OK Tahoe / Yukon owners question for you

[Husker-Q]

Easy question -

bought new to me (03) Yukon with the 5.3 and towing package.

Do you tow in "D" with the towing mode or drop down to 3?

Manual didnt indicate the need to drop down to 3 - I assume the tow mode takes overdrive out of the picture??

Normal midwest towing with 18.5 runabout -

 

[old boat 54]

Re: OK Tahoe / Yukon owners question for you

05 tahoe here. I use "drive" for towing. ALso small boat. I use the tow haul mode when on steep ramps or roads when Going slow.
If you have tow haul, (button is on end of gear shift selector). This changes the shift pattern of the transmission. Helps on steep roads.
Your mileage. Will be better in drive.
And yes, on mine rig, 3rd takes the o.d. Off
P.s. if you have tow haul, when button is depressed a small icon of a trailer on the dash lites up.

 

[KD4UPL]

Re: OK Tahoe / Yukon owners question for you

Tow/haul mode does not prevent the use of overdrive. It changes the shift points. You can certainly leave it in D if you like. If it hunts too much for gears on hills I would drop it into 3rd.

 

[zlman1970]

Re: OK Tahoe / Yukon owners question for you

02 Yukon XL owner. I use "D" unless the tranny is hunting between gears on grade.

 

[Husker-Q]

Re: OK Tahoe / Yukon owners question for you

thanks much all- I was under the impression that the tow mode turned off the O/D as well, so good to know. I have yet to tow with it since only had a week and would have likely towed in 3, just to be safe, but like the idea of using "drive" on interstate type runs where not so hilly.

 

[gtochris]

Re: OK Tahoe / Yukon owners question for you

thanks much all- I was under the impression that the tow mode turned off the O/D as well, so good to know. I have yet to tow with it since only had a week and would have likely towed in 3, just to be safe, but like the idea of using "drive" on interstate type runs where not so hilly.

I will pipe in also- I always use tow mode and mostly just select 3rd, I find though it doesnt shift into OD much when the tow mode is on and a weight is on the back. For a sub 20ft boat I dont think either way is wrong as long as you use tow mode.

 

[bruceb58]

Re: OK Tahoe / Yukon owners question for you

I have the same engine in a Silverado towing the boat in my signature. I always use tow mode and tow in drive until the transmission starts to hunt and then shift down as needed. For the lighter boat that the OP is towing, he will almost always stay in drive.

I use tow mode going up mountains even without the boat. Way less shift hunting with it on.

 

[spdracr39]

Re: OK Tahoe / Yukon owners question for you

Tow mode unlocks the torque converter but does not disable the overdrive. You can pull in D with no problems but like said before if it is hunting alot ( which it shouldn't in tow mode) use 3.

 

[Silvertip]

Re: OK Tahoe / Yukon owners question for you

Tow mode unlocks the torque converter but does not disable the overdrive. You can pull in D with no problems but like said before if it is hunting alot ( which it shouldn't in tow mode) use 3.

Tow/Haul does NOT unlock the converter. It operates normally, just under a different set of parameters (shift points and line pressure).

 

[kawakx125]

Re: OK Tahoe / Yukon owners question for you

per a good friend that is a driveline mechanic for a local chevy dealer---you should ALWAYS use tow/haul in the 4L60-E transmissions (basically an electronically controlled 700R4, chevy has used them in passenger cars, suv's, and half ton trucks for years) any and all silverado, yukon, tahoe 99-2008 uses this transmission. i say those years because i know those were years for the 5.3, but i'm pretty sure they used it on the older body style trucks as well, and after 2008 i believe the 6l80 6 speed became an option. according to him the problem with them is that the overdrive gear very small and it stresses the transmission greatly when under a load. also they set them up to shift grandma style, and when pulling a load a quicker firmer shift is easier on the transmission as it spends less time slipping under a shift. using the tow haul changes the parameters to provide better shifts and longer trans. life. using 3 eliminates overdrive and should be used for heavier loads or when transmission is hunting between gears constantly. the 4l60 is definitely the weak link in those vehicles.

 

[Alwhite00]

Re: OK Tahoe / Yukon owners question for you

I never use OD - Just the tow/haul button - 7k+ with a 5.3 Avalanche 2WD - Works fine - OD seems to bog it down unless you are doing 70mph or more.

LK

 

[Silvertip]

Re: OK Tahoe / Yukon owners question for you

I never use OD - Just the tow/haul button - 7k+ with a 5.3 Avalanche 2WD - Works fine - OD seems to bog it down unless you are doing 70mph or more.

LK

Another bad choice of axle ratio for a tow vehicle. Those vehicles are set up for fuel economy. I do not consider any vehicle fit for tow duty if it has anything less than 3.5 gears. 3.73 is preferred unless you have big engine or a diesel.

 

[kawakx125]

Re: OK Tahoe / Yukon owners question for you

Another bad choice of axle ratio for a tow vehicle. Those vehicles are set up for fuel economy. I do not consider any vehicle fit for tow duty if it has anything less than 3.5 gears. 3.73 is preferred unless you have big engine or a diesel.

What says he has 3.42 gears? I'm fairly sure Chevy offered many options for rearend gears. And actually most new 1500 silverados come with 3.42 gears and mine actually pulls better from a start than my 03 with 3.73. New ones have 6spd trans with a lower 1st gear allowing them to get away with a higher rearend gear for highway economy

 

[kenmyfam]

Re: OK Tahoe / Yukon owners question for you

Tow mode for towing anything significant.
How the outfit is reacting to the conditions should tell you the rest. You develop a "feel" for your outfit.
Keep that tranny cool though.
My thoughts.

 

[Silvertip]

Re: OK Tahoe / Yukon owners question for you

What says he has 3.42 gears? I'm fairly sure Chevy offered many options for rearend gears. And actually most new 1500 silverados come with 3.42 gears and mine actually pulls better from a start than my 03 with 3.73. New ones have 6spd trans with a lower 1st gear allowing them to get away with a higher rearend gear for highway economy

Let's compare apples to apples. Obviously a lower fist gear ratio results in a lower overall low gear ratio. However, once up in the direct drive and OD gears that 3.42 begins to cause the tranny to hunt. That is the most common complaint with these 6, 7, and even 8 speed trannys -- they are too darned busy.

 

[kawakx125]

Re: OK Tahoe / Yukon owners question for you

Let's compare apples to apples. Obviously a lower fist gear ratio results in a lower overall low gear ratio. However, once up in the direct drive and OD gears that 3.42 begins to cause the tranny to hunt. That is the most common complaint with these 6, 7, and even 8 speed trannys -- they are too darned busy.

it's all relative to the gearing of the transmission. but yes with a 4L60 the 3.73 will pull better than 3.42. he never did specify which gears he had. as far as the new trucks with 3.42 my 2011 barely hunts at all in tow/haul mode and when running unloaded hardly ever leaves 6th on the highway. at 80mph its only spinning 2k rpms in 6th. it does shift more than the 03 i had, but it does a much better job of keeping the engine in the sweet spot especially when encountering hills and whatnot. there were times at highway speeds when my 03 wouldn't downshift because there was too much distance between gears, and the truck would end up slowing down. these new 6spd transmissions feel alot more solid as well, plus a nice feature on them is the speed-control system they have which downshifts and uses the engine braking to slow you down or hold your speed on hills.

 

[bruceb58]

Re: OK Tahoe / Yukon owners question for you

That is the most common complaint with these 6, 7, and even 8 speed trannys -- they are too darned busy.

Interesting, I hear the exact opposite. If you are hunting between 2 gears, it would like a gear inbetween which is what the higher number of gears gives you.

 

[jkust]

Re: OK Tahoe / Yukon owners question for you

Interesting, I hear the exact opposite. If you are hunting between 2 gears, it would like a gear inbetween which is what the higher number of gears gives you.

I've driven a number of the 6 speeds but I own all 4 speed GM suv's. Some of them were in the Lamda series, Traverse type vehicles where the 3.6 is just too weak for such a big car. I agree that the 6's are busy and I don't care for them the times I've driven them but I think much of that is simply having driven 4 speeds exclusively since I was 16. The extra two gears take some time to get used to. My 5.3's with 4 speeds with my 4000+ lb boat/trailer in OD almost never drop out of OD but we don't have too many hills here in MN. Of course 4000# and change doesn't challenge the capabilities of the 5.3 with 3.73.

 

[bruceb58]

Re: OK Tahoe / Yukon owners question for you

My 5.3's with 4 speeds with my 4000+ lb boat/trailer in OD almost never drop out of OD but we don't have too many hills here in MN.

I drive my 5.3 with a 6500# load up to Tahoe from LA. A lot of hills and a lot of shifting out of OD. A lot of the time I am downshifting to 2nd gear let alone dropping out of OD. I would love to have a 6 speed especially one that I could force manually like the 6 speed Allison can.

 

[kawakx125]

Re: OK Tahoe / Yukon owners question for you

i never had any issues either towing with my old 5.3/4l60 combo, and it did take quite a bit of getting used to making the switch. however looking back there are alot of advantages to the 6l80 that i prefer. the extra gears are nice in that it keeps the engine in the sweet spot for power, and anyone with a 5.3 would agree most of its power is in the upper end of the rpm range compared to the older 5.7. always seemed like there was quite a large gap from 3rd-4th in the 4l60. i always use the tow mode whenever a trailer is connected, better safe than sorry IMO i'd rather not stress the transmission anymore than necessary. in the newer ones that also turns on the braking assist/speed control system