7
7.3shrk
Guest
Correct me if I'a wrong, but I thought 45 in 4 low was too damn fast for the T-case internals. Besides, how are you going to shift from 4 low to 2 or 4 high at those speeds? Just a thought.
diesel project question
- Thread starter Andylad13
- Start date
Cat_Rebel
Does not compute
You have to shift into N & doing that while your going might just blow up your Transfercase! You try it fist!
Andylad13
DieselBoy
the thought was to put it in 4 lo when pulling. come to a stop and put it in 2 wheel when your done. ive seen the thread about the guy that makes od units, and its a great deal dont get me wrong. but its still a lot of money and i could pick up the parts needed to make this change for under 400, so i figured if i could somehow make it work like i wanted, it would be worth it for everyone.
i tracked my speed with a gps unit and as it turnes out, at 2000 rpms im going about 62 mph. the truck never needs to down shift on the highway, itll loose some speeed going up hills but has never down shifted so i was thinking a higher gear to help on mileage, but not too high to have to down shift.
i like the concept of the od units, just not the price.
i tracked my speed with a gps unit and as it turnes out, at 2000 rpms im going about 62 mph. the truck never needs to down shift on the highway, itll loose some speeed going up hills but has never down shifted so i was thinking a higher gear to help on mileage, but not too high to have to down shift.
i like the concept of the od units, just not the price.
Cat_Rebel
Does not compute
Try a set of 3.73 & go from there. That's what I would do.
Andylad13
DieselBoy
rather than going with an od unit. i just had a thought. my truck pulls pretty good but not great. i think that ill drop gears and go with an under drive unit.
it sounds like it would even out but i looked at the final ratios supplied by us gear, and ill get even more power pulling with 3.55's and a more fuel efficient final gear. still dont like the money, but some things you cant do cheap.
it sounds like it would even out but i looked at the final ratios supplied by us gear, and ill get even more power pulling with 3.55's and a more fuel efficient final gear. still dont like the money, but some things you cant do cheap.
93turbo_animal
Registered User
doing that instead of jus adding an OD your gonna have way mor cost and labor changing gears and still end up with almost the same final drive ratio?
Andylad13
DieselBoy
the final drive ratio is a lot different with 3.55 than 4.10's
93turbo_animal
Registered User
Copied off of the gear vendor site you can see 4.10 gears with an overdrive gives a final drive ration of 3.20 if you have a 4 speed while 3.55 gears with an under drive your only going to end up with 3.55
Axle Ratio
Diesel...............4.10.......3.55
Trans Ratio......Final Drive Ratio
1st.....4.02..........16.48.....14.27
2nd.....2.41.............9.88........8.56
Over....1.88.............7.71........6.68
3rd......1.41.............5.78.........5.01
Over....1.10.............4.51.........3.91
4th......1.00.............4.10.........3.55
Over....0.78.............3.20.........2.77
Axle Ratio
Diesel...............4.10.......3.55
Trans Ratio......Final Drive Ratio
1st.....4.02..........16.48.....14.27
2nd.....2.41.............9.88........8.56
Over....1.88.............7.71........6.68
3rd......1.41.............5.78.........5.01
Over....1.10.............4.51.........3.91
4th......1.00.............4.10.........3.55
Over....0.78.............3.20.........2.77
Last edited:
Andylad13
DieselBoy
im gettin my info off the us gear site. remember animal, im not calling you out on your knowledge please dont take it the wrong way. i was looking at us gear the whole time rather than gv.
3.55's with under drive will give me
Under 12.02
First 9.62
Under 6.83
Second 5.47
Under 4.43
Third 3.55
Under 3.15
Fourth 2.52
now i know that the 4.10 with the over drive will give a final of 2.32 which is higher than 2.52. however, comparing stock finals of 2.52 to 2.91 with the 4.10s id rather have the underdrive and get more power to pull in under, than just throwing an od.
3.55's with under drive will give me
Under 12.02
First 9.62
Under 6.83
Second 5.47
Under 4.43
Third 3.55
Under 3.15
Fourth 2.52
now i know that the 4.10 with the over drive will give a final of 2.32 which is higher than 2.52. however, comparing stock finals of 2.52 to 2.91 with the 4.10s id rather have the underdrive and get more power to pull in under, than just throwing an od.
f-two-fiddy
Registered User
Theres a guy over on FTE that has the 3.08 gears. Might wanna contact him for some info.
Why not just go 3.08/UD? It'll prolly be geared pretty close to 3.73 in 1st under
Why not just go 3.08/UD? It'll prolly be geared pretty close to 3.73 in 1st under
h2odrx
Anti-O
Use 4low a lot with the broncos, (same BW1356 you'd prolly use, diesels wern't any different), and your good for about 45ish in overdrive at 3000rpm with 3.55s and 31's.
Back in the day dad had a flatbed dually with a 300 and an M5OD-R2 backed with a 1356 but no front axle to make up for the lack of granny in the mazda tranny.
Adrianspeeder
Back in the day dad had a flatbed dually with a 300 and an M5OD-R2 backed with a 1356 but no front axle to make up for the lack of granny in the mazda tranny.
Adrianspeeder
93turbo_animal
Registered User
Its no problem Andylad you should be able to decide to do what ever you want its just our job to help point out all posibilities and sometimes the easiest ones get over looked. The cheapest way would be to just throw an OD on your current set up but it sounds like you need or want more power for taking off below first gear so an UD makes more sense although I can't imagine what you would need a lower gear then first with 4.10s for but hey I don't know
Cat_Rebel
Does not compute
With 4.10s even in a N/A IDI you should be able to pull even a large load off the line without too much issue. Unless your really getting into a HUGE trailer, then you might want to think of something else to pull it with.
