Removing Check Valve on Dodge Transmission Oil Cooler Line

wdk450

Well-known member
Dodge Guys:
As most of us know the major subsystem with the poorest performance reputation on the Dodge Ram Trucks is the transmission. Today I bought Amsoil ATF and differential gear oil. I took the oil to a local mechanic I had not used before. He seemed knowlegeable on the Dodge trucks and transmissions, and was adamant along with the fluids changeouts to DRILL OUT THE CHECK VALVE IN THE LINE FROM THE TRANSMISSION TO THE TRANSMISSION OIL COOLER. I had never heard of this "fix" before, but have been reading recent posts on this forum about plumbing check valves sticking and causing problems. A sticking check valve in the line to the transmission cooler radiator would cause overheating of the transmission without you knowing about it. The mechanic said that he has done this on Chrysler products transmission systems many times and it prevents catastrophic failure.
Does anyone on this forum know about this modification? Does it have any side effects? (I found something online about the fluid possibly draining out of the torque converter, and having to wait a few seconds after you start it up, to put it in gear). Would you recommend doing this mod?

I am asking about this because I trusted the mechanic's expertise and experience, paid extra for the mod, but he ran late on time (and said another mechanic ran off with his "special" drill), and asked me to come back on Tuesday or Wednesday to get the check valve mod done. Now I am not sure.
 

wdk450

Well-known member
My answer to my Question. I consulted with my diesel truck performance shop and with a local transmission shop I have used before about the proposed mod. Both of them said that they had not seen Chrysler transmission failures due to overheating from a stuck check valve. The overall opinion on the side effects of the mod, both online and with the local experts, was that the torque convertor would empty of fluid while the vehicle was sitting. The online sources seemed to think that this was no big deal, but the transmission expert said that it wouldn't be good for the torque converter. Bottom line is I've got new premium Amsoil transmission fluid and a new transmission fluid filter. There should be no foreign substances to gum up the check valve, and with the premium fluid it should just work better. I am not going to opt for the check valve drill out mod.
 

westxsrt10

Perfict Senior Member
My 2 cts is beware using the Amsoil atf in the dodge transmission, it is not approved for the Dodge. (I was a Amsoil dealer for a few years) Amsoil 'reccomends' it but its not approved. ATF-4 is a semi-syn fluid made for the dodges clutches. The Amsoil ATF is too slippery and can cause problems. I never heard of stuck check valve issues but normally when a check valve fails it fails open.
 

Miles423

Member
I know I am a little late on this, but i have an 01 Ram 1500. I recently had my transmission rebuilt by my dad's friend. He advised me to remove the check valve. He told me that it can stick, but it isn't likely. So I had it removed. I had put about 500 miles on that new transmission before I had the valve removed and the transmission ran fine. So we removed the valve. On the 40 mile trip back to our house the transmission overheated. The valve must also regulate the flow of the oil through the cooler. We concluded that too much oil was going through the cooler so it overheated. Also, when I start my truck the oil pressure in the transmission doesn't rise as fast, so I have to put it in neutral and give it some gas a couple times. So I wouldn't advise anyone to remove the check valve. To fix the overheating there is a cooler kit that you can buy. It will come with a new cooler that you can mount, it would let the oil cool more before it returns to the transmission.
 

mattpopp

Trouble Maker
My 2 cts is beware using the Amsoil atf in the dodge transmission, it is not approved for the Dodge. (I was a Amsoil dealer for a few years) Amsoil 'reccomends' it but its not approved. ATF-4 is a semi-syn fluid made for the dodges clutches. The Amsoil ATF is too slippery and can cause problems. I never heard of stuck check valve issues but normally when a check valve fails it fails open.

I put Amsoil in my 04 3500 Dodge (Same trans as the op, 48RE) and within the next two weeks the Valve Body gave me issues. It was in and out of the shop a few times after that. That is not the first time I have heard of people having transmission issues with a 48RE after using Amsoil.

OP, Look up Dave Goerend (Goerend Transmission). Speak with him, He is in my opinion the very best at building a 48re in the US.
 

SilverRhino

Well-known member
OP, Look up Dave Goerend (Goerend Transmission). Speak with him, He is in my opinion the very best at building a 48re in the US.

I would whole heartedly agree!!

If you have a Dodge truck with an automatic transmission Dave is the person to talk to about any issues or modifications.....He even talked me out of buying one of his transmissions after I told him what my local tranny mechanic was going to do to mine.......He said that is exactly what they would do, so "save some money and have it done locally"! Great guy with a lot of knowledge.
 
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