Hi all,
I'm biting the bullet and swapping my SROD overdrive transmission out for an NP-435. Bit of work, but I'm looking forward to the results.

Either way, when I pulled it all apart, the tailshaft to transfer case had an orange silicone on it and the adapter from the transfer case to yolk adapter had a blue silicone on it.

Are these specialized silicones? Or are they just what the builder had on hand? Can I use regular black RTV silicone? Or do I need to hunt these down?

Thanks. I'm in the middle of the build, so a timely response is very much appreciated.

 

It sounds like it had been gone through once before for some unknown reason{ maybe to cure a leak and that's all they had ) but the difference would be nil and the black RTV should be just fine. I use it all the time in sealing cases together, I have a NP435 with the adapter to the married transfer case on it but the bronco we got is the 4 speed overdrive unit which is tiny compared to the NP 435. I would be interested in following your build up as like you said it is a lot of work, are you going to convert to mechanical linkage or stay with the slave cylinder?

 

Each one can either go by oil resistance, or how much heat each one can take, etc.

 

The NP435 is installed now and yeah, it's WAY bigger than the SROD I pulled out. And much heavier. I'd say about twice as much. The SROD was easy to pick up and move around. The NP435....not so much.
I decided to go with the hydraulic clutch and convert it over. The bellhousings were 99% identical aside from a place to bolt the slave cylinder, so in all actuality, I really could have just thrown my SROD bellhousing back on there and been done with it. Use my stock mechanical clutch, etc. But, I put the hydraulic bellhousing in and committed myself.

I'll post some pics when it's all done but the two main things I had to do was:

A) Slide the rotating rod out of the pedal assembly. It can be a pain to get out since it's really cramped up above the pedals. The pedals are the same, but you need to use the rod from the hydraulic clutch since it has a different end on it.

B) Drill holes in the firewall to mount the master cylinder. It has to be put in the correct spot or it won't line up with the pedal assembly. Fortunately, I had my '84 Bronco to use as a template. It needs a 1.5" hole so a special drill bit is necessary.

I should have it bolted all back together today or tomorrow. Can't wait to drive it!