[UngerMarkus]

Hi!

I´ve got a problem with the th200 in my Bonneville.

The tranny shifts to the next gear very late. When I normally accelerate to ~30mph and hold that speed, it doesn´t shift to a higher gear, unlike a normal transmission would do, when you don´t need accelerating power. Even when I let off the gas it stay´s in 1st. This is the same situation in any gear.

When I floor the gas pedal, at about 35-40mph it shifts nice and firm. When I let off the gas and drop to a slower speed it stay´s in 2nd.

It down-shifts very nice, just like any other tranny.


I allready checked the trans-fluid level. The oil looks good and it doesn´t smell burned. Since there is no modulator on the TH200, there can´t be any vacuum leaks... What else could be causing this problem?

Hope you guys can help me!

Thanks in advance

Markus

[SSedan64]

Is this a TH200C 3-speed or TH2004R 4-speed trans? Both operate the same.
Since it shifts correct at hard/full throttle the Governor seems to be working right.
The TV/ThrottleValve controls part throttle shifts it's connected to the carb by the TV cable. May have trash in valve, valve is binding or cable is too tight. Unhook the cable from carb(engine off), start engine and give the cable a dozen or so quick snatches to try & dislodge any trash or bind. Turn engine off. Reconnect cable & retry part throttle operation.

[fast68]

yeah make sure the cable isnt pulled too much,

it sounds like might be and is holding the gear(s).


which 200 is it ?

if its the 2004r then the cable has to be set correctly.

i assume you have the little metric 200C 3 speed though. if so then try slacking up the cable

unless the 200c cable is a throttle valve cable then it has to be set correctly too or it wont shift right

im not for sure on the 200c


good luck


good luck

[UngerMarkus]

Thanks for the fast replys!

I guess a too tight cable will cause excessive wear of the clutches, right?

I´m gonna slack the cable a bit this afternoon and let you know if this solved the problem. Do you think a too slack cable will harm the transmission?

[SSedan64]

Originally Posted by UngerMarkus

Thanks for the fast replys!

I guess a too tight cable will cause excessive wear of the clutches, right?

I´m gonna slack the cable a bit this afternoon and let you know if this solved the problem. Do you think a too slack cable will harm the transmission?

If cables is tight it causes high pressure, tight=firm shift or too tight=no shift.
If cables is loose it causes low pressure. loose=soft quick shifts or too loose= can burn clutches very quick.
The TH200C, TH2004R & TH700R4/4L60 use the same TV cable setup & operate the same.
3 Pages of Info TV 101 Article.>
http://www.tvmadeez.com/article/index.php
More Info.>
http://purplesagetradingpost.com/sum...o/700R4p1.html
And More Info.>
http://www.tciauto.com/Products/Inst...ble_adjust.htm

[UngerMarkus]

Got some good news!

The tv-cable had a little too much tension. I slacked it up, about 1/8", and now it workes just like new! Soft and early when you cruise around, and really quick and firm under WOT. Great!


Thanks for the help, guys!

@Ssedan64: Thank you for the links and the explaination on how the cable tension effects the shifting!


Another question: How do you think about the Turbo200? As far as I know, this tranny was intended for light vehicles with little torque. Aren´t the 389 and the heavy body a little "challenging" for it?

[SSedan64]

Originally Posted by UngerMarkus

Got some good news!

The tv-cable had a little too much tension. I slacked it up, about 1/8", and now it workes just like new! Soft and early when you cruise around, and really quick and firm under WOT. Great!


Thanks for the help, guys!

@Ssedan64: Thank you for the links and the explaination on how the cable tension effects the shifting!


Another question: How do you think about the Turbo200? As far as I know, this tranny was intended for light vehicles with little torque. Aren´t the 389 and the heavy body a little "challenging" for it?

Glad you got it fixed.
If you have the TH200C 3-speed trans it is very weak & not recommended for use with a heavy car with a high torque engine. TH350 or TH400 would much stronger.
The TH2004R 4-speed O/D is stronger than the 200C and can be upgraded to handle plenty of power.

[Crosley]

Originally Posted by SSedan64

Glad you got it fixed.
If you have the TH200C 3-speed trans it is very weak & not recommended for use with a heavy car with a high torque engine. TH350 or TH400 would much stronger.
The TH2004R 4-speed O/D is stronger than the 200C and can be upgraded to handle plenty of power.

How is it the 200-4r is stronger than the t-200 when the back half of the 200-4r is the same parts design as the weak t-200 trans?

I've never figured that out?

[SSedan64]

Originally Posted by Crosley

How is it the 200-4r is stronger than the t-200 when the back half of the 200-4r is the same parts design as the weak t-200 trans?

I've never figured that out?

Crosley, I'm not sure what all makes it stronger. One builder told me the metalurgy on several parts was upgraded in the 4R trans. I have seen the spectrograph results of the 4R Forward, Input & Output shafts but not the 200, 200C. Lonnie from ExtremeAutomatics says they're stronger in stock form but equal once internals are upgraded.

I'm using the kolenes & Reds I got from you and 4340 Billet Forward Drum Shaft, Input Shaft, O/D Carrier & Ring Gear from CK in the 4R I'm building now. Just haven't finished rollerizing a few other parts.

[Crosley]

Originally Posted by SSedan64

Crosley, I'm not sure what all makes it stronger. One builder told me the metalurgy on several parts was upgraded in the 4R trans. I have seen the spectrograph results of the 4R Forward, Input & Output shafts but not the 200, 200C. Lonnie from ExtremeAutomatics says they're stronger in stock form but equal once internals are upgraded.

I'm using the kolenes & Reds I got from you and 4340 Billet Forward Drum Shaft, Input Shaft, O/D Carrier & Ring Gear from CK in the 4R I'm building now. Just haven't finished rollerizing a few other parts.

I've never tested any parts in either transmittin for rockwell or any other strength tests. The gear train parts look the same of the t-200 to the 200-4r. Obviously the front end is different from 200 to 200-4r

Although I have not talked to my friend Ed in several years , Ed was an engineer on the 200-4r development. He was in on the development of 700r4 and 4L80E too.

In the early daze of this 200-4r, the failure rate was high and expensive for repairs in the daily driver cars.

With the current trend of billet parts and cryo treatment , I see where a modded 200-4r would be stronger. Does the cost justify the end results is the question in my mind.

For mild street use I like the 200-4r.. I even have a unit in the works for my Dodge Lancer - 1961 car. ... if I ever get back to that transmittin project.