shogun
02-20-2014, 06:39 PM
This shows the innards of the ZF4HP24, but basically same procedure for the others.
And another great story, valve body cleaning helps: quote
I've done it. After two years of investigating and waiting until I had another car to drive so I could tear into my 750 trans, I finally got it fixed. I had to go down the line of many potential problems that could have gotten in the way of it, but ultimately had to get into the valve body. And it was my first time doing an auto trans and I'm damn proud of what I came up with. I wanted to share this because these forums have helped me resolve numerous other issues that I've had along the way, and I thought it was time to give back.
As the beginning of this thread says, I've had two cars that were doing the same thing. The first worst than the second. The shifts in these cars were downright obnoxious. And I mean tooth loosening up and down shifts that were tearing my drivetrain apart.
Changing the fluids didn't do it, the trans switch didn't do it. Cleaning the abs sensors didn't do it. Ultimately, it was pulling the valve body down from the trans and cleaning one simple screen in the torque convertor lockdown solenoid that did it.
On a hunch, I took the valve body out of my parts car trans apart and found tons of what looked like dried, and clumped together, clutch band material in the solenoid in question. Here is what it looked like when I pulled it from the parts car.
http://i78.photobucket.com/albums/j101/vwleadfoot/null_zpsd94e37f4.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/null_zps0dcba936.jpg
Fast forward a few weeks, I dropped the valve body of my other car down and found the same solenoid to have the same crap in it. This solenoid is the ONLY one with a screen in it and apparently gets blocked up enough that the pressure to the torque convertor cannot be changed, therefore effecting the shifts. All you have to do is undo all of the larger bolts that hold the valve body to the trans, lower it down and pull the one solenoid as pictured here;
http://i78.photobucket.com/albums/j101/vwleadfoot/A806E794-CB03-4457-8C15-6D92729AD84B_zpsdwdrmccb.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/BDFD824D-0122-4ADE-B6C7-0B80F2DB5DEE_zpssuob5tm5.jpg
Clean the screen and put it back together. I put a new filter screen in it, and some Synthetic atf. Boom, I now have some beautiful shifts.
Pics of the patient, and the others in my collection, for posterity;
http://i78.photobucket.com/albums/j101/vwleadfoot/D8F08CD3-6B95-41EB-98E1-ACF2D9EB1A6F_zpsukvrht79.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/D3A0AB78-728C-48A3-877B-12710EBCE14B_zpsiidfxfkc.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/308220B5-81E1-4B54-BC55-FBA6671E47B1_zpstyathkbj.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/63B8569C-21B3-48B8-A0B1-535ECC5FEA6E_zpsldjsmipv.jpg
Special thanks to Shogun and all others that have chimed in here. You guys rock.
unquote
And another great story, valve body cleaning helps: quote
I've done it. After two years of investigating and waiting until I had another car to drive so I could tear into my 750 trans, I finally got it fixed. I had to go down the line of many potential problems that could have gotten in the way of it, but ultimately had to get into the valve body. And it was my first time doing an auto trans and I'm damn proud of what I came up with. I wanted to share this because these forums have helped me resolve numerous other issues that I've had along the way, and I thought it was time to give back.
As the beginning of this thread says, I've had two cars that were doing the same thing. The first worst than the second. The shifts in these cars were downright obnoxious. And I mean tooth loosening up and down shifts that were tearing my drivetrain apart.
Changing the fluids didn't do it, the trans switch didn't do it. Cleaning the abs sensors didn't do it. Ultimately, it was pulling the valve body down from the trans and cleaning one simple screen in the torque convertor lockdown solenoid that did it.
On a hunch, I took the valve body out of my parts car trans apart and found tons of what looked like dried, and clumped together, clutch band material in the solenoid in question. Here is what it looked like when I pulled it from the parts car.
http://i78.photobucket.com/albums/j101/vwleadfoot/null_zpsd94e37f4.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/null_zps0dcba936.jpg
Fast forward a few weeks, I dropped the valve body of my other car down and found the same solenoid to have the same crap in it. This solenoid is the ONLY one with a screen in it and apparently gets blocked up enough that the pressure to the torque convertor cannot be changed, therefore effecting the shifts. All you have to do is undo all of the larger bolts that hold the valve body to the trans, lower it down and pull the one solenoid as pictured here;
http://i78.photobucket.com/albums/j101/vwleadfoot/A806E794-CB03-4457-8C15-6D92729AD84B_zpsdwdrmccb.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/BDFD824D-0122-4ADE-B6C7-0B80F2DB5DEE_zpssuob5tm5.jpg
Clean the screen and put it back together. I put a new filter screen in it, and some Synthetic atf. Boom, I now have some beautiful shifts.
Pics of the patient, and the others in my collection, for posterity;
http://i78.photobucket.com/albums/j101/vwleadfoot/D8F08CD3-6B95-41EB-98E1-ACF2D9EB1A6F_zpsukvrht79.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/D3A0AB78-728C-48A3-877B-12710EBCE14B_zpsiidfxfkc.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/308220B5-81E1-4B54-BC55-FBA6671E47B1_zpstyathkbj.jpg
http://i78.photobucket.com/albums/j101/vwleadfoot/63B8569C-21B3-48B8-A0B1-535ECC5FEA6E_zpsldjsmipv.jpg
Special thanks to Shogun and all others that have chimed in here. You guys rock.
unquote