The Transmission in my Bronco has a 152,000 Miles on it. I started hearing a tapping noise when the Bronco was under load in fourth gear. I assumed it was the valve train or a transmission problem.
Since I have already removed the Trans form the Bronco in the process of repairing the Rear Crank seal. While removing it I popped the Rear output shaft form the case. I decided it was time for a rebuild just to be safe.
My Transmission is a 4 speed Manual produced by New Process Gear. The NP435 used by Ford form 1964 to 1987 in there truck. This Trans was used in the One tons too so it will handle the big block power. They have also been called a granny Tranny
The NP435 can be identified by the following characteristics:
• Top loaded, tower shift
• cast iron case and rectangular aluminum top (that is retained by eight bolts)
• This transmission is 10.8" long eight bolts.
• The Ford NP435 has a 1-1/16" diameter, ten spline input shaft that has a stick-out of 6-1/2" from the front face of the transmission.
• The front bolt pattern is the symmetrical Ford "butterfly" pattern; roughly 8-1/2" wide by 6-5/16" tall.
This Trans is also on the low tech side with its non-synchronized in 1st gear. Second gear through 4th synchros are aluminum ring/pin assemblies and the 3rd/4th synchro has outer "pie plates". There are no brass synchro rings.
The shifting pattern for all of the 435's is in the standard "H" pattern with reverse gear being to the right side, and down.
NP435E (Ford)1st 6.68, 2nd 3.34, 3rd 1.74, 4th 1.00, R8.26
The Ideal Lube for this Trans is An 80W-90, API-GL5 or MT-1 rated Gear Oil
Here is were the work begins. With Trans out of the Bronco you can see it has almost 30 years of funk on it.
I started to clean the case up to get it ready for paint and the rebuild.
I then removed the eight bolts form the top cover of the transmission. I tagged and bagged the Bolts Like CSI. So I get back together correct.
Here are some pictures of the inside of the transmissions, and the shift forks.
More to come.