Welcome to the next installment of the

Topic of the Week

Have you built your own bellhousing / engine adapter plate? Maybe you've adapted a Dana 300 to an NP435 without using an aftermarket adapter. Or maybe you've built your own doubler.

If so, spill it.

Tips, tricks, gotchas, what you'd do differently.

Good Topic ........

Its come a bit early for me tho...........

I have started on a T18 ( T18 Chosen vs 435 due to width ) to Dana 20 adapter of my owne devise, but now I dont think the Dana20 will have the strength to hold up behind a 302 and TWO T18 trannies in first gear.

I will prolly do with a NP205 for a case now.

I need to get a few other things progressing before I tear into the two T18 trannies I have to figure out how I can mate them end to end with minimal length.

A friend and I made the adapters for my 203 doubler at his shop. It was quite an experience - a lot of fun, actually.

http://www.bc4x4.com/chrisw/projects/powertrain/np203c.jpg

We used the cut-and-test method of adapter making. After coming up with what the rough shape would be, we just made one feature at a time and test-fit whenever possible.

http://www.bc4x4.com/chrisw/projects/powertrain/np435a.jpg

Tip 1: Don't forget to allow for gaskets in measurements!
Tip 2: Make sure you've got room to get a wrench/socket onto every bolt, and that none of the bolts interfere with anything.
Tip 3: Think about how every block is registering against its neighbour, so you can guarantee that everything's concentric. Hint: bolt holes aren't accurate enough for this!
Tip 4: Take your time.

Chris

Well, not exactly home built, but here's a trick to adapting the common ford T18 to a D20/D18 without spending big bucks.

You can use the output shaft and factory adapter off of a scout T18 (which are prety plentiful in the 4:1 ratio) and use them on a wide ratio Ford T18. You do have to drill and tap the Ford case so the adapter fits. Normally you can get a Close ratio scout case for $100-$125, and if you are lucky, you can get the seller to just strip off the parts you want to save on shipping.

Great topic for TOTW BTW!! Just wish there was some more input. Im thinkin of doin a doubler in my CJ, 999 with stock D300 now. I have considered using another D300, removing the front portion, flippin it backwards and makin an adapter to connect it to the rear 300. I have also considered goin with a 203, but that reduction box is kinda tall, and would require more work to mount to my tranny.

Originally posted by JEEPRZ
Great topic for TOTW BTW!! Just wish there was some more input. Im thinkin of doin a doubler in my CJ, 999 with stock D300 now. I have considered using another D300, removing the front portion, flippin it backwards and makin an adapter to connect it to the rear 300. I have also considered goin with a 203, but that reduction box is kinda tall, and would require more work to mount to my tranny.

While you could make it work, I see that as a recipie for killing the middle 300. IIRC, the 300 doesn't have straight cut gears, and you'd then be running on the coast side - inherently weaker.

Whaa? Some miscommunication here i think...guess I shoulda said it would be upside down. Front output portion of the middle case would on the drivers side so the front d-shaft comming off the rear case would clear. Im still in the pondering stages at this point, but dont see why it wouldnt work.

It's not a homeade adapter, just a cool combo of OEM parts, or maybe it isn't, flame all you want, I was happy when it worked out for me.

Jeep 2.5l 4cyl to SM420 via Chevy 2.8l S-10 T-5 bellhousing, using S-10 clutch slave with Jeep master, must use aftermarket gear-reduction type starter for starter pocket clearance, and you need to fab up a bracket for the Jeep flywheel position sensor piece of crap thing, other than that a complete bolt and go!

Thats good to know since people are often looking for an SM420 type bellhousing.

You could use the same bellhousing for a cheap 3.4 V6 conversion in a small rig...those things are everywhere around here

How about a th350 or th700r4 to a D300 adapter than anyone can make?
Or how to make a 4-1 gear set for the guys with a lathe and a tig welder?
Just let me know and i'll tell you how.

Here is a couple of Links. yj3qtr_ton has some more links on his page.

http://www.geocities.com/yj3qtr_ton/2transfercase.html (Best adaptor so far)
http://www.bc4x4.com/chrisw/projects/powertrain/tcase1.asp*
http://www.rightcoastcrawler.com/LloydC/tech/TrannyProject.html The 435/203/20
http://www.wildhorses4x4.com/33.asp*
http://offroaddesign.com/catalog/doubler.htm (203-205)
http://www.pirate4x4.com/tech/Lintz/index.html (203-TLC T-case)
http://community.webshots.com/album/13852561QnRQRdZuCQ Scans of D20 / 203 / 205 manuals
http://www.bc4x4.com/tech/2002/np435d20/ Not dual but custom adapter*
http://www.therangerstation.com/dualtcase.htm dual Ford Rangers (small)
www.wagonermachine.com*

Originally posted by TheLakeRat
How about a th350 or th700r4 to a D300 adapter than anyone can make?
Or how to make a 4-1 gear set for the guys with a lathe and a tig welder?
Just let me know and i'll tell you how.

Spill it!

:D

Come AWN!

I run a small machine shop and I can put some "extra" hours in for a 4:1 gear set THIS week!

Thank you in advance oh great one :bowing as I back out of the room:

The GM 60degree V6 bellhousing on a SM420 opens up many opportunities for cool engine swaps, how about a supercharged 3.8 V6? Or a 32 valve Cadillac Northstar V8? Damn I glad GM stuck with standard bellhousings, I pity the Ford guys that have to know what day of the week their engine was built to know what trans will bolt up.

Originally posted by TheLakeRat
How about a th350 or th700r4 to a D300 adapter than anyone can make?
Or how to make a 4-1 gear set for the guys with a lathe and a tig welder?
Just let me know and i'll tell you how.

My 700R4/208 adaptor bolted right up to my 300, but what about the input. Novak won't split their kit up, and I'm not so sure how cost effective it would be to have just "any" machine shop broach the input.!?!?!:confused: :D

Originally posted by 4Bangler
The GM 60degree V6 bellhousing on a SM420 opens up many opportunities for cool engine swaps, how about a supercharged 3.8 V6? Or a 32 valve Cadillac Northstar V8? Damn I glad GM stuck with standard bellhousings, I pity the Ford guys that have to know what day of the week their engine was built to know what trans will bolt up.
Another good point. The Northstar uses the S10 style bellhousing bolt pattern.

From what I understand if you need to have an output shaft ground down and resplined Dutchman is the place for that.

yeah! tell us about that 4:1 mod...

i have a lathe...and a tig...and some other stuff...how do i do it?

matt

chevy np208 agapters can be used with dana300's and atlas t-cases. i run a th400 in my jeep. when i was still running my dana300 i needed a 32spline input shft from advance adapters but the adapter plate will work. now i run an atlas and when i ordered it i ordered it with a 32 spline input shaft. the only thing other than that you need to do is redrill one of the mounting holes. it does not line up but teh other 5 do. easy as that. if you are planning an atlas for your build up this is a good place to start because no expensive adapters needed.

How to build a TH700r4 or TH350 to D300 adapter.

Now you have to realize that I first did this a long time before I ever opened my shop or owned a lathe. So it’s very crude and VERY redneck. But that’s what we’re all about, right? I’ve been running the one in my Jeep for 4-5 years now and have never had any problems with it.

First, the actual bolt together adapter is just a stock TH350 to NP208 adapter or a TH700r4 to NP241 adapter. Either one of these should allow you to bolt the two together. You can also clock the D300 by just re drilling the holes in the adapter to whatever position you want.
The only thing that is hard to do is making a spud shaft to adapt the spline from one to the other.
You only need two things. A Chevy 27 spline slip yoke off of a drive shaft and a 23 spline output shaft out of any old Jeep tranny.

First cut off the yoke part of the slip yoke so that all you have left is a piece of female splined tube. Then I used a die grinder and opened it up just a little about a ¼” deep into the tube. Now cut the splines off of the Jeep output shaft and using the grinder again grind it down a little about a ¼” up the end of the shaft. It took me several trys to grind the right amount but you want the two pieces to slide together fairly tight.
Next I tack welded two pieces together and rolled them across a flat surface to check for straightness. After I was satisfied it’s straight enough then I welded the piss out of it with a 7018 rod. Then with a grinder cleaned it up as best I could and I even used a cutoff wheel on my die grinder to cut the splines up into the weld just a little bit. Now you have a crude spud shaft.
The next thing you need to do is do some measuring to figure out exactly how much room you have between your tranny output shaft and your t-case input shaft so you know how much you need to cut off to make your spud shaft fit. I had to cut off the t-case input gear so that there was only about 3/8”sticking out past the seal. But you might have to cut some of the tranny output shaft off also. Depending on what model you have.
Next you need to cut off the excess splines on your spud shaft. Stick the male end into the t-case and measure how much slpine you have left, then cut that much off the end so that it fits down into it as far as possible. Then you need to measure how much output spline is on your tranny output shaft and cut the spud shaft to have the same amount of female spline.
Now make sure that it will all assemble without binding. You don’t want to have to tighten the adapter bolts to pull them together. If you do you might have your spud shaft too long or you might have to cut either your tranny shaft down a little or your t-case shaft down a little.



For those of you that want info on the 4-1 kit i'm sorry. But you may have to actually call me and i can go over it with you. I've been trying to write it up but it's kinda hard to put what's in my screwed up head into text. I'm not a true machinist but i am a damn good Redneck:D ;) :p

Basicly you need 3 sets of D300 stock gears. Or at least 3 of the center double gears. For some this may seem a little stange but i've installed several dozen Tera low kits and had several set just left behind by customers that didn't want hem. A D300 uses2 large gears, 2 medium size gears, and one large double gear with a very small gear on one end and a large gear on the other.

What you have to do is take the two medium gears (one is splined internaly and the other is smooth bore) and turn the gear itself off of the body. leaving the shifter spline on the back of them. I think i turned them down to about 2" OD. Then chuck up the two double gears and on the end with the small gear turn it out so that if will press onto the other body in place of the gear you turned off of it. Make sure that you get it close to being in the same position as the original gear. They are different thickness so you may need to leave some meat on one side. Now using a tig welder weld these together.
Now take a third large double gear and turn the large gear off leaving the small end alone. Then you need to get one of the largest single gears and turn the center out of it so that it fits over the place that you just turned down. Now tig it also. I would recommend that a good welder do this for you. I did mine myself and have been running them for 1 1/2 years now with no trouble but it's better to be safe than sorry. I keep a set of stock gears in my spare parts box just in case, but i hope i never have to use them.
To assemble this you will have to clearance the case so that you can get the center gear in just like the Tera kits.
If i've cofused you i'm sorry. I will be makeing a nother one for a buddy within the next month and will try to get plenty of pics.
i really think this is the same thing Tera used to do until they got big enough that they could have them made for them.

Be warned that these gears are very hard to cut. I ground the teeth off first and then used the lathe to turn them the rest of the way, but i have a very old (1902) very large lathe.

That should get it done for you. If I left anything out please let me know and I’ll try to include it. If anyone does this please let me know how it works out for you.
Good luck.

Lakerat, I think I followed you. The problem is I am running a 'Cruiser case in my Jeep (swap meet special $500 for 2 SM420s, 'case AND adapter). Looks like I may try that AA spliter that replaces the adapter, 3.66x1.96=LOW!

Anyway, anyone that wants to try this and has the parts up here in the Great Northwest let me know. I think this would be a learning experience like no other, and I could do it for pretty cheap too!:D

My new comany name: Built Not Bought
Logo: We machine it, you build it.