'69 Javelin SST on Budget

Thanks guys! I woke up this morning with a pinched nerve in my neck and shoulder that I've been dealing with really killing me. It hurt to breathe even. So I've been slow getting things done today. At this point, I just have to bolt in exhaust and a driveshaft. I'm such a glutton for punishment.

Edited by Red20 - Mar/12/2017 at 9:20pm

There ya go... that five minutes bit ya! Glad you got it going with that pinched nerve... well, even without it, but had to be tougher to crawl under the car!

I'm looking at a couple of options right now. I haven't pulled the rear end apart yet.

1. Completely rebuild the Model 20 with one piece axle conversion. The only thing that may kill that would be worn side bearing bores. With nice Moser chromoly axles, and Timken bearings, it'd be a strong axle.

2. There's a complete drum brake 1992 Explorer 8.8 for $150 locally. It's a 3.73 gear w/posi. More gear than I want, but inexpensive. I'd have to shorten the long end roughly 3" and find another short side axle. That'd make a 57" WMS to WMS rearend. New brakes, set of highway gears, trac-lock clutches, new perches, fresh paint, etc.

3. There's also a complete 1964 Falcon 8" for $350 locally. 3.00 ratio, open diff. Big 2" brakes. The e-brake cables are in very good condition. It's 58" WMS to WMS. Another 1/2" either side won't hurt at all with the 235/60R15s under there now especially with the long shackles. New brakes, gears are good, new perches, paint is already fresh.

The 8.8 can be built up in the future with c-clip eliminator kit, bigger axles, etc. to be the strongest of the 3 options, I think. But I'm not likely to be putting more than 450hp/tq to the axle at any point in the future. And if I ever do, it'll be behind an overdrive and steeper gears which will put less stress on the R&P than if I was putting 600hp to a 2.87 gear set. That said, a built Model 20 would keep it AMC. I like that. But an 8" with the drop out third member is pretty cool. It's plenty strong for my purposes and the allure of building it on the bench is great. They're really sleek and relatively light rear ends. Also, the lack of c-clips is nice if I do twist off a shaft. Although a shortened 8.8 with same length axles means I only have to carry one spare. That'd be a little more involved with a c-clip eliminated axle.

I honestly think I like the 8" route. I could buy it and have it in over a Saturday. Brake parts are still available at the parts store. I'd like to put a Powertrax No-Slip locker in it. I've run them before and really like them. Smoother than their Lock-Right, but still no clutches to wear out. Not as smooth as a limited slip, but once you get accustomed to it, it's fun. Not as scary as some would have you believe.

Well I finally had a day off and I found the source of the noise. The cross shaft retaining bolt backed out causing the cross shaft to try to slide out and hit against the end of the pinion gear as the carrier spun around taking out the very ends of the pinion teeth and wearing into the end surface of the gear. I guess after 48 years it finally couldn't hold on any longer. This is a new one for me. The cross shaft ends are all chewed to bits. There's a nice collection of metal chunks in my drip pan and still in the housing as well. The carrier bearings are making a nice grinding/popping sound too and the pinion bearing feels pretty rough as well.

I could probably rebuild the old girl. I have a posi carrier in a CJ rearend I could rebuild with new clutches and steels maybe. It's a 4:11 gear which is way to low for this setup so I'll need a new ring and pinion too. I might could clean up the ends of the pinion teeth and get away with reusing these gears, but I don't know. The ring gear looks fine. It is a little worn I suppose, but doesn't look beat up from the metal chunks.

I took some videos, but haven't uploaded them anywhere. Here are some screenshots though. You can see the chipped pinion gear and one chewed up end of the cross shaft. I can slide the cross shaft in and out easily with one finger. I read in another forum after a google search about a guy with a similar issue and his carrier ended up with the cross shaft bore egg shaped after it banged around in there for a while.





I do have that trac-lok carrier in the CJ Model 20 in the garage. It has some spider gear chips and possibly side gear chips as well. I just remember they were minor and the guy I got it from "said" it didn't make any noise and he didn't even know they were chipped until he pulled it for an axle swap. Maybe a new gear set, rebuild kit with all new bearings, and trac-lok rebuild will get me back in business. And MAYBE, if my accountant(wife) approves it, a pair of Moser one piece shafts too!

I'm still thinking about a Ford 8" from an early Mustang or Maverick. They're 43" perch width and within 1/2" WMS to WMS. And I REALLY like the idea of building a center section on the bench then bolting it in. A centered 8.8 from an Explorer is also an option, but it's hard to find one close to 3.00:1 ratio it seems. My 2.87:1 gears are just about right with my tires and 3 speed automatic. I found a really nice one already shortened and centered and rebuilt with a posi but it's 3.73 gears. That'd be great for 0-60mph, but I drive this car on the highway to work and weekend cruises.