Crawl Ratio??

[GotSandH3]

I did a search and didnt find any results. Does anyone know the crawl ratio for a manual transmission with off-road package? Iv never needed to
be in 1st gear and 4 low at the sametime. Anyone know that ratio?

[HummBebe]

Manual 69:1, auto 56:1:D


ooops sorry forgot to post my source

http://www.hummer3.net/specs.html (http://www.hummer3.net/specs.html)

[Sewie]

Not sure how accurate that is. Its from 2004 and they still list the two different rear axle ratios. :rolleyes: ;)

From Hummer's site:

CRAWL RATIO:
BASE VEHICLE: 45.0:1
WITH OPTIONAL OFF-ROAD SUSPENSION PACKAGE: 68.9:1

No mention of man v. auto. :confused:

http://www.hummer.com/popups/h3/h3_full_specs.pdf

[Sewie]

Iv never needed to
be in 1st gear and 4 low at the sametime.

Sounds like you need to come out with us again. ;) :D

[f5fstop]

Sounds right to me, can't remember the auto, but know it is in the mid to high 50s, so I would say you have it correct.



Manual 69:1, auto 56:1:D


ooops sorry forgot to post my source

http://www.hummer3.net/specs.html (http://www.hummer3.net/specs.html)

[f5fstop]

H3 came out in 2006, what they listed in 2004 is innacurate. The H3 uses only one gear ratio for any model in 2006 and that is 4.56:1.

Not sure how accurate that is. Its from 2004 and they still list the two different rear axle ratios. :rolleyes: ;)

From Hummer's site:

CRAWL RATIO:
BASE VEHICLE: 45.0:1
WITH OPTIONAL OFF-ROAD SUSPENSION PACKAGE: 68.9:1

No mention of man v. auto. :confused:

http://www.hummer.com/popups/h3/h3_full_specs.pdf

[Desert Dan]

Look at the H3 Brochure from the dealer.

It has both the auto and manual ratios. Sorry my book is at home.

[FormerJeeper]

You also need to factor in the torque multiplication of an auto, usually giving a 4x at the lowest revs needed for rock - crawling.

This will equate to closer to 200:1 for an auto transmission (and you won't need three feet while rock crawling).

-C

[PARAGON]

You also need to factor in the torque multiplication of an auto, usually giving a 4x at the lowest revs needed for rock - crawling.

This will equate to closer to 200:1 for an auto transmission (and you won't need three feet while rock crawling).

-Cthat's just stupid.

You are suggesting the automatic transmission quadruples the torque over a standard transmission?

[H3 Hummer]

LOL - I thought I was stupid or uneducated. Please explain how (if true)

[f5fstop]

Look at the H3 Brochure from the dealer.

It has both the auto and manual ratios. Sorry my book is at home.

This has been discussed a few other times, and sorry to tell you, the brochure from the dealer is incorrect. (That's why it has a little disclaimer on the bottom talking about errors.) :D
I have personally checked with the axle engineer in charge of the H3 (quite a few times on other subjects too:eek: ), the brand quality chassis manager has been in our facility quite a few times, and the service engineer for this part is a close friend...it is a 4.56:1 ratio in the Diffs.

(Trans 1st gear ratio x transfer case ratio x axle ratio = crawl ratio)

AUTO
Off-Road:3.059 x 4 x 4.56 = 55.796 (rounded to 56:1)
Non-Off-Road: 3.059 x 2.64 x 4.56 = 36.825 (rounded 37:1)

MANUAL
Off-Road: 3.78 x 4 x 4.56 = 68.947 (rounded 69:1)
Non-Off-Road: 3.78 x 2.64 x 4.56 = 45.505 (rounded 46:1)

NOTE: The manual first gear might be 3.79, I came across two specs in my PAD drawings for this gear.

[HummBebe]

HA!!!:D

No correction for Bebe this time:D :D :D :D

[Sewie]

HA!!!

No correction for Bebe this time



You got lucky. :p :D

[Sewie]

Thanks for the info F5. It would have been nice if Hummer posted both the manual and auto specs on their site. But I guess that's marketing for you. :rolleyes:

[Wisha Haddan H3]

The torque converter has a multiplier value depending on RPM, but 4x seems high. I have seen numbers between 1.5 and 2 for some auto trannies.

For example, the H1 torque converter ratio is 2.2:1, according to this link http://www.kellyhummer.com/h1.htm

[PARAGON]

The torque converter has a multiplier value depending on RPM, but 4x seems high. I have seen numbers between 1.5 and 2 for some auto trannies.

For example, the H1 torque converter ratio is 2.2:1, according to this link http://www.kellyhummer.com/h1.htm Ok, so.......

[Wisha Haddan H3]

Does anyone know the multiplier value of the H3's 4L60e? I'm curious about the torque multiplier curve too ... at what RPMs do you get the most out the converter?

[PARAGON]

Does anyone know the multiplier value of the H3's 4L60e? I'm curious about the torque multiplier curve too ... at what RPMs do you get the most out the converter?wouldn't a better question be "when does stall occur and lockup occur?"

[f5fstop]

Every equation I have ever seen for a crawl ratio has never taken into account the torque converter. Reason is it is next to impossible since the converter slips at a different rate at different engine rpms. Therefore, the calculation would be next to impossible. You would have to figure out all the different rpms you would have in a given range.
All crawl ratios are figured without the torque converter taken into account by any manufacturer I have ever seen.
I have seen calculations for the H1, but it also takes into account the wheel multipliers too.

[Wisha Haddan H3]

Thanks f5fstop ... I appreciate the info.

[GotSandH3]

69:1 sounds like a great ratio. How does that compare to brands such as Jeeps and Toyotas??

[PARAGON]

Every equation I have ever seen for a crawl ratio has never taken into account the torque converter. Reason is it is next to impossible since the converter slips at a different rate at different engine rpms. Therefore, the calculation would be next to impossible. You would have to figure out all the different rpms you would have in a given range.
All crawl ratios are figured without the torque converter taken into account by any manufacturer I have ever seen.
I have seen calculations for the H1, but it also takes into account the wheel multipliers too.as flywheel RPMs increase the torque converter is less and less efficient. The torque multiplication only occurs during a small RPM range on most small trucks due to many reasons. With electronics controlling lockup, along with the inefficiency of the converter itself, it's moot to consider it a factor for crawl ratio.

If one could effectively figure out the actual RPM range to hold the vehicle at and the electronics wasn't controlling the converter, you would burn the converter up and overheat the transmission.

[Michael1]

Crawl ratio with an automatic is just about meaningless anyway, with the torque converter disconnecting the driveline from the engine. Unless you like to launch off the top of rocks, and test your brake reflex skills, get a manual, with which the H3 has an exemplary crawl ratio.

Michael

[f5fstop]

Crawl ratio with an automatic is just about meaningless anyway, with the torque converter disconnecting the driveline from the engine. Unless you like to launch off the top of rocks, and test your brake reflex skills, get a manual, with which the H3 has an exemplary crawl ratio.

Michael

I will never have a manual, again, for off-roading. Too many times you have to ride the clutch to get out of sand, over rocks, etc., and if you have to stop going uphill, an auto makes it a lot easier.:D
When riding over a boulder with a manual, you have the same problem at a very low speed, you ride the clutch, then have to test your brake reflex skills just like an auto.

[PARAGON]

I will never have a manual, again, for off-roading. Too many times you have to ride the clutch to get out of sand, over rocks, etc., and if you have to stop going uphill, an auto makes it a lot easier.:D
When riding over a boulder with a manual, you have the same problem at a very low speed, you ride the clutch, then have to test your brake reflex skills just like an auto.agreed

besides, crawl ratio is something web wheelers get all warm and fuzzy about

[GotSandH3]

Same here! I regret getting a manual transmission for four wheeling. My last truck was an auto and was a lot better!!

[h2co-pilot]

No no no. Don't fret. I rode along with " 4-lo" (I dunno if that is his name here or not) in Tellico. He had a Yota pick-up manual and it was sweet.

There are a lot of things you can do with it that help you tailor the tranny. It really crawls in 1st. He taught me some moves with his shifter (;)) when turning and maneuvering around, it was a lot of work but pretty darn cool.

There are manual techniques that are to your advantage. You just have to stay off the clutch. Plus they are easier to fix etc. Maybe you could check it out or pm him and ask.

[NEOCON1]

I prefer an auto for offroad :D jmtcw;)

[usetosellhummer]

Auto, good enough for H1 and H2 good enough for me and my three

[HummerNewbie]

No no no. Don't fret. I rode along with " 4-lo" (I dunno if that is his name here or not) in Tellico. He had a Yota pick-up manual and it was sweet.

Ken had a fun and wild ride across the creek with him at the bottom of #5 on Sunday night too :eek: :cool:

[Wisha Haddan H3]

69:1 sounds like a great ratio. How does that compare to brands such as Jeeps and Toyotas??
It's best in class for 2006 models, but the 2006 JK Rubicon Ultd will beat it next year. The source I used for this graph supplied different numbers than the ones in this thread. I'll update them when I get a chance.

[Wisha Haddan H3]

In the Automatic, the H3 will have best in class crawl ratio bar none. (Here are some updated graphs ... easier to read.

[HummBebe]

Wisha, can you do a power to weight ratio comparison??

[bjc]

Too many times you have to ride the clutch to get out of sand, over rocks, etc., and if you have to stop going uphill, an auto makes it a lot easier.:D
When riding over a boulder with a manual, you have the same problem at a very low speed, you ride the clutch, then have to test your brake reflex skills just like an auto.

I think offroad driving techniques really aren't that different for automatics vs. manuals. Brake-throttle-modulation techniques used for wheeling automatic transmissions are comparable to feathering the clutch in manuals. There are times I love the control of a manual (usually offroad), and times I wish I had an automatic (like when I go to pay a parking garage attendent located on a steep grade and some A-hole pulls up 2 inches behind me).

[Michael1]

When riding over a boulder with a manual, you have the same problem at a very low speed, you ride the clutch, then have to test your brake reflex skills just like an auto.

Have you tried an H3 rock crawling with the 4:1 transfer case and adventure package? With a 68 to 1 crawl ratio, how much riding of the clutch do you need to do? That thing barely moves. That thing eats rocks for lunch with the clutch fully engaged. No slipping requred.:D

Michael

[Wisha Haddan H3]

Wisha, can you do a power to weight ratio comparison??

Sure, but imho you have to factor in the gearing to get the whole picture. Here ya go.

[Wisha Haddan H3]

Here's a chart for Geared Crawl HP to Weight ratio

[HummBebe]

I heart teh neeeerds:D :D

[Wisha Haddan H3]

Here's a look at the Geared Torque - Weight ratio

[HummBebe]

THAT"S more like it!!!

[Michael1]

It's best in class for 2006 models, but the 2006 JK Rubicon Ultd will beat it next year. The source I used for this graph supplied different numbers than the ones in this thread. I'll update them when I get a chance.

You forgot the Dodge Power Wagon with manual transmission at 78.3. That ought to be enough for any of you ladies.:D

Michael

[f5fstop]

Actually, I found the 56:1 ration quite substantial and almost felt too low from my Jeep days.:D

After spending 4.5 hours cleaning red dust out of the interior, treating the leather, pressure washing the red tires back to black, washing the vehicle, all in 90+ humid heat, my personal crawl ratio is lower than any on that chart.

[HummBebe]

poor f5....would you like me to get you a Lemonade???:D

[Idaho-Hummer]

Nah, he just needs some cheese to go with that wine. :D

[f5fstop]

poor f5....would you like me to get you a Lemonade???:D

Prefer Captain Morgan's Silver....:D

In the Kroger Parking Lot after the wash job:
http://images1.snapfish.com/347624674%7Ffp339%3Enu%3D3262%3E738%3E7%3B%3B%3EWS NRCG%3D3233949%3B6%3B999nu0mrj

Eye of the Whale Arch, Arches NP:
http://images1.snapfish.com/347624674%7Ffp339%3Enu%3D3262%3E738%3E7%3B%3B%3EWS NRCG%3D3233949%3B653%3A%3Anu0mrj

Monument Valley (darn kid in the way and taking photos):
http://images1.snapfish.com/347624674%7Ffp345%3Enu%3D3262%3E738%3E7%3B%3B%3EWS NRCG%3D3233949%3B6%3B99%3Anu0mrj

[rkcrawl]

There are advantages to both: Manual vs Auto.

I have run both in competive (UROC Rockcrawling competitions) environments.

The biggest advantage, IMO, is down hill engine braking. A super low crawl ratio in a manual transmissioned vehicle gives you excellent control of the vehicle (way more then an auto) as long at the tires have traction.

Auto's on the other hand are a ton easier to drive, you've got one less peddle to deal with and very granular control of the vehicle motion. And yes, the GENERAL consensus in the 4x world is a factor of 2 when considering the torque convertor in the crawl ratio, however its just that when CRAWLING at low rpms. Its not exact, nor scientific, but I can tell you from the seat of the pants, its noticable when crawling level or uphill grades. I drove my old rig with both, and the only change being going from a SM465 4 speed with a granny 1st gear to a Turbo 350 with a full manual valve body. The difference was VERY noticable. The TC is not a factor down hill. Thats the auto's biggest disadvantage (again, just my opinion) because you need to rely more on the vehicle brakes, rather then engine braking. I think the second biggest issue/concern is transimssion failure potential.

[f5fstop]

There are advantages to both: Manual vs Auto.

I have run both in competive (UROC Rockcrawling competitions) environments.

The biggest advantage, IMO, is down hill engine braking. A super low crawl ratio in a manual transmissioned vehicle gives you excellent control of the vehicle (way more then an auto) as long at the tires have traction.

Auto's on the other hand are a ton easier to drive, you've got one less peddle to deal with and very granular control of the vehicle motion. And yes, the GENERAL consensus in the 4x world is a factor of 2 when considering the torque convertor in the crawl ratio, however its just that when CRAWLING at low rpms. Its not exact, nor scientific, but I can tell you from the seat of the pants, its noticable when crawling level or uphill grades. I drove my old rig with both, and the only change being going from a SM465 4 speed with a granny 1st gear to a Turbo 350 with a full manual valve body. The difference was VERY noticable. The TC is not a factor down hill. Thats the auto's biggest disadvantage (again, just my opinion) because you need to rely more on the vehicle brakes, rather then engine braking. I think the second biggest issue/concern is transimssion failure potential.

Are you saying in an auto the transfer case is not a factor? I just finished some extremely steep mountain roads in Canyonlands (park and area), and in 4-low lock, the car hardly moves downhill, in fact, you have to gas it a few times. In 4-wheel hi lock, it crawls a lot slower than when in 4-wheel non-lock. This was in first or second gear, not in drive.
I have also driven a Jeep manual down the same roads, and with the manual, I had to use the brakes (first or second gear). Granted the H3 has a 4:1 while the Jeep did not, but if I'm reading you correctly, you are saying the t/case has no affect on downhill? That I will dispute, since I have tried all the ranges and there is a noticeable difference.

[PARAGON]

Are you saying in an auto the transfer case is not a factor? I just finished some extremely steep mountain roads in Canyonlands (park and area), and in 4-low lock, the car hardly moves downhill, in fact, you have to gas it a few times. In 4-wheel hi lock, it crawls a lot slower than when in 4-wheel non-lock. This was in first or second gear, not in drive.
I have also driven a Jeep manual down the same roads, and with the manual, I had to use the brakes (first or second gear). Granted the H3 has a 4:1 while the Jeep did not, but if I'm reading you correctly, you are saying the t/case has no affect on downhill? That I will dispute, since I have tried all the ranges and there is a noticeable difference.No, I don't think that's what he was saying.

A lot of times an auto will "free wheel" some or something that seems to give less engine braking than a standard, transfer case remaining the same. I also keep my shifter in first or second depending upon what I am doing and most times first will allow the truck (H2) to ease down but there are steeper situations where braking is required.

The biggest difference between auto and standard is on an actual obstacle. When on most obstacles, rarely can you just crawl up it with out some stoppage and/or re-alignment, etc. This is a big reason why you see so many trucks with their foot to the floor bouncing and banging around.

With an auto, you can easily stop ON the obstacle, hold your brake, get your RPMs up to a higher torque range and ease off the brake to continue. Huge advantage over a standard transmission where you would have to heel/toe drive to accomplish the same.

[f5fstop]

I agree, if you keep an auto in Drive, it will feel like it is freewheeling. I guess, I learned to run an auto similar to a manual, by using the shifter.
Oh well, if I read it wrong and rkcrawl meant the Torque Converter (TC), then I apologize and will lay off the Morgan's on Saturday night (no I won't:D ).

[HummBebe]

The opinions on Auto Vs Manual, are like the opinions on IFS vs Straight axle.

If one more person starts talking to me about a straight axle swap, I'm gonna have t-shirts and stickers that say:

NO SAS for this girl:D

BACK OFF MY IFS:D

STRAIGHT AXLE IS FOR SISSIES:D

GOT STRAIGHT AXLE??? SUCKS TO BE YOU:D

IFS RULES, STRAIGHT AXLES DROOL:D

Not that I actually believe that, because I have some friends with straight axles, (yes, I am not prejudice). I understand the benefits, and the drawbacks. But I've had 2 shops figure that an SAS would run $7,500-$10,000, including top of the line Dana 60, steering fabrication, lift and driveline upgrades.

WHY??? I don't want a rock buggy, yet.

[rkcrawl]

With an auto, you can easily stop ON the obstacle, hold your brake, get your RPMs up to a higher torque range and ease off the brake to continue. Huge advantage over a standard transmission where you would have to heel/toe drive to accomplish the same.

Well said.

[rkcrawl]

I agree, if you keep an auto in Drive, it will feel like it is freewheeling. I guess, I learned to run an auto similar to a manual, by using the shifter.
Oh well, if I read it wrong and rkcrawl meant the Torque Converter (TC), then I apologize and will lay off the Morgan's on Saturday night (no I won't:D ).

Yes, I was referring to the torque convertor. Hope you enjoyed the Morgan's :D

[rkcrawl]

Not that I actually believe that, because I have some friends with straight axles, (yes, I am not prejudice). I understand the benefits, and the drawbacks. But I've had 2 shops figure that an SAS would run $7,500-$10,000, including top of the line Dana 60, steering fabrication, lift and driveline upgrades.

WHY??? I don't want a rock buggy, yet.

But you'd have one kick ass H3. Someone's got to be the first to SAS an H3 :D

[evldave]

With an auto, you can easily stop ON the obstacle, hold your brake, get your RPMs up to a higher torque range and ease off the brake to continue. Huge advantage over a standard transmission where you would have to heel/toe drive to accomplish the same.

Handle throttle does the same thing - just set the throttle, keep right foot on the brake, and then feather the clutch. Same as an auto, plus you get the advantage on downhills of full lockup in 1st gear.

...unless your foot slips off the clutch, in which case then you are totally f'd because your throttle is high and you are dumping the clutch, making your jeep hop over the rock you are on, smashing the right front fender on the next rock, ruining your day and costing thousands of dollars. So I hear:rolleyes:

I was a manual guy, still am sorta, but really like an auto for the ease of use.

[rkcrawl]

I was a manual guy, still am sorta, but really like an auto for the ease of use.

That was me too, until I started competing... Auto's rule in rock crawling competition and it made me a convert.

[HummBebe]

Handle throttle does the same thing - just set the throttle, keep right foot on the brake, and then feather the clutch. Same as an auto, plus you get the advantage on downhills of full lockup in 1st gear.


So now, for those with manual, can you install a hand throttle? Sounds like the way to go:D

[f5fstop]

Anyone make a hand throttle for the H3? Haven't seen one for the electronic throttle (accelerate-by-wire) system on the H3.

[PARAGON]

Anyone make a hand throttle for the H3? Haven't seen one for the electronic throttle (accelerate-by-wire) system on the H3.Sure you have, it's called a walking cane.;) :eek:

[PARAGON]

that or you could just wire in a potentiometer :D :D :D

[HummBebe]

That was mean Para;)

[PARAGON]

That was mean Para;)I guess now you're going to tell me Fstop walks with a cane :confused: :confused: ;)

[HummBebe]

No....he walks on Water;):D

[KenP]

Not that I actually believe that, because I have some friends with straight axles, (yes, I am not prejudice). I understand the benefits, and the drawbacks. But I've had 2 shops figure that an SAS would run $7,500-$10,000, including top of the line Dana 60, steering fabrication, lift and driveline upgrades.We've looked into that, too. Just cost prohibitive.

But, a rock buggy... Hummmmm

[KenP]

I guess now you're going to tell me Fstop walks with a cane :confused: :confused: ;)Fstop has to use a cane? Man, that sucks. Sorry to hear that, Fstop.

[f5fstop]

:D Fstop has to use a cane? Man, that sucks. Sorry to hear that, Fstop.
http://hometown.aol.com/f5fstop01/images/rollingonfloorlaughing.gif

I did at one time for almost a year...eight months on crutches, three months with a cane. Not anymore though, and it only hurts a few times each year, and I hike hundreds of miles each year.
http://hometown.aol.com/f5fstop01/images/crazy.gif

I wonder if a Potentiometer would work without setting PCM codes? I will have to look at the schematics and think about this...

[HummerNewbie]

We've looked into that, too. Just cost prohibitive.

But, a rock buggy... Hummmmm

Do you think you could go ahead and get that rock buggy this month. Then you could loan it to me and I can see how it does on Lower #2 and Wood Pecker for you :D

[PARAGON]

Do you think you could go ahead and get that rock buggy this month. Then you could loan it to me and I can see how it does on Lower #2 and Wood Pecker for you :DIsn't it Peckerwood?

You don't need a rock buggy for those. Seems like one of the pecker woods that was on here before said a stock Liberty made it.;)

[HummerNewbie]

Isn't it Peckerwood?

Yeah, you might be right about that. Whichever it is, I know I kept calling it the other.

You don't need a rock buggy for those.

Don't need one but would rather take Ken's buggy up it than my H3 :p

[Ipedog]

Don't need one but would rather take Ken's buggy up it than my H3 :p

When did CP get a rock buggy and allow Ken to drive it!? :p ;) :D