1.4 Transfer Case into D1

[R_Lefebvre]

But then again, the Wrangler is a six speed, to the Disco's five.

Well sure, but we are comparing the vehicles as they sit. Advantage goes to the JK.

Even the older TJ's with the 5 speed had a better ratio.

I stand my my statement. The Land Rover crawl ratio is not that low. It's being handicapped by the use of a 1.2 ratio in the LT230, and then 3.54 gears in the axles, and a car-like 1st gear ratio rather than a granny 1st gear. And that also causes problems getting a big ************* trailer rolling from a stop, let me tell you. You've gotta be gentle and slow or you roast the clutch. When manoevering in my driveway, or at a campground, etc. I always just put it in low range now.

 

[David Harris]

Well sure, but we are comparing the vehicles as they sit. Advantage goes to the JK.

Even the older TJ's with the 5 speed had a better ratio.

No, according to your figures, the advantage still goes to the Disco against a standard JK. Also, you state that the I-6 TJ has 4.10's which is inaccurate. All sixes besides the Rubicon came with tall 3.07's standard. The 4.10's were only on 4 bangers and the Rubicon. This changes the picture considerably for the TJ:

First: 4.01
TC: 2.72
Axle: 3.07
Crawl Ratio: 33.49

Compared to the LR's 39.84 with the R380.

 

[SeaRubi]

niggle

Auto-boxes enjoy a roughly 1.5x multiplier from the torque converter in 1st gear. You can't compare the ratios on the gear value alone when looking at auto vs. manual shift transmissions and effective "crawl" ratios. In that light, the Disco / RRC / DII comes out to a bit over 40:1. You need to multiply that value as well for the autoboxes on the Wrangler.

As for the manual shift Jeeps - 2003 and 2004 SWB Rubicon's had the NV3550 5sp. All 2005 and 2006 SWB and LWB Rubicon's were fitted with the new NSG370, bringing the crawl ratio up to 73:1. The NSG370 was carried over into the JK platform virtually untouched.

My driving impressions off-road of my own 2008 JK X with a 6sp and 3.73 diffs is that it felt roughly equivalent to a coiler Land Rover. Computing it all out leads to a 45:1 1st/low ratio, so it basically was. Taking the 1.5x at face value, the computation for Rover is 43:1.

I really prefer this range over the Rubicon's 73:1 for general purpose off-road work. Even in 6th gear the low range was often too low for a good chunk of being in the dirt. It's great for rock crawling, but when you're just heading up soft dirt roads while loaded up for a trip it gets very tedious. You also keep getting out-run by your Land Rover driving buddies and find yourself swapping between high and low range to keep up :sombrero:

cheers,
-ike

 

[SeaRubi]

To get back to where you were at with the autobox, you need to re-gear the diffs to 4.11's

I was going to mention this before but I figured you'd have to experience it for yourself before being convinced that you needed the upgrade :elkgrin:

Well sure, but we are comparing the vehicles as they sit. Advantage goes to the JK.

Even the older TJ's with the 5 speed had a better ratio.

I stand my my statement. The Land Rover crawl ratio is not that low. It's being handicapped by the use of a 1.2 ratio in the LT230, and then 3.54 gears in the axles, and a car-like 1st gear ratio rather than a granny 1st gear. And that also causes problems getting a big ************* trailer rolling from a stop, let me tell you. You've gotta be gentle and slow or you roast the clutch. When manoevering in my driveway, or at a campground, etc. I always just put it in low range now.

 

[R_Lefebvre]

No, according to your figures, the advantage still goes to the Disco against a standard JK. Also, you state that the I-6 TJ has 4.10's which is inaccurate. All sixes besides the Rubicon came with tall 3.07's standard. The 4.10's were only on 4 bangers and the Rubicon. This changes the picture considerably for the TJ:

First: 4.01
TC: 2.72
Axle: 3.07
Crawl Ratio: 33.49

Certainly possible. I'm "magazine racing" on this stuff. Still, the option was there (Rubicon or axle ratio) if a customer wanted. With the Land Rover, nope, 3.54 is the only ratio.

And let's throw something together. Guessing at some of this as I don't have all the vehicle details. But for a mid-80's Bronco, let's say you have the T-18, you've got the granny 1st at 6.32, say you've got a "bad" TC at 2.0, and horrible 3.55 gears. That still gets you 44.8!

Compared to the LR's 39.84 with the R380. (BTW: Your figure of 39.0 for the Disco is also wrong . . .)

How is it wrong? I rechecked it.

Auto-boxes enjoy a roughly 1.5x multiplier from the torque converter in 1st gear. You can't compare the ratios on the gear value alone when looking at auto vs. manual shift transmissions and effective "crawl" ratios. In that light, the Disco / RRC / DII comes out to a bit over 40:1.

I've seen up to 2.0:1. Just depends on how you figure it. Full stall, or partial. I doubt many people are doing full-stall on anything off-road. At least not for long.

But it's not just those number either. If you need to go ultra slow on an obstacle with an auto, the crawl ratio can be infinitely slow. Just go easy on the gas and let the converter work, or even left foot brake if you have to. With a manual, if you want to go slower than your crawl ratio, your only option is to burn the clutch. I'm talking about climbing, or trying to pop a tire over a rock.

To get back to where you were at with the autobox, you need to re-gear the diffs to 4.11's

Ah yes, but then I'm turning too many RPM's on the highway. IIRC, the R380 5th and ZF 4th are equivalent, so when the torque converter locks, they're the same.

So back to my original point. I think it's better to regear the axles and leave NOT change to a 1.4 Tcase. Changing the axles, you can get the ratio you want, AND lower your crawl ratio.

I really prefer this range over the Rubicon's 73:1 for general purpose off-road work. Even in 6th gear the low range was often too low for a good chunk of being in the dirt. It's great for rock crawling, but when you're just heading up soft dirt roads while loaded up for a trip it gets very tedious. You also keep getting out-run by your Land Rover driving buddies and find yourself swapping between high and low range to keep up

I dunno. I can't think of a single time I used 5th gear low. I used to occaisionally use 4th with the ZF, but never 5th with the R380 yet.

 

[David Harris]

How is it wrong? I rechecked it.

OK. I was checking it on a different calculator than I usually use. I checked it again with another one and it comes out to 39.02, so let's go with that.

I like manuals, but I have to say that off-road, a good auto beats a manual every time. For the reasons mentioned above. The only real disadvantages to an auto are that some don't have very good engine braking ability on descents, and they produce more heat, so need better cooling. However, I would say that the ZF is about as good an auto as you can get in a 4x4. Engine braking is superb and the LR cooling system does a good job (two trans coolers stock). So, I really don't see a real advantage in switching to a manual with the stock V8, or a similar engine in most Rovers. However, if you are going to run a diesel, I can definitely see why manual would be better, with the narrower power band. With that said, in your case the swap makes good sense with the D2, which as an electronic trans, doesn't like water crossings. Still puzzling how you got water inside with a functioning breather system. Maybe the HP24 has a weakness there that you don't see in the HP22 of the D1's, which seem to be able to run submerged without problems. I like the idea of pressurizing the bellhousing on crossings. This would solve the problem of water ingress.

David

 

[R_Lefebvre]

I like manuals, but I have to say that off-road, a good auto beats a manual every time. For the reasons mentioned above. The only real disadvantages to an auto are that some don't have very good engine braking ability on descents, and they produce more heat, so need better cooling. However, I would say that the ZF is about as good an auto as you can get in a 4x4. Engine braking is superb and the LR cooling system does a good job (two trans coolers stock). So, I really don't see a real advantage in switching to a manual with the stock V8, or a similar engine in most Rovers. However, if you are going to run a diesel, I can definitely see why manual would be better, with the narrower power band. With that said, in your case the swap makes good sense with the D2, which as an electronic trans, doesn't like water crossings. Still puzzling how you got water inside with a functioning breather system. Maybe the HP24 has a weakness there that you don't see in the HP22 of the D1's, which seem to be able to run submerged without problems. I like the idea of pressurizing the bellhousing on crossings. This would solve the problem of water ingress.

David

I really can't disagree with any of that.

The engine braking problem is solved in the D2's with the HDC. It worked well.

My problem with the water had NOTHING to do with electronics however. All auto trans clutches disintegrate soon as you get water inside.

 

[David Harris]

My problem with the water had NOTHING to do with electronics however. All auto trans clutches disintegrate soon as you get water inside.

Don't you think the fact that the trans controller got wet and stalled you there contributed to the water getting in? Just sitting there submerged for a time increased the chances of water getting in?

 

[AxeAngel]

All auto trans clutches disintegrate soon as you get water inside.

Rob, didn't your AT fail months after the crossing?

 

[R_Lefebvre]

Don't you think the fact that the trans controller got wet and stalled you there contributed to the water getting in? Just sitting there submerged for a time increased the chances of water getting in?

The truck never stalled, and was never stuck due to anything to do with the trans. The truck always had drive. When the trans controller was wet, I had Park, Neutral, Reverse and 1st. When I removed the controller, I had Park, Neutra, Reversel and 3rd. I was stuck in the mud. I didn't even realize the trans was in trouble until after I was unstuck.

The electronics were absolutely not a factor in any of this.

Rob, didn't your AT fail months after the crossing?

Yes. It took some time to completely fail. I didn't mean they disintegrate instantly, though I guess it looks like that's what I meant. What I should have said was, the experts say, the instant you get water in, the trans is done, it's practically impossible to change it fast enough. The water instantly attacks the adhesive or something.

It lasted so long, I started thinking "well, maybe Land Rover used better clutch material, good for them." Then Fffttt

 

[AxeAngel]

You flushed the tranny fluid I'm guessing as soon as you got home. Just wondering why the delayed failure.

-Sam

 

[muskyman]

I




I don't really care about what happened 20+ years ago. I'm talking about contemporary history here.

The problem with the LT230 is it doesn't have a 1:1 High Range. It's typically 1.2:1. The low range may appear to be low-ish at 3.3:1, but the fact is, it's really only 2.76 times the high range. This is important to keep in mind because most of us gear our trucks with overall drive ratio in mind. The LT230 1.2:1 high range ratio is why Land Rover can get away with a relatively steep 3.54:1 axle ratio. Most other trucks have a 1:1 high range, and maybe 4.11 axle gearing.

So the LT230 high-low range ratio is only 2.76. Let's go back 20 years and look at other transfer cases:

.

You really are a complete ************* idiot

a LT230 can not be in both high and low range so when discussing the low range crawl ratio the high range ratio really does not matter.

You really dont have a clue as to what old 4x4's were all about at all and the posts you are making here make that very clear.

I dont even know why I bother responding to your blabber...your a idiot!

 

[muskyman]

Auto-boxes enjoy a roughly 1.5x multiplier from the torque converter in 1st gear. You can't compare the ratios on the gear value alone when looking at auto vs. manual shift transmissions and effective "crawl" ratios. In that light, the Disco / RRC / DII comes out to a bit over 40:1. You need to multiply that value as well for the autoboxes on the Wrangler.

As for the manual shift Jeeps - 2003 and 2004 SWB Rubicon's had the NV3550 5sp. All 2005 and 2006 SWB and LWB Rubicon's were fitted with the new NSG370, bringing the crawl ratio up to 73:1. The NSG370 was carried over into the JK platform virtually untouched.

My driving impressions off-road of my own 2008 JK X with a 6sp and 3.73 diffs is that it felt roughly equivalent to a coiler Land Rover. Computing it all out leads to a 45:1 1st/low ratio, so it basically was. Taking the 1.5x at face value, the computation for Rover is 43:1.

I really prefer this range over the Rubicon's 73:1 for general purpose off-road work. Even in 6th gear the low range was often too low for a good chunk of being in the dirt. It's great for rock crawling, but when you're just heading up soft dirt roads while loaded up for a trip it gets very tedious. You also keep getting out-run by your Land Rover driving buddies and find yourself swapping between high and low range to keep up :sombrero:

cheers,
-ike

Ike

Great impressions!

I have a buddy with a Rubi and he had alot of issues trying to find the right gear. In snowy conditions he was sunk! low range was too low and high range way to high.

If all you were going to do was crawl rocks the 4 to 1 might be great but for all kinds of wheeling a auto box rover was far superior.

 

[R_Lefebvre]

a LT230 can not be in both high and low range so when discussing the low range crawl ratio the high range ratio really does not matter.

Only to those who cannot grasp the concept that both ratios are important when setting up a truck. The underdriven high range ratio in the LT230 requires you to put taller gearing in the axles to achieve a given highway RPM. That taller gearing then hurts the crawl ratio.

If the high range in the LT230 was 1:1, you could run 4.27 gears in the axles and have EXACTLY the same highway RPM, yet the crawl ratio would drop from 39 to 46.8.

It is that simple.

The fact is, the low range ratio can be nearly anything at all. What is important for crawl ratio, is the spread between high and low. This is what gives the desired spread between street use and off-road.

As usual, when you run out of logic, you resort to name calling.

 

[R_Lefebvre]

You flushed the tranny fluid I'm guessing as soon as you got home. Just wondering why the delayed failure.

-Sam

The clutches kept disintegrating. I flushed a couple times, and clutch material kept coming out. You can see the condition of the fluid in my thread. No water, full of clutch particles, and the filter was clogged.

The box worked fine until it just ran out of clutch material.