Hey everyone, I currently have a 3 speed auto with a 318 engine, first gen 4x4. I have been getting very bad fuel economy, and since i drive a lot on the highway, I want to change that. I had to questions. First of all, I know that my truck used to have a 5th wheel on it, so what are the chances that there is a high tourque diff in the back? Does this even exist? Secondly, I would like to convert the 3 speed to a 4 speed (AUTO)

I currently have the 4 speed auto out of my D100, and want to put it into the W150. I have been told that the output flange is different, but I want to know exactly what is different and what needs to be done to swap the tranny out.

If anyone would know what parts I need, and if there is a link or some information that might help me carry this out, I would really appriciate it. Thanks for any help.

Jacob

 

you may be looking at the loss of your transfercase, depending how its set up.
You could also be looking at purchasing a new drive shaft.

as for the rear end... it could be geared for more torque. there may be a sticker under the front lip of your hood with those specs on it.

I Dont know for sure, but I /think/ if you change out the rearend, you have to have a matching front axel gearing.

 

Yes I believe you'll need a transmission out of a 4x4 so the t-case has something to mount to.

And yes, both axles MUST have the same gear ratios!!

 

No just to clarify, did the 4x4 models actually come with the 4 speed auto? Because I have been going around to the junk yards, and I have only seen them with the 3's in them. The only one that was a 4 speeds was a manual, and I dont think I want to get into that kind of conversion.

 

Just phone a junk yard and they can tell you not only if our trucks came with a 4 speed or not but if another application will fit and if one is available anywhere by using their computer.

 

I think there's a transfercase that don't bolt to the tranny, but kind of goes in line on the drive axel... I'm not positive on that, my pal who was trying to explain it to me wasn't talking drunkinese enough at the time to me :S