Dana 80 gear question

Blackdog

Blackdog

Hillbilly Deluxe
Joined
Jan 31, 2008
Messages
801
Alright, I am changing out my dana 70 for a dana 80 finally and running 35" tires but the dana 80 has 3.55 gears and I know I am not keeping those. I had thought I would run 4.10's but since this is mainly just a trailer hauler I thought maybe I would go with 4.30's. Any thoughts? I just want the best gear for towing.

Also, Just so I am clear that no matter if I go to 4.10's or 4.30's I am going to have to get a new carrier also correct?
 
I have towed with 410s and 354s. If I was starting from scratch I would look for some 373s - 390s. I hated the 410s because my rpms were always to high and with the 354s I was usually down a gear unless I was driving on the flat at 65 and above. hear in Kalifornia the max tow speed is 55 which is always a problem for gear selection. Actually the 410s were ok at 55.



good luck
 
For the rear D80 4.10 and 4.30 use the same carrier.
For the front you can use a ring gear spacer.
 
Yes you will need a new diff case to go from 3.55 to 4.10. I think with the auto I would run the 4.10's.
 
3.73's

but that's just me... u get the best of both worlds.... and with the bigger tires u won't rev as much
 
Kronic_187 said:
3.73's

but that's just me... u get the best of both worlds.... and with the bigger tires u won't rev as much
Click to expand...

Same here. I used to start of in second with the smaller, slightly bigger then stock tires that came on the truck. First gear was basically useless, now with the 35s i start off in 1st.

I think 3.73s would be perfect.
 
j-rod said:
How heavy are you hauling?
Click to expand...

Well, That varies from an empty 2k trailer on up to my 45' gooseneck which is 9k covered or 8k just flat. If I don't pick up another gooseneck that is shorter and lighter I will be using the 45 footer with 5k of suitcase weight and a stock IH 1066 for somewhat stock tractor pulling. Reason I thought I would go 4.30 gears is once a year I am pulling the load to Maine and New Brunswick to hit some big money pulls with other family members. With this load I am not worried about fuel mileage, I just want to get up the road with plenty of grunt. I have hauled the 45' trailer empty with 3.55's and it wasn't any fun.

Just need to know which gear would be better, 4.10 or 4.30. I am pretty sure rpm wise it won't be too high running 4.10's around 70 mph but I wonder how much worse it would be with 4.30 gears.
 
I don't have any issues with my auto and 3.55's have hauled 30' gooseneck 3 horse trailer loaded with 3 mares gear, water etc and 3 people in the truck with no issues. turn off od when needed. maybe you just need some more fuel
 
I think the 3.55 gears and 5th gear would be perfect. Why not 3.55 and 285 tires? The direct gear is stronger anyway.
 
i wouldent go 4.30 you prob wone make highway speed empty. 4.10 will be the mest choice imo. i have 3.55 in mine with a 6 spd and i hate them for towing anything heavy. and i have more than enough fuel.
 
Towing heavy and if you want to run 60 MPH 3.55 seam great. I run 285 tires, and direct is perfect. You can even get up to about 65 and it is good. The issue is I want to tow about 70-75 and direct is running more rpm than I want, and 6th gear is not enough to keep the EGT's down. Now if I get up to 80-85 it will run just fine, EGT's will peak about 1200 or so. That is just faster than I want to run.

I have Mach 2's HTBG with a 13CM SS. I kind of think if I went with the 12CM or even an HX40/35 hybrid with a 12cm would be a little better.
Ideally I would like a set of twins, something with say with either the HTBG on top or the HX35 and then a s475 on bottom with the 83x74 wheel and like a 1.10 housing.
 
I guess I am going to have to start with re-gearing just the rear for now with 4.10's and see how I like them and go from there. Thanks for all the inputs.
 
I had 3.54's, worked great with 285/75's... Then I went up to 35's and my clutch didn't like it so much. But I didn't think it made that much of a difference for towing. I swapped in 4.10's finally, and the EGT drop was pretty substantial when climbing hills and tows so much better. If I towed heavy more often, I'd stay with those to run 35's.. But for only hauling heavy every now and then, and more in the 5-10k on a more regular basis. I'd love to have some 3.73's. I think they would work perfect with the 35's.

But now I'm lowering the truck and going back down to 33's, I have a feeling that I am going to really hate the 4.10's... :bang
 
4.10's and 35's would put you around 60MPH @ 1600 RPM. That should be where you were with w/ 31's and 3.55's. With 4.30's your speed will drop to around 56MPH w/ 4.30's.

Me personally, I'd stick w/ 4.10's. If I felt the need to gear lower I'd skip over 4.30 and do 4.56.
 
I would go for the 4.10. I think that the 4.30 are going to low for what you want to do. I have 3.55 and have towed 10-15k without a problems. it was slow at time but will most likey be happy with the 4.10. if money wasnt a problem I would get 4.10 and a gear vender overdrive. just my 2 cents.
 
If money wasn't a problem I would be buying what I want from the factory instead of building it. But, The gear vendors did cross my mind if I went with 4.30's. I guess it looks like 4.10's will be the answer. Thanks guys for the inputs.
 
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