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General Category => Tech - Help Area => Engine-Driveline-Wheels-Tires => Topic started by: remingtongoose77 on April 02, 2018, 08:16:55 PM

Title: rear gear change in dana 80
Post by: remingtongoose77 on April 02, 2018, 08:16:55 PM
Has anyone swapped out the 4.62 gears in their dana 80? I am fully restoring my truck and will probably end up using for regular use, no heavy towing or hauling, just using it for the sort of jobs a 1500 truck would do. With that in mind I was thinking of dropping to a 3.73 gear set and picking up some gas mileage on the highway. In case your wondering that would take me from 2500 to 2000 rpm with my thirsty 454.

Anyone done this?

Title: Re: rear gear change in dana 80
Post by: someotherguy on April 03, 2018, 07:29:08 PM
You might not pick up the mpg you expect - those gears help that heavy truck get moving.  Going down numerically will make it harder to get off the line and to accelerate.  Maybe 4.10's would be a good compromise?

I can't think of any example of someone doing this on an HD that I can reference, though.

Richard
Title: Re: rear gear change in dana 80
Post by: RPF207 on April 04, 2018, 07:35:17 PM
AZtim has put 3.73 in his Cummins swapped HD and seems to be happy with it. His HD also has a NV4500 Which has a nice 1st and 2nd gear. Not sure what you have for a trans but if it’s the 4l85e you might want to go to 4.10s instead. The 4l80e and 4l85e(found in the HD) have a high first gear and off the line acceleration is a little unimpressive with the 3.73s I have in my 5200lb 3/4ton with a 350 vortec. Even the 6.0 vortec seems to be held back by the 4l80e. So your heavy HD when towing off the line sporting 3.73s might not be impressive, But I can assure you that highway towing will be nice. But At the end of the day, it’s your choice and your truck!