Boost valve

[LTLux]

Was going to do a little tune up on the trans and was doing some research. I saw an old GM bulletin about needing to change the Transmission Boost Valve on the 4L60E transmission at 50,000 or 60,000 miles.

Does anyone know about this or have you changed it when you dropped the trans pan? Its supposed to be easy to change once the pan is dropped.

 

[LTLux]

Anyone?

I will try and dig up the GM anouncement and I know it was from awhile ago but it was for the 4L60E.

 

[Regency]

That's the 4 speed right?

 

[LTLux]

Yes, I have an 07 with a 4 speed. It seems like I saw a post somewhere and they said that they always replace the boost valve for longer life and that they can fail and screw up transmission.

The problem is I cant find much online and it seems like Sonnax is the only company that makes these valves. I think I might give them a call in the morning and see what they say.

 

[fire730]

Yes a boost valve can wear out. Im not sure about how long they typically last but Ive seen significant enough wear on them at 80k miles. My buddy changes them on every rebuild and sometimes during fluid changes just to keep the tranny operating properly.

Sonnax is definitely the best if not the only manufacturer of problem solving parts for transmissions. Apparently TCI makes them also but I would go with Sonnax.
http://www.tciauto.com/tc/4l60e-4l65e-490-inch-diameter-boost-valve-with-o-rings.html

And it's not too difficult to change. It's just held in by a snap ring in the pump housing.

 

[LTLux]

Alright, talked to Sonnax and transmission place and guess what, in order to change this on the newer models 07 and up, you have to drop the whole transmission and take the pump out. The older models you could just drop the pan and change it but not anymore.

My trans guy said if you are doing that you would need to change the pump as well to keep the pressure correct and if you are doing that, you might as well do a whole rebuild.

So, looks like I will be chaging filter and fluid only. I hope GM started to make these boost valves better and I dont start to have problems.

 

[fire730]

Alright, talked to Sonnax and transmission place and guess what, in order to change this on the newer models 07 and up, you have to drop the whole transmission and take the pump out. The older models you could just drop the pan and change it but not anymore.

My trans guy said if you are doing that you would need to change the pump as well to keep the pressure correct and if you are doing that, you might as well do a whole rebuild.

So, looks like I will be chaging filter and fluid only. I hope GM started to make these boost valves better and I dont start to have problems.

I didn't know that about the boost valve. All the 4l60Es I've fooled with have been in NBS or older.

 

[Regency]

That's crazy would rather get a new transmission