Hello,

Sorry about the newb post but I need some opinions. I am currently running a SBC with a Ford Manual 4sp and a Dana 18 transfer case. The axles are custom Dana 60's with 4.10 gears and Humvee 36's with runflat/beadlock inserts. Off road in low range the gearing seems ideal, with 2nd gear being used the most for hill climbing and mud. In high range however, it seems way overgeared. Starting from a dead stop caused the clutch to heat up and 4th gear is almost unusable. I've checked the gear calculation programs but am still left with doubts as to the correct ratio. I was thinking 5:13's but a friend (there's always one) insists that ratio is going to kill the low range performance. Anyone have any opinions as to what ratio to run ? Please bear in mind a trany swap is not an option and my local terrain is limited to woods, fireroads and sandpits, mud, ect.

Thank you,
Extreem

what is your t-case low range ratio?
what is your tranny first gear ratio?

this would help guys give an answer.

my setup:

tranny 1st gear= 4:1
t-case: 4:1 low/1:1 high
axles: 4.10:1
tires: 38"

crawl ratio: 66:1

for crawling (which is all the rig does, no pvmt)i would like lower gears but i get by.

edit: i made a mistake on my t-case high range:flipoff2:

what is your t-case low range ratio?
what is your tranny first gear ratio?

this would help guys give an answer.

my setup:

tranny 1st gear= 4:1
t-case: 4:1 low/2.7 high
axles: 4.10:1
tires: 38"

crawl ratio: 66:1

for crawling (which is all the rig does, no pvmt)i would like lower gears but i get by.



Thanks for the Reply,

The tranny ratio's are

1st 3.29
2nd 1.84
3rd 1.0
4th .81


The Dana Model 18 Transfer case:

Low 1.97:1
High 1.0:1

Tires : 36"
Axle Ratio 4:10

Extreem

ok so your current crawl ration is 27:1. WOW that's not near low enough, you're right about that.

i don't know if a set of low gears are available for your t-case but we know you can re-gear the axles. even if you went with 5.13's in the axles your crawl will only be 33:1. not sure that would be low enough for what you want to do.

how about another t-case(doubler)?

With a four speed, 4.10's are _ok_ for the highway, but I would not go lower than 4.56 or 4.88 due to high RPMs on the highway.

It sounds like you would be better served (probably cheaper than re-gearing too...) by changing your tranny/transfer.

A t-18 with a d300 will drop your crawl ratio to ~67:1 and should bolt up (with the right bolts and parts, of course) to your 302.

With a four speed, 4.10's are _ok_ for the highway, but I would not go lower than 4.56 or 4.88 due to high RPMs on the highway.

It sounds like you would be better served (probably cheaper than re-gearing too...) by changing your tranny/transfer.

A t-18 with a d300 will drop your crawl ratio to ~67:1 and should bolt up (with the right bolts and parts, of course) to your 302.

Hello,

As much as I hate the idea of changing out the driveline, it does seem to be the best answer. I've got some homework to do....

Thanks for all the replies...

Extreem

4.56 with a 36 is ok on the road. I loose fifth in long hill pulls. Granted my fifth is an overdrive.
I have to echo everyone else. Look at an Atlas or D300 to drop your low gear. Then go 4.56 or 4.88 for the axles.

4.56 with a 36 is ok on the road. I loose fifth in long hill pulls. Granted my fifth is an overdrive.
I have to echo everyone else. Look at an Atlas or D300 to drop your low gear. Then go 4.56 or 4.88 for the axles.

and his tranny gears are such a high ratio i would not doubt that the 5.13 gears may be even better on the highway with 36" tires, ya think?

i know i ran 37" tires with 4.56 gears, the 3550 tranny and still wished a had lower gears for the highway.

I dodn't even look at his 4th. .81 is an overdrive
Looking at this chart
http://4lo.com/calc/geartable.htm
4.88 would be the perfect on road ratio, if he were to run in 3rd all the time. 5.13 would allow him to step up to 4th. Still leaves him with a shitty CR of 33