Towing questions...

[gman]

wrangler,
I just looked it up. Its 6500 lbs for the suburban with a 5.7L (350) and 3.73 gears not 5000 lbs as you suggested. If your suburban came with towing package it should have an auxilliary trans cooler. Its easy to find. It sits in front of the radiator. One transmission fluid line from the radiator goes the the trans cooler and then the other goes back from cooler to the transmission. Hope it will help you find it. )ne other thing that may help you is change the standard muffler. Put on a dynaflow or a flowmaster. The flowmaster is a bit louder though. This will give you a little more hp. and overall better gas mileage. Hope this helps you.

[bneub]

Wrangler,

After thinking about this I looked at my owners manual on my 2003 expedition 4x4 with a towing package and did some research on the web.

There are some different numbers that you need to consider.

The gross vehicle weight rating (GVRW) is defined as the vehicle, passengers, fuel, cargo, etc. but does not include the trailer. Mine says 7300 lbs.

Looking further in the manual if find gross combined weight raiting (GCWR) which is the maximum allowable weight of a fully loaded tow vehicle plus its fully loaded trailer, including passengers and cargo. Mine is 14500 lbs.

Also listed in my manual is the maximum trailer wieght which for me is 8699 lbs.

You might want to dig through your owners manual because I would think your suburban is similar to my vehicle and should handle your boat if the maximum trailer weight is somewhere between 8000 - 9000 lbs.

The only reason I checked further is when I added the weight of my 20i and trailer, the GVRW wasn't high enough to pull my boat and I knew that couldn't be right!

My father-in-law has been pulling his 20' four winns for 7 years with his 1/2 ton suburban with no transmission troubles. He pulls it over the colorado mountains every year to go to powell.

[wrangler]

Good thoughts and thanks to everybody so far... I did go to the trailerlife.com site and looked up our burban and it is rated for 6500 pounds. I also got into the manual as you describe and it seems that we should be able, given the gcwr as bneub mentioned and I found in our manual...to be able to pull our boat all over kingdom come wtih no problem. I am going to keep digging a bit more and see what I can come up with. Thanks for all the feedback so far...

Now...nobody has given me justification yet to support my desire to go buy a cool looking differential cover with fins and increased capacity...come on guys...help a brother out here. Are they helpful and just cool looking???

Thanks again all...JCK

[gman]

Wrangler,
If You may want, you can change your 3.73 gears to 4.10 gears. A little less mileage per gallon but a LOT more pulling you can do. That way you do not have to purchase a new vehical. You may want to think about air shocks. They work also. I had them on a previous vehical.
Have fun with the boat!

[jsz]

You already have a bunch of good comments here but I thought I'd throw a few more in. I had a 2000 silverado and now have a 2005 GMC Sierra both w/ 5.3 and full tow package (I know they're both different from your 99)

The rear end can make a big difference in the amount you can tow. I think the 99 also offered a 3.23 (not good for a big boat) Make sure you have at least the 3.73

If it came w/ a tow package you may already have a trans cooler and/or oil cooler. follow the lines from the "baby" radiators to see where they go.

GM now has a Tow/Haul button that stretches out each gear (reduced shifting and more power). Very nice to tow with.

[wrangler]

Thanks for the continued good comments... We do have the 3:73 rear end and the "tow package" that came with the 99s. No oil cooler though... I like that idea... Thanks again and keep those posts coming... wrangler

[TeamAllen]

Does your current Trans oil pan have a drain plug? If not there is your excuse, I mean reason, to get a new oil pan with cooling fins, drain plug and more capacity. The larger oil capacity will add to the cooling along with the new aluminum cooling fins. The drain plug will allow you to do the oil changes more frequently and save you money by doing it yourself. Without a drain plug it is a messy deal.

[TeamAllen]

Here are a few links on the subject. The only temperature decrease numbers I saw were on the last website. Up to 45 deg. cooler on the trans. and 15 to 20 deg. on the diff.

Trailer Life
Transmission Life Expectancy
Heavy Duty Transmission Pan

[NICKYPOO]

Came from a 96 3/4ton 454 Burb with tow package to an 04 3/4ton HD Duramax/Allison GMC crew s/b with tow package. No comparison. I think it was pablo who mentioned died and gone to heaven. That's no joke man. They are awesome. If you are any where near your capacity, you're too close. I also put on air bags in the rear along with a class 4 Titan hitch. I've gone over 50,000 miles and haven't needed to touch the brakes once. Suburban; brake job every 12,000 miles. There was a great point on tires also. I put on a set of Pirelli Scorpion xta's that are load range E. What a difference. My point is, when you do get a new truck, get one that is overbuilt for the job, then overbuild it. The stonger ALL the pieces are, the less chance one will break. What is piece of mind worth to you? At least that is how I sold it to my wife. Seriously though, be carefull with that 1/2ton Burb. They are not built for that monster of a Tige.

[wrangler]

That is good guidance and how I will no doubt need to go. My malibu owner friend has a 3/4 ton longbed with the duramax and he loves it. As a matter of fact, he pulled our old deck boat out to Havasu several times at the beginning of the season the last several years.

Thanks again for all the good info and we'll be careful until I get up the nerve, having just bought the new boat, to broach the subject with my wife that she really needs a new truck... Thanks again...wrangler

[NICKYPOO]

Plant them seeds dude. The sooner you do, the sooner you can harvest.

[gman]

wrangler,
If you have a 99 your oil should be cooled through the radiator. Take a look when facing the engine, you should have two metal lines to your radiator on the right hand side. On the left you should have two lines also and these are for your trans. Check to see. You should have the oil cooing option but maybe not.

[raythompson]

Better System is...

to have seperate coolers. Using the radiator for cooling will guarantee that the temperature of the oil or transmission fluid will never get below about 200 degrees, sometimes higher.

Mounting seperate coolers for the transmission and oil in front of the AC condenser is the preferred method for removing heat. And if you really want help in that area mount electric fans in front of the coolers.

Keeping the transmission cool is very important when towing. Cooling the oil allows heat deep within the engine to be removed. Cooling both is highly recommended.

[wrangler]

Trans cooler yes...oil cooler no...

I do have the trans cooler but not the oil cooler as mentioned. That sounds like a good thing to get. I'll do some internet surfing to check out oil coolers... Thanks again... Great thread!!!

[NICKYPOO]

See, now you can tell your wife about how your going to do "all" these modifications to the Burb. Make it sound as technical and as expensive as you can and that your going to do all the work yourself to help "try" and afford them. This will accomplish two things. It will get her thinking about all the money your going to put into a vehicle that you want to sell anyways and even worse, you doing the modifications to the family wagon. Hello Duramax!

Either that or or you get it done under budget and ahead of scedule.
What a guy.