At what miles can I start to tow?

[DuckhunterInTN]

I have about 900 miles on my lly/alli and I assume that this is enough miles to tow with it now, right? I plan on towing around 11k with it.

Is there anything I need to do before or after I tow, i.e., change rearend fluid, etc?

[BLUMAX]

You should be pretty good to tow, I waited until 1500 miles changed oil/filter, even the ally spin-on filter. Thats a bit of weight so take it easy the first few miles, remember your tranny is still in the learning mode until about 4000 miles I think. Also plan on changing that rear end fluid after about 500 mles or so of towing. Of course opinions will vary and hopefully others will add their experience, but sounds like your on the right track to make sure it's "broke in" before hookin' up.

[Heartbeat Hauler]

Ditto what Blu Max said. 500 miles of town driving, then hook up and go which helps breakin the rear gears. How many miles round trip are you towing? After about 500 miles towing is when you should change the rear diff oil...it was 1000mi for me. Also, changing your Allison spin-on @ 500 miles is a good idea, but make sure you do it @ 5000mi too. I did mine at 500 miles and then right around 5200mi. I started throwing a code. GM said it was a clogged spin-on filter. Enjoy.
JP

[DuckhunterInTN]

Thanks guys. I pulled it around some yesterday...about 60 miles or so. It towed great.

Someone else said to keep it under 50mph the first 500 miles of towing? Is that true? it seems like an awful long time...


Heartbeat,
So it was clogged because you went 200 miles over? Geez...

[Kennedy]

I'd suggest changing your oil now, and again after another 1000 miles.

[Heartbeat Hauler]

Originally posted by DuckhunterInTN:
Thanks guys. I pulled it around some yesterday...about 60 miles or so. It towed great.

Someone else said to keep it under 50mph the first 500 miles of towing? Is that true? it seems like an awful long time...


Heartbeat,
So it was clogged because you went 200 miles over? Geez... No, it was because I went 4500mi over. I changed it at 500mi and didn't know to change it at 5000mi. AS far as keepin' it under 50 while towing, makes for a very long trip. My first tow as I said was a 1000mi round trip. After about a 100mi of 55mph I couldn't take it anymore and finished the trip at around 70mph.

disclaimer: Gm suggests a 500mi break-in period of stop & go driving before towing, and a 500mi break-in while towing at reduced speeds. "Experts" suggest a gear oil change after the 500mi of towing.
JP

[silverback]

Based on my milage records, I did my first short tow at approximately 700 miles. I've done quite a bit ever since. My Chevy service manager basically scoffed at my questions about changing the rear diff fluid as it's synthetic in the 04's. He said not needed until 50K miles.

[mark45678]

change the rear end fluid with your first oil change, dont listen to the service MGR! its WAY to late and its out of warrenty! If your still not sure if you should ask a tec that does the work how much fine metal is in the oil in the rear end after just a few hundred miles!!!! both my 2001 and the 2004 had a nice siver metalic fluid in them....

[jbplock]

Here is a snip from TxDoc's original Eaton Locker topic: Eaton's Recommendations on Locking Rear Diff Service (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=7;t=002814). ... Note the comment about carbon from the clutch surfaces...

"From Mr. Ralph Holmquist of Eaton, the maker of the locking differential: "The maintenance schedule for the rear axle was developed by American Axle & Manufacturing and GM truck based on multiple tests. The Eaton locker does not require additional maintenance nor does it add heat to the lube. The lube will darken due to the carbon wear on the clutch surfaces, much the same as a disc brake pad & rotor. This does not damage axle components such as seals or bearings. However, a new axle can produce excessive temperatures (plus 350 degrees F) due to the ring & pinion breaking in that will break the lube additives down. Avoid high loads, trailer towing and high speed extended driving during the initial break in of the vehicle. After the break in period axle temps will level at a much lower figure. Lube changes are a good idea because the additives are replenished and contaminates such as casting sand are eliminated. The axle is filled at the factory with a synthetic 75w90 GL5 rating made by Texaco under part # 2276. The GM service # is 12378261."

smile.gif

[DuckhunterInTN]

Is the best rear end oil to use still the "grape" juice from GM?

Should I change the Alli filter too? What about the trans fluid?


Heartbeat Hauler,
I did not mean that you said that about the 500 miles of towing at 50mph...someone else said that on another forum

Kennedy,
So I assume the motor will be "broken in" at that mileage? What oil is recommended? Is it true that synthetic oil should not be used until some more miles are on it?

[dakotakid]

Some of these posts have brought up changing the rear end fluid early. At 4500 miles I just changed it (and the tranny filter) this morning. It seemed like there was plenty of deposits on the magnetic plug - and it was definitely not all fine stuff. At what stage do I become alarmed at what comes out with the diff fluid? I had one of the guys change it on the 2002, so I can't remember what that one looked like...

Pat

[BassinRVer]

My 02 owner's manual says to change the rear diff after 500 miles and 01,02,03,04 and 05 all have synthic oil from the factory.