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For the crawlers...Standard or Auto?

0313

Full Member
Joined
Aug 7, 2004
Messages
261
Loc.
Salt Lake City
I was wondering the preference with everyone. Being here in Utah and having Moab fairly close makes it a rock crawling haven. Which do you prefer, automatics or standards? I know you can get a lower range with a standard but theres always that only having 2 feet problem while climbing. I prefer the auto, I am kind of lazy that way. What makes you prefer which to go with? Im just wondering if I should keep the C-6 or change to NP435.
 

TexasBronco

Bronco Guru
Joined
Sep 8, 2002
Messages
3,014
Loc.
Waterford, MI
I have been told an automatic works better for most conditions. Plus with you body flexing and everything moving the shiftering linkages and clutch linkages could bind. I would stay with the C6.
 

Steve

Bronco Guru
Joined
May 5, 2003
Messages
2,986
Loc.
Grand Junction, CO
I've recently researched this exact same question, and I'm closer to Moab than you are. :cool: I've been running a NP435 for several years, and have recently purchased a new motor (EFI 302), tranny (built C4) and t-case (Atlas 4.3) that's going into mine this winter. There are pros and cons to each, but I finally decided to switch to an auto for crawling, which is mostly what I use mine for.

It's also interesting to note that the vast majority of the comp rigs, at least in UROC, now run autos.

Stick with your C6.
 

Gummi Bear

Bronco Guru
Joined
Jul 8, 2003
Messages
3,647
I'm in the auto crowd. Keep in mind that you can pretty well double your low gear in an auto to get your more 'realistic' crawl ratio.

Example

Lets say that the transmission has a 2.36 low gear
The transfer case has a 2.46 low gear
The rear axle has a 4.88 gear

2.36 x 2.46 x 4.88 = 28.33

But it feels like:
(2.36 x 2) x 2.46 x 4.88 = 56.66

Not the greatest explanation, but hopefully it'll help you to understand what I'm getting at. Run the lowest stall RPM converter that you can

GJBroncoMan is putting in the same drivetrain that I am working toward. (Lucky bugger :p ) It should put him knocking on the door of 100:1 crawl ratio (considered by many to be ideal)
 

Steve

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Joined
May 5, 2003
Messages
2,986
Loc.
Grand Junction, CO
Gummi Bear said:
I'm in the auto crowd. Keep in mind that you can pretty well double your low gear in an auto to get your more 'realistic' crawl ratio.

Run the lowest stall RPM converter that you can.
Gummi Bear is right. Due to an effective multiplication in the torque converter, a 40:1 crawl ratio (low gear x t-case gear x axle gear) is effectively 80:1 with an auto. As for the stall speed, that's very true. A high stall speed converter would make for a "point-n-shoot" vehicle; not good in the rocks.

Most comp rigs run autos, and they typically have crawl ratios between 30:1 and 40:1 (60:1 - 80:1 with the torque converter.)

Gummi Bear said:
GJBroncoMan is putting in the same drivetrain that I am working toward. (Lucky bugger :p ) It should put him knocking on the door of 100:1 crawl ratio (considered by many to be ideal)
;D That's because I found a smoking deal on the entire drivetrain. A guy out here built a UROC comp buggy a couple of years ago with a new Howell-injected 302, built C4 and Atlas 4.3. He ran in 3 competitions and lost interest. When he couldn't sell it for anywhere near what he had in it, he decided to part it out. I paid $3500 for the entire, almost-new drivetrain. I can't wait to get it installed and see how it works. :cool: My effective crawl ratio will be around 90:1.
 

welndmn

Bronco Guru
Joined
Nov 12, 2001
Messages
2,112
Sticks are great, if you have a crawler.
Autos are nice, want to crawl slower? step on the brake.
I run an NP435 with not near enough gearing
 

bsaunder

Bronco Guru
Joined
Nov 14, 2001
Messages
1,064
Another vote for Auto - however I would say to get your crawl ratio >40, I'm currently at 32.7 (before multiplication of TC) and I'm not nearly as low as I would like. If I could afford an atlas I would jump on it in a heart beat, a low range ~4.0 would be great!
 

BRONKEN

Sr. Member
Joined
Jun 5, 2002
Messages
844
Loc.
Morgan Hill, Ca
I have had 3 speeds, 4 speeds & auto's. I now run a c-4 with a cold duck and love it. I vote for the auto.............. ;D
 

SaddleUp

Bronco Guru
Joined
May 23, 2004
Messages
9,655
Loc.
Vancouver, WA
You people are mean. I had finally decided to pull my C4 and replace it with a ZF. Now I'm thinking a good C6/203/205 might be the way to go. Anyone running that setup?
 

mxpaz

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Joined
Jun 21, 2001
Messages
2,901
Loc.
KC
SaddleUp said:
You people are mean. I had finally decided to pull my C4 and replace it with a ZF. Now I'm thinking a good C6/203/205 might be the way to go. Anyone running that setup?
too bad your not closer I would let you ride in mine. I like my set-up. I did the whole thing including buying, and having tranny rebuilt for $1000. I had an np435 and got rid of it to go back with the C-6. I went from c-4 to a np435 to a c-6. So I vote auto all the way.
 

Dusty

Bronco Guru
Joined
Jun 28, 2001
Messages
2,965
SaddleUp said:
You people are mean. I had finally decided to pull my C4 and replace it with a ZF. Now I'm thinking a good C6/203/205 might be the way to go. Anyone running that setup?

I currently run a C4/D20 but I just picked up a SB C6 with a 205 attached. I'm now looking for a 203 to cannibalize the range box off of for just the combo you mentioned. It will probably coincide with a future wheelbase stretch to get it all under there.

FWIW, I can't think of any kind of wheeling or even regular driving where I'd rather have a manual. I know a lot of people like them because they're simpler and not as much "black magic" about them. In my experience the people who are still clinging to their stick trannies are the same people who think if you just put enough Sancho 9000's under there it will be as good as Bilsteins, and who will argue til they're blue in the face for their carburators over EFI. Some folks just don't want to embrace change ;D

Dusty
 

kb6677

Contributor
Bronco Guru
Joined
Jan 19, 2004
Messages
2,175
auto vs. clutch

Here we put it this way-how many feet do you have? ok, how many pedals are in the floor with a manual-ok, well, clutch, brake, and gas, dang, without a hand throtle and a steady thumb I am one foot short of working all the pedals. Obviously, sefi makes the above a bit irrelevant, but the concept is close.
Auto all the way. OverBuilt C4, Atlas 4.3 and 4.88s do well.
KB
NC
ebsss
some with a few mods
 

SaddleUp

Bronco Guru
Joined
May 23, 2004
Messages
9,655
Loc.
Vancouver, WA
mxpaz said:
too bad your not closer I would let you ride in mine. I like my set-up. I did the whole thing including buying, and having tranny rebuilt for $1000. I had an np435 and got rid of it to go back with the C-6. I went from c-4 to a np435 to a c-6. So I vote auto all the way.

How much lift are you running on the suspension? How long is the rear drive line? It looks like you are set up just about the way I am headed. I was looking at 37" tires instead of 38" though. Other than that mine would be pretty close to what you are running I think. I.E. 4.56 gears, 37" tires, C6, 203, 205. I assume you are also running a low stall convertor?

Guess I'll start making some calls and see about getting a C6 put together. I've been running autos for quite awhile. The last manual I ran was on my old h**p about 20 years ago. The reason I was looking at the ZF was to get both a super low and an OD. If I go with the 203 doubler though I don't need to go that route.
 

rjlougee

Bronco Guru
Joined
Dec 26, 2001
Messages
1,959
I'm gonna wade in here too. I absolutely love and prefer manual trannies for just about everything, EXCEPT hard core rock crawling and mudding.

I've had a NP203/D20, then one of the first ZF/D20s, and now a built C-6 and D20 combo.

The only disadvantage to having about a 30:1 or 40:1 crawl ratio with an auto is the requirement to ride the brakes going down (torque multiplication doesn't work down hill). You're going to want to have a lower set of gears for down, or make sure you spend the $$ on a well tuned and easily manipulated set of brakes.

I'm swapping in a Klune-V this winter, that'll give me a pretty good crawl ratio (@97:1 with an auto, plus TM).
Joe
 
OP
OP
0313

0313

Full Member
Joined
Aug 7, 2004
Messages
261
Loc.
Salt Lake City
Ok when i started this thread i was considering changing trannys. Im not going to, im keeping the c-6/205 but adding a 203. I will post another thread stating my dilema and my solutions that I came across today. As is it fitting for a new thread to come of it. I will title the thread, "a long day of thought."
 

mxpaz

Bronco Guru
Joined
Jun 21, 2001
Messages
2,901
Loc.
KC
Its hard to lay under my Bronco and get a good pic.
 

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