Would this make a good crawl ratio?

Would a dauntless motor with a Ford t-18 granny low, the spicer d18, and 3.73's make a decent crawl ratio with 33" tires?

Right now theres a t-14 transmission. Its got great top speed but dosn't crawl at all. I might be out there, but wouldn't the ford t-18 cut the crawl speed roughly in half? Would it be worth the $1000 to swap in the t-18?

 

I have that same combo in my 71 with 31" tires. The 3.73s are just to high. With 33" tires it will start to be very hard on the clutch. Great combo, but with 33s it would be better to go with 4.56s or 4.88s. There is a great calculator on randys ring and pinion site.

 

Novak has a handy "crawl" calculator:

http://www.novak-adapt.com/knowledge/gearing.htm

TD

 

I don't know. Really depends on what you're gonna be doing with the Jeep.

I had 4.88s, a 4.01:1 1st NV3550, and a 2.46:1 Spicer 18 in my CJ-6 with a 225. That's a crawl of 48.13:1 and I did the Rubicon pretty well with a 2GC carb and 31s and never wanted any deeper out in Ocotillo, Truckhaven, etc. Should be pretty livable for a mild trail rig, but if you're building a rock crawler you'll probably want a low gearset in the T-case along with it.

Think about this. My old Dodge Ramcharger ran a stock 318 with a Q-Jet carb, the stock NP435 with a 6.68:1 1st , a 2.72:1 Klune V, a 1.96:1 Chevy NP205, and 4.10s in the Dana 60s. I wheeled that thing hard on everything from Johnson Valley, Montrose Colorado, Upper Helldorado etc in Moab, and more. Most of the time I had the tranny in 1st and the NP205 in Low. That's a crawl ratio of 53.68:1 - and I was running 42-inch Swampers. I usually only doubled down with the Klune when I had a long, intricate crawl to negotiate and that was usually only to keep the engine rpms up to keep it running with the carb.

 

Hmmm...I've never had a problem with my 33's and 3.73's on my 74 cj5. Is there a difference? Both motors seem to have power at low rpm.

 

I'm 88-1 running 35's and it works very well while rock crawling. Not so much on the freeway with 538's

 

Going off novaks site, it would give my jeep a 58:1 crawl ratio. Isn't that pretty good?

Ok, I understand what your saying about starting in second gear. Often when driving a ford truck with a t-18, I frequently found myself starting in first. What if I didn't mind all that much?

 

3:73's stink, I hate them with my stock 28" tires never mind 33's. I run :v6:, ford t-18 and 5:38's, 32" ss, and an OD and love it. best of all worlds.

 

58:1 ain't bad tho, right? Thats pretty slow I think

 

copied from Novak's knowledge section:

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Crawl ratios in the 60's are quite capable; in the 80's, very respectable, in the 110's, impressive and anything beyond the 130's is usually considered the point of diminishing returns.
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I take as, it will accomplish the job, but its not the optimum setup. You would be on the very low end of capable.

TD

 

The 3.73's would work but would be harder on the clutch. My setup is very similar but I switched to the 4.10's and it seems almost perfect (crawl ratio around 70). Even the speedo is right on. I say almost perfect but if I was going to do it again I would choose the 4.27's - now THAT would be perfect . . . . Of course if you're in the rocks you would want to look at going lower.

On your second question. Yes, it's worth swapping in the t-18 even for $1000 but that seems a bit higher than what it costs others. Still worth it if the rest of the Jeep is good.

 

for what it's worth-- in my CJ-7, I ran a granny T-18, D300, and 3.31 gears in my modded 258 w/ 34x9.50 TSL's (measured out to 33"). It was great on the highway-- did about 70 at 2200 RPM & pulled all but the most serious hills. Crawlin, it was a little high, but still worked well. 3.54's might have been perfect for the street.

I finally put a 4:1 in the t-case and that made low gear (in the T-18) almost too low. Mostly used it for crawling or setting up for an obstacle.