Boost valve upgrade on high mileage 4l60e

[mdmcinti]

Hey everyone. I wanted to make some minor improvements to my tranny keep it running as long as possible. I think it’s the original tranny at 241k miles. I was planning on doing a vette servo and a 4th gear servo, but I was reading about boost valves and seeing the benefit of bumping up line pressure. I found a sonnax boost valve that has o rings and is the stock diameter size to compensate for the walls on the pump wearing overtime. I was thinking of doing this to restore stock pressure because I read a .490 size boost valve will kill the tranny. The transmission works fine and is not slipping. It shifts great and the fluid looks like it has been changed before because it’s red in color and does not smell burnt. I know it was changed because it is high on the dipstick line. I have done the same thing in previous trucks when topping the tranny off after changing the fluid and filter and then running it through the gears on initial startup and putting in a little too much fluid. Also as for a fluid change, should I just do pan and filter, or should I do the method where you pull the cooler line and have the Tammy pump the fluid out on its own? I just hate the slush box shifts these things have from the factory.

 

[Tonyrodz]

Hey everyone. I wanted to make some minor improvements to my tranny keep it running as long as possible. I think it’s the original tranny at 241k miles. I was planning on doing a vette servo and a 4th gear servo, but I was reading about boost valves and seeing the benefit of bumping up line pressure. I found a sonnax boost valve that has o rings and is the stock diameter size to compensate for the walls on the pump wearing overtime. I was thinking of doing this to restore stock pressure because I read a .490 size boost valve will kill the tranny. The transmission works fine and is not slipping. It shifts great and the fluid looks like it has been changed before because it’s red in color and does not smell burnt. I know it was changed because it is high on the dipstick line. I have done the same thing in previous trucks when topping the tranny off after changing the fluid and filter and then running it through the gears on initial startup and putting in a little too much fluid. Also as for a fluid change, should I just do pan and filter, or should I do the method where you pull the cooler line and have the Tammy pump the fluid out on its own? I just hate the slush box shifts these things have from the factory.

I changed the fluid in my work van by cracking open the cooler line and letting it run out that way. It has the 4l80 in it. But 1st I drained the fluid in the pan and changed the filter and cleaned the magnet.

 

[mdmcinti]

I changed the fluid in my work van by cracking open the cooler line and letting it run out that way. It has the 4l80 in it. But 1st I drained the fluid in the pan and changed the filter and cleaned the magnet.

Are there a lot of miles on the tranny in the van?

 

[Tonyrodz]

Are there a lot of miles on the tranny in the van?

At the time around 140k. No ill issues--at the time.

 

[mdmcinti]

At the time around 140k. No ill issues--at the time.

Well mine has about 100k more lol. I heard mixed reviews of the pump fluid exchange vs pan drop and filter change at very high miles.

 

[Tonyrodz]

Well mine has about 100k more lol. I heard mixed reviews of the pump fluid exchange vs pan drop and filter change at very high miles.

I have too. Some people trust the procedure, some don't. As long as you don't let it run dry as the trans pump is running, I think it would be ok. Just my opinion tho.