Now the question...what is the ideal crawl ratio?

[cpmarcani]

Hello everyone!!

I have been reading this forum for awile and I like what I see. There are some smart people on this forum.
I have had 4 FJ40s over the years, I have a 65 now (See Below).
So I want to ask your opinion...

I need to make a move on my ring & pinion. I have 4:10 now, with my set up it gives me a 160:1 Crawl Ratio (I think my math is right).

4.88 would give me 190:1
5.29 = 207:1
5.71 = 223:1

Again the question... what is ideal crawl ratio?

I live in VA so I can run it with Antique tags (no state inspection) to local trails, I'm lucky I live in the mountains with lots trails of close by. So I want to run up to 45-50 mph.

 

[e rock]

Have you ever used 160:1 and thought that you needed to go slower or needed more torque?


From my experience wheeling in tight NW woods, crawl ratios in excess of ~150:1 are superfluous and purely for bragging rights. Obviously this depends a little on the rest of your drivetrain, but the point is that the functional difference between 300:1 and 150:1 is miniscule and not worth the money in my opinion.


With your setup, I'd keep the 4.10s. They're relatively cheap and plentiful (compared with any other cruiser r&p) for when you start busting pinions.

 

[rusty_tlc]

Never mind tire size is in your sig line.
I was under the impression that diff erential gearing was more about compensating for tire size than crawl.

 

[Poser]

Welcome.


Ideal?


Ideal would be whatever works best for you, wherever you run your junk.


Someone playing on steep vertical shelves and large, bolder-strewn trails is going to want gearing one way, and someone that plays in sand, mud, or wet rocks and steep, tree covered hills will not likely be able to use anything beyond 90:1 very often.


I run 148:1 in my junk, but rarely do I use first gear, unless I am trying to navigate a dry, tight line. (420/4.3AtlasII/4.88’s)


The Orange truck I have built for a customer has a 313:1 low range. There have been many instances where he has needed to get out of ridiculow and use just the 2.28 Toybox because it was simply just too low. (465/2.28Toybox/4:1 Orion/5.29’s)




There really is not a simple answer to this question.


The more you travel around the country and run your truck on different terrain, the more you will realize that gearing, just like everything else, is a balance.

but the point is that the functional difference between 300:1 and 150:1 is miniscule and not worth the money in my opinion.

For you and your application.

300:1 has it's place. I have operated trucks through identical obstacles, and I felt that there was a lot more control going slower through some really difficult lines.



It all really comes down to what you want to do with your junk. Once you have the gearing dialed in, you will then find the next limiting factor......

 

[Mark W]

My current setup in my '40 is a 465 with a 203 in front of an Orion and 5.29 gears.

My ultimate crawl in Stupid low (8:1) is 274:1.

I've used it and been glad that I had it. No "bragging" involved. Just getting out of tough spots.

But the 137:1 crawl of the 4:1 Super low is used a lot more. And the 68:1 of Low gets used even more than that.

There is no Ideal crawl ratio for all uses. Just depends on what you're doing with it. For years the guys with 79:1 (SM420/"3 speed case"/4.88s) were the king of crawl and they took their rigs just about everywhere you could possibly want to go.


Mark...

 

[cpmarcani]

Thank you for the info. After reading your posts I agree that "Stupid low" in my truck is not used much in the steep rocky wet trails that I usually run. Though there has been times that I wanted a lower gear for crawling, Its not the reason I'm looking to change gearing.

One post above talks about compensating for tire size. I guess that is more what I am looking for. The truck seems sluggish driving on the road. Especially from a dead stop, compaired to the stock trucks with small tires.

Like everyone else I am looking for the best all around gearing. What I have now works great on the trails here in my area. I just seem to not have the power from a dead stop that I would like.

 

[shelfboy1]

if you have the original f engine thats probably the loss of power maybey an upgrade to a 2f would help your cause .elecronic ignition may also help made mine run better good luck

 

[cpmarcani]

I have a 78 model 2F engine,webber carb, headers, and an H.E.I. vacuum advance distributor from Performance Distributors. I also added a one wire GM style marine alternator when I installed the painless wiring harness. What a job that was, but thats another story.

 

[cpmarcani]

Hey Shelfboy1, 7 40s...wow I would like to have the money you must need to keep all those running. Whats 6745v ?

 

[Poser]

The truck seems sluggish driving on the road. Especially from a dead stop, compaired to the stock trucks with small tires.

Are you starting out in first gear with your H41 or second?

 

[cpmarcani]

First gear.

Don't get me wrong, Ive got power.

Its just... I had a 70 fj40 stock,3 sp, ect., that thing ran like a scalded dog. When I let out the clutch it jumped. This one drags the motor down starting out. Thats the best way I can explain it. I know its the 37" tires, and I know its a lot different setup than the 70. But, I would like to get some of that off the line power back. Of course without screwing up the off road preformance.

 

[shelfboy1]

67 45v is a landcruiser wagon have been working on photos forever. i just dont get it .my computer wiz son will be here in a week and i hope to introduce myself at that time .only 4 trucks are driven heavy the rest get maybe 200 miles a year i have a 37 year pile of parts so havnt had a great expense yet . i run 38 hawgs on my dd in summer same engine as yours and 4 speed h42 but being 57 maybey speed doent matter so much . these guys on here are good so im sure help is on its way good luck

 

[kellyo]

I would keep exactly what you have and spend any extra money on gas and 4 wheeling. What you have will work fine in 95%+. Now just wheel it.

 

[JJS]

I would keep exactly what you have and spend any extra money on gas and 4 wheeling. What you have will work fine in 95%+. Now just wheel it.

I'm with him.

 

[cpmarcani]

I would keep exactly what you have and spend any extra money on gas and 4 wheeling. What you have will work fine in 95%+. Now just wheel it.

Working on it is half the fun for me!

 

[Poser]

First gear.

Don't get me wrong, Ive got power.

Its just... I had a 70 fj40 stock,3 sp, ect., that thing ran like a scalded dog. When I let out the clutch it jumped. This one drags the motor down starting out. Thats the best way I can explain it. I know its the 37" tires, and I know its a lot different setup than the 70. But, I would like to get some of that off the line power back. Of course without screwing up the off road preformance.

Working on it is half the fun for me!

Well then, install some 5.29 gears sets and call it good.

 

[cpmarcani]

Well then, install some 5.29 gears sets and call it good.

Where would you get them from?

 

[1973Guppie]

so, checking my math, so with an earlier nv4500 (6.34), a stock 3spd TC (2.31) and 4.11's in the axles, I would be at about 60:1 crawl ratio in low / low??


thanks,

Noah

 

[cpmarcani]

so, checking my math, so with an earlier nv4500 (6.34), a stock 3spd TC (2.31) and 4.11's in the axles, I would be at about 60:1 crawl ratio in low / low??


thanks,

Noah

Huh??

 

[Poser]

so, checking my math, so with an earlier nv4500 (6.34), a stock 3spd TC (2.31) and 4.11's in the axles, I would be at about 60:1 crawl ratio in low / low??


thanks,

Noah

Your math is accurate Noah.

Where would you get them from?

Hit the vendor section, there are a few folks out there that could help you out.