September 29, 2016

the '77 behind the scenes

This is just one of the major projects that I've done to the '77. I usually don't post about it, but am this time for some reason. The '77 had been leaking from the transmission for a while. 


A lot of guys say; well that's what they do...they leak! I figure that's just a likely excuse for lazy assery. Sure many of these trucks were famous for being pieces of shit, but only because they had negligent owners.

Owning one of these is an...shall we say...more of an interactive experience. I work on my garbage all the time, but the difference is that I don't mind. I find a sense of accomplishment in making it reliable to drive a thousand miles, then swinging in for the annual test and passing.
Last year some time I bought a used SM465 4 speed and NP205 t-case off the classifieds for $200. I figured that I'd get around to rebuilding it some day and replace the leaky one with the rebuilt one. Last spring with two trips to Oregon totaling about 4,000 miles the throw out bearing on the clutch was going out so the transmission R&R was moved to the front burner. It'd only been a couple years since I'd replaced the engine and clutch so I was a bit perplexed at why the TB was failing already. Once I got things apart I could see that it failed due to a clutch fork, that was broken in two places, not properly engaging the bearing groove. 
Anyway it's a complete bitch to remove and replace a cast iron transmission and t-case combo by yourself and I probably wouldn't recommend it at risk of smashing your face like a grape. I did it as a combo because it was the easiest way to mount it on a transmission jack adapter. I drilled an automatic transmission adapter plate to accept the t-case adapter, which I think you can see in the pics. 
The used donor set I got online included a 1350 driveline yoke which was pretty rad, but it opened a hell-acious can of worms that proceeded like this:
I figured now was as good a time as any to get a 14 BSF rear axle, which also came with a locker and a 1350 yoke. I added new backing plates, drums, seals, cylinders, all of it. My old 12B e-brake set up mounted perfectly to the 14 bolt drum backing plates. The offset track width of chevys has always driven me nuts, and some six lug semi float 14 bolts are within a half inch WMS-WMS compared to the stock width Dana 44 front.

I knew there was no way I'd turn the 39 year old brake line fittings off the old 12 bolt so next was a set of brake lines...all of them...clear to the master cyliner.

Next in the chain was replacing the 1 1/8" Master Cylinder with a 1 1/4" bore. Not sure why I didn't replace the booster.

Sheesh, as if that wasn't enough, I figured now was a good time to install ORD frame brace kit to avoid the notorious cracking of the frame at the steering box mount, especially with the newly added 35's.

Since I'd come that far I replaced the steering box too. $100 from Rock auto was more fool proof than trying to reseal the old one with 39 year old bearings.

I'm not really any good at photo documenting my work as I go so the pics are about all I've got.

No comments:

Post a Comment