TH400 Converter Charge Pressure Reduction - LS Swap S10

[@djrowe10]

Just watched this and had a few things to help you out. The hole size is dictated by psi of trans and size of stall either NA or Turbo. That range is usually (.110-.150). Set scew can be threaded into nut and placed in vice instead of wood. Always use brass set screws in pump converter feed hole simply because if you need to drill larger hole in future is easier and I have seen hardened set screws crack brittle pump passages. Amazon and eBay sell them from a pair at $5 or 100 pack at $40. The cost of 2-5 hardened drill bits is more the brass screws. The converter feed hole doesn't need drilled out when you use brass either since brass is soft and threads will smash in perfectly made from tap. Plus only run tap down hole like a few threads and it will create a stop for screw like NPT fitting. Last thing to mention is cleaning out pump holes from metal shavings which putting grease on tap will keep some debries on it. I'm thinking of creating a KZbin channel just for transmission work since nowadays seems to be more interest. I had a video 10 years ago but the old shop didn't want recording done during work hours. Now I have my own business so will see about making one now. Good luck with your build!👍🏼

[@dtperformance256]

djrowe10 Man!! Thanks for the information!!! I had thought about using brass but those set screws weren’t readily available when I did this. I will order some and keep them on hand for sure now. That makes a lot more sense to be able to easily drill the hole out. I had a hard time drilling the set screws I had. I even heated one or two and quenched them in oil to retemper the steel where I could drill them. This was after I already drilled one out. I was looking for an easier way to drill them out in the future, but now I will go with brass. You should definitely start your channel back up. If you do, let me know the name and I will subscribe for sure. With the information you have shared with me I am sure everyone else would like to see/hear it as well. Thanks again for watching and sharing your experience in the comments. I am not a transmission guy, but I am learning to be and am enjoying the process. Thanks again!!!!!

[@yourpcmd]

Wow! 2 videos back to back, you're spoiling me, brother. That is a crucial bit of information for those using TH400's for LS swaps. I wonder if the same should be done for the TH350?

[@dtperformance256]

@yourpcmd Yeah I have been getting things caught up at home. Gives me more truck time. Not sure if TH350’s have the same issue. I read multiple articles and watched many KZbin videos where this is a big problem on the 400’s and the 7/64” orifice is the fix.

[@jeffallen3382]

You dont test pressure with the cooler line ports. There is a pressure teat port on the drivers side of the case that is used. This is a 1/8th npt theeaded port.

[@dtperformance256]

@jeffallen3382 Thanks for the correction. I am learning how to work on the TH400 and I saw where someone said one of the cooler ports was pressure and one was return. Thanks for letting me know and thanks for watching! I will go back and make the correction in the video!

[@jeffallen3382]

@@dtperformance256 no problem! Technically there is a pressure and return on those cooler line ports. But those are not what's used for diagnosis of the transmission "pressure" circuit.

[@dtperformance256]

@jeffallen3382 Good to know. Thanks again for commenting. I picked that info up from someone else and I didn’t think that one of the cooler lines had that much pressure on it, but again I didn’t know and was trusting of what they told me. What you are saying makes more sense to me. I dont want to give out incorrect information so I really appreciate it!

[@jeffallen3382]

@@dtperformance256 you're welcome!

[@dtperformance256]

@jeffallen3382 I got the video edited and found a pdf of the ATSG TH400 manual that details the port to check pressure. Thank God for people like you that are helpful and not jumping on here to beat me up. Again, I appreciate the info Jeff.