I have the Spicer kits with new hardware for $70/delivered for forum members or a Britpart version for $32.

Or you could just get the rotoflex alone for $16

 

Thanks Erik,

What is the spicer kit? I was looking on the site but didn't see the Rotoflex

Is your genuine low temp thermostat the 180 degree version?

I installed a scangauge 2 today, running 204 - 209 degrees on surface streets, temp rose to 215 in the driveway, would like to bring that down some in order to preserve my second motor

 

This sounds like something other than a thermostat problem. Even the standard thermostat should have your truck cruising in the mid-190s. Remember, the cooling system is only as good as its weakest link.

That said, a friend of mine had an '04 that ran at temps like yours for years despite him replacing the thermostat, radiator, water pump and fan clutch. It may be that's the best you'll get. Those temps aren't dangerous to the engine despite the pissing contest on this forum about who can get the lowest temps.

 

Not to change the topic of my own thread... but where do I start my diagnosis?

The radiator, thermostat, belts, and water pump were all replaced by my mechanic at 72K - is there a chance he skipped the fan clutch?

Thermostat was done again with the motor replacement at 92K, currently at 102K

 

When the engine is hot, open the hood and spin the fan with your hand. If it spins a full rotation, the clutch needs to be replaced.

Perfect time to install an electric fan!

Have you verified the A/C fan is working?

Big picture is your truck should drop to the thermostat temp when you are cruising at >45mph. If it doesn't, you have an issue that's not the fan clutch.

 

Fan has plenty of resistance when hot, temperature maxes out at 216 when coming to a stop in traffic or the driveway, 206 - 211 while driving

 

that rotoflex isn't THAT bad...but sure why not.

definitely get that drive shaft rebuilt or buy another. Mine is a Tom Woods and i've had it rebuilt once.

couldve been cause I didn't grease it enough.

and lastly, DAMN! The underside of your truck is cleaaannnn...do you wash it or is it a pavement princess?

 

Although many will say it's within the normal operating temperature that to me is way to high. With the temperature range that you have when off-roading and under load I would be staring at my temp gauge the whole time and not having a good day.

Anything over 205 and there better be a good reason why it's spiking like climbing up hill with rev's in the 3k+ for a good period of time. Other than that you should be from 195-205 with a increase only under load.

I would recommend removing the radiator and have it flushed at a local shop. Usually costs around 25 dollars and has proven great results. Changing the thermostat is recommended but not needed with those temps.

As far as the roto flex I would purchase a new oem one and keep the current one as a spare like everyone else has mentioned.

 

Yeah I agree with the pissing contest on low temps. I have done so many comparisions and test here in TX. 35-60MPH with an OEM 180F will get you cruising around in the upper 180's for sure, but once out on the expressway temps are going to rise from 60MPH and up. What happens is eventually you're creating more heat than the radiator/cooling system can regulate. It comes from a rather small grill opening, small radiator, and it's just the nature of the beast. As long as you aren't passing 205F out on the open road your fine. If at idle the temps spike I'd look into replacing your fan clutch. As not cooling properly at idle is a sign of a weak fan clutch not pulling enough air thru the radiator. At speed the fan clutch isn't as needed as you've got air passing thru at speed.

Either install a Saudi Grill, a 180F OEM thermostat, or get into a crash cause you were eyeballing engine temps like a crazy person. I glance at my temps from time to time, but I'm not concerned unless I see anything past 205F.

Here in TX once ya turn off the engine heatsoak sets in and you can see temps 205-210F until the engine is running again. No gaskets blew, no heads warped, and no engine damage was done either.

 

So is his rotoflex really not that bad?

I purchased the Rover's North aftermarket variant (not sure of the brand, but the price was good. It seems a bit thinner than OEM) and was going to replace mine this winter.

Mine is showing some surface cracking, but nothing like the OPs. Now I'm thinking it might be best just to store it as a spare and see how long the original will last?

Do they fail suddenly, or are there indications prior to failure (such as cracking worse than the OP?)