: Brougham Tranny and Catalytic converter questions



Cadillac Giovanni
01-27-07, 07:39 PM
A couple of questions here about a 89 Brougham.

A few months ago my catalytic converter was on it's last leg and was clogged pretty bad. to alleviate the problem, i took it off and hollowed it out, so at least it would LOOK like i was obeying emissions laws. However, this caused the exhaust to reverberate rather loudly inside the hollow converter. I've dealt with it until today, and now I have replaced it with a direct fit converter from advance auto parts. This has decreased the noise somewhat, but it is still not silent like the original converter was. I was just wondering if anyone else experienced this. It's no big deal. it only gets loud when i really lay into the pedal, like when accelerating.

Secondly, my car has the TH400 3 speed transmission, but finding a fluid change kit at the local auto parts stores has proven difficult. They seem to stock a 13 pan gasket for the 3 speed, or a 16 bolt pan gasket for the 4 speed, but my tranny has 15 bolts in it. What gives?

Advice, explanations, and off-color jokes are appreciated.

90Brougham350
01-27-07, 07:47 PM
Can't really help you on the cat, but your vehicle shouldn't have a Turbo 400, it should be a 200-4R 4-speed. Look again!

Cadillac Giovanni
01-27-07, 11:13 PM
I look at it every day. It's a 3 speed. You are right though I never checked what type of tranny was supposed to be in these cars and that year was supposed to have the 200-4R.

I am scared and confused.

Do they include the torque converter clutch as a speed? Also, there are supposed to have overdrive aren't they? I know mine doesn't.

Destroyer
01-28-07, 01:16 AM
I look at it every day. It's a 3 speed. You are right though I never checked what type of tranny was supposed to be in these cars and that year was supposed to have the 200-4R.

I am scared and confused.

Do they include the torque converter clutch as a speed? Also, there are supposed to have overdrive aren't they? I know mine doesn't.Why do you look at your transmission everyday?. Anyway, if nobody switched the trans out it has a 200r trans. Why you dont have overdrive?. Gotta get it checked out I suppose.

N0DIH
01-28-07, 02:49 AM
The THM200 4R pan has 2 sump areas, front and a small one in the back. The THM400 looks like a kidney.

Unlikely you have a THM400, for sure, not factory, unless it is a limo, I think the THM400 was std limo fare according to car-part.com.

http://tech.oldsgmail.com/trans_ident.php

Cadillac Giovanni
01-28-07, 12:59 PM
Why do you look at your transmission everyday?

Gotta do something to kill time before lunch.


I meant i always saw the gear indicator on the dash, clearly showing only three gears with no overdrive, which is what the TH400 has. I wasn't thinking of the torque converter lock-up as a fourth "speed", but if that is the case, it still doesn't explain the lack of overdrive.

N0DIH
01-28-07, 07:36 PM
Look at the carb, THM400's have NO kickdown or TV cable. THM350 and THM200/THM200 4R have a cable attached.

The THM400 either had the kickdown switch at the carb or on the throttle pedal inside the car. That is a sign.

THM350/400's have a vacuum modulator and a vacuum line running from the engine down to the pass side of the trans.

THM200C/THM200 4R's have only the TV cable (throttle valve) and no vacuum modulator.

THM400's did not have lockup, but the later design, 3L80 did.
THM350's did have lockup as the THM350C
THM200C's were lockup THM200's. I believe the THM200 (non C) did not have "METRIC" stamped into the oil pan. I think these were limited to 1976-1978 only, and limited to V6's. They didn't put them behind the V8's till later, but it IS possible the Pontiac 265 and Olds 260 got them. They were as weak kneed as they come....