Rebuild: Bronco the Debilitated

I didn't realize owning a Bronco was like owning a house or a boat...I've done loads of things, but don't really feel like documenting it all, lol.

Cleaned my heater box and replaced the heater core. I ultimately ended up with a Spectra Aluminum one. As with most Bronco things, I had to buy it twice. (actually three times, I bought a TBP copper one that I did not use).

The first spectra was shipped in a box by itself, I wasn't impressed with how the tubes fitted so I got a replacement. The replacement, same part number, was double boxed.

Pictures are of the first Spectra, the second one, then the cleaned heater box and the inner firewall location for the heater box.

Distributor fun. Not sure why, but seems that every bought part these days has something off with it.

When I pulled the engine, I tossed the original distributor (and kicking myself) - and bought a re-manufactured Cardone unit from Summit. This was a mistake, as *eventually* I realized the bearings on the reluctor plate were notchy and causing the vacuum advance to work incorrectly, get hung up. This was a source of drivability issues.

The machinist that I took my failed engine main bearings too said they looked like they were a result of detonation. If the vacuum advance was hung up, then possibly he's correct - I'll try not to think about that too much.

Anyway, I bought a new Duralast distributor from Autozone, tossed the other distributor. Drivability improved.

Timing seemed a slow, so I decided to 'recurve' the distributor. Then timing seemed off the charts at 48 degrees total advance. Opening the distributor revealed 18L and 21L slots (measured with calipers, and by advance reading showing 36 degrees mechanical advance).

Thinking I could swap reluctor arms to a smaller slot one. I bought a remanufactured Motorcraft distributor for a 460 engine, and got 13L, 18L slots. Unfortunately the Motorcraft reluctor arms won't fit on the 'new' distributor shafts, the new distributor shafts are bigger diameter than the Motorcraft ones. In addition, the 460 distributor shaft is too short to fit into a 302, so I couldn't use the unit.

I accidentally bought a new Cardone distributor for our engines, and it came with 10L, 13L slots (approximate). The Duralast and Cardone distributors are different. They appear to use the same core, but machining and shafts are different. Reluctor arms do not swap between the two (so close, the height of the shaft is slightly different). The Duralast electronics are (seemingly) better quality, but it comes with 18L,21L advance slots.

I bought another remanufactured Motorcraft 302 distributor, and it came with 16L, 21L arms.

All remanufactured Motorcraft distributors I've bought (3 total) come with notchy reluctor plate bearings. For some reason Cardone tries to reuse the stock plate and when crimping the bearings back on, they seem to over crimp them. This is a problem because vacuum advance may not work properly.

Some pictures added, the silver unmarked weights and arms are the Duralast distributor, the black unmarked weights and arms are the Cardone new distributor. The marked arms (16L,21L) are from the remanned 302 distributor.

Wow, what a pain. You're starting to sound like a Chevy Corvair owner!
I think they used like thirty different distributor setups over the years and everyone seems to end up with the wrong one after a rebuild because the manufacturers don't make note of the differences and consider them all generically the same (because almost all will bolt in to almost all years engines) but the curves are all over the place.
As you can imagine with turbocharged and non-turbocharged engines, 2-carb, 4-carb, A/C equipped and smog pump equipped, and everything in between.

Be careful you don't end up becoming a distributor whisperer as a side job!

Paul

Heh, yeah, lots of permutations with the Duraspark system. It's unfortunate that the remanufactured units have such varied quality. None of the vacuum advance units work well, either bad canister or crunchy bearings. It's interesting that they chose to remanufacture the vacuum advances, rather than just replace them.

The new Duralast seems to be the best quality of the bunch, but has the 18L/21L slots. The stator assembly/ignition pickup looks to be of better quality than the generic one used in the Cardone new distributor.

I'll either use the new Cardone, or use the reman with the 13L slots. The 13L slot will give 26 mechanical advance. Total advance at 36 degrees assuming 10 degrees initial.

DirtDonk said:

Wow, what a pain. You're starting to sound like a Chevy Corvair owner!
I think they used like thirty different distributor setups over the years and everyone seems to end up with the wrong one after a rebuild because the manufacturers don't make note of the differences and consider them all generically the same (because almost all will bolt in to almost all years engines) but the curves are all over the place.
As you can imagine with turbocharged and non-turbocharged engines, 2-carb, 4-carb, A/C equipped and smog pump equipped, and everything in between.

Be careful you don't end up becoming a distributor whisperer as a side job!

Paul

Click to expand...

Suppose I should add some things to this, lol...

Finally got around to connecting the heater hoses. Heater works!!

A drip at the rear diff, lead to some changes. I pulled the pinion support to change the seals. The pinion bearings were a bit rough/notchy, so I decided to replace them. Peeking into the diff housing showed some big bolt heads on the carrier...Marti says my truck came with a trac-loc...

...so I bought one of those generic trac-locs that are floating around (Summit's version). In addition to Summit's basic install kit, which appears to be a master kit with Koyo bearings. Summit's price on the trac-loc isn't the best (JBG's actually is), but it ships quickly. The install kit was very reasonably priced though, they have 3 versions, choose wisely.

...much cleaning, but broke my pinion support housing...grrrr...I used a brass drift to punch out the races. BUT-I hammered on the thin lip of the oil hole instead of the race and cracked it. It's probably still usable, but I'll be sourcing a different one.

Repost from another thread...just keeping things sort of up to date in this thread...

Just to follow up. In addition to the crack, my original 9" case had bolt scrapes as well as a porous casting. So I bought a Currie 9" nodular case. I was happy to see that the case was stamped with a Currie part number and not a generic private label that pervades the industry.

I put the 3rd together with new Timken bearings and Summit private label 3.50 gears. Unfortunately I couldn't get a decent pattern on the gears...which resulted in unacceptable levels of noise. In addition to ridculous amount of LSD groan. So, I tore it back a part.

I ordered a set of US Gears 3.50 gears, and sent the Summit ones back. I bought new Timken pinion and carrier bearings *again*. I could've reused the carrier bearings, but what's another $30 as I wanted to eliminate any noise from before. I soaked the LSD clutch plates in LSD additive (Ford).

I bought a checking tool, which got things close. However checking distance measurements varied 6 thousands or so...a few pattern checks (and shims) got me to what I wanted.

Sooo...attempting to save some money buying private label gears and carrier ended up costing me quite a bit in time and bearings. The case I couldn't do anything about, oh well.

Rear is silent now...just took a lot of time to get it that way.

Some pics of pattern, old case, new case...