to the axle tubes, when they decided to stop putting those slots in the gasket for a few years axle bearing failures went up though I think the just quietly started putting the slots in again and never truely admitted the mistake.

 

 

 

I really hope this is the case. I will say though I got good at tearing it down and giving them a look over and replacement if needed:)

[ChevyTech77]

At the 50000mi intervals (listed for transmission service for severe use) I'll just have everything done: both axles, transm, and transfer case.. and keep that up. Better to be safe than sorry

Thanks for all the replies.

Sounds like a solid plan.

 

There was a time at least during the mid 90s when GM omitted the lube slots in the 8.5" cover gasket this caused a lot of outer axle bearing failures and corrisponding ruined axle shafts. The slots allow oil slung by the ring gear to hit the cover and get pushed out to the axle tubes, when they decided to stop putting those slots in the gasket for a few years axle bearing failures went up though I think the just quietly started putting the slots in again and never truely admitted the mistake.

 

Very true and synthetic oil, just made it worse.