Time for a quick update on the Cadillac. Last time you read about the caddy, I shared my discovery that it had the rather desirable “Switch Pitch” variation of the Turbo 400 transmission. As such, I decided it was best to have it examined before I put the car back together. I took it over to Alphonso’s Transmission in Goleta, hoping that it just needed to be cleaned up, and perhaps have a few smaller parts repaired or replaced. Unfortunately, this was not to be. As he started dismantling the transmission he very quickly discovered that the main forward band was broken, the forward drum was burnt, and the 2/3 clutch pack was nearly worn down to the steel. So, the only real choice at that point was to go ahead and rebuild the transmission completely.

Now, I’m totally stoked that the trans was rebuilt, and Alphonso has been building these things for longer than I’ve been alive, and did a spectacular job. I also have a brand new variable pitch torque converter. All for the (quite reasonable) price of $1100. Problem is, I only had $600 to spend, which I was hoping would be enough to get the trans repaired, and buy a few small parts I needed to get the car back together. Instead, I had to borrow the rest of the money from our savings. This means for the next 3 months I’ll be paying our savings back from the caddy’s fund, at which point we’re expecting our new son Tate! So as you can imagine I’m not going to have the time, nor the presence of mind to be working on the caddy for a while after that, and I won’t have any money to spend on it until then.

As a result, I’m trying to do little things on the caddy until Tate is born that don’t cost me anything. So I’m tearing the motor down a bit further, and trying to clean it up. I popped the timing cover off to check the timing chain/gears. Turns out this is yet another part which is going to need replaced! The chain is SUPER loose, like enough that I almost feel like I could cause it to skip a tooth with the slack. Also, apparently in the late 60′s it was all the rage to install and market “silent” timing gears. I had the same get-up on my 1967 Ford Thunderbird. It’s essentially a hard plastic cam gear for the timing set, which is supposed to reduce the normal timing set noise. I seriously don’t get this, since the other noises that these machines make more than drown out any noise that the timing set might make. But, I digress.. The point is that the hard plastic cam gear is also showing signs of stress, with hairline cracks forming down the middle of each tooth. It’ll definitely have to be replaced.

I had hoped that I could just throw the engine back together without buying a whole lot more parts for it, and as such had sorta planned not to inspect it too thoroughly. With events unfolding as they have, I think I am going to go ahead and check all the rest of the clearances and see what else (if anything) may need replaced. Depending on how things turn out, I may or may not stick with this motor. As I’ve stated before, the 429 is a low production motor and the parts are surprisingly hard to find, as well as expensive. If I find that it needs more than bearings (a cam, or some machine work for instance) I may simply sell this motor to someone who’s working on a numbers matching restoration and buy a 472/500 to put in it’s place. The good news is that my 429 is in generally good shape, and certainly does not need a lot of work, so it should have some reasonable value to someone who’s looking for original parts.

So that’s where we stand. I had hoped to have her all back together and be driving ‘er by now, but it looks like I’m going to be taking my time even a bit more, and being even a bit more methodical. I can’t wait to experience that finely crafted and tuned transmission!

It's been a while since I've provided an update about the progress of on the Caddy.  Mostly because things have been slow due to a busy work and family schedule.  Here's the rundown of what I have gotten done though.

I have rebuilt the carb, and realized that a broken vacuum pot on the carb was actually only used to crack the throttle open a bit and increase the idle RPM when the A/C was running.  Since the A/C system is not holding pressure, and looks like it hasn't in many many years, I went ahead and removed this "extra" part.  Hopefully this'll fix the hesitation problem that I detected on the few short drives I took.  

Now, when I first got the car, I immediately noticed that there wasn't any sort of linkage that I could see for the tranny kickdown.  So while I've been staring at the service manual to get my carb back together properly, I've also been trying to figure out how the heck this thing is supposed to get a kickdown signal from the throttle.  Turns out there is a switch which is supposed to be mounted on the intake manifold, near the carb which actually sends a +12v signal to the transmission for kickdown!

Even more interesting than that, the transmission in this thing is at least as rare as the engine.  I've got a THM400 with "Switch Pitch", which was only offered in the Caddy for like 3 years.  Basically the torque converter has two stall settings, one around 1000RPM and another around 3200RPM.  It switches between the two with another +12v signal (also sent by the switch which I don't have) which causes the angle of the blades in the converter to change.  So, that means two things.

First, instead of just throwing everything back together and hoping the trans "just works" I'm actually going to take the time to yank it out and have it gone over to make sure it'll work well for me.  No sense it blowing this thing up since it's a stout and apparently rather desirable piece!  I'm hoping to have it yanked out this weekend, and over to Alphonso's Transmission by Monday.

Second, because I don't have the original switch to operate the "Switch Pitch" mode and kickdown I've got to either find one (fat chance) or devise my own.  Currently, my plan is to mount up a TPS (Throttle Position Sensor) to the carb and feed that signal to an Arduino Microprocessor which will send the +12v signals to the trans for both the switch pitch, and trans kickdown.  There is actually a guy who built a controller for the switch pitch part of the trans back in the mid 80's, and I've actually been in touch with him.  His solution uses vacuum, the brake light, and timers to operate just the pitch change of the torque converter.  Then a mechanical switch for the transmission kickdown.  His name is Bruce Roe (bcroe@juno.com) and I've been in touch with him to get some feedback on how his device works.  He's been very helpful and encouraging, I can only hope my device is as effective as his.

So, with that I've decided I'm going to nickname my Caddy "Bionic Caddy" in honor of the fact that "we have the technology, we can make it better".  It's especially fitting since I'm going to put a CarPC in it, and hopefully put a Megasquirt EFI on it one day.  Also, it abbreviates nicely to a personalized license plate *BIONCAD*.  Should be good fun.

While my simple project of identifying (and fixing) a mysterious "clunk" has sorta exploded into a much bigger project of getting the engine back together and building a controller for the transmission, I still hope to get it done reasonably soon and keep the complexity to a minimum.  Stay tuned for updates!