Mishimoto transmission thermostat- preliminary review

[Dubstep Shep]

Ok ran through this thread again top to bottom. Is this just as simple as removing those 4 fittings to remove the old TBV and installing the Mishimoto in its place? There's no separate T-stat to buy or mess with somewhere else in the system/line/etc? Also, I dont see O-rings in the pic but imagine each of the 4 lines has it's own o-ring (that may need to be replaced if damaged)?

So assuming we lose no tranny fluid (b/c we do the install on the moon for example haha) - Only a total of 2 parts to buy: Mishi TBV + O-reilly or Harbor O-ring kit?

Yup, that simple. all four lines have their own O-Ring. I had to remove the bolt that holes the brace for the lines to get them out, but that was the only other thing. Be careful torquing the lines back on as well

Side note, I would get the O-Rings BEFORE you remove the OEM thermostat, that way you can avoid having to borrow your wifes car to drive to O'Reilly.

 

[Psifer]

Good up to ___ ponies?

I was told that it's good for over 1500hp. The factory input shaft is a weak point around 1200whp, and the factory converter mounting plate is good for around 1000whp.

The supposed weakest link in my drivetrain should now be the transfer case. Jon Sipple told me the TRX factory t-case holds up well to 1300whp. He offers no upgrades and said people rarely break them. I see that Pure offers a slight upgrade. If I run into issues, then I may look into Pure's rebuild kit.

Besides the TRX-specific transfer case, I would take all those numbers with some slight caution. I'm not sure if those power ratings are specific to a TRX. I would expect the TRX to be the most punishing on the transmission compared to the rest of Mopar's offerings.

 

[FULLTHROTTLERICK]

Yup, that simple. all four lines have their own O-Ring. I had to remove the bolt that holes the brace for the lines to get them out, but that was the only other thing. Be careful torquing the lines back on as well

Side note, I would get the O-Rings BEFORE you remove the OEM thermostat, that way you can avoid having to borrow your wifes car to drive to O'Reilly.

O-ring kit will be here tmrw from Oreilly! DId you have to find a way to hold the line with a channelock or smthin while torqing the lines back on?

 

[FULLTHROTTLERICK]

I was told that it's good for over 1500hp. The factory input shaft is a weak point around 1200whp, and the factory converter mounting plate is good for around 1000whp.

The supposed weakest link in my drivetrain should now be the transfer case. Jon Sipple told me the TRX factory t-case holds up well to 1300whp. He offers no upgrades and said people rarely break them. I see that Pure offers a slight upgrade. If I run into issues, then I may look into Pure's rebuild kit.

Besides the TRX-specific transfer case, I would take all those numbers with some slight caution. I'm not sure if those power ratings are specific to a TRX. I would expect the TRX to be the most punishing on the transmission compared to the rest of Mopar's offerings.

Dang bro i couldnt imagine my truck with 1000whp let alone 1200+ whp. I'd be lucky to put 550 down even with S&B/Predator with my current setup haha. What are you putting down again?

 

[Dubstep Shep]

O-ring kit will be here tmrw from Oreilly! DId you have to find a way to hold the line with a channelock or smthin while torqing the lines back on?

No, you just hold the thermostat housing while you torque it on. Doesn't take too much oomph, and make sure to lubricate your O-Rings when installing.

You'll need to visually match the O-Rings that come off to ones out of the kit. You can try to measure the cross section thickness, that's the most important to match, and then eyeball the overall diameter.

 

[Psifer]

Dang bro i couldnt imagine my truck with 1000whp let alone 1200+ whp. I'd be lucky to put 550 down even with S&B/Predator with my current setup haha. What are you putting down again?

I'm still breaking in the motor and trans, so I'm just on a base tune for now. I don't have any plans on dynoing it.

Here's a charger with a very similar setup to my TRX. They could squeeze more boost out of the Kong if they went to the smallest 2.35" upper and went to a 15% overdrive lower. I'm not quite sure how much power that would net them. The TRX will definitely have more drivetrain loss than the charger, so I won't be able to put up identical numbers. I do have a few extra mods, such as headers and an interchiller.

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[saturnfire]

O-ring kit will be here tmrw from Oreilly! DId you have to find a way to hold the line with a channelock or smthin while torqing the lines back on?

I am waiting for your step by Step YouTube video...getting the popcorn ready.

 

[ONEMEANTRX]

I did the bypass on the truck today went smooth o rings were bad I bought new ones and we will see if it leaks ....ill post some photos so far happy easy job I didn't take out the drive shaft can be done but tricky
defiantly need finesse not gorilla strength for this job
O and don't worry about leaking it dripped a few times thats it, half of a shot glass

I DID USE HARBER FREIGHT O RINGS SET fyi lol it worked for me

temp 167 transmission highest stop and go red lights traffic 92 degree out and 40% humidity
ill take it !

Hope this helps love having photos to see what it looks like before starting haha

 

[FULLTHROTTLERICK]

Yup, that simple. all four lines have their own O-Ring. I had to remove the bolt that holes the brace for the lines to get them out, but that was the only other thing. Be careful torquing the lines back on as well

Side note, I would get the O-Rings BEFORE you remove the OEM thermostat, that way you can avoid having to borrow your wifes car to drive to O'Reilly.

this the o-ring kit you got that worked right?

 

[FULLTHROTTLERICK]

No, you just hold the thermostat housing while you torque it on. Doesn't take too much oomph, and make sure to lubricate your O-Rings when installing.

You'll need to visually match the O-Rings that come off to ones out of the kit. You can try to measure the cross section thickness, that's the most important to match, and then eyeball the overall diameter.

Good stuff. Wud you lube ur rings with?

 

[FULLTHROTTLERICK]

I'm still breaking in the motor and trans, so I'm just on a base tune for now. I don't have any plans on dynoing it.

Here's a charger with a very similar setup to my TRX. They could squeeze more boost out of the Kong if they went to the smallest 2.35" upper and went to a 15% overdrive lower. I'm not quite sure how much power that would net them. The TRX will definitely have more drivetrain loss than the charger, so I won't be able to put up identical numbers. I do have a few extra mods, such as headers and an interchiller.

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SIIIICK!!!!

 

[FULLTHROTTLERICK]

I did the bypass on the truck today went smooth o rings were bad I bought new ones and we will see if it leaks ....ill post some photos so far happy easy job I didn't take out the drive shaft can be done but tricky
defiantly need finesse not gorilla strength for this job
O and don't worry about leaking it dripped a few times thats it, half of a shot glass

I DID USE HARBER FREIGHT O RINGS SET fyi lol it worked for me

temp 167 transmission highest stop and go red lights traffic 92 degree out and 40% humidity
ill take it !

Hope this helps love having photos to see what it looks like before starting haha

Always take pics/vids b4 I mess with anything for the 1st (or 2nd-3rd) time haha. Good stuff man!

 

[FULLTHROTTLERICK]

Ok so Here's a Q for the group:

If we assume they're going to replace my tranny under warranty soon, should I install the MIshi TBV BEFORE they replace the tranny? Ideally, i'd do it before so i know i'll have a full factory fill moving forward. BUT if there's any chance they pull the OEM line/thermostat/etc when they remove the old tranny, then obviously i dont want them to take my new shit lol.

Also, not sure if having the Mishi TBV in there will be a "red flag" for tranny warranty too. Doubtful they'd give me a hard time for that vs. everything else on the truck though

 

[OnTheReel]

Good stuff. Wud you lube ur rings with?

ATF works fine and it’s kinda right there…

Ok so Here's a Q for the group:

If we assume they're going to replace my tranny under warranty soon, should I install the MIshi TBV BEFORE they replace the tranny? Ideally, i'd do it before so i know i'll have a full factory fill moving forward. BUT if there's any chance they pull the OEM line/thermostat/etc when they remove the old tranny, then obviously i dont want them to take my new shit lol.

Also, not sure if having the Mishi TBV in there will be a "red flag" for tranny warranty too. Doubtful they'd give me a hard time for that vs. everything else on the truck though

I’d probably wait. Not because it’s really a warranty red flag. But on the off-chance that they want to replace the cooler lines (which the TBV comes as an assembly with from Mopar). Think they only do that in the case of a catastrophic failure but who knows.

At any rate, the fluid loss is so minimal after installing the Mishimoto it would be totally fine to install after the trans is replaced. PS, I’d be inclined to do a level check after they replace the transmission anyway…

 

[ONEMEANTRX]

Im sorry I added another photo of the size I though I did earlier re-edited the post

 

[Fifty]

Just an aside:
Oreilly sells that o-ring kit for $30.99

eBay and other places have it for $14.99

 

[FULLTHROTTLERICK]

ATF works fine and it’s kinda right there…

I’d probably wait. Not because it’s really a warranty red flag. But on the off-chance that they want to replace the cooler lines (which the TBV comes as an assembly with from Mopar). Think they only do that in the case of a catastrophic failure but who knows.

At any rate, the fluid loss is so minimal after installing the Mishimoto it would be totally fine to install after the trans is replaced. PS, I’d be inclined to do a level check after they replace the transmission anyway…

Good call, i'll wait on installing it. And the Level check aint a bad idea. But what I'd probably do is throw the Mishi TBV in and then just change the tranny oil around 10-15k or something just to give the new tranny the best possible chance at a happy life. Cooler temps + an early change to get the rif raf out (and to a superior oil) sounds like a decent plan!

 

[FULLTHROTTLERICK]

Just an aside:
Oreilly sells that o-ring kit for $30.99

eBay and other places have it for $14.99

Yep, i got smoked on it then haha. I always pull the trigger too fast & then do my research afterwards.

Turns out the ideal o-rings for our TBV are likely a different material & durometer then the Oreilly & harbor specials anyway. Assuming @ONEMEANTRX is on point with his size rec, these should be ideal so I've got em on the way: https://amzn.to/3IFaDaU

@OnTheReel what are your thoughts on those o-rings?

Pack of 100 o-rings coming so anyone who wants a few can send me 50c and a jawbreaker and i'll mail a few sets out

 

[OnTheReel]

Yep, i got smoked on it then haha. I always pull the trigger too fast & then do my research afterwards.

Turns out the ideal o-rings for our TBV are likely a different material & durometer then the Oreilly & harbor specials anyway. Assuming @ONEMEANTRX is on point with his size rec, these should be ideal so I've got em on the way: https://amzn.to/3IFaDaU

@OnTheReel what are your thoughts on those o-rings?

Pack of 100 o-rings coming so anyone who wants a few can send me 50c and a jawbreaker and i'll mail a few sets out

Viton is a great material choice. I just wound up using nitrile because it’s what I had on hand. No leaks or issues either way. Don’t overthink it too much!

 

[Dubstep Shep]

I did the bypass on the truck today went smooth o rings were bad I bought new ones and we will see if it leaks ....ill post some photos so far happy easy job I didn't take out the drive shaft can be done but tricky
defiantly need finesse not gorilla strength for this job
O and don't worry about leaking it dripped a few times thats it, half of a shot glass

I DID USE HARBER FREIGHT O RINGS SET fyi lol it worked for me

temp 167 transmission highest stop and go red lights traffic 92 degree out and 40% humidity
ill take it !

Hope this helps love having photos to see what it looks like before starting haha

Pretty much exactly what my OEM O-Rings looked like lol.

this the o-ring kit you got that worked right?

View attachment 151930

Yup!