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Post by Chuck on Dec 1, 2006 11:55:29 GMT -5
You could always do a three speed case. Actually, you can buy something similar already, either as a case or (more interesting) as a conversion for existing cases. LoMax just came out with a 3:1 kit for the NP205 (includes a new case because the stocker can't fit a big enough gear to get the ratio), which means you can now combine the 2:1 NP203 range box and a 3:1 NP205 to get 1:1, 2:1, 3:1, and 6:1. ;D
I've actually been interested in building a very durable TC that could do 2WD (front or rear preferably), 4WD open (full time), or 4WD locked (part time). Based on looking through the drawings of the internals, I think you could actually do this relatively "easily" by modifying an NP203. The 203 already has the range and diff lock controlled by two separate external rails, which means you can twin stick it to get a "Hi-Lo" shifter and a center diff "Lock-Unlock" shifter. Looks like if you made a new, longer front output housing with a rail and a fork, you could add either dog engagement or a synchro to the front output, which would also let you lock the diff and uncouple the front, running in 2WD.
The 203 has three main drawbacks to most people -- heavy weight, a weak center diff, and lousy gas mileage on the highway. That mod would take care of #3. It would probably be do-able to build a tougher diff, too. I would think anyone who could do the above mods could manage that. The result would be an absolutely killer DD transfer case (2WD in the summer, 4WD even on dry pavement or patches of dry and ice in the winter) that would also work well for weekend wheeling ...
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Post by CORE 4WD on Dec 1, 2006 14:40:23 GMT -5
Check these specs- www.jeepfan.com/products/gear/advad_atlas4sp.htmI think the 10-1 is under $3k but barely. You don't need that much gear anyway, especially since you'll be running the "smaller" 36" or 38" tire. Also, you can use the range box off the 203 to double it up as well. There are different companies that will sell you the d20 adapter (Wild Horses sells'em for the Early Bronco) or it sounds like you can make one. But yea that would be a gnarly crawl ratio! Git 'r done and git 'r wheelin'! ;D |
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Post by Chuck on Dec 1, 2006 15:02:00 GMT -5
I've gotten most of the steel for the Bronco for $.30 a pound up at Old Dominion Recycling. Can't beat scrap ... it's not milk, it's not like it spoils if you don't refrigerate it. ::grins::
The 6:1 203/205 combo actually isn't that bad. The main problem is fitting the 3:1 gears in the 205. I'd say if you want to go as high as 6:1 the best way to go is compound gearing ... that'll keep your gear sizes reasonable. If you want to home-brew, you could probably do it by leaving the 205 at 2:1 and building a 3:1 (or 3.5:1 if you want 7:1) range box (instead of using the NP203's box) to go ahead of the 205. The 205 is pretty indestructible, and that way you could spend your machining time on the range box, which would probably be simpler.
Of course, if you go as far as building your own range box for that solution, why not a three speed range box? If you did a 1:1,3:1,5:1 range box, you'd get six speeds -- 1:1, 2:1, 3:1, 5:1, 6:1, 10:1. If one of those won't do it ... haha
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Post by 87B2XLT on Dec 2, 2006 22:27:09 GMT -5
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Post by 87B2XLT on Dec 3, 2006 12:16:12 GMT -5
If you get a chance to take a peek at that dark blue '93 (?) ford explorer 4-door that -was- 2nd from the roadway, see if the radiator is still there... if you have a knife and the time, could you snag it for me? I'd appreciate it ;D
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Post by CORE 4WD on Dec 3, 2006 21:29:28 GMT -5
Yea for doubler you'd definitely have to stretch the rear axle out back a little!
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Post by Chuck on Dec 6, 2006 17:13:47 GMT -5
Lookin' sharp!
I wonder -- could you do these splines in a single setup per spline with something like a contour-ground flycutter? I've seen setups like that in older books, and it seems like it might be simpler/cheaper than getting a special full-on cutter made, and you could probably use the head of the flycutter for multiple interchangeable spline profiles ...
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Post by Chuck on Dec 6, 2006 18:14:18 GMT -5
Man, wish I could watch you do that. I do have base access (work for the Army), but I suspect your shop may be a little pickier than that on access (?). I've seen pics of setups like that, but there's a big difference between that and actually getting to see the process done.
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Post by Chuck on Dec 9, 2006 9:53:36 GMT -5
So how does that work -- is that actually a deeper spline cut? What's the process? I think I was understanding what you meant by offset and roll, but my brain isn't wrapping around this one.  |
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Post by 87B2XLT on Dec 13, 2006 23:19:04 GMT -5
Lookin' pretty sweet... and all it cost you, I'm guessing is a little bit of mathematical frustration! Pretty awesome that you're able to do projects like this yourself... I'd hate to see what some machine shops would charge  |
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Post by Chuck on Dec 14, 2006 9:34:09 GMT -5
Nice! Do you have heat treat capability too? I know you said you had an oven with a high enough temperature to anneal. If not, who around here does heat treating? Might be worth knowing one day. ::grins::
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Post by PaulC on Dec 15, 2006 21:14:46 GMT -5
Rich,
What kind of D-Shaft do you plan on running? C/V or not. Will those u-bolt holes on the 14 bolt yoke line up with a CV? Looks good. Are you going to make a front 32 spline output now?
PaulC
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Post by Chuck on Dec 20, 2006 11:00:33 GMT -5
On that seal -- sure you want that flange to sit all the way flush? That'll make it a pain to pull if you need to re-seal it. You might want to cut a shallow slot in a couple of spots so you could tap a wedge under the lip and loosen it the easy way ...
I can't say without seeing how your axle actually sits, but you might be able to get away with a regular single cardan front joint if you use a steep enough pinion angle. You basically have two options for standard two joint shafts (vs. three joint, a DC up front and single third joint in the back).
Option 1 is to use the normal two joint setup, which has a downward angle from the TC output to the shaft (say 5* down for example), and a matching upward angle from shaft to pinion (5* up) -- which puts the pinion and TC output parallel.
Option 2 is a downward angle from TC output to shaft (say 5* again), and an equal additional downward angle from shaft to pinion (another 5*). This would put the pinion inclined down 10* total from the TC output. Basically, as long as the angles are the same across two joints, whether cancelling (opposite) or adding, the speed difference across the pair of joints will cancel. That's actually how a DC joint works, it splits the angle across the top two joints so there's no speed difference between the TC output and the shaft. That's also why the third joint in a DC shaft has to be straight on with the pinion for normal operation -- any angle there will cause vibration too.
Anyway, the high pinion angle setup will cut way down on your joint angles compared to parallel TC and pinion, so that leads to the questions of (1) will it reduce the cardan joint angles enough, and (2) will the pinion angle be high enough to cause oiling problems with the pinion bearings.
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Post by 87B2XLT on Jan 4, 2007 6:07:28 GMT -5
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Post by 87B2XLT on Mar 16, 2007 11:04:27 GMT -5
*blinks* alrighteythen! I think the Torqueflite 727s were what was normally behind those engines. I think there were other ones as well... here is some good info: www.allpar.com/mopar/torqueflite.html. I believe the A-727 was the brute of the bunch, though. I do know that a buddy of mine had one in a 383 stroker-powered Satellite, and that car had some serious balls. And, yeah, Rich, you better plan on buying a dozen rozes every day for like 6 months or something, among other things... lol. I think you should reconsider and continue building it for offroad, though, but that's just me and my $0.02  |
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