I'm thinking about changing my sm465 and np205 combo for a turbo 350 and np205 combo. How do I determine my crawl ratio so I dont wind up with a rig thats worthless? Will I need a stall converter? I have 39.5s at this time with hopes to go to 42s or 44s later, what gear ratio do I need to run in my axles with the auto as compared to the manual since I wont have the granny low anymore? If it matters now, I have a 300 horse 350 and 4.10s in one ton axles... Thanks in advance.
Crawl Ratio
- Thread starter 02dmax
- Start date
RatLabGuy
You look like a monkey and smell like one too
- Joined
- May 18, 2005
- Location
- Churchville, MD
crawl = differential gears X tranny gear X transfer gear.
drkelly
Dipstick who put two vehicles on jack stands
- Joined
- Mar 21, 2005
- Location
- Oak Ridge/Stokesdale, NC
SM465/NP205:
6.55 x 1.96 x 4.10 = 53.71
TH350/NP205:
2.52 x 1.96 x 4.10 = 20.25 (This will suck running your 39.5" tires) Yeh the converter will come close to doubling this due to slippage etc, but your tranny won't like it.
If planning on stepping up to 42's or 44's, you are probably going to be best off regearing your axles to 4.88 or 5.13 and running a 203/205 doubler TC setup. With the 39.5's, you could probably get by with skipping the axle regear and just do the doubler when you changeover to the TH350/NP205.
6.55 x 1.96 x 4.10 = 53.71
TH350/NP205:
2.52 x 1.96 x 4.10 = 20.25 (This will suck running your 39.5" tires) Yeh the converter will come close to doubling this due to slippage etc, but your tranny won't like it.
If planning on stepping up to 42's or 44's, you are probably going to be best off regearing your axles to 4.88 or 5.13 and running a 203/205 doubler TC setup. With the 39.5's, you could probably get by with skipping the axle regear and just do the doubler when you changeover to the TH350/NP205.
Metto
Well-Known Member
- Joined
- Mar 20, 2005
- Location
- Cornelius, NC
i ran 39.5's on my k5 with the th350/205/4.56 gear setup and it sucked. you really need a lot more reduction than that, like min 40 to 1 with an auto
I dont mind re-gearing the axles, I was planing on going to 5.13 or 5.38 anyway. If I do that, and dont do the doubler, will this work ok if I go to 42s or 44s? I,m running Dana 60 axles so I could go as high as 6-something if needed. Dont really want anything lower because the pinion gear gets too small.
- Joined
- Mar 20, 2005
- Location
- Morganton NC
Something else you can do to help out. Not sure about there, but here, well in Chesnee SC there is a tranny shop that will put a 700R4 front output and plantary into a T350, givint you a lower first gear.
Just a thought
Just a thought
carolinastreaker
Active Member
- Joined
- Mar 15, 2008
- Location
- Hampstead
I'd get a 3speed Monster box transfer case 1.1- 3.0- 5.75. as the doubler is so long!
