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what is a lock up or lock out tranny

3K views 21 replies 6 participants last post by  Foperfoauto 
#1 ·
I bought an old 89 Camaro with a 305 years ago the main reason was it had a brand spanking new tranny in it that I could use in my old coupe I was building, 500 for the whole car an he drove it to the shop.
So, I don't know Jack about transmissions. I believe he said it was a "metric " maybe 200 metric? I never heard of one, sound right so far?
Any way it has a lock out or lock up in it too. All I know is that has something to do with the torque converter, I was wondering what that is and how it works and maybe if the two wires going into the tranny are for it. I don't have them hooked up and it seems to run fine around the block, it shifts and everything. should I just leave them unconnected ? I can post a pic if theres no such thing as a GM metric tranny
 
#4 ·
Is it a three speed or four speed automatic? There are both under the "200" name - the TH-200 and the TH-200R4....the 200 is a three speed non-overdrive with lock-up converter, and the 200R4 is a four speed where 4th is an overdrive and also has a lock-up converter.

Both were available around that 1984 time frame and who knows what might have been swapped around.

Post pics if you got them. Transmission oil pan shape is usually the easiest identifier.

Normally V8 Camaros and Firebirds got the beefier TH-700R4 overdrive Automatic.

The TH-200 "Metric" is an extremely light duty transmission, usually only behind small V6 and four cylinder engines, sometimes the 267 V8.

There are Super Stock racers using the TH-200 "Metric" because it is very light internally, but by the time they get it built enough to hold a good V8 its a $4000 piece. They only like it because the low amount of power lost through it rivals the Powerglide 2-speed, but still gives them 3 speeds. Otherwise, nobody ever rebuilds one of these anymore.
 
#5 ·
It's probably a 200-4R if it's a six banger or a 700-R4 if V8. There's a couple different 200 versions. Lockup is for MPG, to eliminate slippage when feasible. Lockup and non lockup trans are sold, with most performance applications wanting the non-lockup setup.

There's a hundred guys in here who can answer this better than me. If you were to Google turbohydramatic and go to the Wikipedia page for GM transmissions, you might find the explanation in an organized and more digestible format. At least that might help you figure out what's what and why. I'm no trans guy!
 
#6 ·
200r4 is a close cousin to the 700r4, both can be built to ungodly hp
either one needs a lockup kit to run in a non computerized vehicle
google '200r4 lockup kit' you will find lots of info on them and youtube videos :D
most use a pressure sensor in the 4th gear to lock the torque converter when it shifts into 4th gear

the 200r4 is a direct replacement for the th350 without any drive shaft changes
both require 12v and a relay on the brake circuit to cut power when the brakes are applied
 
#7 ·
OK, I think I got it now. when the tork is locked its like direct drive . I'm pretty sure this is a 3 spd. I remember when I put the 4spd Impala shifter in It was a 3spd,its been so long ago ,who knows . I'll get some pics so I can at least know what it is. It all bolted right up to my 350. The reason I ask is because I got my floors all pulled out and theres two wires coming out of it that I have no clue as to where they go .thanks for the help
 
#8 ·
Purty simple; Does this trans have a "bolt on" tail housing? it would be 4 bolts in a square pattern.

A T-200 3 speed trans and the 200-4r 4 speed trans , do not have bolt on tail housings.

A 1989 Camaro should have a 700r4 trans in it. On the passenger side, near the 2 cooler line fittings.. would be a round servo cover poking out from the trans case , about 4 inches in diameter. The 700r4 trans would have a bolt on tail housing with 4 bolts
 
#15 ·
If it's just a cruiser and you never intend to spin the tires, just drive it like an old lady it will live okay. Start hotrodding on it and it won't last at all behind anything with more than 300 ft.lbs of torque.

The 700R4 is a lot stronger....but are you geared high enough in the rear to need an overdrive?? You'll need at least 3.31 rear gearing to make efficient use of the overdrive 4th gear and the lock-up.
 
#18 ·
I've been working on the trans ID page on the wiki, I just posted a pic of the TH2004R, some call it TH200R4. The other posters are correct..., your is a THM200, and common in G-Body and F-Body with V6 and chevy V8 267/305 and Sedans you will find them all through the platforms and yes some of them don't make sense at all. GM was under the gun to get their average fleet MPG down to make Uncle Sam happy as well as keeping sales and looking for marketing points. The V6 2.8 and the Iron Duke 2.5 got the Narrow bell housing 700R4, internal components the same and can use them for parts, but they won't bolt up to the SBC or the BOP V8's. Most of the late 70's to early 80's with "OD" on the dash and an Olds 307 under the hood will have the THM2004R, yet I have pulled some TH250C and TH700R4s, but not often.

THM200 has eleven bolts on the pan, some stamped "Metric" yet some were not. Was never planned to be used for 4 x 4 so was never designed to have a removable tail shaft. If it has the 4 plug connector on the driver side of the case it is lock up converter. Another sure way to tell is if the input shaft has a small diameter stub on it with an O-ring on the end, its a lock up, as the O-ring is needed for secure fluid coupling to operate the lock-up.

The idea behind the THM200 was lighter overall mass and less rotational mass, and this was supposed to equate to higher fuel mileage. Racers are now finding benefit of the lower rotational mass, but the internals are mostly poor quality cast or thin stampings. High speeds (RPM) and any heavy torque as the other poster mention, tends to turn the inside of it to paste. The nice thing of the THM200 is very low first gear ratio and a wide ratio between 1 to 2 shift.

Issues of the stock unit is a lower number of friction and steels, light weight stampings, and weaker sprags. Sonnax and Mako Trans Parts have some of the upgrades.

THM200 or the THM200C is a good cruiser, definitely needs a deeper pan and external cooler, but is reliable if maintained properly and if you don’t mash on the gas as a regular thing. Summit has the lock up kit for about 75 USD, Sonnax or Mako has the Servo unit that is highly recommended.

I getting ready to build one this month so can post some pics, overall its not a bad basic trans. If you do not use it set it to the side, sometime when I’m in the area I’ll buy it up from you.

The 700R4 is excellent Trans, basically a THM350C with overdrive and can be built to some very impressive levels. Just remember if swapped for a 3 Speed it has an extra detent so the linkage needs to be adjustable to accommodate this. It needs to be properly matched to the rear gears. If you don’t use the OEM ECM you need the after market lockup kit. If the car is going to be custom build, then from the beginning decide which one to use. Swapping from 3 speed to 4 speed (3 + 1OD), you need to design in the linkage or cable driven shifter such as the B&M, rear gears, drive shaft length, etc… . B&M has both universal shifters in both 3 or 4 speed.
 
#20 ·
TH250C "Slush Box"

These are some pics of the TH250C being built at the same time going through the TH200. Note it looks like a TH350, but has the Band Adjuster on the Passenger side behind the cooler lines. The customer complaint was…, "slush box" behind his OEM base Chevy 305. Pulling it apart and it was found that the band servo return spring is broken and both pieces were lying on top of each other in the bore. This caused the servo and accumulator to sit crooked in the bore and jammed. Inspection shows that the direct clutch and steels are burnt, and the forward clutch and steels are burnt.
 

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