Hello, I'm new to the forum but not new to forums.

I own a 2006 Chevy Express 3500 2WD 15 Pax van. I use this for my business to pick up kids but i also use it to tow my boat. (Cheaper than buying a new Pickup) The boat is 3100lbs and the trailer is about another 1000lbs. Gear and junk in the boat maybe 500lbs. My van has the tow/haul feature, so I can turn the overdrive off.

My problem is; when I'm towing the van starts hunting for gears even if I go up the slightest grade. I have the Vortec 6.0 so I'm not sure why I'm have so much trouble pulling this relatively light load. If I cruise between 60-65 it does it less but it still hunts up inclines. It really sucks because on long drives I can't use the cruise and it makes for a long trip. However even if I'm operating the gas pedal manually it still hunts, loses power and thus speed.

Please help. Thanks.

 

Something isn't right there. That's not a heavy load, trans should not be hunting. How does it behave with the tow haul off and towing? When was the transmission last serviced? Dealer visit might be in order.

 

I'm going to tow the boat again on Sunday and I'll see how it does in both modes. I will take some good notes and report back.

 

Greenfire's right. I've got a '97 Express 1500 Conversion Van with the 5.7 V8 and trailer package. My boat and trailer weighs just over 3000# and my transmission never hunts. On slight inclines it may shift out of and back into overdrive. I usually don't use cruise control when towing because I can do a better job of controlling the throttle to avoid hunting. It does drop out of overdrive on hills, and on steep hills it downshifts to second.

 

Your description doesn't sound right. I checked out the operation of the tow/haul mode and found that it locked the transmission into shifting at rpm points. The transmission would upshift when the rpm reached about 2100 rpm and would downshift when the rpm was reduced to about 1700 rpm. This would put it into 6th gear at about 65 mph for my van. Thus if I was towing at about 62 mph it would never go into the top overdrive gear. I certainly did not have a problem with the trans hunting while in this mode. Another option for mine is to use the manual shifting feature (like paddle shifting).

 

Good point... Tow Haul mode does not eliminate over drive. Try using the trans selector to limit to 5 or 6th gear. If you get a flat stretch of road you can always up shift it.

 

I'll try that. I'll let you know the results.

 

You could also check for any codes. There may be a bad sensor causing issues.