Does anyone know where I can get my hands on a service manual for a NP435 4-speed Trans. or info to rebuild one?

 

I just rebuilt mine a couple weeks ago. I ordered the $165 master rebuild kit from Bronco Graveyard. Here is a link to a copy of the manual for an NP435 on their site. http://broncohq.com/pdf/66-77/chassis/435rebuild.pdf
I recommend you print it out and refer to it often. It is also a good idea to take lots of pictures with a digital camera as you take it apart to aid in reassembly, especially if it will be a few days between dissassembly and reassembly.
The kit was very complete and has all the parts you will need, except for any damaged gears themselves. It took me about 10 hours to do, but I wasn't in a rush or anything. It was all pretty straight forward and the only special tools you need to do the job right are an assortment of pullers to get the old bearings and races out, a feeler gauge, and a dial indicator to set the input shaft end play. Although my trans had 186,000 mi on it, the internals seemed to be in good shape, but it did growl on the highway, the shifter rattled, and it leaked pretty bad. All fixed now though.
Just take your time, keep a clean work space (I set up a large table in the garage for this task) and replace all the bearings. BTW I didn't have the pullers, so I ended up cutting a couple bearings out with a dremel tool. It took time, but at least I didn't have to pay someone else 700 bucks to do it for me.
Good luck!

 

The rebuild is not hard. Do as Dave said and take your time. The link he gave you is where I got my instructions as well. I never book marked the location and have been trying to remember where I got that from. I didn't even think to look on the same site I got the kit from.

Thanks Dave!

 

Thanks a million guys! Now to get GREEEESSSSYYYYY!!!!