1-tonmudders 241/205 Doubler

[1-tonmudder]

After much deliberation and study I decided to build a 241/205 doubler instead of the traditional 203/205.My main reason for doin so was more lo-range(5.33-1) and lesss money.I'm usin the 241/205 kit from D&D machine(360-779-2500).Kit includes 241 adapter plate,indexing ring,shaft,and misc hardware. $514 shipped.

This kit is built around the round pattern 205 and a DSD 241 case that can be found in the late 80's Chevy/GMC trucks that had the SM465 4speed trans or the late 80's/early 90's model trucks with the 4L80E automatic trans.My 205 case was pulled from a 89 model 3+3 with the SM 465 trans.


I started with a teardown and inspection of things.Case was real clean inside.

[1-tonmudder]

That was pretty much it for the 1st day,but I did put the indexing ring on just to get an idea of how much I can clock it and I ordered some seal's for it.

[1-tonmudder]

That was pretty much it for the 1st day,but I did put the indexing ring on just to get an idea of how much I can clock it and I ordered some seal's for it.

[1-tonmudder]

This was spread out over a 2-3 day period of working on it a little at a time.I went to Napa and got a roll of cork gasket material to make my gaskets with..


After that I put the LH shift rail back in to determine where it would need cut.I cut it two inches from the end.


Since the index ring covers the hole for the shift rail you can't use it.

So I capped it with a 1-1/4 freeze plug.

[1-tonmudder]

I am twin sticking the 205 while it's apart so I notched the rails too.

Sice I have plugged one of the shift rails I have to run the rail out the back of the case.

So while we were at lunch one day we stopped by one of the local machine shops and picked up a scrap piece of 3/4 cold rolled rod.

I beveled both the rod and the shift rail so the weld would penetrate good.

I couldnt find a piece of angle that I didnt have to go out in the rain and cut off so I broke a piece of 16ga to lay the rod and rail in while welding.

I had the rail/rod tigged together

[1-tonmudder]

I spent about an hour smoothin it out to it would'nt bind when shifted.


Next on the list was to drill out the tailsection so the new shiftrail could go thru it.I used the rail print on the tailsection to go by and just center punched it and drilled it.


The rod/rail is 3/4 so I drilled it 7/8 to give it plenty of room to pass thru.This will give you an ideal of what it will look like.



I'm sure somebodies noticed how close the rail is the the speedo hookup,so to remedy that Im goin to use a Dodge 205 tailsection.The Dodge is the very same it just puts the speedo on the opposite side of the case

[1-tonmudder]

The 241 I got was basically a core.It had a big hole knocked in the back 1/2 of the case from where the chain had broken.All the needed parts for the doubler were still good and for $50 I bought it.
This is all the parts from a 241 thats needed.



The kit came with no instructions at all,and there is very little info on the net about a 241/205 doubler.So with that bein said here's where I messed up.I ride with a guy who has a 231/300 doubler that was built usin D&D's kit.He said to cut the case along the casting mark.

WRONG!!! I know I should have checked before cuttin it but I didnt and it wound up bein about an 1/2 inch short in some places.So that put me to findin another case 1/2.I use to work at a trans shop and luckily enuf he had another one.I assume the 231's are cast a little different than the 241's.
I went and got another case and started over(after takin careful measurements).I used a port a band to cut it.

The kit comes with an alum slug to weld in but for some reason I didnt get one and wasnt waitin for it to get here so I used some square alum stock we had to plug the gap.The slug will need to be tapped for the bolts to seal off that end of the case.
Drake spent about 30 min weldin it up.

[1-tonmudder]

While he done that I made more gaskets.



I spent about 20 min with a file cleanin it up so it would seal good.

Here's what it looks like finished.

[1-tonmudder]

No real work done to it today,but I did get my case back from the machine shop.I had the case bored to accept a seal for the new shift rail.

[skchevota]

Cool idea. When i first saw the thread tile I thought you wee putting the 241 behind the 205, I was wondering why not use the 203 rage box, but I see now it is the other way.

[vtblazer]

Really cool idea, nice work!

You say your running a twin stick-ed 205, so you'll be running three total, yes?

Say hello to front digs.

[1-tonmudder]

Yeah it'll be 3 sticks.Do I need to run linelocks or will it be enuf just havin one end disengaged???

[Yukon Jack]

Awfully cool - wasn't aware of this combo - always learning something here!

[snj8198]

the detail and pics are great. nice work! -steve

[1-tonmudder]

wasn't aware of this combo - always learning something here!

Thanks guy's I appreciate it.This has actually been around for a while but for whatever reason it seems to have never taken off.This was what got the 231/Dana 300 kits started and their was more demand for the 231/300 kits so its my understanding that he kinda benched the 241/205 and concentrated on the 231 stuff.

If you do a google search for 241/205 doubler there is almost nothing out there.Some references and talk of building one but that's about it.D&D has no website and as far as I know he is not on any of the boards I'm on so I had to call Duffy(owner of D&D)to get any info.

[vtblazer]

Originally Posted by 1-tonmudder

Yeah it'll be 3 sticks.Do I need to run linelocks or will it be enuf just havin one end disengaged???

You don't 'need' line-lock but when I installed it on mine, you can definitely feel a difference, it works better and is a lot easier on the drive-train.
(takes the strain off the front end since the brakes aren't being applied)

I ran two, one to each rear caliper with a momentary contact switch to each mounted in the console, hoped to use em like cutting brakes but after using the set up for awhile, both together work better IMO.

One wheel locked up alone isn't enough to really hold the truck back.

Last trip out, mine got tore off by a huge tree limb hiding in the mud.
I plan to do it again but this time, I'll use only one solenoid and it will be mounted on the firewall, not above the diff.

[Walts_restoration]

Im sorry but what use would line locks be? this is the first time ive ever seen them used on a 4x4 lol, ive only seen and used them on street cars.

Btw, been ghosting this thread from the beginning, looking good i like it.

[snj8198]

i think most of the guys are using them as a make shift ebrake when switching to rear discs using calipers without an ebrake. that, and as cutting breaks like VT stated. -steve

[Burt4x4]

Originally Posted by Walts_restoration

Im sorry but what use would line locks be? this is the first time ive ever seen them used on a 4x4 lol, ive only seen and used them on street cars.

Btw, been ghosting this thread from the beginning, looking good i like it.

I use one all the time off & on road.

The #1 reason I have one is for 3foot manovers = clutch,gas & brake.
On a hill stoped, set the linelock (front calipers only) one foot on gas the other on clutch...as I let the clutch out I move my lever at the same speed..makes a smooth..no roll back start
#2 is a temp parking brake, not for extended time use only temp use. Hydro calipers will bleed off in time and no longer hold the truck.
I did test this overnight in my driveway, when I removed the block from the tire in the morning my rig did not roll. So I know my calipers can hold overnight but I don't use it that way...
Burt

[1-tonmudder]

Sorry,I have a bad habit of assuming everybody is as up on 4wd stuff as I am.When you twin stick a transfer case you can disengage one end (front or rear) and only the other end will pull,be it front or rear depending on which you engaged/disengaged.

A line lock will allow you to brake the disengaged axle.What this does is let the engaged axle pull the rest of the truck into a better line.Thats where the term front dig and rear dig comes from.

[Walts_restoration]

Originally Posted by 1-tonmudder

Sorry,I have a bad habit of assuming everybody is as up on 4wd stuff as I am.When you twin stick a transfer case you can disengage one end (front or rear) and only the other end will pull,be it front or rear depending on which you engaged/disengaged.

A line lock will allow you to brake the disengaged axle.What this does is let the engaged axle pull the rest of the truck into a better line.Thats where the term front dig and rear dig comes from.

I think i saw a video of a honda using his ebrake to get into a parking spot like that lol.

So basically, you lock the back axle and allow the front axle to pull you, or vise versa? I bet it would work nice with 4 wheel steering.

I will hopefully have a 4x4 frame for my blue truck, or a shorty to play with soon. My old man only collected 2wd trucks and suburbans and cars, never really any 4x4s. We have 150 some cars, but the only 4bys are a 57 napco thats in pieces and a 76 3/4 ton 4x4 we use to haul wood on the farm, and my 86 k5, which my only concern is figuring out how to get a th350 to wrok with my np208 so i dont have to worry about the 700r4s.

Your doing great work, im 18 years old been in this field for most of my life, but never really got into the custom side of the field until now, and its just amazing to see how many ways there are to get the truck down the road lol. I first read about twin sticking in todds thread on his 78.

[vtblazer]

Originally Posted by Walts_restoration

I think i saw a video of a honda using his ebrake to get into a parking spot like that lol.

So basically, you lock the back axle and allow the front axle to pull you, or vise versa? I bet it would work nice with 4 wheel steering.

I will hopefully have a 4x4 frame for my blue truck, or a shorty to play with soon. My old man only collected 2wd trucks and suburbans and cars, never really any 4x4s. We have 150 some cars, but the only 4bys are a 57 napco thats in pieces and a 76 3/4 ton 4x4 we use to haul wood on the farm, and my 86 k5, which my only concern is figuring out how to get a th350 to wrok with my np208 so i dont have to worry about the 700r4s.

Your doing great work, im 18 years old been in this field for most of my life, but never really got into the custom side of the field until now, and its just amazing to see how many ways there are to get the truck down the road lol. I first read about twin sticking in todds thread on his 78.

Not meaning to hi-jack but FYI on your tranny set up, that th-350 will be 3"s shorter than the 700r.

[1-tonmudder]

Yeah and they make a factory 350/208 adapter.

[tractor1963]

Would this double work with a 208?the 208 and 241 are similiar,IIRC

[1-tonmudder]

I dont know for sure but I'm thinkin its a 241 only.