Time for First Full Service

04Chevy2500HD · January 24, 2004

Well I have now almost reached 5000 Miles on my DMAX and it is time for its first full service. Should I just go with the recommend fluids or does someone have anything better to recommend.

Motor Oil?

Diff Fluid?

T-Case?

Tranny?

Now I am also a little confused on the Allison filters. Are there two filter or just the spin on?

Thanks,

David

JayMan · January 25, 2004

You'll notice I have a 1500 but a buddy has a 2002 2500HD D/A and is almost as picky as me. This goes a LONG way to explaining why we're still single ...

He works on his truck in my heated shop, and we appear to at least agree on truck maintenance: for example, we intend to keep them forever. Anyhoo, here is what I'd recommend and currently use, see if you agree:

Front axle: Mobil MobilLube SHC 75W-90, changed yearly

Rear Axle: Mobil 1 Gear Oil 75W-90, changed yearly (Need LS additives for G80)

Motor: Mobil Delvac 1 5W-40 year round.

Trans: Mobil 1 ATF (Allison approval for HD C4 applications)

Transfer case: Mobil 1 ATF. Better cold temp operation, case stays cleaner

I don't know how long you intend to keep the truck. If you intend to trade off every 2-4 years, or are currently leasing, I wouldn't even open the hood. Just drive it.

If you DO intend to keep the truck forever, the earlier you get the "initial" service out of the way, the better. Virtually 100% of wear particles are generated within 2,000 miles of initial use, so the faster you get that crap out, the better.

You'll notice I use/recommend some Mobil Commercial lubes, as I have them in stock in my shop. You can't use a commercial gear lube intended for Eaton Dana extended warranties in the GM rear axle if you have the G80 "locker" or the clutch plates will slip - that's why Mobil 1 Gear Oil in the rear to keep the G80 working.

Some picky folks like to wrestle the sheet metal cover off the rear axle to inspect the magnets for pieces. I did this on my truck at 600 and 1,200 miles initial, so did my buddy. Nothing dramatic found, very light fuzz. Don't forget that the Helm shop manual recommends another rear gear oil change within 600 miles of towing for the first time.

Delvac 1 5W-40 is GM approved for year round use. It's superior to regular 15W-40, reduces oil consumption, offers much better turbo bearing protection, and is good for most cold climates. Hot temp use under load or towing is superior to regular 15W-40.

Especially if you live in an area of cold temps - below 0 F - using a synthetic in the front axle, motor, transmission, and transfer case will ease operation and prevent cold temp wear/failure.

Note that Allison recommends a "preheat" on their automatic transmissions. With a regular ATF, this "preheat" starts at around -12 F. With a synthetic you "preheat" at -22 F. The term "preheat" means to warm the fluid up before operation: using a special electric pan heater or letting the motor run in Park for 20 minutes.

Local Allison operators report that using Mobil 1 ATF works very well in cold temps such that at -40 F, 3-5 minutes preheat is all you need. I strongly recommend/encourage you to venture to the Allison web site and download the Quick Service manual. It's free and chock full of good tips to ensure long life.

There are two Allison filters: the external spin-on and a filter sock in the pan. Allison suggests all you do is drain the pan and replace the spin-on: don't forget there is a magnet above the filter that must be inspected/cleaned. The filter sock in the pan is designed to protect the main pump from obvious chunks and is only replaced during overhaul.

Picky folks like to also drop the pan to inspect/clean the pan magnets and inspect the filter sock. My buddy did this at around 2,000 initial miles. There were a few pieces of fuzz on the pan magnets and the filter sock appeared clean, though he replaced it anyway.

The spin-on filter and magnet appear to do a VERY good job, so I'm not sure if it's worthwhile dropping the pan. Once you do the initial service, the Allison should be good for 50,000 miles or 24 months.

Can't think of much else to recommend, the initial service is the most important.

BlackSilver · January 25, 2004

Well I have now almost reached 5000 Miles on my DMAX and it is time for its first full service.

Motor Oil? Rotella 15W/40, WIX filter

Diff Fluid? Leave it alone - you're only at 5K - waste of $$

T-Case? Leave it alone - you're only at 5K - waste of $$

Tranny? Leave it alone - you're only at 5K - waste of $$

Take the money you saved and change the fuel filter --- that's the place to be picky on these high-pressure injector systems.

Now I am also a little confused on the Allison filters. Are there two filter or just the spin on? There are two --- a small spin-off and a traditional internal one. Change the spin-off and leave the internal one alone.

JayMan · January 25, 2004

Allison recommends the initial service at or before 5,000 miles. This is in the official Allison Quick Service book. Good tip on the factory fuel filter. My bulk tanks run Racor two-stage filter heads, so I have much less of an issue of water/dirt in my commercial trucks.

I figure it cost me an additional $35 to service the axles when I did ($4.25/quart SHC 75W-90, $5.25 / quart Mobil 1 Gear Oil). If you want maximum long life, change the axle gear oil early. Places like Reider Racing and Randy's Ring & Pinion strongly recommend the initial service at 600 miles, then every year or two.

You live in MN, right? The front axle will have short life thanks to the factory fill 80W-90. GM must have had enough failures and complaints to finally issue a TSB: new trucks at the dealer immediately receive a front axle fluid change to synthetic 75W-90.

The Allison especially I would NOT skimp. I'm sure it'll last through warranty, but this nickle-n-diming nonsense will NEVER save enough money to approach the cost of a new/rebuilt part.

Since I service my front/rear axles and AutoTrak every fall, the additional fluids cost me $35.

I figure over the past 4 years all this "wasted" servicing has cost me about (Initial service $110 plus yearly axle and AutoTrak servicing at $35) $250 over doing NOTHING.

I like to go almost every morning to Tim Horton's for a coffee and something yummy to nibble on: $2.50 to $6.75, depending on what I pick. Over the course of a year, about $672 on average. I suppose if I really REALLY want to nickle-n-dime, and do something about the start of my spare tire, I'd cut out the morning yummy routine. Thing is, most folks p*** away at least this much money each and every single year on snacks and yummies.

These trucks are VERY easy to DIY service. The Allison service will cost about $75 if you do it yourself, assuming you use Mobil 1 ATF. After this initial service, every 24 months or 50,000 miles.

The local dealer strongly recommends at least the Duramax oil change AND the initial Allison service at 2,500km / 1,500mi. Wonder why??

BTW: a 15W-40 should NOT be used in cold temps -10 F or colder. My local dealer recommends either a blend 0W-30/0W-40 or a synthetic 5W-40 for these temps. Especially at -30 F or colder, a 15W-40 is hard as a brick.

As I stated earlier, if you lease or trade often, never open the hood. Just drive it. There are some folks who like to keep vehicles a long time, so they figure the "wasted money" with this extra servicing is worth it.

I still have a 1984 Ford F-150 with +300,000 miles. Since new, the extra cost of yearly rustproofing and aggressive initial servicing has cost me about $2,800. Looks and runs like new. If this isn't important, that's fine.

04Chevy2500HD · January 25, 2004

Well the amount I paid for this thing. I will never be allowed to get anything else. LOL. Anyway thank you for all the information. You have any idea off the top of your head how much fluid I should plan on dumping in each one of those?

-David

JayMan · January 26, 2004

My friend has a 2002 GMC Sierra 2500HD with Duramax and Allison. I could ask him to check his book to verify the capacities but no guarantee it's the same for yours.

There should be a section near the back of your Owner's Manual that lists all fluid specifications and levels. Check the index under "Fluid" "Specification" or "Level."

Take your time and it's a very easy truck to service. Not like certain trucks out there with artsy ovals on their grilles, or certain baaaaaaaaaaaa sheep horns on the hood.

If you know what I mean.

Roofer · January 26, 2004

Rear axle- about 4 quarts

front axle- 2-2 1/2 quarts (I think) order extra, can always use it

changing allison filter-less than 1 quart

I know lots of guys with diesels here in MN and most just use 15-40 Rotella. Synthetic would be nice in winter, but I would never go lighter than 10-30 in any V8 engine.

Last winter we went to 10-30 Rotella on the PSD and it started maybe a tad better in really cold weather. That old tractor engine only starts good in cold weather when it is plugged in. The Dmax starts much better.

Synthetic oil flows well at low temps. I see no reason going to such a light grade.

JimWilson · January 26, 2004

Diff Fluid? Leave it alone - you're only at 5K - waste of $$
T-Case? Leave it alone - you're only at 5K - waste of $$

Tranny? Leave it alone - you're only at 5K - waste of $$

Can't say I agree with any of this. For the price you paid for the truck the amount you would spend swapping these fluids, whether or not it actually could be classified as "too soon" (which is really just a matter of opinion anyway), is incalculably small. In other words, it's silly not to.

Mobil 1, which is what I went with, can be had for a decent price. Certainly better then those VERY over-priced GM fluids. And M1 is 100% compatible, so there's no worries about using it.

All in all, "early" driveline maintenance is a good thing. And certainly worth the money spent.

JayMan · January 26, 2004

Rear axle- about 4 quarts
front axle- 2-2 1/2 quarts (I think) order extra, can always use it

changing allison filter-less than 1 quart

I know lots of guys with diesels here in MN and most just use 15-40 Rotella. Synthetic would be nice in winter, but I would never go lighter than 10-30 in any V8 engine.

Last winter we went to 10-30 Rotella on the PSD and it started maybe a tad better in really cold weather. That old tractor engine only starts good in cold weather when it is plugged in. The Dmax starts much better.

Synthetic oil flows well at low temps. I see no reason going to such a light grade.

If I recall the pan drain and spin-on for my friend's 2002 D/A was about 14.5 quarts.

I would never EVER use a 15W-40 in temps below 0 F. The "borderline" pumping temp for a 15W-40 bottoms out at around -4 F. Any colder than that and you run the risk of slow or no lubrication on startup.

I've seen large Cat, DDA, and Cummins motors ruined because some fool was too cheap to switch to a winter grade. One guy with a Cat 3406 series motor: On start-up at -35 F, the oil pump drive off the gear sheared off and he was so busy poking the Ether button to keep the motor running he didn't happen to notice the oil pressure firmly on "0." Ka-boom.

I run commercial trucks and they run Mobil Delvac 1 5W-40 year round. My friend with his 2002 Duramax tried the Delvac 1 for the first year but felt it was too expensive.

Instead, he runs Esso XD-3 15W-40 summer and Esso XD-3 0W-40 winter. This is a VERY reasonable compromise and I would see no reason not to run it either, except I'm sold on the pure synthetic Delvac 1 5W-40.

FWIW the Esso XD-3 0W-40 is now a pure synthetic as well, priced about 1/2 of what Delvac 1 is, and actually has a lower BPT compared to Delvac 1.

Check with your local Cat dealer: they also stock their rebranded synthetic 5W-40 and "Arctic" 0W-30. Like Cummins, Cat does NOT want a 15W-40 used in cold ambient temps, and their cutoff is 15 F for a 15W-40.

I would check with GM to see if they recommend a 15W-40 in MN temps. I know here in Canada they want you to use a synthetic 5W-40, or a 0W-40 / 0W-30 Blend in temps below -18 C / 0 F.

It's not so much how well it starts in cold temps, but how quickly they build oil pressure. Turbo's are especially sensitive to needing quick oil flow on startup. True, I would be leery running any xW-30 in a HD diesel due to the lower HTHS and increased hot wear, but you can get synthetic 5W-40's and nice blended 0W-40's that give great low temp flow AND operating temp protection.

Just a friendly bit of advice. Those motors are expensive and I sure would hate to see it die in cold temps. You don't "save" any money by running a heavy oil in temps colder than 0 F.

Roofer · January 26, 2004

Great info Jayman. When I changed the spin on filter on the allison I did not drain the fluid. If I remember correctly, the filter change at 5K does not require a drain. I thought the drain was at 25K for heavy towing and 50K for normal use, but I could be wrong. I also thought it requires Transyn (sp) Castrol fluid. The newer Mobil stuff might have the correct specs. Not sure.

BTW, what is that stuff you say you use as an additive on the G80 locker? What is it for?

JayMan · January 27, 2004

Diff Fluid? Leave it alone - you're only at 5K - waste of $$
T-Case? Leave it alone - you're only at 5K - waste of $$

Tranny? Leave it alone - you're only at 5K - waste of $$

Can't say I agree with any of this. For the price you paid for the truck the amount you would spend swapping these fluids, whether or not it actually could be classified as "too soon" (which is really just a matter of opinion anyway), is incalculably small. In other words, it's silly not to.

Mobil 1, which is what I went with, can be had for a decent price. Certainly better then those VERY over-priced GM fluids. And M1 is 100% compatible, so there's no worries about using it.

All in all, "early" driveline maintenance is a good thing. And certainly worth the money spent.

A man after me own heart! For my friend with the 2002 2500HD, this "aggresive" initial service schedule at 600 miles for the axles/Allison/transfer and 1,500 miles for the Duramax cost around $165 total.

That's not a reall big deal is it? I figure how much I p*** away every morning at Tim Horton's having a coffee, a yummie, and socializing, the initial service is pretty tame to swallow.

If you want to keep it forever, this is real cheap to do. If you lease or trade often, never open the hood.

Though I bet you don't change your power steering fluid as often as I do!

JayMan · January 27, 2004

Great info Jayman. When I changed the spin on filter on the allison I did not drain the fluid. If I remember correctly, the filter change at 5K does not require a drain. I thought the drain was at 25K for heavy towing and 50K for normal use, but I could be wrong. I also thought it requires Transyn (sp) Castrol fluid. The newer Mobil stuff might have the correct specs. Not sure.

BTW, what is that stuff you say you use as an additive on the G80 locker? What is it for?

Roofer: those are good questions.

Here is what I recommend on the Allison. First of all, my friend with the 2002 GMC Sierra Duramax/Allison is a field service tech for the local Cummins shop. He puts on a lot of miles and has to usually drive to some God Forsaken part of the bush to work on kaput logging trucks and skidders. No thanks, that's no fun at -40 F!

He didn't even look at the GM Allison supplement but got his information straight from Allison. Like any commercial equipment maker, Allison has a web site that is chock full of good operating and service tips:

http://www.allisontransmission.com

The AL1000 used in the GM brand "light" trucks is part of the 1000/2000/2400 family. If you wish, you can order the detailed service manual from Allison. I recommend the On Highway Operators Guide, which is a FREE Adobe Acrobat file. Look at:

http://www.allisontransmission.com/publica...bs/OM3063EN.jsp

On the manual my friend downloaded and printed, Page 56 has the suggested service interval schedules: initial filter change at or before 5,000 miles, then pan drain and filter change every 24 months or 50,000 miles.

My friend has some service experience with Allison and in no uncertain terms made clear to me that you should do a pan drain as well at 5,000 miles. It's really foolish to not drain the pan as well to get the factory crud out. The extra "cost" was around $74. He was really adament about this.

You have to understand he depends on his truck for work in temps from +98 F in summer to -40 in winter. He wanted to get in the synthetic ASAP so he wouldn't have to worry about cold temps when he was stuck working in the bush somewhere.

TranSynd is awfully expensive and is primarily intended for extending drains in severe service in HD applications, such as refuse packer and city transit bus (Otherwise every 12 months or 25,000 miles, up to 100,000 miles on TranSynd). For LD applications like the Gm trucks, I don't think Allison approves an extended-drain anyway.

For the 1000/2000/2400 series, Allison's primary fluid recommendation is Dexron III, same as any other GM truck. Many of Allison's off-highway and HD auto's carry dual Dexron III / Allison C4 lube requirements. Mobil 1 ATF meets/exceeds Dexron III and C4.

Mobil 1 ATF actually has "builder approval" to Allison C4 specs, which are for HD Allison use. TranSynd is Allison's answer to extended drains in their HD auto's, you can also use Mobil 1 ATF but not get extended drain approval in those particular HD applications. I guess Allison realized they were losing money by not having a unique branded product.

Note: do NOT use TranSynd in a 4L60E or 4L80E, the unique friction modifiers might cause shift problems.

I had to use extra additives in my G80 due to a boo-boo I made at my initial service at 600 miles. I have pails of commercial gear oil in my shop, and at the time was finishing off a pail of Exxon SGO 75W-90. I intended to use it in both axles and found out about 2 months later my G80 was slipping and chattering like crazy.

I called Exxon and they were just horrified: their SGO is designed to meet extended warranty and extended drain for HD axles like my Eaton Dana HP-40's. Even though it meets GL-5, the additives used for meeting Eaton Dana extended warranty specs are so slippery that clutches in a Limited Slip stop working and can glaze. They have since put a tiny warning on their pails "not for limited-slip service."

I drained and refilled with a cheap NAPA 80W-90 (Claimed limited slip service fill) and 3 tubes of CRC Trans-X Posi Trak Limited Slip additive. After about 2 weeks of driving around the G80 came back to life. I drained and refilled with 1 tube of CRC and Mobil 1 Gear Oil 75W-90.

The Mobil 1 Gear Oil claims suitable for Limited Slip service, so I probably don't need to add the CRC. But I figure I had some glazing on my G80 clutch plates so felt I might as well continue using the additive. My G80 still seems to work good in winter.

Hopefully, you won't make such a dumb a** mistake like I did, so just use the Mobil 1 Gear Oil as it is.

Shark Bait · January 27, 2004

From JayMan

Front axle: Mobil MobilLube SHC 75W-90, changed yearly

Rear Axle: Mobil 1 Gear Oil 75W-90, changed yearly (Need LS additives for G80)

Motor: Mobil Delvac 1 5W-40 year round.

Trans: Mobil 1 ATF (Allison approval for HD C4 applications)

Transfer case: Mobil 1 ATF. Better cold temp operation, case stays cleaner

JayMan - You have me a liitle confused. Many years ago I used M-1 SHC 75W90 but lately I have only been able to find "M-1 High Performance Synthetic Gear Lube 75W90".

When I checked the M-1 web site they only reference the Synthetic Gear Lube. I can't find a reference to the SHC 75W90.

Are they both still made? (Can't call the M-1 distributer tonight)

If so what is the difference? It would seem to me that you could use the M-1 Gear Lube (not the SHC) in the front diff as well as the rear.

Anyone else using the "M-1 High Performance Synthetic Gear Lube 75W90" in the front diff??

Roofer · January 27, 2004

I still see no reason to drain the tranny fluid at 5K. It is just a waste, especially for an average driver. The filter has a nice big magnet on it, and when I changed mine, the fluid looked like brand new. If someone wanted to for peace-of-mind, fine. Otherwise, it is not worth it. Just my opinion. $74 might not be much at all, but I have seen more gripe over a 5 cent increase in gas prices.