Transmission Downshifting issue???

zogg · Feb 18, 2015

I towed my sons utility trailer the other day and was a bit surprised.
It has the ramp type trail gate that acts like a big billboard being towed....big wind drag. Anyway, every time I came to a hill, the transmission would downshift from 6th directly to 4th, and then up shift almost immediately to 5th. Kind of irritating, but it this normal???

Seems like it should only drop one gear at a time.....

NYCruiser · Feb 18, 2015

What tranny? Tow/haul mode?

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NewBlackDak · Feb 18, 2015

You weren't in tow/haul if it was in 6th.

I have the problem sometimes on mine unloaded. A little throttle input, and it goes from 6th to 4th, and sometimes breaks the tires loose. It's scary on the highway. I suspect it's the transmission trying to protect itself. 5th is an overdrive gear, just not as steep as 6th.

Put it in tow/haul, or manually work the transmission.

shaftman_05 · Feb 18, 2015

I assume 6 speed trans... sounds normal still. It is the way these transmissions work.

granite14 · Feb 18, 2015

what were the rpms when in 4th? are you giving more throttle also when getting the hill? How many miles on your truck?

I think I encountered this when my truck was new, but the transmission either learned shift points, or my driving style changed to more constant throttle. If lots of hills, I usually gear limit to 4th anyway to keep it in the power band.

zogg · Feb 18, 2015

Thanks for the feedback.....
I never even thought about putting it it tow haul mode....silly me. I am sure that would have made it better.....ugh!!!

KarL45 · Feb 25, 2015

That is normal although, I wouldn't say "good". Word of caution, be wary of the downshift when getting into 3rd at about 50 mph. If you attempt to throttle too hard, you will get a downshift. And I don't mean from 3rd to second. Third to first and will hit lock up at 6k or better. Had it happen "once" to me. Truth, at 50 mph, will turn the tires with a 5th wheel 13k toyhauler behind. Pulled so hard that it broke paneling screws in the front of 5'er. Until that happens, you have no idea the power that 6.4 can put out. "Will make your blood run cold!!!

NewBlackDak · Feb 25, 2015

KarL45 said:
That is normal although, I wouldn't say "good". Word of caution, be wary of the downshift when getting into 3rd at about 50 mph. If you attempt to throttle too hard, you will get a downshift. And I don't mean from 3rd to second. Third to first and will hit lock up at 6k or better. Had it happen "once" to me. Truth, at 50 mph, will turn the tires with a 5th wheel 13k toyhauler behind. Pulled so hard that it broke paneling screws in the front of 5'er. Until that happens, you have no idea the power that 6.4 can put out. "Will make your blood run cold!!!

Done it a couple times getting on the freeway around an idiot on the ramp. Kicked the reared out. Scary as hell!

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SouthTexan · Feb 25, 2015

NewBlackDak said:
You weren't in tow/haul if it was in 6th.

Is this only for the 66RFE? Mine goes into 6th in Tow/Haul mode while towing.

loveracing1988 · Feb 25, 2015

SouthTexan said:
I this only for the 66RFE? Mine goes into 6th in Tow/Haul mode while towing.

Cummins vs gas motor.

Transmission Downshifting issue???

zogg

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NYCruiser

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NewBlackDak

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shaftman_05

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granite14

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zogg

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KarL45

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NewBlackDak

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SouthTexan

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loveracing1988

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