Hey Guys,

I started stripping down and rebuilding my 89 D250 recently, and I've got it down to the frame. I've become more and more concerned with my transmission as I've been working around it.

It's an original transmission, never been rebuilt, and while I'm almost at 300k miles, I think it may be on it's last leg. When I was still driving it, it would slip occassionally, and it leaks around the pan, and around the shifter as well. I'm looking at rebuilding this 727, and getting a Hughes converter put on while it's down.

At the same time, I'm wondering if it may not be better to drop in a 47RH while the the transmission's easy to get at so I can get overdrive. It would simply be a question of finding a 47RH and getting it looked over, and if necessary, rebuilt.

I'm leaning towards the 47RH route, but I want to know what you guys think before I do anything. So, your thoughts?

Thanks.
Harlan

 

47 RH all the way!!, I am going to be putting one in my crew cab from 1975 someday soon.

 

Cool are there any good resources you could reccomend for snagging one, even if just a core that needs building?

 

Well, if you just want overdrive you can always go the really wicked route and get a gear splitter or auxilliary overdrive. Most of those units run around $1000 new, though, so it'd probably be cheaper to just use the newer automatic.

But don't think that the 727 is a bad transmission; it's at least as strong as the 47 is...

 

THe 47 will give you a locking TC but its not quite a direct bolt up to the NP205 case you have now.

 

Are there adapters available, or am I going to need a different case too?


I don't think the 727 is a bad tranny, I just don't like the lack of od. Driving my father's 96 with the 47RH is like night and day to my truck.

 

47RH is the way to go, done it and want to do it again. Needs a new bellhousing adaptor that is about an inch thicker than the one thats in there now. Driveshaft lengthen/shorten will be necessary and trans mount modifications will be needed also. Get a 3 pin plug from a junkyard to operate the OD and lockup funtions. Get good converter and valvebody and you have one nice unit right there.

 

Why? I went from a 518 to a 47RH and the only thing I did was pull the seal out the back of the trans and use RTV to seal the transfer case to trans.

 

I've never had to modify a driveshaft before. What does it consist of? Is it the sort of thing I can do at home in the shop?

Thanks for the replies.

 

I would look for a local shop that builds farm equipment and have them reweld your driveline they usually have the right tools (welders, driveline balancers, lathes and such). I have known people that have done them at home but they almost always get a vibration at about 45 MPH.

 

Sorry, I should have asked this earlier, but, what would getting the driveshaft modified cost, ballpark figuring?

Thanks again.

 

A....a maybe $100.00 don't no, mine was, free 99, from a good friend

 

The overdrive with a lockup converter will make you smile, and it's a lot cheaper that a Gear Vendors $2,800 overdrive. You will get much better mileage and be able to cruise faster doing it than with the 727 (which is a great trans, don't get me wrong).

 

So I could pull a driveshaft off a 2nd Gen and it'll bolt up to the 47RH and my rear axle okay?

 

A....i don't think so and the drive shaft will be did with standered, cab and ext.