Tow Mode - Automatic Transmission

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Only if you're towing.

:)

~:~ mm ~:~

Tow/Haul mode changes the shift points and doesn't allow the OD to lock in as quickly and holds it in longer than it would if not in tow/haul mode when under a bit of strain. It all depends on your setup and how the truck handles it. I never use tow/haul mode towing our 32' fifth-wheel unless in stop and go city traffic to keep the tranny from shifting as much and when going down mountain passes to have the tranny help hold me back. Of course I have an 8.1L and Allison tranny w/ a 4.10 rear!!! Yep, it kills mileage (as if the 8.1L needs help there :-) ), but safety over mileage wins and not destroying a tranny over mileage tend to win. When I towed the same 5'er w/ a 6.0L and 4.10 rear, I used the tow/haul mode often. The lighter tranny had to work much harder.

Read your manual and see how it acts while loaded up.

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Your explanation of the TowHaul was dead on.

The OP should keep in mind a couple things......

You have an Allison now, your "lighter" tranny had to work much harder, he has the lighter tranny.

but....most importantly....

Heat is the number ONE cause of transmission failure. He IS.....towing. He HAS the towhaul feature. Break jobs run around 90-120 dollors. That tranny runs around 1800-2400 bucks to make better than new.

anywhoooooo

good facts...

~:~ MarshMonster ~sips his crownroyal...takes a toke~ ~:~

I apologize for not posting something completely relevant, however I have asked the question before and not received a definitive answer from a gm tech or someone with equivalent qualifications.

I have an 01 Jimmy 55,000 mile on it. When the road is wet from steady rain am I going to do any damage by putting the transfer case in Auto 4WD? If it ok when the road wet from rain what about under dry conditions ? I must also say that I am not worried about reducing gas mileage because it stinks as it is now when I keep it in HI 2. I only get 13-14 in city driving with a VERY light touch on the gas peddle.

Thanks Double tap

I have an 01 Jimmy 55,000 mile on it. When the road is wet from steady rain am I going to do any damage by putting the transfer case in Auto 4WD? If it ok when the road wet from rain what about under dry conditions ?

Thanks Double tap

========= ========= You shouldn't apologize..you should start a new topic.

:)

anywhoooooo.....

You can use the auto 4w/d under the conditions you stated.

~:~ MarshMonster ~sips his crownroyal....and reminds you.....google is yer friend... so are this ng's archives~ ~:~

I'm not sure what kind of auto 4x it is...but if is like the one in my 99 old style Tahoe, the "axle connector" on the front engages but the transfer case stays in 2h waiting for a chance to go to 4h. This system is to enable

2h to 4h and back again without waiting for and over exercising the axle connector. Sounds good right? Then when the computer detects the back axle and front axle rotating at different speed, "BANG" ...4h. ....then 2h.....then slip....."BANG" 4h ... repeat...the series goes on.

Now, what value would this be to you at highway speeds in slippery weather? It does not create an all-wheel-drive "system"

The only reason I use the auto 4x button is to pre-engage the axle. (This was especially important with the old thermo-actuator...especially on a cold duck hunt day. My motor version takes only a moment.) Once I need the 4h...I just press the button. This is especially the case at the beach. Once we happened on a woman stuck in the sand....she was in 4 auto. Every time she gave it throttle...the back wheels would slip "BANG" and she would let off the throttle. I told her to put it in 4h and it walked right out.

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it shouldn't BANG, clunk, clank, or boink....... if it does...sumtins wrong. fact, not fiction.

here...more... facts......not fiction

~:~ MarshMonster ~takes a toke of his homegrown....and wonders...... if google only applies to him~ ~:~

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it shouldn't BANG, clunk, clank, or boink....... if it does...sumtins wrong. fact, not fiction.

here...more... facts......not fiction

~:~ MarshMonster ~takes a toke of his homegrown....and wonders...... if google only applies to him~ ~:~

Hay Marsh, Best damed article on 4WD I have read, and it gives the definative answer from a GM Engineering Specialist. Thanks Double Tap

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." Benjamin Franklin, 1759

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DT, for future reference, I don't take gratitude very well.....

i prefer being called names.....where's the fun in jest saying........

yw

:)

~:~ marsh ~takes a toke.......sht....i was hope'n to be called an ass...... now i can't keep the thread goin~ ~:~