Cat D4H Torque converter overheating

I will post photos when I reassemble. Nige, do you have the parts listing for the resonator valve, my parts book does not show that valve.

Does this work..?

Perfect, thanks

Hi guys, problem solved! Installed new resonator base connector, spring, and plug, and just for safety sake blue lock-tite on the plug so it don't come loose again. Now my converter inlet pressure is 142 psi, converter outlet pressure is 55 psi, converter temp only went to about 170° after 30 mins of operation and worked flawlessly. I attached pics of resonator valve location and parts that I replaced - #20, 22, 24, & 25 of the above parts listing. I'm glad that I opted to replace the spring as the new one was about 1/8" longer that my original. I also posted a pic of my block off plate with the steer/brake & drivetrain supply pipe locations. I have to thank all of you for your help and input on this problem, it's been quite the learning experience. Cheers!

Test plate.

Not surprising that the old spring was tired if that valve bounces back and forth with the type of frequency I'm imagining.

Great read chaps with a good ending

Hello sirs.


I have same problem with my D4H Cat is overhesring, I did overhaul werror replaced seals, rings, even the spein, and special conector,...

And the temperature going on up...

Crisanta, I suggest you start a new thread -- and ALWAYS include your equipment (here, dozer) serial number with your inquiry. Kind regards from the U.S.

Hi guys, I'm back working on this dozer again. Pulled the trans earlier this week for tear down and inspection. Found the the 1st gear clutches toast and some of the piston seals have failed. Looking for the rebuild procedure for the planetary unit just to be sure it's reassembled correctly. Buying all new clutches and seals from Cat and would like to finish this up next week. Tried to get info from my local Cat dealer, but just like before they haven't been much help. Any help on this would be great.
Thanks Gary

Is this what you are looking for.?
If you want anything for the transmission control valve assembly it will be a separate document.

Yes, this will be great help. Thanks Nige

As The Wrench Turns said:

Yes, this will be great help. Thanks Nige

Click to expand...

I do not know if that is a welded converter or not. It is recommended to replace a welded converter after a clutch failure like that. Have drilled a hole and threaded for an 1/8 inch pipe plug. Then pressure washed the heck out of them. Would never do that with a machine that parts cost so much and are so labor intensive.
On a JCB I bought a converter from Perfection or Precision in Iowa. It worked great at 1/3 dealer cost.