I found a local 2wd 47rh from a 94 with known high miles but unknown working order for $500.
Assuming I could use the 4wd tail housing from my 518 on the 2wd 47rh.(can I?) What do you guys recommend?

1. Converter and valve body upgrade on the 518?

2. Build the 47rh and swap it in?

I will be plowing snow and on occassion, towing 7-10k.
More then anything it will be a DD.
TIA

 

$500 is too much for a core IMO. Output shaft on the 2wd is longer than a 4x4 output shaft. the 47rh swap can get expensive and your 518 should have no problem towing 7-10k. build the 518 the right way and you should have no problems.

 

You could make that 2wd a 4wd but in addition to the output shaft and OD assy you`ll need a 47rh intermediate shaft.

 

The intermediate shaft has to be from a 4x4 47rh I take it??

 

yes, you can use the 518 int shaft you already have but would also need to use the earlier (and weaker) 4 pinion aluminum planetary assy.

 

aluminum planets + modded truck = . If you're going to source from a 47rh just use the entire thing and do the conversion, but from what it sounds like you want to do you shouldnt have to go that heavy duty.

 

I would like to use the entire thing but its 2wd

 

I vote for upgrading the A518. Why? Because it is plug and play, it goes right in. and then it works like stock.

Many times I have contemplated a 47RH and then I read threads about guys having to manually control OD and LU. Kind of defeats the purpose of having an automatic if you ask me. Then you have to modify the truck and the mounts and driveline to get it to fit. Too much trouble.

You might be more handy with the wrench though, as I am not.

 

Very good point head!
I just can't believe how easily theCTD pushes through the stock converter. And I figured the lockup feature of the 47rh would help with that. I hope I'm not expecting to much from a converter upgrade as I could be dissappointed afterwards.

 

You know, that would prob work also sort of six of one half doz of the other though, swap the 2wd input and reaction shafts and also the lock up VB (and converter of course). Youd still have the weaker planet set (and now a weker 518 case but now were into trivial stuff) but unless your going to push 300hp (or so) and up and/or beat on the thing it will prob live a long life. The one in mine went 200k and altho the splines were a bit loose/tired it worked fine.

 

i wouldn't mix and meddle with combining parts from the 46rh and 47rh. A 518 built the right way by a reputable transmission shop should work just fine for your needs as long as you tell them your goals.