66RFE Sonnax Thermal Bypass Eliminator Kit

[PowaaaWagoon]

Has anyone installed or heard of success when using the Sonnax thermal bypass eliminator kit? It just looks to be a cartridge valve swap while retaining the OEM body.

I have warranty for another 3 years and don’t want to install an ATS or REV if that’s what they’ll use as a reason to void it when they see an aftermarket part bolted on.

My hesitation on trying this comes from a thread that I can’t find anymore which had pictures of the OEM valve body ports showing how big of a restriction to flow there is and I’m wondering if that was in the valve cartridge that would be swapped out with this Sonnax part or if the restriction is in the port sizing of the body itself?

https://www.sonnax.com/parts/5458-thermal-bypass-eliminator-kit

 

[HEMIMANN]

I had warranty too and put RevMax bypass in. This part prolongs transmission life - not shortens it.

The OEM valve body has a thermostat in it. I don't know what Sonnax did, but RevMax and ATS gives you a new valve body with NOTHING in it - in essence, no valve body was ever needed to begin with, but the oil cooler hoses were already cut to length for the OEM valve body, so to re-use the hoses a bogus retrofit valve body is necessary.

The overly-small OEM thermostat, even when working, is also part of the lack of transmission oil cooling. This is obvious when you look at the diameter of the hoses compared to the tiny thermostat housing orifice. It's a flow restrictor. And the thermostat fails as well. A horrendous design I never would have allowed my engineers to forward to production. It seems obvious to me they found an oil thermostat and just went with it - regardless of heat transfer requirements.

 

[Burla]

Save the old block, if the trans tanks, put it back before taking it in....

 

[PowaaaWagoon]

I had warranty too and put RevMax bypass in. This part prolongs transmission life - not shortens it.

The OEM valve body has a thermostat in it. I don't know what Sonnax did, but RevMax and ATS gives you a new valve body with NOTHING in it - in essence, no valve body was ever needed to begin with, but the oil cooler hoses were already cut to length for the OEM valve body, so to re-use the hoses a bogus retrofit valve body is necessary.

The overly-small OEM thermostat, even when working, is also part of the lack of transmission oil cooling. This is obvious when you look at the diameter of the hoses compared to the tiny thermostat housing orifice. It's a flow restrictor. And the thermostat fails as well. A horrendous design I never would have allowed my engineers to forward to production. It seems obvious to me they found an oil thermostat and just went with it - regardless of heat transfer requirements.

No doubt at all that the OEM unit is garbage and not needed. I guess my big hesitation lies with the warranty person saying otherwise… any loophole they can find, they’ll use it. I had them try to reject a warranty on my Jeep because I had a more aggressive tread on the new tires and they were Toyo instead of OEM. Ridiculous.

 

[HEMIMANN]

No doubt at all that the OEM unit is garbage and not needed. I guess my big hesitation lies with the warranty person saying otherwise… any loophole they can find, they’ll use it. I had them try to reject a warranty on my Jeep because I had a more aggressive tread on the new tires and they were Toyo instead of OEM. Ridiculous.

You have access to other dealers that might be better?
A guy's gotta have a reliable truck, too!

 

[PowaaaWagoon]

Save the old block, if the trans tanks, put it back before taking it in....

… genius. I feel dumb, haha thank you!

Side note - your posts regarding oils are gospel.

 

[PowaaaWagoon]

You have access to other dealers that might be better?
A guy's gotta have a reliable truck, too!

The warranty on the truck is third party so I may inquire to see if a certified shop can diagnose or fix issues instead of the dealer. There’s a few good shops in town I’d love to use if I could.

 

[HEMIMANN]

The warranty on the truck is third party so I may inquire to see if a certified shop can diagnose or fix issues instead of the dealer. There’s a few good shops in town I’d love to use if I could.

I only use my local private shop for larger routine maintenance work. Never a dealer, and certainly never for oil changes. No quickie lube places, either. Notorious for critical errors and obnoxious upselling.

 

[PowaaaWagoon]

I only use my local private shop for larger routine maintenance work. Never a dealer, and certainly never for oil changes. No quickie lube places, either. Notorious for critical errors and obnoxious upselling.

Absolutely. Avoid dealership at all cost… I’d use a shop for setting up new gears in the diffs etc., but I’m tooled up and capable of most anything else.

Plus I got two young boys that follow me around like shadows and are more than happy to learn and help… it only extends the job completion time by a few days or so… /s