Replacing a TH400 with a 200-4R

[pantera928]

Has anyone documented everything needed to replace a TH400 with a 200-4R in an Avanti?

I have read a lot of info but wondering if someone has actually documented what is needed. 

Thanks

[silverstude]

Here is a process  path to put one in a Studebaker Avanti.  It may not be everything you need  but it can help.

 

https://www.studebaker-info.org/Tech/Bhend/Avantaodtransmissionswap4.pdf

 

[pantera928]

1 hour ago, silverstude said:

Here is a process  path to put one in a Studebaker Avanti.  It may not be everything you need  but it can help.

 

https://www.studebaker-info.org/Tech/Bhend/Avantaodtransmissionswap4.pdf

 

Thanks. This is good stuff. I only wish it was for an Avanti II with a SBC but still good to know.

Thanks Again

[AD]

I believe there's been articles in Avanti Magazine about doing this, and it's been discussed on this forum many times. I converted my own '72 Avanti from the TH400 to the TH200-4R many years ago, and while I did not document the process I'd be happy to answer any question that I can. 

[pantera928]

2 hours ago, AD said:

I believe there's been articles in Avanti Magazine about doing this, and it's been discussed on this forum many times. I converted my own '72 Avanti from the TH400 to the TH200-4R many years ago, and while I did not document the process I'd be happy to answer any question that I can. 

Thank you

I know that there has been a lot of back and forth but a nice comprehensive write up would be great. Maybe I will be the one to do it.

Did the bell housing bolt up the same? No change of starter or flywheel/flex plate?

What about the the drive shaft? The transmission length is very close to the same. Are the splines different?

[AD]

 

Did the bell housing bolt up the same? Yes, the TH200-4R transmission will bolt to your Chevrolet engine without a problem. 

No change of starter or flywheel/flex plate?  I had to change the flex plate because the mounting holes for the TH200-4R torque converter did not line up with where the TH400 converter was mounted. I bought the correct flex plate at NAPA and was able to reuse my original starter. 

What about the the drive shaft? The transmission length is very close to the same. Are the splines different? The TH400 and TH200-4R tailshaft splines are not the same. At minimum, you will need to replace the yoke. In my case, I had to have a new driveshaft made. 

In addition, you will also need:

1. TV Cable and mounting bracket

2. TH200-4R flex plate stone guard

3. Dipstick & tube

4. PRND321 shifter lens and linkage (available from Nostalgic Motors)

5. Lock-Up torque converter system (several ways of doing this, from a simple toggle switch to full electronic. I designed my own and will be happy to share the idea if you're interested)

[pantera928]

2 hours ago, AD said:

 

Did the bell housing bolt up the same? Yes, the TH200-4R transmission will bolt to your Chevrolet engine without a problem. 

No change of starter or flywheel/flex plate?  I had to change the flex plate because the mounting holes for the TH200-4R torque converter did not line up with where the TH400 converter was mounted. I bought the correct flex plate at NAPA and was able to reuse my original starter. 

What about the the drive shaft? The transmission length is very close to the same. Are the splines different? The TH400 and TH200-4R tailshaft splines are not the same. At minimum, you will need to replace the yoke. In my case, I had to have a new driveshaft made. 

In addition, you will also need:

1. TV Cable and mounting bracket

2. TH200-4R flex plate stone guard

3. Dipstick & tube

4. PRND321 shifter lens and linkage (available from Nostalgic Motors)

5. Lock-Up torque converter system (several ways of doing this, from a simple toggle switch to full electronic. I designed my own and will be happy to share the idea if you're interested)

1. TV Cable and mounting bracket. Anywhere special to get this?

2. TH200-4R flex plate stone guard. Not sure what this is. Are you talking about the bottom cover under the torque converter?

3. Dipstick & tube. I have a 200-4R from another car. Can I use the one that came with it?

4. PRND321 shifter lens and linkage (available from Nostalgic Motors). Pricey but I have talked to him about this

5. Lock-Up torque converter system (several ways of doing this, from a simple toggle switch to full electronic. I designed my own and will be happy to share the idea if you're interested) Would love to know about your idea and design. 

Do you want to take this off line to direct email? I am pantera928@yahoo.com

[AD]

1. TV Cable and mounting bracket. Anywhere special to get this? They are available at TCI (tciauto.com) Bowtie overdrives (bowtieoverdrives), Summit Racing and JEGS

2. TH200-4R flex plate stone guard. Not sure what this is. Are you talking about the bottom cover under the torque converter? Yes, it's just a cover to keep debris out of the ring gear.

3. Dipstick & tube. I have a 200-4R from another car. Can I use the one that came with it? Yes, that should work.

4. PRND321 shifter lens and linkage (available from Nostalgic Motors). Pricey but I have talked to him about this. 

5. Lock-Up torque converter system (several ways of doing this, from a simple toggle switch to full electronic. I designed my own and will be happy to share the idea if you're interested) Would love to know about your idea and design. I'll work on a write up with a description and drawings. Basically it uses two vacuum switches and a relay.

Another thing you will need to check are the speedometer gears in your TH200-4R transmission. You may need to change one or both of them to get your speedometer to read correctly. Here's a link that should help: https://www.tciauto.com/speedometer-gear-calculator#2004R

[pantera928]

20 hours ago, AD said:

1. TV Cable and mounting bracket. Anywhere special to get this? They are available at TCI (tciauto.com) Bowtie overdrives (bowtieoverdrives), Summit Racing and JEGS

2. TH200-4R flex plate stone guard. Not sure what this is. Are you talking about the bottom cover under the torque converter? Yes, it's just a cover to keep debris out of the ring gear.

3. Dipstick & tube. I have a 200-4R from another car. Can I use the one that came with it? Yes, that should work.

4. PRND321 shifter lens and linkage (available from Nostalgic Motors). Pricey but I have talked to him about this. 

5. Lock-Up torque converter system (several ways of doing this, from a simple toggle switch to full electronic. I designed my own and will be happy to share the idea if you're interested) Would love to know about your idea and design. I'll work on a write up with a description and drawings. Basically it uses two vacuum switches and a relay.

Another thing you will need to check are the speedometer gears in your TH200-4R transmission. You may need to change one or both of them to get your speedometer to read correctly. Here's a link that should help: https://www.tciauto.com/speedometer-gear-calculator#2004R

Thanks

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