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Discussion Starter · #1 · (Edited)
Here are some pics of the underdrive and Dana 300 flip kit that I made.



These are all of the parts used for the underdrive (except for the shift fork)



This pic shows the planetary ring gear pressed into the aluminum housing. If you look closely you can see the splines on the outside of the gear that bite into the aluminum. It took 16 tons to press the gear into the housing


Here is the planetary gearset in place. The S-10 cases had a 6 gear planetary set.



You can see the two holes going into the side of the rear half of the case. The inspection cover and the shift fork can be interchanged for use in other applications.



Here is a back view of the underdrive showing the output shaft in place and rear seal.



Here is the complete D300 with the underdrive mounted. The Atlas assembly shifts firmly and will hopefully keep the front axle from popping out of low range and the interlocks should keep me from shifting into high and low range.

Hope I didn't suck up too much space with all of these pics.

I will do a more detailed writeup if there is any interest.

Chris



[This message has been edited by chris siebert (edited March 12, 2002).]
 

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maybe I am being a bit of a goofball - the pics are good and explain..

But what exactly does the underdrive do for the jeep?

Thanks for helping out a silly monkey.

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1987 3" lifted YJ with 31" KOs new paint etc.
 

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Originally posted by chris siebert:
I will do a more detailed writeup if there is any interest.

Chris
[This message has been edited by chris siebert (edited March 12, 2002).][/B]
Interest? Sheesh...spill the beans dude! :p

What is the diameter of the case?

What machines did you use for the work?

What is the gear ratio of that unit?

The machining doesn't look too complex...hmm...maybe even a hack machinist like me could do it.




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jo-jo
http://island4x4.com

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Superfly
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Originally posted by jo-jo:
What is the gear ratio of that unit?
I'd guess 2.72:1.

So how 'bout it Chris, you gonna be makin' some of these? What's the overall length of the unit?

Oh, and don't worry about the photos' bandwidth. That doesn't come out of our pocket 'cuz those pics aren't hosted on our site.

...lars

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19911995409993004:144444.103512.58274

[This message has been edited by lars (edited March 13, 2002).]



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Silverback
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Originally posted by chris siebert:
Here are some pics of the underdrive and Dana 300 flip kit that I made.

Chris
Cracky! How much does it weigh? Did you have it installed as of Monday (waved back to you near the Elephant & Castle/Hotel on Cessna Way, Rmd)?

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DMMcG
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Discussion Starter · #8 ·
What is the diameter of the case?

The material I started with was 8 inch diameter 6061 aluminum.

What machines did you use for the work?

lathe, milling machine, accurate drill press, rotary table with custom jig, boring head, welder, 20 ton press and various hand tools.

What is the gear ratio of that unit?

2.72 is the ratio. This is the only ratio available in the factory 231 cases.

The machining doesn't look too complex...hmm...maybe even a hack machinist like me could do it.

It wasn't difficult to machine, but there is a lot of material to be removed. Some of the more difficult parts were establishing where everything needed to be.

So how 'bout it Chris, you gonna be makin' some of these? What's the overall length of the unit?

I suppose it would come down to whether anyone would be interested in buying them. I can definately build them alot cheaper than Klune, but it doesn't use brand new parts as theirs does. I would have to charge at least $1000 to justify the costs and time, possibly more. Is there any interest?

The overall length is 6.5 inches plus a 1 inch adapter. The Dana 300 requires the adapter because the splines are mostly outside of the case and the bearing retainer must be cleared as well. You wouldn't need the spacer on a 231 case and could even use the same output shaft.

Cracky! How much does it weigh? Did you have it installed as of Monday (waved back to you near the Elephant & Castle/Hotel on Cessna Way, Rmd)?

It weighs just under 40 lbs. I had to install it mounted to the case like in the picture there. The total combination weighs around 130 lbs. You certainly notice how much heavier it is when your hoisting it up on the skid plate

Ya I had the underdrive in when I saw ya there. I have actually had it in for about a year now. I just made some changes to the Dana 300 and had to reinstall it.
 

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I'd be a little worried about the sun gear spinning in the housing, because the thermal expansion of aluminum is greater then the 3120 steel that the sun gear is made from. If you look at klune underdrives they have 6-8 set screws arranged raidially on the housing and little flats on the sun gear to keep the whole thing from spinning. When I make my UD for my SuperDuty I'm going to use the low range out of a NP271 to handle the diesel's torque, but pretty much the same idea.

JP

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99 F250 Super Duty,7.3PSD,reg cab,auto, "Offroad Package"

[This message has been edited by strong_like_tractor (edited March 14, 2002).]
 

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Discussion Starter · #10 ·
I'd be a little worried about the sun gear spinning in the housing, because the thermal expansion of aluminum is greater then the 3120 steel that the sun gear is made from.

I had considered this myself when building it. The 231 case that the sun gear came out of is only pressed in as well and it doesn't seem to be a problem in that application.

The only problem with the set screws is that if heat expansion was the problem, the set screws would become loose as well and I wonder if there would be any benefit.

It actually doesn't get that hot. I checked it on a trip to Quesnel. It gets a slightly hotter than the NV-4500 in front of it, but I attributed this to the better heat dissipation of aluminum. Possibly with more horsepower put to the ground such as in towing it would generate more heat.

When I make my UD for my SuperDuty I'm going to use the low range out of a NP271 to handle the diesel's torque

I would be interested to see if there is any different between the two planetary gearsets. I have heard that they are rated for 1500 foot lbs, and that a 4:1 is the weaker than the 2.72:1, but never that there were any stronger than another.

Chris
 

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How much would you charge just for the machined parts, I have at least one other person interested over here at this point. I would prefer to buy the machined parts and dig up my own gears etc., than have to machine it myself and possibly screw it up. ;)
 

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Discussion Starter · #13 ·
I am a little busy right now. If I ever decide to mass produce these I will let everyone now.

I am working on a writeup for it for BC4x4. (It has been sitting on the shelf for a while now) It will give quite a bit of detail. I still have to do an Autocad pic with dimensions.

If you have the equipment, give it a try.If you screw it up, it will only be one of the three pieces and won't hurt your wallet too much.;)

How did that rearend pic get bundled into those pics?
 

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Superfly
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chris siebert said:
I am working on a writeup for it for BC4x4. (It has been sitting on the shelf for a while now) It will give quite a bit of detail. I still have to do an Autocad pic with dimensions.
Let me know if you need any help at all, Chris.

BTW, is your Jeep going to be on the road during the winter?

...lars



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chris siebert said:

I am working on a writeup for it for BC4x4. (It has been sitting on the shelf for a while now) It will give quite a bit of detail. I still have to do an Autocad pic with dimensions.

Wicked...the more details the better. I have a lathe, and TIG if needed, but don't have a milling machine yet. Good thing the machinist across the parking lot owes me a favour. ;)
 

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I still have to do an Autocad pic
Wow! I would be interested in that! I have a couple of buddies who are CNC machinists. The problem is they are too lazy to do the drawing/thinking work (in fact they said "find a drawing and we'll make it up for you"). If you wouldn't mind, I'd love to have a copy (I'd even pay for it!) I have all the "parts" sitting on the garage floor and would love to get them in the truck.
e-mail me or call me, (604-536-5991)
Please? I'll be your best friend!!!! :laugh

Dave :)<== me normally, :D <== me with a new Klone V
 

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Yeah, a set of very detailed instructions/drawings with a softcopy of the autocad drawings, for $20-$50 or something.

That'd be sweet.

If I understand correctly, it's a couple machined pieces and parts from a scrapped NP231 ??

I sure most foks could find a Jeep or S10 or something in a scrapyard, and a local machine shop.

you might make some good scratch with less effort than making and selling complete crawl boxes.

Shogunator said:

If you wouldn't mind, I'd love to have a copy (I'd even pay for it!)
 

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JP, if you ever are going to make an adapter or your own version for the big boys, let me know... im very interested in buying one....

thanx Brian
 

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Discussion Starter · #20 ·
BTW, is your Jeep going to be on the road during the winter?
I am still driving it. It is still a daily driver unfortunately. My plan is to complete all of the parts for the rearend swap and link suspension ahead of time and pull it off the road for a week or so to do the changeover.

As for the drawing, it may not be entirely complete dimension wise. I am missing some dimensions on it as some things were made to size working with the transfercase pieces. I didn't write them down as I never expected to make another. Think of it as part of the challenge in making one.

;)
 
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