2007 Avalanche towing Corvette on trailer?

whitestingray81

New Member
Hi all,

I am moving next month from Virginia to Connecticut. I have a 1981 Corvette (~3200 lbs.) that I would like to tow behind my 2007 Avalanche. This is a 450 mile trip, but it would be just the one time. I was planning to rent one of those open car trailers from Budget truck rentals. I have the factory tow hitch, and the previous owner installed an aftermarket tow brake that I have never used. I have the 5.3L flex with the 4L60e.

My question is, is this safe? My transmission has already been replaced at 100k miles (currently has 133k miles). Trans temperatures routinely sees 210 degrees on hot days on the highway, and when there's major NYC traffic stop-and-go, I have seen it as high as 229 WITHOUT towing. I have talked to my transmission shop, and they say installing an aftermarket cooler would almost definitely introduce a leak, so I haven't installed one. They also say that these temps in the summer are normal for my truck.

Anyways, will this one-time 450 mile trip burn up my transmission? Can the high mileage engine handle it? Should I just pay to have it shipped instead? Thanks for all replies!
 

ygmn

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I see no issue as well under truck limits
 

batmanntexas

Full Member
Agree with YGMN, your load is well within the Av's towing ability. GM makes an auxiliary cooler specifically for our trucks, but it does require some effort to install. It utilizes the factory style connectors at all connection points, so you will not have any leaks. Cheap insurance for your transmission, I say.

Most rental car haulers will utilize a surge break, which is an inertia activated hydraulic brake system incorporated into the trailer, so you won't even need your installed brake controller.
 

2004Slickside

Full Member
Do you have the tow button on the end of your gearshift?

Best way to ensure no damage to transmission is to keep your TCC locked up as much as possible. This way the converter does not generate heat from slipping. This means take it easy, and use that tow button. Your Avalanche will tow that Corvette on an aluminum trailer with ease as long as you don't expect to go 70 mph up hills.

I routinely pull my 3000# race car on a 2000# trailer with my 2004 Z71. I watch the trans temperature on an OBD2 app on my phone if I'm going long distances. It should go up to same as coolant temperature and stay there (which yours seems to be doing). If it goes up from there further, you need a trans cooler. My trans temp has never got much above coolant temp, even in August running down the Interstate and I only have the original factory trans cooler.

240 is the magic temp to keep it under. Above 240 bad things start to happen.

If you don't have the tow button (which firms up and raises shift points), you might be better off to stay out of overdrive, slow down a bit to maybe 60-65 mph, and run in 3rd. That way with the RPMs up a bit you are more likely to keep the TCC engaged.

A lot depends on if you have flat land to tow over, or if there are a lot of grades to pull up.
 
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whitestingray81

New Member
I do have the tow button, yes. Thanks for all the great information everyone! I feel much better about towing now. Good to know 240 is the number to stay away from. If I drive her easy (I always do now since the transmission was replaced), I can keep it at 210-212 on a 100 degree day at 70 mph. It's the constant stop, and full acceleration to highway speeds that I see it creep up.
 
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