700r4/np208 swap

[broylz]

I know these swaps are talked about often but i cant seem to find the answer im looking for. Is there a way to bolt up the 242 to the 700r4? I thought i had read there was a similar bolt pattern on another tcase model that would bolt up and not need any driveshaft modification...

The trans im currently looking at is coming out of a diesel duburban. It has what should be a 208 tcase. If i went this route, would it require a driveshaft mod?

 

[nattieleather]

I'm no expert so I hope someone else chimes in, but if you have the TH400 trans and are swapping to the 700r4 I believe the 700r4 is longer than the th400 and therefore your front shaft will be too short and the rear shaft will be too long. Basically any transmission swap will most likely result in some type of modification to the drive shafts.

 

[osteo16]

Is this thread dead? My set up will be 700r4..Advance Adapters 51-6901....NP218 with Input gear from an NP208.... All same length when bolted together and fits cross member. No mods... This is what I have found recently in my research .. Just need to find a donor 700R4 I can rebuild...


Ocho out

 

[Sharecropper]

The 700R4 is the exact same length as the TH400 and will not require driveshaft modification. However the spline count of either component must be changed for them to mate together. I’m installing a completely rebuilt and strengthened 700R4 behind my new 6.5 P400 engine for my M1028 CUCV truck. I purchased my 700R4 from Chris Gardner at Bowtie Overdrives who is extremely knowledgeable and who also drives a CUCV as his daily driver. For my 700R4, Chris installed an Advance Adapters 32-spline output kit to mate with my OEM NP208.
Hope this helps.

 

[Mogman]

Is this thread dead? My set up will be 700r4..Advance Adapters 51-6901....NP218 with Input gear from an NP208.... All same length when bolted together and fits cross member. No mods... This is what I have found recently in my research .. Just need to find a donor 700R4 I can rebuild...


Ocho out

I am curious about the 51-6901, why would you have to change the input gear, that adapter kit looks like it has a 700R4 output shaft and a 32 spline adapter.
Advanced adapters offers this same kit for the 32 spline NP208 and the NP241, so if it works with the NP218 then all three of these must clock the same.
SO if you change the NP218 input gear to a 27 spline why would you need the adapter?

 

[87m998]

The advance adapter kit bolts up just fine without any further mods, at least mine did.

 

[Mogman]

The advance adapter kit bolts up just fine without any further mods, at least mine did.

That is what I was thinking, it is made to mate a 32 spline transfer case to a 700R4, it does not matter if the 700R4 is 4wd or 2wd because it provides the output shaft, which of course is different depending if it is a 2wd or 4wd transmission to begin with, it looks like the output shaft supplied is a standard 4wd 27 spline shaft.
They do not make one to mate a 27 spline transfer case because I don't think one is needed.
If you use the advanced adapter kit it uses the TH400 transfer case adapter and adapts it to the 700R4.
I am still thinking if you change the input gear to a 27 spline one can use the 700R4/NP241 transfer case adapter without any aftermarket parts.
Geez, I need a NP218 to play with!!

 

[osteo16]

6 bolt to 4 bolt. 700r4 has 27 spline so need 27 spline input from 208 that fits into my 218. 700r4 needs adapter to fit 218. 6 hole to 4 hole... but that is only from what i researched....open to any input..

Ocho out

 

[osteo16]

The advance adapter kit bolts up just fine without any further mods, at least mine did.

So you did a 700r4 to np218 conversion.. Can you provide parts for your conversion. Im looking to do this and thought i was on right track..but now everyones post has me wondering.. Im assuming you also have a 6.5l NA GEP you are attaching it to.. Thanks

Ocho

 

[87m998]

Yes I did 6.5 to 700r4 to 218, just get a 700r4 k case built up and a kit from advance adapters, give them a call for the right adapter. You will need a diesel flex plate and tq converter from trans shop. Don't need a special cable bracket just mod the one the 400 uses to fit new cable. The dust cover can be re drilled to fit the 700r4. Get a new 4 speed shifter. https://ktperformance.net/b-96101-1207687-advanced-vehicles-assembly.html. You will also need to make the trans shift linkage, I just used some all thread.
Cheers

 

[Mogman]

Ocho, go look at the adapter kit at Advanced Adapters, it comes with a 27-32 spline adapter, if you go that route you do not need to change the input gear, but apparently you do need to have your transmission built with their output shaft.
There is a seller selling the new 4 speed shifter on eBay for $510 shipped.
The original 700R4/NP241 adapter is a 4 to 6 bolt adapter but I have not found anyone yet that can say if the 6 bolt pattern is the same on the NP218 as is on the NP241.

 

[broylz]

I see a ton of np241 talk but is that the same bolt pattern as the 242 amg? Should i be looking for a 241 or 218 to make the swap easier?

 

[Mogman]

No the 241 and 242 have different "clocking", this is assuming the 242 is the same as the 218 which I am familiar with.
I am working with a small shop that builds clocking rings to get one for the HMMWV and the 700R4, then only the input gear on the 218 would need to be changed, I think the same thing can be done with the 242 with a 241 gear as they are in the same "family"
There was some chatter on the CUCV forum about the Advanced adapter setup having a 700R4 output shaft being too long causing failures, I just don't like running a splined shaft into another splined shaft, the input gear on the transfer case is actually the transmissions output shafts rear bearing as it supports the output shaft, having said that I am sure many folks run the A.D. setup with no issues..