Lt230 transfercase high ratio conversion

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Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Thursday, June 14, 2001 - 12:13 pm: Edit

Good afternoon everyone! I need a second opinion on something. I wish to convert my lt230 from the orginal 1.22 high range ratio to the 1.003 ratio. However a reputable rover enthusiast shop I have discussed this with claims the ratios can not be swapped so this change would require me to purchase a complete case. Could any of you shed any light on this?
Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Ron on Thursday, June 14, 2001 - 12:25 pm: Edit

Call ashcroft. They will know for sure.

www.autoconv.com

Ron

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Chris on Thursday, June 14, 2001 - 01:15 pm: Edit

Why do you want to raise your gearing?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Thursday, June 14, 2001 - 01:42 pm: Edit

Its a long story involving a heavily modified Discovery I, but basically I want to drop my rpm on the highway in overdrive.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jon Williams (Jonw) on Thursday, June 14, 2001 - 02:02 pm: Edit

As in "sufficient power increase" modified, or as in "13-inch mac daddy wheels with 30-series tires" modified? That 1.003 ratio is found in the transfer case of a late model Ford Ranger, at least. Maybe other vehicles use it, too. And I think the Ranger's low ratio is close to that of the LT230 on the Disco.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Thursday, June 14, 2001 - 02:16 pm: Edit

As in "500 cubic inch efi Cadillac making 635lb/ft of torque" modified. The Cad is a torque monster (made 400 lb/ft at only 1400rpm when it was dyno tested prior to install)so with my 32 scorpions and 3.73 gears I should turn about 1850 down the highway at 65 in OD versus my current 2300rpm. Or to look at it another way that same 2300rpm will translate into 80mph.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jon Williams (Jonw) on Thursday, June 14, 2001 - 02:25 pm: Edit

LOL I see. Well then you can definitely drop the rpms down. How'd you get that engine in there? But I think that'd kill a Ranger's t-case in no time ...probably a Disco's too.

...or you could try 2.93 final gears (Chevy) and leave the transfer case as is

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Thursday, June 14, 2001 - 04:47 pm: Edit

Conversion to 500 Cad is surprisingly straight forward. Bellhousing pattern is the same except for a simple starter relocation. The zf auto was gone through by Renntech to increase durability and improve the shifting. Local hot rod fabricator built me a set of stainless steel headers. Cadillac produced 500 efi (port not tbi) motors in 1975 and 1976 and 368 efi units through 1982 I used one of these systems with bigger injectors and an Accel DFI controller, conversion looks factory. Besides big CID and a matching bellhousing the Cad has another strength it was designed in 1969-1970 using modern lightweight casting techniques compared to any of the other GM V8s. The Cad 500 with the aluminum efi intake and headers is 65lbs lighter than a 350 Chevrolet. My truck had a front ARB bull bar and warn 9000 with the engine swap, ditching the bar, relocating the winch to the rear along with both batteries I now have 40 lbs less weight on my front axle than I had before. So much for "big block swaps don't work they are too heavy" that I heard from most of the "knowledgeable rover shops".

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Murray (Cdnrvr) on Thursday, June 14, 2001 - 05:23 pm: Edit

Jay - you have to post that bad boy in the PhotoGallery with pics of the hood up. I am considering swapping my engine for a 4.6 after completing my suspension - I was under the impression that putting anything else under the hood would require heavy modifications to the suspension because of the added weight.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By RVR OVR (Tom) on Thursday, June 14, 2001 - 05:26 pm: Edit

VARRROOOOMMMMM!!!!

Post some 0-60 times, too!

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Chris on Thursday, June 14, 2001 - 05:44 pm: Edit

Jay I guessed you answered my question. FWIW the original RR three speed auto (using Chrysler A727) 1.003 ratio to.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Friday, June 15, 2001 - 02:37 am: Edit

The one thing I guess I neglected to mention is that the Cad really demonstrated what a total piece of crap all the Rover axles are by eating one standard rear, one front, and one big bad salisbury rear all in less than 5000 miles. The disco now rides on a full floating disc brake Dana 60 with a Detroit locker in the rear and a rare Dana 44HD (basically 60 ring and pinion with heavy duty 44 axle shafts) with lockouts and an ARB in the front. Also my LT230 has been converted to a part time unit by removing the spider gears in the center differential. This combination has proven quite durable. The truck has been seriously wheeled, hill climbed, and even made a few passes on the drag strip with a best ET of 14.1 at 98mph on scorpion A/Ts, had to lock in the front end to get enough traction:) The combination is most impressive though when booted from cruise mode at like 65 mph in overdrive to say pass some cars on a two lane. The Cad which had been quietly burbling along at 2300 rpm suddenly and I mean suddenly cause the Renntech trans shifts hard under wot shows about 4000 rpm on the tach and starts pulling like mad towards the 6000 rpm redline with the twin flowmasters producing a nice "NASCAR race off in the distance" sort of muted roar. The real unexpected fringe benefit of this conversion is that the combination knocks down a consistent 14 mpg in combined driving and 17 mpg down the highway. Now how much of that is the part time conversion and how much is the motor being a better match for the load and not working so hard I don't know.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By MTB on Friday, June 15, 2001 - 03:27 am: Edit

Jay
Are you going to put some wheely bars on that BEAST. You need to post some pics. of the motor & some offroading. We all would like to see this.

Michael B

Top of pagePrevious messageNext messageBottom of pageLink to this message   By wisker on Friday, June 15, 2001 - 09:06 am: Edit

wow

wisker

Top of pagePrevious messageNext messageBottom of pageLink to this message   By John C. on Friday, June 15, 2001 - 09:21 am: Edit

Jay, where have you been all my life?

:)

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay on Monday, June 18, 2001 - 02:10 pm: Edit

Just thought I'd let you guys know that contrary to what I was originally told I have confirmed it is possible to swap the gear ratio in an lt230 from 1.22 to 1.003. However as I have modified my case for force feed oiling there is some concern over the clearance of the larger gearwith the new ratio. I also learned 1.003 was/is still a standard ratio in many diesel rovers and discos all over the world.


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