Pros and cons of transmission check valve delete

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Moparornocar0346

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Hello all I have a 99 Dodge Ram1500 4x4 automatic trans. Was just wondering. A friend of mine said that I should delete the check valve in my transmission line. Does this help a lot? What does it do? What r the pros and cons of this mod and where the heck is it located


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Fast69Mopar

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The "check valve" your friend is referring to is called the torque converter drain-back valve. What this check valve does is keep the fluid from draining out of the converter with the engine off. When the fluid drains from the converter after engine shutdown, what you will begin to experience is a delay in forward and reverse movement when you first start the engine and put the shifter in gear. The delay comes from the converter filing up with fluid. If you try to accelerate it acts like you have a 4000 stall converter and the engine RPM will flare up until the front pump has filled the converter with fluid again.

These check valves would start leaking around the metal hose crimps where the rubber hose is at and people would cut them out and splice in a new hose without a check valve. Then they would start noticing bthe RPM flare and think the transmission was slipping and bring it to the dealership with a trans complaint only to find the check valve had been removed.

My suggestion to you is to leave it intact and if it starts leaking then pick up a replacement.
 
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SportRam00

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I would delete it. The check valve has been the main suspect for causing the transmissions in these truck to fail. After a while they can get clogged with sludge and debris and can restrict the flow of the fluid through the trans cooler.

The check valve in my truck has been deleted and I have not noticed any adverse effects.
 
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Moparornocar0346

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I would delete it. The check valve has been the main suspect for causing the transmissions in these truck to fail. After a while they can get clogged with sludge and debris and can restrict the flow of the fluid through the trans cooler.

The check valve in my truck has been deleted and I have not noticed any adverse effects.

Well I thought about bc I looked it up and my truck still has the check valve and when I do first start the engine and put into gear it does seem like it has a stall in it. Now if I let it sit in neutral for a min and then take off it’s fine. But why would it be that way if I still have the check valve. Check valve possible stopped up? Am I looking at transmission problems? My fluid is new haven’t had this problem up til now


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SportRam00

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Yes, the trans pumps the fluid when its in neutral, so that's why the symptoms disappear when you sit in neutral for a minute or so. I would double check your fluid level to make sure you aren't low...

To check the fluid the trans needs to be up to operating temperature. The truck needs to be on a level surface and the trans needs to be check in neutral while the truck is idling.
 

G-Ride990

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I deleted the one in my 5.9 Dakota R/t. Supposed to help with trans temps and avoiding any issues from it getting clogged.

After the delete I needed to let the truck idle a bit longer and I would cycle from neutral to drive once or twice before the truck would move easily.

I only ever noticed that when the truck would sit for a few weeks at a time though. If you drive it everyday you shouldn't really notice it much. IMO no downsides to removing it.
 

EvilSpirit

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I would delete it. The check valve has been the main suspect for causing the transmissions in these truck to fail. After a while they can get clogged with sludge and debris and can restrict the flow of the fluid through the trans cooler.

The check valve in my truck has been deleted and I have not noticed any adverse effects.

It has been debated that another cause for the trans failures was actually that the lube holes in the intermediate shaft were too small, which overheated the fluid in the O/D unit and caused the trans failure. The overheating condition was creating faster wear and creating extra debris, which ended up in the check valve. The spec fluid was ATF +3, which is dino based and didn't take the extra heat created by the O/D unit. When they modified the intermediate shaft with larger coolant holes and went to the higher temp rated ATF +4 the trans failures lessened tremendously.

But in any case - if you remove it you will probably notice the engagement lag as been mentioned. I start my truck, then let it idle in neutral for about 15-20 seconds before I engage drive or reverse, no matter if I have removed the valve or not. Old habit.
 

DodgeTx

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I've removed two check valves on previous truck, one at a gas station my lowered ram. one on my old 4x4 2500. MY current 5.2l v8 had the check valve already removed.

On my lowered ram it had 201k miles and it was very restrictive caused the trans to overheat on a drive longer than an hour or so.

on the 4x4 truck 76k miles, I removed it as a precaution.

This new 5.2l truck was probably removed due to restriction it has 197k miles
 
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Moparornocar0346

Moparornocar0346

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I've removed two check valves on previous truck, one at a gas station my lowered ram. one on my old 4x4 2500. MY current 5.2l v8 had the check valve already removed.

On my lowered ram it had 201k miles and it was very restrictive caused the trans to overheat on a drive longer than an hour or so.

on the 4x4 truck 76k miles, I removed it as a precaution.

This new 5.2l truck was probably removed due to restriction it has 197k miles

Ok so in y’alls opinion should it be deleted or left alone or replaced


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DodgeTx

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If it works, don't mess with it until you need to. Keep a razor blade quick disconnects and some tools in the truck for long trips in case it clogs.
 

SportRam00

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IMO remove... Better to be safe. Once that debris clogs the valve up, it will overheat as the other guys said. The engagement lag issue is minimal (or non-existent in my case). There are a few write ups that are hopefully still floating around on various Dodge Ram sites that give a fairly comprehensive parts list on how to cleanly delete this valve.
 

Hereismylife

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What if you remove the valve and have remote start? Will it hurt letting it warm up for 5 - 10 min with the valve not there if it drains back since it only pumps back up in neutral?
 

97RedRam

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Hello, had to replace my 46RE with a remanufactured one. The TC antidrain valve is no longer available from Mopar or any parts outlets. If you have to rebuild or replace your transmission the only option is to remove the valve. All the transmission experts I have talked to tell me you should NEVER reuse the old valve with a rebuilt or replacement transmission.
 
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