First off, I'm sure this topic has been beaten to death and I'd search it if I had the time, but we're heading out tomorrow and just picked the 'Burb up last night with a million things to do before we depart.
Anyway.....
The 'Burb is a 2500 with the 8.1L and 4.10 gearing and we have a 6400lb loaded TT it will be towing. The manual says that while towing you should have the gear selector in 3. It also recommends using Tow/Haul mode when "heavy" towing, but also mentions that unless you're actual weight is over 75% of the GCWR, the Tow/Haul mode may not be of benefit.
My initial thoughts when I got the truck were that I'd have it in Drive with the Tow/Haul engaged, but now I'm a wee bit confused....3rd w/ Tow/Haul, or 3rd w/out Tow/Haul....sigh.
Also, is it recommended to use cruise while in Tow/Haul mode?
Any advice would be greatly appreciated, and thanks for your patience.
That is a fairly light trailer. I would put it in drive and use the tow/haul. If it was heavier I would say use 3rd. Tow/haul simply changes shift points and it will put less stress on your tranny. I use cruise only when on flat roads. When taking hills or mountains, I disconnect cruise.
Defiantly use 3 since the manual states that. Some transmission OD's are not suitable for towing. I would use the tow/haul mode. It will keep the torque converter clutch locked up more of the time thereby reducing heat buildup in the transmission. You can use cruise control in 3rd with no problem.
On flat ground and a 4.10 plus a easy load I'd use 4th with the tow/haul on. In hilly terrain if the torque converter stays locked up I'd still use OD but if it unlocks then heat will build and 3rd locked is the better choice. On a long hill 3rd is the only choice.
I see nothing conflicting in the advice from the owner's manual, if accurately paraphrased in the original post:
1. Tow in 3rd, period.
2. Use Tow/Haul, but UNLESS total combined weight exceeds 75% of the GCWR (listed on the door post), Tow/Haul may not provide any advantage.
Nothing confusing there. Are you over 75% of GCWR? That's an easy math question... You're probably close to 15,000lbs loaded between the 2500 burb at ~8000lbs and the ~6400lb (dry?) camper. Is that more than 75% of the GCWR on the door post sticker?
If it's over 75%, then use Tow/Haul. Otherwise, do what works best for you, so long as the torque converter is in "lockup" most of the time.
Count gears when you're accelerating from a stop... Start in one, bump, now you're in 2, bump, now you're in 3, bump, now you're in O/D.... Now watch for a 200-300 RPM drop on your tach. That's the torque converter going into lockup.
Now you know how to identify when you're in lockup. Same thing happens in 3rd with Tow/Haul mode engaged.
Gm's towing in overdrive has been OK for quite a few years now.
I do not know how your manual reads but my manual is use overdrive unless trans is hunting between OD and 3rd, then place gear selecter in 3rd gear. You should be able to use OD quite often with the 4.10 gears. Tow haul will also stop some to most of the hunting. 75% of the rating will work but with a headwind and some grades the tow haul setting will be very helpfull.
2005 2500 Avalanche
2004 30' Terry Quantum 290FLS
Equal-i-zer,Prodigy
Calgary Alberta
mkirsch wrote: 2. Use Tow/Haul, but UNLESS total combined weight exceeds 75% of the GCWR (listed on the door post), Tow/Haul may not provide any advantage.
I have never seen the GCWR listed on the door post. It often can be found in the owners manual however. The door post lists the axle weight ratings and the Gross Vehicle Weight Rating but not the Gross Combined Weight Rating.
Barney
2004 Sunnybrook 30FKS TT
Hensley "Arrow" 1400# hitch
2002 Ford F250 Super Duty, 7.3L PSD
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I have a 2001 Chevy Suburban 2500 8.1l w/4:10 ratio and used to tow our 32' Avion TT wt. 7600# in Regular Drive (OD) w/0 Tow/Haul unless in city traffic and doing a lot of start and stop which changes the shift pattern. We traveled from Central IN. to Myrtle Beach, SC. and never had any problems and used the Cruise Control the entire trip. MPG used to avg. 9-10 for the entire trip.
Arnie
2003 Travel Supreme MH
38KSO1 Cummins ISC 350HP
Car Dolly w/1996 Toyota RAV4 2WD
1963 Pontiac Grand Prix
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