46rh to 47rh swap

[CumminsKid]

Anyone know what it takes to swap a '95 47rh(618) into a '91. 5 46rh(518)?

Both are 4x4 trans. Does the transfer both up? O-drive and lock-up solutions? Overall length the same?

Any help appreciated.

 

[BJMarshall]

It is my understanding that the OD unit from your 518 will have to be used on the 618. The 205 transfer case will not bolt directly to the newer OD unit. I'm not sure what is involved. The OD unit isn't a direct bolt on, but I don't think extensive modification is required.

Check with one of the many transmission vendors about their solutions for lockup and OD. I think on the RH's lockup can be handled with just a switch if you want to work it manually.

 

[CumminsKid]

does anyone know of an adapter to bolt bolt the first gen. transfer to second gen. transmission? I have a friend who wants my transmission to replace his 727 so he can have O. D. So if I could utilize the all of second gen. transmission that would be great! Does anyone manufacture one? Other wise I'll try to get one made.

 

[BJMarshall]

I'd be willing to bet that you can buy an OD unit, or trade the one from the 618 for much less than the cost of an adapter.

 

[bvanetten]

The 47rh will bolt up to a 205, I did it and one other member has also that I know of (forgot his call sign... ) The rear seal on the transmission needs to be removed and the input shaft on the 205 needs to be for a Cummins powered auto, that's it. I'm not sure if the overall length is different, I needed to have d-shafts made anyhow. I have over 60k miles on this combo without any issues whatsoever. Do a search, their is info on the list about this swap.

 

[cerberusiam]

According to Standard Transmissions the 95 trans and adapter should bolt to the NP205 after the removal of the seal. The only problem you may run into is the spline count on the transmission output shaft. The later transmissions switched to a 29 spline shaft for autos and manuals both but when the switch happened I am not sure.



Your transmission should be a bolt in for your friends truck. The only issue may be the engine adapter but not sure. Your truck will need the 2nd gen engine adapter, starter, and while your at it a newer style flex plate. The 47RH is longer than the 46RH. Some length is in the engine adapter for the lockup TC and the rest is an upgraded OD unit. You will have to build/relocate the trans mount, relocate the shift linakge for the transmission, and lengthen the linkage for the t-case shifter. The rear drive shaft will need to be shortened but you may be able to get by with front depending on the height your truck sits at.



The TC lockup is pretty easy to wire to a switch or if you want a more complete installation a couple pressure switchs will make it prety much automatic.



Other than that, a piece of cake.

 

[CumminsKid]

Thanks for the info guys, your great! By the way forgot to mention both trucks and both transmissions are diesel. If anyone finds anymore info. or posts please let me know, I'm not that great with the searches yet "new user". Does the OD on the first gen. control the 47rh?

thanks Kid

 

[cerberusiam]

The 1st gen OD will control the 47RH. It just grounds the OD circuit to engage. The wiring is pretty straight forward. The 47RH had one additional wire for the lockup converter but everything else is pretty much the same.



Now if want to do 47/48RE thats a little different story.

 

[phillips5]

It's just nuts and bolts what could go wrong.