Suburban/Yukon XL 2500 6.0 mpg

[Sonia]

Davis,


I have the Yukon Xl 2500 8.1 litre engine with 4.10. I use it everyday and for pulling our 2005 30' Classic. The tow mirrors that extend are great and make the towing experience much more comfortable.
I get around 12mph in the city and 15 on hwy. With the Airstream and the family loaded for trips, we get around 10mph.
Go on the internet and look for the car that you want, then have the dealer get it for you.

Good luck.

[SilverToy]

John HD, Ken J and all:

Saw the posts on getting the trans checked and fluid changed. Is that all there is to it - fluid swap? Seems to me I heard about a trans flush and filter blah, blah, blah. Tuned it all out at the time as it didn't apply. Now it does and I can't recall what they were hawking at the time.

BTW John HD - drive way is only about 45 long so not to much backing as I have got it 1st time, every time. That actually makes me think of an amusing story. Took ST to an Elks refuge ( not slamming Elks! or their refuges here!) and the "leader" directed me to a spot in an open field. I said, something with some shade?? Well, there is a spot over there but it's toooo tigiht for you to get this rig in. I said, no its not. Went over and checked it out, walked it off and checked clearances. By this time there was quite a crowd of Elks standing around to watch this "Kid" tear up his nice rig. Got in and backed her in the spot right straight on the concrete wheel pads, first time - dead balls perfect! I think I ruined the entertainment for a few guys that day.... So sorry - not! Appearances can be deceiving!?! Boys got skills!

Anyway, back to the point. What does a comrehensive trans service mean anyway? Have a tranny manual somewhere but you guys are faster than me finding that right now....

eric: my passion is early 80's Ballys. Current collection: Supersonic, Night Rider (SS) - sat for 20+ years in a garage, Black Hole (made one great machine out of 2 so-so ones) and my "on the way" one is Theatre of Magic (mid 90's).Actually owned ToM in Austria when we lived there. Nothing collector quality but they (first 3) are some of the machines I played at UIC (you should be able to see the campus from your window - Al's still there? Too bad about Maxwell Street aka Blues Brothers. Is Salvage One still there?) back in the days of college and freedom and.... ;>). I love em, my kids love to bang on em, and they are a GREAT stress relief when I need to get away without going anywhere. Looking for a Xenon and EightBallDeluxe!!!! with the bank shot, Paragon, Lost World, Space Invaders, if you know anyone!

Thanks again to all for the insights and wisdom. Appreciate it more than you can know!

Axel

Thanks all!

Axel

[Bradjun1]

Axel.
The tow/haul mode will make the transmission shift at a higher rpm to help keep you in the power band. The 200 degree temp won't hurt the transmission unless it is maintained for a long period of time and 200 still isn't that bad. If the fluid smells like it's burnt or appears to be burnt after it has cooled down have it replaced. It might be a good investment anyway because you are only 11,000 from scheduled maintainence. I don't think you did any damage.

[john hd]

axel

Is that all there is to it - fluid swap?

umm no!

a good service of your trans would include a complete change of the fluid including the torque converter. something like 21 quarts for a 4L80. the filter would be changed, the pan cleaned, and the magnet in the pan would be "de fuzzed".

not much more than that, a new pan gasket would be included.

check with your chebby dealer and see what get for a price. i couldn't do mine myself for what the dealer charged me. nor would i want to!

john

[SilverToy]

John et al

Called the dealer and made Appt for Wed afternoon. 89 bucks plus misc.... will check that they do the detail things too! Thanks for that heads up! Will get oils changed while its there for that. Been using 10/30 even though recommended it 5/30. Should I go back to 5/30 or will I be setting up a possible valve blow by situation going back to 5/30? Thoughts?

Is the Synthetic trans fluid really all that much better, worth the extra $?

On another related thread. Been trying to get an answer to my question about "over hitching". Vehicle and trailer as previously mentioned. Have a 12K Equal-i-zer hitch with 1200lbs bars. Towed really nice but some of the reading on this site indicates I might be too high with the 1200 bars. Turns out Equal-i-zer hitch heads and bars are sized accordingly, so no 800 bars with a 12K hitch head. Options??? Do I even have any? Just asking as I have the 'rub' on the trailer when the rock skirts/aprons curve on the front of the trailer. Don't want to beat the poor thing to death but really can't get away from the 12K head, and no other bars work with it.... Sigh. Thoughts?

Axel

[Silvertwinkie]

Here is my take and it's my opinion.....others agree and other don't, in the end it's a personal call.

I have dyno in the Suburban for the break in period. Once that is done, I am going full synthetic as I did in the Impala SS. Fully synthetic oils take more abuse than conventional oils. Keep in mind though that even though the syn oils take more abuse, some of the drivetrain components won't take the heat or beatings the oil can. So you can have this bulletproof oil, but still melt your trans if you can't keep it cool as the bands, disc, clutch packs are starting to die after 215 degrees. Here is a breakdown on temps for the trans and what Amsoil state (in their own propaganda tools):

http://www.amsoil.com/storefront/atf.aspx


In addition, once the break in is complete, I plan on adding a deep pan trans cover to the 4L80e trans when I do the basic fluid changes as well as a larger capacity diff cover from Mag-Hytec:

http://www.mag-hytec.com/

My goal is not to overcome long term heat, but to overcome some of the flash heat that happens. On the Impala when I did this, flash heat was kept to a bare min on mile long tows, fully loaded on a similar 14% climb. I was very pleased. I also plan on buying or fabricating a torque converter cover that has an air scoop kind of like this one that I found from Neal that made one for the 4L60e trans that I added to the Impala. You can see one here:

http://www.clearimageautomotive.com/...Drivetrain.htm

One more thing I'd consider if your vehicle is being put into a situation of being at or beyond where it should, would be to add a larger trans cooler. I've watched my in 80 degree outdoor temps and the trans does stay below 200, but it varies between 150 and 195ish. Comes back down, fairly quickly from 195, but I like 150-175 far better and with this possible mods, I think they will help as they did with my 5.7L Impala SS. I did a before and after on the same mountain drive, same distance, same car and Safari without the stated mods and with. The flash heat took me straight to 200 degrees before I got to the top of the mile long hill. After the mods (deep pan, diff cover (though not effecting trans temps), ram air torque converter cover, additional trans cooler, same mile long hill, same outdoor temps, same load, trans got up a bit above 175...maybe 180ish. So in the end I lost 10 to 20 degrees. I also forgot to mention that I put a 160 degree thermostat in and had the car re-programmed to run with the 160 stat...can do that on an LT1, but not on the LS1 based 6.0L (at least I think I can't...for now.....).

[john hd]

axel

Been using 10/30 even though recommended it 5/30.

again, check your manual. if you look closely you will find a chart for oil. you can use 10w/30 for a certain temp range. something like 0 to 100 degrees. seeing that you are currently in new mexico i imagine you fall into that range.

chevrolet reccomends straight 30 wieght for high temps.

as for your WD bars, just lower your chain by a link and try it. don't sweat that too much. all you are doing is putting a little less preload on the bars.

john

[john hd]

axel

one other thing, you may want to consider changing your rear differential oil when you have your truck in for service.

it comes with synthetic oil from the factory.

john

[Davis]

Hi,
I appreciate all the replies. I am going to look at one this weekend at a dealer that is about an 2hrs away and see what I think about it. I already told my local dealer about it and they were not sure if they could transfer it in and at any event they did not give me a good trade value for the vehicle I have so I will try the owning dealer and see if they will give a better trade value.Thanks Davis.

[Bradjun1]

Axel,
In an earlier post I said you could have your fluid erplaced. I should clairify that and say that you cloud have your transmission serviced. This is a more complete service procedure.

[Condoluminum]

For Axel... Change the transmission fluid more often than 50K miles, and especially when funky transmission smell occurs.. It is life-blood of unit, and cheap insurance, and once cooked, it does not have same chemical properties.. Also, while OD is fine for cruising solo, Chevy is very clear in manuals and tech info that OD should not be used when towing a trailer... No disclaimers for level or downhill, it just says don't do it... You might get away with it once or twice for short runs when you forget, but it will shorten life..

And for Davis... Buying a Suburban with a 7700# tow rating to pull a 10,000# trailer and get good mileage is false economy... There are a number of threads on site pointing out that 70 to 80% of rated tow capacity is fair upper limit on trailer weight, given that passengers, fuel in truck, luggage etc count towards that Gross Vehicle Weight Rating.. If you have to drive it every day, and fear the next round of gas wars, I'd even consider buying used (GM's lowball prices on new ones have depressed prices on used ones a lot!!) and bank the difference into gas fund, but get a tow capacity/GVWR of close to 10,000#..

John McG

[Silvertwinkie]

Just for reference....I towed about 20,000 miles in OD, with about 8,000 miles towing both a Bambi and a 25' Safari. Now I heard what Chevy said, but I had the computer re-programmed to lock the TC sooner than later. With 3.73s in 3rd gear it was just way too many RPMs, even with 17" rims. No trans issues at all....so far. But now the car is retired, and we now have a Suburban with Tow/Haul.

Now if you don't activate tow/haul, your driving in OD actually from what I gather on the trucks.

[Foiled Again]

Originally Posted by JBMcG

... Buying a Suburban with a 7700# tow rating to pull a 10,000# trailer and get good mileage is false economy... There are a number of threads on site pointing out that 70 to 80% of rated tow capacity is fair upper limit on trailer weight, given that passengers, fuel in truck, luggage etc count towards that Gross Vehicle Weight Rating..

Towing capacity is important, but BRAKING is more important.

You want an engine that can help slow a heavy trailer coming down a grade! I've got a 2500 Suburban that is big enough to tow a considerably larger trailer than the one I have and on just two trips out I've had one 11% down grade that made me glad I had a big engine!

Tin Lizzie

[SilverToy]

Thanks for that reality check Tin Lizzie!

Just for comparison, how many miles have you 2500 owners gotten on a set of brakes? How many miles on the tires? Are they all tow miles or mixed use? Curious to see the replies.

Axel

[john hd]

axel

tires, 50K from the original firestones.

brakes, still going good at 55K. i'm one of those folks that believes in wearing out the trailer brakes ($200) vs. the trucks brakes ($1200+) so i set my brake controller accordingly.

i also tow almost exclusively in OD, my truck shifts into OD at 67 mph. the trans has seen 200 degrees once, that was in chamberland south dakota. out side air temp was 105 degrees. normal is 180+or-.

john

[Jim W]

The following is a Suburban web site that has very good information on it. They have some members that know more about Suburbans then GM does. Some of these recommendations about oils & cooling devices are very useful. I had my org tranmission replaced by GMC at around 25K miles. I towed a lot in the mtns out west where I live & that probably was the biggest reason for the problem. I only towed in OD on the flat areas. Every thing was standard. No deep trans oil pan, no oil temp guage or extra big trans oil cooler. I hadn't had my first trans service yet, so it still had the org trans oil in it. I was going to have a flush done at 25K miles. GMC replaced it under warranty. Its a 1999 GMC 2500 with the 454 eng & 4:10 rear end with factory tow package.


http://forums.vmag.com/

[driftwood]

Try Edmunds web site for more intellegent conversation ...

For chevrolet suburbans:

HERE

[Silvertwinkie]

Originally Posted by john hd

axel

i'm one of those folks that believes in wearing out the trailer brakes ($200) vs. the trucks brakes ($1200+)

john

Please tell me you're kidding about $1200 for brakes! What kind of brakes do these things have? I figured $500 tops, but $1200 for truck brakes seems a bit high. What's involved?

[john hd]

twink

you haven't tried to get your rotors off yet. they are not like the half tons that just slide off the wheel studs. <read> pull the hubs apart on the front. i have never had one of the new disc rears apart, can't imagine they are cheap either. (wonder why chev went back to drums on the rear in '05?)

i doubt you would even get out of a midas shop for a complete brake job for less than a grand.

like i said, the fully loaded backing plates are way cheaper than your trucks brakes.

john

[Silvertwinkie]

So what yer saying is that the fronts alone cost $1200 and the rears would be similar....so in reality if I read you right there is the *potential* to have approx $2000+ for all four to be replaced. That's completely wacked....I mean I can get a rebuilt 4L60e trans for that price!

So depending on use, is it common to get 50k out of these 3/4 ton brakes and rotors?