New Dmax just turned 240miles before I found this site and read about the rear end getting hot during break-in. (had been drivin it 70 plus to keep up with traffic) This morning I took it easy 60-70 (you gotta understand I-75 through metro Detroit you can not run much slower than that), then put my hand on the rear cover when I got to work and it was hot! Haven't checked fluid level yet--will do that tonight. Is the rear different than any other? I mean, I put 170k miles on my last truck ('98 Z71) and I never even changed the diff. fluid let alone checked it! I should have 500 by this weekend and will change all fluids except trans (will only change filter). Dealer said I must bring it to them or at least use original filters filters to be covered under warrenty--I said bull___, all I gotta do it document it and keep reciepts--the NAPA guy down the road will have everything I need! Hello, to all you y'all, you'll be hearing from me alot as I learn more about my new diesel. thanks. ps. what is the external-control main filter that the booklet says to change at 7,500 miles? Is that the allison spin on filter?

Well, call me newbie too. Whats this about breaking in the rear end and changing its fluids? I havent ever had a vehicle that required that. My F350 sure didnt.

New Dmax just turned 240miles before I found this site and read about the rear end getting hot during break-in. (had been drivin it 70 plus to keep up with traffic) This morning I took it easy 60-70 (you gotta understand I-75 through metro Detroit you can not run much slower than that), then put my hand on the rear cover when I got to work and it was hot! Haven't checked fluid level yet--will do that tonight. Is the rear different than any other? I mean, I put 170k miles on my last truck ('98 Z71) and I never even changed the diff. fluid let alone checked it! I should have 500 by this weekend and will change all fluids except trans (will only change filter). Dealer said I must bring it to them or at least use original filters filters to be covered under warrenty--I said bull___, all I gotta do it document it and keep reciepts--the NAPA guy down the road will have everything I need! Hello, to all you y'all, you'll be hearing from me alot as I learn more about my new diesel. thanks. ps. what is the external-control main filter that the booklet says to change at 7,500 miles? Is that the allison spin on filter?





Sounds like your dealer has never heard of the Mangum-Moss warranty act. If any vehicle manufacturer requires them to use their filters they MUST provide the filters to the customer at no charge. Sounds like a pesky salesman. Keep in mind that salesmen sell vehicles and often times don't know more than you would about the product after doing 10 minutes of intense research online.


It is that Act that allows aftermarket companies like Purolator and Fram to stay in business (worked at Purolator for 9 years in the engineering dept).


Have a good one.

I took mine into Wal-Mart at 1K miles and they tried to talk me out of getting an oil change. They said it would void the manufacturers warranty. I told them to change it anyway and that the manufacturer cannot void your warranty if someone other than the dealer changed the oil. The dealer may not honor a repair under warranty if the cause for the repair is determined to be the fault of Wal-Mart or whomever you chose to change your oil.

Any idea what that external-control main filter is?

That is the spin-on filter for the Allison.

It is very common to be low on the rear end lube with the Duramax. I have about 1200 miles on mine and changed the oil at 500. I used Delvac 1300 15/40 with the AC Delco filter. I also checked my rear axle and it was very low. I drained it and refilled it with synthetic. MAKE SURE YOU CHECK THE LEVEL IN THE AXLE! even if you don't change it. it holds about 5 1/2 quarts.

It is very common to be low on the rear end lube with the Duramax. I have about 1200 miles on mine and changed the oil at 500. I used Delvac 1300 15/40 with the AC Delco filter. I also checked my rear axle and it was very low. I drained it and refilled it with synthetic. MAKE SURE YOU CHECK THE LEVEL IN THE AXLE! even if you don't change it. it holds about 5 1/2 quarts.


Hmm...


If you put 5 1/2 quarts in it, I think you've overfilled it....http://www.dieselplace.com/forum/smileys/Ermm.gif


GM says it takes 3 3/4 give or take a few hundreths of a quart, that will bring it to about 1/2 inch below the hole which GM says .4 inches is okay. I think 4 quarts will bring it to the fill hole which is what most are doing.


I'd double check if you put that much fluid in the rear end?

I just changed my rear end oil at 500 miles . I Put in Amsoil 70 W 140 for heavy duty towing. I carefuly measured and it had 3 quarts from the Factory and was about 1 In. low. I put back 4 Quarts and it filled to the hole. You should notice a thimble full, more or less, of metal dust on the magnet of the drain plug. Wipe it clean of those fileings that come from the break in. You can use 70 W 90 if you don't tow heavy loads but it should be a good synthetic. Your dealer will charge about $27. or so PER QUART. I bought Amsoil for $12 per Qt.!!!!! The Ole General saves at least $5 per truck by putting in 3 instead of 4 Qts. Then the Dealer charges $27 X 4 to replace it. Quite a racket wouldn't you say???????? http://dieselplace.com/forum/smileys/Evil%20Smile.gif Oh Well I guess I like it when the GM didvidend comes around but I can't do business thata way and sleep at night.http://dieselplace.com/forum/smileys/Confused.gif

Finally checked my rear diff. at 480miles last night. I could not find the level with my little finger! I added a whole quart of 75-90 mobil 1 (that is what I had in the garage). Then figured I better check the front and it was low and took about 1/2 quart. Then checked the transfer case and it was full--in fact as soon as I pulled the plug fluid came out. So I figure I'll put 1000 miles on this thing then change Engine oil and rear diff. and a new allison filter. Then at 5000 miles change out everything. Oh ya, don't buy the AC Delco 2232 filters on ebay, there're charging like $8 each. I went to the local auto parts last night and they are $3.59 !!

What auto parts store (chain) is selling the Duramax AC 2232 oil filter for $3.59? That's sure a lot cheaper than I can find...

I thought it was a miss price at first. Then went back and took two filters to the counter and they were 3.59--should have bought four! Murrys auto parts in MI.

You should have bought a case... Anyone else have any sources for prices like that on oil filters?