So it begins... NP241/NP205 doubler

Both cases are apart...

I've got Tate's enourmous tranny over here to measure the 31 spline shaft...


First an adapter plate has to be made to bolt the 241 to the 205. This should be easy enough. Bring both cases up to the machine shop and use the digital readout on the mill to get the bolt hole patterns and to ensure the input and outputs are concentric.

Next I need to respline and cut the 241 shaft. I plan to leave it full length and turn the part I need to spline to the right OD, then I'll cut it to lenght. My thought behind this is it's already center drilled so it "should" be concentric in the lathe.

The only glitch I didn't forsee until tonight is one of the 205 range shifters will hit the 241 case. Regular doublers solve this buy moving the 203 box out ~2 inches from what I can see. However, there is nothing but empty space in this part of the 241. From my 5 minutes of looking at it tonight I think I'm just going to cut this part of the case out and tig weld in a concaved piece of aluminum.



So thats the doubler part... then I get to do it all over again between the tranny and the 241. There are stock adapters to do this, however they are around 8"s from what I remember. I have one in the blazer and I really don't want that long ass setup. My entire doubler setup should be the same length as whats in the blazer.

So my plan is to take a 2wd SM465 and then machine it from 35 splines to 27 splines. Then make another adapter...


P.S. Anyone have a parts washer I can borrow? I'm going to but one as soon as they go on sale at harbor freight. Maybe I'll take the 205 **** up to the car wash and blast it, the inside is kinda gunky...

Go to a pressure wash place and clean them up.

educate me why a 205 to a 241?

doug i have sent you pm's you got any answers to them. pm me back gracias frick

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Originally Posted by Graystroke

educate me why a 205 to a 241?

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In order... SM465 to the planetary front housing of a 241 to an entire 205.

Reasons?

If I'm going to make my own adapters and shafts for a some kinda of doubler I might as well do what I want.

The 241 is much lighter than an NP203 and offers better gearing than an 203. 2.72 compared to 2.0 I believe

I paid $150 for the 241 which was too much, but I wanted in short notice. I paid $60 for the 205. Everything else should be either free or very cheap. This will take me a while to do, but I'll learn **** along the way.

We had a thread going on lonestar4x4 but I guess it grenaded. I first saw this setup using a 208 a couple years ago. A guy in finland sent me the CAD files...

MadRooster4wd is the first one to actually produce a similar setup. He's using a 231 which is essentially the same as a 241 minus 3 planetary gears and mating it to a dana 300. It's a little easier as the range selectors are on the rear of the case.

Link to madroosters setup...

hmm, never thought about using the dro on a lathe and a tap to copy patterns before, should work out great.

so how big is tate's tranny's shaft? :D

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Originally Posted by robertf03

so how big is tate's tranny's shaft? :D

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Jesus his shaft is huge! It's a ***** to pick up yourself, and my 6" calipers wouldn't fit it :rainbow:

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Originally Posted by Doug Krebs

Jesus his shaft is huge!

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Stop your gonna make Mike jealous....

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Originally Posted by KrazyKarl02

Stop your gonna make Mike jealous....

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crooked > huge

this is interesting Krebs, I have a spare 241 so this may be the route I go.

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Originally Posted by Jackasic

this is interesting Krebs, I have a spare 241 so this may be the route I go.

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I'm going to take the 241 case up to work today and get the bolt patterns recorded...

Once I figure out whats going to be done for 205's range selector clearance I'll start splining the intermediate shaft.

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Originally Posted by Doug Krebs

If I'm going to make my own adapters and shafts for a some kinda of doubler I might as well do what I want.

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have you ever built shafts?

ive done several and turns out it works better if you cut to size +.050" or so, then heat treat, then finish machine and cut the splines.

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Originally Posted by agjohn02

have you ever built shafts?

ive done several and turns out it works better if you cut to size +.050" or so, then heat treat, then finish machine and cut the splines.

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I'm using the original shaft... From what i've heard, when moser does a shaft, they don't anneal, they turn down to size, spline and they are done. They don't heat treat again. I'm going to leave it oversized, and take a hardness test.

I guess their thinking is the dimensions of the previously machined part will change...

I'll see how this works, I'll probably build another one out of 4340 sometime in the future.

i do it that way to keep from burning up tools as fast and can cut faster. i started doing this way when i had to turn 4" material down to 1" due to a flange on one end of the shaft.. this way i can cut it down most of the way without it being as hard. i leave the extra material so i can take care of the size change after heat treat. when your done, its heat reated and the correct size.

Hmmmm... just stuck the shaft in the lathe, it's harder than piss. I need to see if jim has labs today so i can get a hardness test...

Going to have to check on a 1.75 Diameter X 10" long piece of 4340... Maybe they have one laying around the ME shop. I'm thinking it may be easier to start with a new piece of material and go that route.

the ME shop has the tools to do the splines. indexing head and spindle for a cutter. you'll have to find out what the spline profile is like and order a cutter with the correct angle on it.

give me a call if you want me to help out.

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Originally Posted by agjohn02

the ME shop has the tools to do the splines. indexing head and spindle for a cutter. you'll have to find out what the spline profile is like and order a cutter with the correct angle on it.

give me a call if you want me to help out.

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yeah, i saw the SAE car guys do it last year... I might go ahead and order some steel as once it's set up it's not too bad to cut the spline.

By the way it's Rockwell Hardness 60c

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Originally Posted by Doug Krebs

yeah, i saw the SAE car guys do it last year... I might go ahead and order some steel as once it's set up it's not too bad to cut the spline.

By the way it's Rockwell Hardness 60c

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they were following the manual i wrote :flipoff2:

John Cox knows Shaft! (you might say he loves the shaft) :flipoff2:

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Originally Posted by agjohn02

they were following the manual i wrote :flipoff2:

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where's the manual?

Here's how I was going to do it:

Use dividing head and set up cutter to the center.

Find the correct disc for 31 splines.

Chuck up the shaft in the dividing head.

Cut first spline.

Rotate dividing head on disc x amount of times.

Repeat 30 more times.


Sound like a plan?

Our shop has the right cutter. However, it doesn't seem like it's that sharpest thing in the world.

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Originally Posted by Doug Krebs

yeah, i saw the SAE car guys do it last year... I might go ahead and order some steel as once it's set up it's not too bad to cut the spline.

By the way it's Rockwell Hardness 60c

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You can not use carbide on that they prob finish ground it.

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Originally Posted by fbronco86

You can not use carbide on that they prob finish ground it.

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yes

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Originally Posted by Doug Krebs

yes

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1. Dont talk to me like that you a$$ I got you that job in the first place :flipoff2:

2. I really dont think you need the DRO to find the Bolt circle anyway. Damn 2nd rate machinist

3. Dont you have a 24'' caplier over at the big press?

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Originally Posted by fbronco86

1. Dont talk to me like that you a$$ I got you that job in the first place :flipoff2:

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I appreciate it. Cable co. :flipoff2:

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Originally Posted by fbronco86

2. I really dont think you need the DRO to find the Bolt circle anyway. Damn 2nd rate machinist?

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No, but to get everything concentric it's about the only way i know of doing it... See I'm not only measuring the bolt circle at the front of the case, I'm measuring the bolt holes at the split in the case... In review I'm measuring both at the same time and the relationship between them.

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Originally Posted by fbronco86

3. Dont you have a 24'' caplier over at the big press?

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No, only 12"

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Originally Posted by fbronco86

You can not use carbide on that they prob finish ground it.

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PS smarty pants. If I anneal it so I can cut it, how much do you think the overall dimensions will be off?

PS I know **** about annealing and heat treating :flipoff2:

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Originally Posted by Doug Krebs

where's the manual?

Here's how I was going to do it:

Use dividing head and set up cutter to the center.

Find the correct disc for 31 splines.

Chuck up the shaft in the dividing head.

Cut first spline.

Rotate dividing head on disc x amount of times.

Repeat 30 more times.


Sound like a plan?

Our shop has the right cutter. However, it doesn't seem like it's that sharpest thing in the world.

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line the indexing head up with a dial guage. chuck it up in the indexer and check the runout on both ends with a dial guage as you turn the shaft. this'll get you straight and its easier than trying to find the center of the chuck.

as far as finding the verticle center, measure the width of the cutter. touch it off to the top of the shaft and move down half the distance on the cutter plus half the diameter of the shaft.

be sure you keep track of what hole you're on in the disk. its usually not something nice and easy to remember. like one round plus 16 holes. be sure you mark the one your on before you try to move to the next. you'll lose count and be screwed.

i guess trying to line up on existing splines will just be an eyeball thing....


crap. it'd just be easier for me to find the maual for you. i dont wanna type this out.

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Originally Posted by Doug Krebs

PS smarty pants. If I anneal it so I can cut it, how much do you think the overall dimensions will be off?

PS I know **** about annealing and heat treating :flipoff2:

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I don't think annealing it will change the dimensions, only heat treatment like quenching.

I wish you would all stop your bickering, I worked at the ECAE lab before any of you and managed to mess enough stuff up to give you both job security in fixing things.

I also worked at Pasta Co. before both of you.

All this makes me very mad, cause you are forgetting the one person that made this all possible, Chuck Norris, Let us not forget that on the zeroth day Chuck Norris created god, he then made god do all the rest of the work while he banged chicks.

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Originally Posted by KrazyKarl02

All this makes me very mad, cause you are forgetting the one person that made this all possible, Chuck Norris, Let us not forget that on the zeroth day Chuck Norris created god, he then made god do all the rest of the work while he banged chicks.

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my dog shat on his lawn once

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Originally Posted by robertf03

my dog shat on his lawn once

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key word ONCE, just like the dinosaurs, they pissed Chuck Norris off, ONCE!!!

realisticly, how much will the dimension change when it's heat treated? there are no bearings that ride on this shaft, just spline engagement. On the other hand the tranny shaft is another story, but I'll cross that line when I get there.

quit tainting the thread karl

oh, and I spent the last half of today working on the "company car" 2001 kawasaki ninja. Been in storage since 03. japanese wiring sucks

Doug I would be surprised to see if the expansion causes any problems, but what do I know, I'm still taking 2000 level classes

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Originally Posted by Doug Krebs

realisticly, how much will the dimension change when it's heat treated? there are no bearings that ride on this shaft, just spline engagement. On the other hand the tranny shaft is another story, but I'll cross that line when I get there.

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i dunno. never could find a definite answer. thats the main reason i finish machine after heat treat.

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Originally Posted by agjohn02

i dunno. never could find a definite answer. thats the main reason i finish machine after heat treat.

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Did you do the heat treat at school? Or have it sent off. I think I need to have a few beers with you and talk this over.

Mr T pities tha fool who pisses off Chuck Norris

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Originally Posted by Doug Krebs

Did you do the heat treat at school? Or have it sent off. I think I need to have a few beers with you and talk this over.

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sent it off to conroe. its really not very expensive as long as you're not in a hurry. they'll just piggyback it with another order and throw it in with something else they're running at that temp.

So did you figure out what you are going to do about clearancing the 241 yet? I assume you are still planning on running the ford 205 and just flipping the 241?

back into business...

after further research, this **** can be cut. I need to by ceramic inserts which can cut up to HRc70. I dicked around more on the lathe with carbide inserts and made steel wool, which proceeded to catch on fire :flipoff2:

once you get past the tranny-tcase bolt pattern and input are all 231s essentially the same?
Will the planetaries from a 241 swap drop right into the front of a 231?
Are the input and bolt pattern on a chevy 241 and 231 the same?
how's the positraction on a plymouth work?
post some pictures doug...

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Originally Posted by uglyota

once you get past the tranny-tcase bolt pattern and input are all 231s essentially the same?
Will the planetaries from a 241 swap drop right into the front of a 231?
Are the input and bolt pattern on a chevy 241 and 231 the same?
how's the positraction on a plymouth work?
post some pictures doug...

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From what I understand:
Cases are similar if not identical

Only difference in the planetaries are the 231 has 3 satelite gears and the 241 has 6

If someone has a 231 they can bring it over and we can compare, shafts and length of engagement :rainbow:

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Originally Posted by Doug Krebs

realisticly, how much will the dimension change when it's heat treated? there are no bearings that ride on this shaft, just spline engagement. On the other hand the tranny shaft is another story, but I'll cross that line when I get there.

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I bet it wont change more that .001-002 size od wise. The problem with heat treating and stuff is warping. Round matl generally has high stresses around the OD so when you machine on them or heat treat them they tend to wanna move on you. I would not worry about the size changing on you but I would have it supported/laying flat when you heat treat.

Also make sure you wrap that dude up and put some graphite(sp) with it to keep it from getting all messed up.