727 low gear issue

[Stew1337]

Folks,
Hoping for some advice - I have 74 Plymouth satellite with 440 and a 727 with transbrake and full manual, purchased complete from Hughes, and have an issue when in low gear. First noticed when slowing and shift to low trans would occasionally "lock" with obvious result.
At track recently after burnout and moving forward in low if i took foot of throttle it would lock.
This is as if the transbrake is applying whilst moving, have removed connection to transbrake and still occurs. Tried multiple times to get feedback from Hughes, no reply - guess they got my money!
Any thoughts or advice appreciated

 

[Lefty71]

By Hughes you mean; http://www.hughesperformance.com/trans-solenoids/ correct?? Who did what? You bought just a Transbrake, and installed it yourself, or they did more for you?? What was the status of the trans before the Transbrake got installed, meaning in use in one of your cars? You know any history?

You could have broken a planetary or torn up the over-running clutch. If I were you, I would pull it down and check for any damage. If you are talking transbrake car, you are using enough horsepower to break stuff and hurt yourself. It might be as simple as the valvebody causing the problem, but I'd want to know for sure.

 

[Stew1337]

Complete new transmission with transbrake (part nujmber 22-3e) from hughes performance via Summit.
Installed and done run in miles only

 

[Lefty71]

Complete new transmission with transbrake (part nujmber 22-3e) from hughes performance via Summit.
Installed and done run in miles only

That sux.... But it sounds to me like if Hughes is not helping on the support end, and I would think this is really their problem, as you said. Maybe Summit can escalate your problem, and either get you an exchange unit, or get Hughes moving on it. I've seen them three way call (with you and hughes) to get some answers. There are several possibilities to your problem, but if it was created at the vendor's shop, it's the vendors problem, IMO. I do realize Australia makes it a special PIA. If you give up on that as a possibility, then you should get a repair manual and a 727 guide, such as this one;

https://www.amazon.com/Torqueflite-727-Transmission-Handbook-HP1399/dp/1557883998

Now the reason I would recommend that one is because it covers transbrake units.... read it carefully, do all in car tests you can, including pressure tests, as outlined in the book, then tear it down whilst bearing in mind your findings with the in car tests. Pressure readings will be higher, but you should be able to use the readings for comparison across the board. I trust you will find the offending issue, repair/replace and move on. Boo on Hughes!

Lefty71