hope this is the right forum. I have 1987 Bronco II 2wd, AT with 3.73 gear. Just bought parts vehicle, 1984 Bronco II, 4wd with 5 speed (4+1) and axle code shows it also 3.73. I plan to swap the front axle, transfer case, driveshaft, etc and keep my AT and existing rear end in the 1987 model. Do you guys see any problems in this swap? Thanks so much to you all.

 

Welcome to the site;

It has been several years, I mean several years since I have been under a BII, but I do remember some key points to this swap and have a couple under my belt.

Since you have a donor vehicle, you will have everything that you need. Know that the beam brackets and radius arms are different from 2wd to 4wd, so you will have to grind all of the old brackets off of both vehicles, and you will use the 4wd bea, brackets for the conversion.

Next small issue is simply the removal of the dummy transfer case. I always though this was interesting, but unlike several of the other 2wd vehicles, the BII was intended to be a 4wd so it had a dummy transfer case.
SImply remove the dummy, and install a real case. No issues there at all.
You will have to verify that the speedo drive gear is the same, or equal to what you require. These are color coded and are specific to the particular speedo unit, so in some cases you may have to swap this, but it is easy, once the dummy unit is removed.

I do believe that there is a driveshaft length issue, but my notes do not indicate this. I do believe that there is a total length difference between the auto and manual trans. This might require some driveshaft modifications, but I am not 100% sure about this.
My gut tells me that this statement is true, but I have no data to support this.
This is a minimal problem, and is easilly fixed.

Good luck on this swap. Sounds like fun...........

 

thanks so much for response. looking forward to the swap.

 

I hope this isn't a too dumb or out of place question but Bronco II's had mini versions of the TTB for a front axle, didn't they???

 

Yes, just like the ranger.

 

I'm guessing since the rangers and Bronco II's were fairly lighter than their fullsize counterparts, they didn't have as many issues with TTB breakage under heavy duty 4x4 usage? I hear some people build them into pretty decent wheelers.....

 

If you plan on taking it off road at all you are definetly gonna want to go to the dana 35 found in 93-97 rangers and explorers, not sure what years the explorers had them. The dana 28's in the BII and early rangers have tiny axle shafts and u-joints. I find them cute lol. D35 inner shafts I believe are actually stronger then the d44 because they dont neck down by the splines, the stub shafts are noticable smaller then the inners but much bigger then the 28. I've heard you can put d44 outers on the 35 by re-tapering the knuckle to make it stronger then the d44! Same 1310 u-joint as d44. Its a direct bolt in going from the 28 to 35. Win win to me. I would find a 93 doner truck that way you can have an 8.8 in the rear too. I have a buddy that had a BII with 33's and couldnt keep a shaft in it and that's why he got rid of it. Another guy I wheel with has a ranger with the d35 and 39.5's and only broke one shaft in 2 years, he has alot of luck on his side though cause he is not at all easy on the throttle! There is a huge difference in shaft size between the two axles.

 

oooohhh. and did the 8.8 always come stock in rangers? or when did that start?....

 

I think when the 4.0 came out in the rangers, all ranger 8.8 are 28 spline though, only gain there is a bigger ring and pinion and bigger bearings. Otherwise shafts are the same size as the 7.5. Explorer 8.8's are 31 spline and is stronger. I would keep my eyes peeled for an explorer for the doner truck. Do you plan to have this truck offroad quite a bit?

 

Who, me? I'm not building a Bronco II/Ranger or anything like that. I just always wondered what one was like. I was gonna buy one almost at one point. Sorry I kinda made the thread run off like that.

 

No, I am 71 yrs old and don't do off roading. just want a 4x4 to use on my farm a little. My 2x4 would probably be OK, but have a chance to convert it to 4x4. (Bro in law is mechanic) thanks to all for the advice.