LML fan clutch on an LLY?

[Kevan]

Anyone know if it's possible to swap out the stock LLY fan clutch for one meant for an LML? I believe the LLY ECM has a temp trigger circuit, if i've read it right; just means adding the appropriate pin(s) to the ECM connector for triggering the clutch in & out?

Reason i ask is because i tow a big-ass horse trailer with my '05, i don't push it hard but we have some 13% grades around here & in the summer i usually end up stopping part way up & waiting for things to cool off. Running a CTS2, keep in the mild tow tune setting, put in a cold air intake, changed the turbo inlet, put in a Mishimoto rad last summer (which did virtually nothing) ... the stock fan hub doesn't kick in until 220 or higher, by then it's just too hot to cool down. I'm thinking since the LML fan clutch is electronically controlled, i could put a manual over-ride switch in & get the fan turning earlier, or just program it come on sooner.

 

[DAVe3283]

I've been toying with the same idea, but I'm not sure if they physically interchange.

You can get a lower temp fan clutch for your LLY and that should help. I put a Hayden in my LB7 and it made a big difference.

Kennedy Diesel sells a low temp unit that's supposed to be better than the Hayden even: https://www.kennedydiesel.com/categoryresults2.cfm?Category=3&SubCategory=209

If you do end up fitting a LML fan clutch, please post up how it all goes. I'm curious!

Sent from my FlashScan V2 using Tapatalk

 

[Bdsankey]

Have you tried the Kennedy fan clutch yet? It's a MAJOR improvement over the OEM clutch.

 

[Chevy1925]

iirc the LML fan clutch is PWM controlled, not sure how it would do on a full 12v for an extended period?

I would put a Kennedy fan clutch on and call it good. Also, pull the mishimoto radiator, put a stock one back in and sell the mishimoto before your's starts to leak. its not a matter of "if" but "when" with those radiators.

 

[gmduramax]

Define cold air intake? It needs to be sealed and pulling air from a cool source. Also cutting a hole in the middle of the hood will drastically reduce temperatures.

 

[THEFERMANATOR]

The 09 van fan and fan clutch will directly interchange with the lb7/lly fan clutch. It is an evc design like the lml. Several 6.5 guys have swapped them in and use a temp sensor in the head to trigger a relay to engage it. You will have about a 20-30 second lag in this setup from when it is triggered until it locks up. The evc clutch uses a pwm signal to engage a heating element inside the fan clutch to engage it. There are pwm controllers out there for electric fans thatat I would think would do a better job controlling them. The 6.5 guys that have run them said they are night and day better than a standard viscous clutch.

It's a long thread and covers a couple of different evc's. I personally use the kennedy fan clutch in mine.

Electric Fan clutch

So for those who want accurate fan clutch engagement this could be for you. I know on my 96 the fan clutch has never engaged the entire time I've owned it. Living in cooler climates does have it's advantages. I even tried modding the spring to no avail. This clutch will only work with the spin...

www.thetruckstop.us

 

[Kevan]

The 09 van fan and fan clutch will directly interchange with the lb7/lly fan clutch. It is an evc design like the lml. Several 6.5 guys have swapped them in and use a temp sensor in the head to trigger a relay to engage it. You will have about a 20-30 second lag in this setup from when it is triggered until it locks up. The evc clutch uses a pwm signal to engage a heating element inside the fan clutch to engage it. There are pwm controllers out there for electric fans thatat I would think would do a better job controlling them. The 6.5 guys that have run them said they are night and day better than a standard viscous clutch.

It's a long thread and covers a couple of different evc's. I personally use the kennedy fan clutch in mine.

Electric Fan clutch

So for those who want accurate fan clutch engagement this could be for you. I know on my 96 the fan clutch has never engaged the entire time I've owned it. Living in cooler climates does have it's advantages. I even tried modding the spring to no avail. This clutch will only work with the spin...

www.thetruckstop.us

The reason for going with an electric option is to provide a manual over-ride. This sounds like the ticket; more homework ... thanks for the lead!

 

[NevadaLLY]

I put in a Hayden and towed 20K over some 7% grades (7mi long) at 98deg and it seemed to do well. Did you try kennedy? I also run lower temp T-stats (just prolongs the temp rise) a 2020 L5P oil cooler, and an external oil cooler.

Also make sure your shroud is completely installed - when I did my tear down, a shop had replaced my front radiator support due to a small accident and it wasn't hooked on the lower lip. You loose a lot of efficiency if the fan shroud isn't installed properly.

 

[Kevan]

I put in a Hayden and towed 20K over some 7% grades (7mi long) at 98deg and it seemed to do well. Did you try kennedy? I also run lower temp T-stats (just prolongs the temp rise) a 2020 L5P oil cooler, and an external oil cooler.

Also make sure your shroud is completely installed - when I did my tear down, a shop had replaced my front radiator support due to a small accident and it wasn't hooked on the lower lip. You loose a lot of efficiency if the fan shroud isn't installed properly.

Thanks for that! I've emailed John, think i'll go with his hub

 

[Pure Diesel]

Has John gotten more in stock? I talked with him last month and he didn't have any and didn't know when they would be back in stock.