KurtAKX
KurtAKX New Reader
5/18/17 8:30 p.m.

So guys, I bought this 1986 Cadillac Fleetwood Brougham for $400 to run the Michigan Gambler 500 rally. It sat for something like 12 years while the (deceased) former owner's belongings went through probate, and it got dumped at an independent garage by the heirs for repairs and abandoned, blah blah. Didn't end up doing the Gambler because Mrs. KurtAKX didn't want to be home alone all weekend long with three screaming kids.

Anyway...I threw a set of steel brake lines, a gas tank, a sender, some belts, and about 8 replacement 194 bulbs in the dash and cluster in it. Now drives great (for a boat), as it should with 75,200 miles on it.

Here's the rub: I have now put about 100 miles on it, and it has suddenly decided to mess up the coast-down downshifts... crappy/late. It now lugs the engine down before reluctantly dropping to the next lower gear when stopping.

I double checked that the TV cable isn't kinked/stuck/binding (though that would theoretically cause the opposite of early upshifts/late downshifts).

Next I checked "the internet"... Some folks claim that the 200-4R torque converter clutch solenoid will stick and cause symptoms kind of like I'm experiencing, and some folks claim that the 200-4R governor will occasionally chuck a spring and cause these symptoms.

I have carnal knowledge of the 700-R4, as I have been (check) balls deep in one (Completely rebuilt the on in my 1992 GMC pickup from a bare case) but I know little to nothing of the 200-4R.

Any trans gurus on here that can provide a bit of advice to help diagnose? I don't see a pressure port on the trans to check for Torque converter clutch pressure, like some trans have...

Stampie
Stampie SuperDork
5/18/17 8:36 p.m.

I have the solution. Cadillac 472/500 with a 400 trans behind it. Bolt in.

Dusterbd13
Dusterbd13 UltimaDork
5/18/17 8:40 p.m.

I traded a pack of cigarettes for an 82 el dorado once.

It was the third worst automotive mistake ive ever made.

Your isse sounds like a plugged up passage in the trans. Luttle seafoam trans ina a can and fresh fluid filter could be the droid you are looking for.

But im not a trans guy, nor did i sleep in a holiday inn express last night.

Crackers
Crackers HalfDork
5/18/17 8:57 p.m.

I don't know either, but I'll be following to see if it can't help demystify these voodoo contraptions for me a little.

conesare2seconds
conesare2seconds Dork
5/18/17 9:14 p.m.

Curtis73 will know. I'll take tc lockup solenoid, though.

dorri732
dorri732 Reader
5/19/17 5:45 a.m.
KurtAKX wrote: It now lugs the engine down before reluctantly dropping to the next lower gear when stopping.

Failing to downshift wouldn't cause the engine to lug when stopping; the torque converter has enough slip to allow the engine to idle fine in any gear. It sounds like the torque converter lockup clutch isn't disengaging. That would cause the symptoms you see no matter which gear it's in when you're stopping.

GTXVette
GTXVette HalfDork
5/19/17 5:49 a.m.

I built a 200r4 for my Skylark, If you did a 700 go for it .It's better trans anway

KurtAKX
KurtAKX New Reader
5/19/17 8:08 a.m.
GTXVette wrote: I built a 200r4 for my Skylark, If you did a 700 go for it .It's better trans anway

I like the 700-R4 ok but don't think there's a 700R4 for the BOP rear bellhousing pattern.

KurtAKX
KurtAKX New Reader
5/19/17 8:10 a.m.
dorri732 wrote:
KurtAKX wrote: It now lugs the engine down before reluctantly dropping to the next lower gear when stopping.
Failing to downshift wouldn't cause the engine to lug when stopping; the torque converter has enough slip to allow the engine to idle fine in any gear. It sounds like the torque converter lockup clutch isn't disengaging. That would cause the symptoms you see no matter which gear it's in when you're stopping.

This is a good point. I don't know enough about the 200-4R to know if this is true, but I think in the 4L80-E and some others, there's no fluid flow to the hydraulic circuits that lock the converter in lower gears.

KurtAKX
KurtAKX New Reader
5/19/17 8:18 a.m.

Man you guys are great and the internet is great.

Here's a "geocities-esque" page that nonetheless exactly describes my problem. Helpful, but not exactly web-design gold

xflowgolf
xflowgolf Dork
5/19/17 8:45 a.m.

Can you just unplug the TC lockup?

My wife had a POS Corsica years ago when we were first dating, and the TC would lock up and stay locked up when decelerating. I was able to just unplug it, and it isolated/eliminated the issue. Obviously it wouldn't go into OD any more, but around town it really didn't matter.

It may not be the fix, but it might be a simple diagnosis.

KurtAKX
KurtAKX New Reader
5/20/17 11:38 p.m.

I thought I was out of the woods on this thing...i am not.

What I am, is pissed. I wanted a real ACDelco TCC solenoid. Rock didn't have it. Amazon didn't. None of the parts stores had it. I settled, and went with the nicest looking aftermarket one I could find.

Turns out, the damn thing is supposed to be "universal" and fit both 700 and 200 series Trannies.

So I put it in (which requires splicing inside the trans oil pan, already a turn off to my sensibilities) ... And then find that the coil winding part is bigger in diameter than the oem piece and the pan won't go back on!!!

Total bull excrement.

Keith Tanner
Keith Tanner MegaDork
5/21/17 1:25 a.m.

Does the Cadillac dealership sell parts?

patgizz
patgizz UltimaDork
5/21/17 6:39 a.m.

Thank you for correctly calling it the 200-4R. There is no such thing as a 200r4.

I believe the cure to your issues is a 472/500, th400, drop the rear gear into the 2.56 range and forget overdrive. It's a bolt in with pan/mounts for a 77-79 425 deville engine.

KurtAKX
KurtAKX New Reader
5/22/17 10:04 a.m.

In reply to patgizz:

It already has 2.73s in it. I kinda like having a lock-up converter, I just don't like the 140hp/255tq Olds 307. Maybe I'll keep the 200-4R but take the advice on the 500 cube Caddy motor.

G_Body_Man
G_Body_Man SuperDork
5/22/17 11:00 a.m.

In reply to KurtAKX:

If it's the 307 Olds, a THM350 from a G-body Cutlass Supreme should pretty much bolt in. Or you could see if a junked G-body has a 200-4R and hope for the best.

KurtAKX
KurtAKX New Reader
5/22/17 11:54 a.m.

In reply to G_Body_Man:

I don't think this trans is borked just yet, patiently waiting for a correct (OEM) TCC solenoid in the mail, and then I should be good to go.

Esoteric Nixon
Esoteric Nixon UltraDork
5/23/17 6:18 a.m.

I have no idea why people would recommend a TH350/400 over a transmission with overdrive, but that's the internets for ya. Have you tried scouring eBay and other like sites for the part? Also, did you happen to check Napa? A lot of their Echlin parts that have been on the shelf for awhile are NOS AC Delco items.

Did it shift fine from a stop when warmed up? I used to have an HT4100 backed by a 200-4R that would lug itself upon takeoff. I never got a chance to look into it, however.

And as an aside, should you ever go with a 472/500 with a bloody three-speed I would change those wheels. They look like the rare factory spokes, and they will most likely not handle the torque you'll be putting down.

KurtAKX
KurtAKX New Reader
5/23/17 3:05 p.m.

This shouldn't be that hard.

I have two criteria for buying parts

1) Quick- choose a seller who can get me the parts in a timely fashion

2) Quality parts- choose a seller of OEM parts where possible

First I looked all over locally for an ACDelco part. Nobody had one.

Next option, Amazon an ACDelco since that they ship quick; Amazon didn't have one.

Can't get OE quickly, what can I get... found and Amazon'd an aftermarket TCC solenoid. Experienced problems fitting it, turns out the ATP-branded solenoid is a "universal" 700-R4/200-4R replacement.

Back to the search for a genuine ACDelco. Rock Auto showed they had the ACDelco real deal (PN:8634960). I tried to order it and the site changed it's mind to "out of stock" three separate times.

Falling back to eBay I found a GM dealer selling Open Road GM of NJ with an eBay listing saying they had sold one and still had 2 available. Sent them money... They generously took it and then canceled my order.

I went to another dealer today (Les Stanford), unlike the other dealer they didn't just laugh and hang up on me. Instead they printed me a list of dealers that might still have inventory. $94 later and I'm supposed to be getting one out of Nebraska; we shall see.

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