RevMax 8 speed thermostat bypass

[crazykid1994]

I agree the instructions need to be revised,the option of pulling the thermostat by itself,needs to be removed,as it's not quite right
My company vehicle is in the shop today for some work,a day off yeehaw,lol. So i decided to play with the thermostat. The rod on the end is the key component,that uses a pellet thermostat to control it's length ,and it's removable. I'm not sure how a guy could defeat the pellet part of the thermostat,but if there's a way to defeat it,all it'd take is a longer push pin/rod to put the thermostat into the open position. But i don't know where you'd find a hardened pin the right length ,so between defeating the pellet and finding a longer pin,that option is probably out,lol.
Wifes not home,so i even borrowed one of her pots and tested the thermostat in boiling water.About 180F the pin was starting to move,and by 185 it looked to be fully extended,as even taking the water temperature to 210,didn't really extend the pin any further.

All it’s doing is pushing the plunger away from the plug to open flow to the radiator so it would not need much motion.

 

[crazykid1994]

I’m pretty proud of myself. However I would never recommend doing this to anyone... it was quick and easy but also a pain in the butt. In the last picture you can just barely see the plate sandwiches in there. You can do it on the truck but it’s messy. That oil heat exchanger really holds a lot of oil. I did not notice any loss from the transmission however. If it wasn’t for the battery ratchet than I would not have been able to do this in the truck. Unfortunately I won’t be taking the truck anywhere until my trip the following weekend.

 

[Wild one]

All it’s doing is pushing the plunger away from the plug to open flow to the radiator so it would not need much motion.

I think it would need probably a good 3/8" maybe more to put it into full flow to the cooler though.

 

[Wild one]

I’m pretty proud of myself. However I would never recommend doing this to anyone... it was quick and easy but also a pain in the butt. In the last picture you can just barely see the plate sandwiches in there. You can do it on the truck but it’s messy. That oil heat exchanger really holds a lot of oil. I did not notice any loss from the transmission however. If it wasn’t for the battery ratchet than I would not have been able to do this in the truck. Unfortunately I won’t be taking the truck anywhere until my trip the following weekend.

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That's good news. There is some differances between the early trucks and the later ones,as my assembly uses bolts to hold it to the transmission,while it looks like they've updated the later trucks to use studs to hold the unit to the transmission. I'm wondering it that's to combat the leaking issue that seems more prevalent on the earlier 8 speeds. Are you going to disconnect the coolant hoses at the the engine,or leave them hooked up Khristopher. I was looking at disconnecting them at the tranny,but they're a bit of a pain to get at in that location,with out dropping the tranny crossmember out so you can lower the ass end of the tranny and t-case to get a hand up on top of the thermal unit

 

[crazykid1994]

That's good news. There is some differances between the early trucks and the later ones,as my assembly uses bolts to hold it to the transmission,while it looks like they've updated the later trucks to use studs to hold the unit to the transmission. I'm wondering it that's to combat the leaking issue that seems more prevalent on the earlier 8 speeds. Are you going to disconnect the coolant hoses at the the engine,or leave them hooked up Khristopher. I was looking at disconnecting them at the tranny,but they're a bit of a pain to get at in that location,with out dropping the tranny crossmember out so you can lower the ass end of the tranny and t-case to get a hand up on top of the thermal unit

More than likely I’ll be deleting the hoses completely. It doesn’t look to hard. And the heater is separate. It’s actually held on by 5 bolts to the thermostat housing. The thermostat housing is held to the transmission by 3 other bolts separate of the heater core

 

[crazykid1994]

Noticed a mild oil drip. Hard to tell if it’s from the remaining oil in the heater core boiling out. Tried letting the truck get up to temp so I could check everything.

 

[Wild one]

More than likely I’ll be deleting the hoses completely. It doesn’t look to hard. And the heater is separate. It’s actually held on by 5 bolts to the thermostat housing. The thermostat housing is held to the transmission by 3 other bolts separate of the heater core

If you could get the heater off the thermal unit,the hoses would be a little easier to get at,but it looks like you can only swing it out a little bit,before it runs into the cast in coolant hoses.You'll want a decent pair of flexible hose clamp pliars to get at the clamps on top of the thermal unit. There might be enough room to get at the coolant hoses with the 3 bolts/studs removed,but i'm not sure.I know those hoses were a ***** to get at,when i replaced the tranny a few years back,but back then i didn't try getting at them with the thermal unit unbolted and floating,i removed them with the thermal unit still attached to the side of the transmission,and getting a hand up there to get the hose clamp pliars on the clamps,left some blood ,lol.

 

[caulk04]

Does anyone with the thermostat removed want to send it to me? I'd like to make a dummy plug that replicates the dimensions of the tstat when it's open. I've done this for my Harley to eliminate it as a failure point. Simply removing it in the Harley means the oil doesn't follow through the cooler, it routes around it.

I'd gladly give you the dummy plug for sending me your tstat.

 

[Wild one]

Does anyone with the thermostat removed want to send it to me? I'd like to make a dummy plug that replicates the dimensions of the tstat when it's open. I've done this for my Harley to eliminate it as a failure point. Simply removing it in the Harley means the oil doesn't follow through the cooler, it routes around it.

I'd gladly give you the dummy plug for sending me your tstat.

I'm in Alberta,where abouts are you,lol. It's actually pretty easy to pull the plastic plug,you need a T-40 Torx to undo the 2 bolts holding the shifter cable in place,the cable itself just pops/prys off the linkage,then you'll want to have a decent set of bent nose or 90 degree internal snap ring pliars to pop the snap ring out,the plug just pulls out. If you're trucks a 4X4,pulling the front shaft will give you more working room.

 

[Musky Mike]

So if I'm reading this right, only installing the blocking plate, the trans temp should be reduced ~20 degree. Blocking plate only, trans temps ~165-175.

 

[crazykid1994]

So if I'm reading this right, only installing the blocking plate, the trans temp should be reduced ~20 degree. Blocking plate only, trans temps ~165-175.

I have a concern about doing the blocking plate only. The blocking plate covers one route of oil flow. The thermostat blocks the other. If you don’t pull the thermostat then you won’t have oil flow till the thermostat opens but it’ll never open so you’ll never have oil flow and could fry the transmission.

 

[Wild one]

So if I'm reading this right, only installing the blocking plate, the trans temp should be reduced ~20 degree. Blocking plate only, trans temps ~165-175.

I agree with CrazyKid,i think you'd cook the tranny fairly quick with just the blocking plate. I think RevMax seriously needs to revise their options as both option #1 and option #2 will both cook the transmission eventually. After looking things over close,the only viable option is #3 where you remove the thermostat and install the block off plate

 

[caulk04]

I'm in Alberta,where abouts are you,lol. It's actually pretty easy to pull the plastic plug,you need a T-40 Torx to undo the 2 bolts holding the shifter cable in place,the cable itself just pops/prys off the linkage,then you'll want to have a decent set of bent nose or 90 degree internal snap ring pliars to pop the snap ring out,the plug just pulls out. If you're trucks a 4X4,pulling the front shaft will give you more working room.

I'm an hour or so south of Lake Erie, few hours below Niagara Falls. Middle of the PA/OH border, so pretty far from you.

I figured I could pull my own, but I really don't want to, to be honest. I'd have to do it at least twice since I don't possess the machinery to make the dummy/plug at home, I'd be doing it at work and my truck is my daily.

 

[Wild one]

I'm an hour or so south of Lake Erie, few hours below Niagara Falls. Middle of the PA/OH border, so pretty far from you.

I figured I could pull my own, but I really don't want to, to be honest. I'd have to do it at least twice since I don't possess the machinery to make the dummy/plug at home, I'd be doing it at work and my truck is my daily.

Plus the fact there's that damn border between us,lol. You might be able to talk CrazyKid into sending you his end plug to use though.

 

[caulk04]

I'm not looking for the end plug, I want the thermostat that's in there.

 

[crazykid1994]

@Wild one Heres an idea that just came to mind. Easy quick solution to the whole problem with removing everything. Someone could get a used thermostat housing and building a plug that actually reaches down into the thermostat hole with a second o ring towards the back that would seal off the heater core hole and only allow flow through the radiator. No removing the entire assembly. Unless of course the assembly is not round all the way back... “Facepalm”

@caulk04 What do you mean by dummy plug?

I'm not looking for the end plug, I want the thermostat that's in there.

Does anyone with the thermostat removed want to send it to me? I'd like to make a dummy plug that replicates the dimensions of the tstat when it's open. I've done this for my Harley to eliminate it as a failure point. Simply removing it in the Harley means the oil doesn't follow through the cooler, it routes around it.

I'd gladly give you the dummy plug for sending me your tstat.

 

[caulk04]

I'd do exactly what I did with my Harley.

Heat the thermostat up and take measurements of it when it opens up. Then make a solid plug (likely aluminum) that copies those dimensions. This way, the cooler/heater operate exactly as the factory designed it to when the trans is HOT. It would just trick the mechanical components into thinking it's hot all the time, if that makes sense.

If anyone isn't clear on how that thermostat works, the small plunger that fits down into the plastic plug will extend as the thermostat gets hot and opens, that pushes all the other parts down into the body of the heater which will open/close passages. I've not had my hands on one to see how they open/close and what the fluid paths are to see just how the flow is designed.

 

[Wild one]

I'd do exactly what I did with my Harley.

Heat the thermostat up and take measurements of it when it opens up. Then make a solid plug (likely aluminum) that copies those dimensions. This way, the cooler/heater operate exactly as the factory designed it to when the trans is HOT. It would just trick the mechanical components into thinking it's hot all the time, if that makes sense.

If anyone isn't clear on how that thermostat works, the small plunger that fits down into the plastic plug will extend as the thermostat gets hot and opens, that pushes all the other parts down into the body of the heater which will open/close passages. I've not had my hands on one to see how they open/close and what the fluid paths are to see just how the flow is designed.

That was sort of where i was going with defeating the pellet thermostat and extending the pin,only cause i don't have access to the tools to make a dummy plug,lol. I think you have a great idea Caulk. Khristopher would you be up to sending him your thermostat.

 

[Wild one]

@Wild one Heres an idea that just came to mind. Easy quick solution to the whole problem with removing everything. Someone could get a used thermostat housing and building a plug that actually reaches down into the thermostat hole with a second o ring towards the back that would seal off the heater core hole and only allow flow through the radiator. No removing the entire assembly. Unless of course the assembly is not round all the way back... “Facepalm”

@caulk04 What do you mean by dummy plug?

That's what Caulk was thinking of building,which i think is a great idea,but he needs the thermostat itself to work with.I'm a bit far away and north of the border,otherwise i'd send him my original thermostat,it's not doing anything but laying on my bench after i played around with it yesterday,lol

 

[caulk04]

If nothing else, it's something to satisfy my morbid curiosity. I have no intention of keeping the thermostat or doing any damage to it. It will be returned and I'll give the donor one of the dummies that I make.