ATS transmission thermal bypass valve

[Drumminguy81]

I havent seen many posts about these just wanted to see what peoples opinions are. Has anyone replaced the Thermal Bypass valve on their truck with an ATS or similar? I have an AISIN so not a huge concern with temps, im mainly considering it because I will be doing my 60k trans service soon swapping this valve would make it easier to drain all of the fluid and it would be a good time to swap it. its only $100 and doesnt seem like there is any negative to swapping it.. not sure how it would effect my warranty.. chime in if you have any experience with them or an opinion.

 

[AH64ID]

Unless you’re always towing in a hot climate the negative is that your transmission will never reach operating temp.

 

[joshuaeb09]

I've never heard of one on an Aisin getting stuck like RFE's where the converter can dump a lot of trash (still not super common for one to stick). Down here in the heat I run the PPE delete and deep pan on my 68RFE with zero issues, gets up to temp just fine, and does run a bit cooler under certain loaded conditions. Even when we do get a cold snap I don't really have warm up issues as the grill shutters seem to do their job, but we don't get that brutal cold like folks further north do.

Know a few tranny rebuilders many of them always say the valve is stupid on the RFE's, but again we're a hot climate and RFE's ain't exactly stout transmissions. They can be built up and the '19+ ones are a bit better, but heat is still very much the enemy of these things per the guys I've talked to that rebuild the things all the time. When it comes to the Aisin's I don't hear much of anything which should tell you something there. I know of a few folks down here that do heavy pulling in the heat who run one of the various delete blocks on their Aisins, but these guys are working the trucks day in and day out with heavy loads and well outside of warranty.

 

[Brutal_HO]

In 60K have you ever been concerned about the trans temp?

That said, I think if Mishimoto made one for the current AS69RC, I might consider it, but installing one without a removable thermostat is a non starter for me.

Pull 16K in the mountain west and through traffic and never once had a concern with the Aisin temps.

 

[H3LZSN1P3R]

RFE's ain't exactly stout transmissions. They can be built up and the '19+ ones are a bit better,

Simple trans tuning or the protect 68 plate and line pressure booster allows the 68RFE to hold 550HP they are not a bad trans at all. They get a bad name due to the very early valve body issues from 07.5-09. Then you get the people putting large tires on the 4th gen 3.42 gears and adding power but no trans tuning which cooks the OD clutches. Just like the 48re if abused they don't last but taken care of they have almost no issues

 

[IndyRamMega]

Unless you’re always towing in a hot climate the negative is that your transmission will never reach operating temp.

Not true....do you know what the operating temp range is?

 

[IndyRamMega]

I havent seen many posts about these just wanted to see what peoples opinions are. Has anyone replaced the Thermal Bypass valve on their truck with an ATS or similar? I have an AISIN so not a huge concern with temps, im mainly considering it because I will be doing my 60k trans service soon swapping this valve would make it easier to drain all of the fluid and it would be a good time to swap it. its only $100 and doesnt seem like there is any negative to swapping it.. not sure how it would effect my warranty.. chime in if you have any experience with them or an opinion.

My opinion is put one in....had one in my 22 HO....temps stayed in the 140's....on my 21 SO...they stay around 130-145 unless I'm doing a lot of stop and go....they are great for a tow rig tho.....

 

[AH64ID]

Not true....do you know what the operating temp range is?

Ram specs state the normal operating temp is 180°. Your posted temps match what I’ve seen in person, temps don’t reach normal operating temp.

 

[IndyRamMega]

Ram specs state the normal operating temp is 180°. Your posted temps match what I’ve seen in person, temps don’t reach normal operating temp.

So if his Aisin hits 165 and stays there with the factory block.....for the life of the truck it never gets up to temp.....

 

[AH64ID]

So if his Aisin hits 165 and stays there with the factory block.....for the life of the truck it never gets up to temp.....

180° is what Ram publishes in the FSM as normal, but they also state normal temp range for checking fluid level is 158°-176°.

It’s not difficult to get an Aisin to 180°, so the “life of the truck” is a pretty extreme and unrealistic statement.

It’s not any different than coolant temp. The thermostat is a 190° thermostat, but when working the truck hard 207°-215° is normal. Don’t ever work it hard and 190° is also normal.

 

[John Jensen]

180° is what Ram publishes in the FSM as normal, but they also state normal temp range for checking fluid level is 158°-176°.

It’s not difficult to get an Aisin to 180°, so the “life of the truck” is a pretty extreme and unrealistic statement.

It’s not any different than coolant temp. The thermostat is a 190° thermostat, but when working the truck hard 207°-215° is normal. Don’t ever work it hard and 190° is also normal.

I can't agree with, "It’s not difficult to get an Aisin to 180°". Pulling my 9900 lb vacation trailer, in 99 degrees weather, at 65 mph, up a 7 mile, 6-8% grade it will stay at 63 degrees and top out at 165 degrees. How do you get one to 180 degrees?

There's disagreement about installing a bypass valve on an Aisin. I would agree, it doesn't need it but I believe most install the valve because the factory valve has been known to fail. I haven't read or heard of any damage to an Aisin with the valve, so it seems like a good idea.

 

[tchur1]

I can't agree with, "It’s not difficult to get an Aisin to 180°". Pulling my 9900 lb vacation trailer, in 99 degrees weather, at 65 mph, up a 7 mile, 6-8% grade it will stay at 63 degrees and top out at 165 degrees. How do you get one to 180 degrees?

There's disagreement about installing a bypass valve on an Aisin. I would agree, it doesn't need it but I believe most install the valve because the factory valve has been known to fail. I haven't read or heard of any damage to an Aisin with the valve, so it seems like a good idea.

I would agree with this based on my personal experience. Pulling 10k in the sierras I never see my trans get over 167*. The only time iver ever seen it get above 180* was driving in stop and go traffic in the pac heights neighborhood of San Francisco. Where I was constantly stopping and starting and never got over 20 MPH so the torque converter wouldnt lock and it was creating a lot of heat.

Other than that, its never gone over 167*, towing or not.

 

[AH64ID]

It’s pretty easy given the proper conditions. Do some towing under 20 mph where the torque converter doesn’t lock. It’ll get to 180° very easily, even 200° if you’re not ERS in 1st.

Stop and go does the same thing.

Once the torque converter is locked they cool down and hold 165-167° all day.

 

[jetrinka]

It’s pretty easy give the proper conditions. Do some towing under 20 mph where the torque converter doesn’t lock. It’ll get to 180° very easily, even 200° if you’re not ERS in 1st.

Stop and go does the same thing.

Once the torque converter is locked they cool down and hold 165-167° all day.

^^^This^^^

Torque converter slip makes lots of heat.

 

[Drumminguy81]

I appreciate the feedback from all. Was hoping for anyone who has experience with the bypass to chime in. I personally have seen my aisin in the 200 range a couple times towing 10k up extremely steep grades going fairly slow or varying 15-35mph speeds with switchbacks on the million dollar highway between durango and silverton. Most of my towing is in the san juans or south rockies. But I agree in all normal conditions 168 is typical. I wouldn't say I'm concerned with the Temps so much as the fact that I'll be draining my tranmy fluid anyway so is it worth swapping the part while I'm there?

Sent from my SM-S918U using Tapatalk

 

[AH64ID]

At 200° the thermostat is wide open, so removing it wouldn’t have any impact on temps. Your torque converter unlocked driving would get you just as hot.

Per the owners manual you should downshift to 1st below 20 mph to keep temps down, and it works.

Above 25 you should be able to get the tq converter to lock in 2nd and temps will rapidly drop.

I do lots of similar driving/towing and don’t feel the thermostat bypass is a worthy use of my money. I do swap out the conventional ASRC for a synthetic that is ASRC compatible, and that makes me feel a little better about the temps. All in all, I haven’t seen temps that bother me yet.

 

[IndyRamMega]

I appreciate the feedback from all. Was hoping for anyone who has experience with the bypass to chime in. I personally have seen my aisin in the 200 range a couple times towing 10k up extremely steep grades going fairly slow or varying 15-35mph speeds with switchbacks on the million dollar highway between durango and silverton. Most of my towing is in the san juans or south rockies. But I agree in all normal conditions 168 is typical. I wouldn't say I'm concerned with the Temps so much as the fact that I'll be draining my tranmy fluid anyway so is it worth swapping the part while I'm there?

Sent from my SM-S918U using Tapatalk

Unlike the naysayers....I do have experience with it...your temps will start down around 135...instead of 165....when your 165 climbs to 185....with the block installed you'd be at 155...you'll appreciate the cooler temps....you get a built trans from ats or revmax and they suggest you put one in...they suggest it even if your trans isnt built....and like you...I've pulled those passes with almost 10k hooked to my rig....east of Montrose there was a serious pass that took us up to like almost 13k or so...I didn't think that climb was ever going to end....

 

[AH64ID]

Unlike the naysayers....I do have experience with it...your temps will start down around 135...instead of 165....when your 165 climbs to 185....with the block installed you'd be at 155...you'll appreciate the cooler temps....you get a built trans from ats or revmax and they suggest you put one in...they suggest it even if your trans isnt built....

The point is to not start at 135°…. But your truck, your money.

Lots of companies survive off of selling parts for problems than don’t exist.

There are also plenty of aftermarket parts that improve upon OEM stuff, this just isn’t one of them.

 

[IndyRamMega]

Of course you have the data backing your claim....post it up or leave the conversation to those of us with experience with the part in question....in your spare time you could write all the companies that make these and tell them how they are destroying trucks.....just a suggestion....

The point is to not start at 135°…. But your truck, your money.

Lots of companies survive off of selling parts for problems than don’t exist.

There are also plenty of aftermarket parts that improve upon OEM stuff, this just isn’t one of them.

 

[IndyRamMega]

Didn't think so....