603 1987 300SDL Fan Clutch Question - PeachParts Mercedes-Benz Forum

mj_sid · #1 05-01-2006, 02:10 PM

Hello All,
I have a 1987 300SDL I am having a problem with the fan and or the fan clutch. When I shut off the car at normal temp. (80-85 Deg C) the fan just spins and spins untill it slows down. At higher temps (just shy of 100 Dec C) it does the same thing. I've searched on the forum and from what I've found the fan is not supposed to start working untill about 105 Deg but i'm not sure if this is in Faranhite or in Celcius. The other problem with the fan is that it wobbles while it is running. I think that I need a new clutch but I just wanted to make sure that I wasnt missing anything obvious.
Also If the clutch is bad should I consider trying to put new gel in it? The P.O.(sixto) did this and I wasnt sure if I should try it again or not. Also will clutches off of other 126 engines fit? They have different part numbers but I think I might be able to take the blades and clutch and make it work.

Sorry about the lenght of the question
--Matt

sixto · #2 05-01-2006, 02:24 PM

The fan is bad? I guess it couldn't hold the Toyota silicone fluid.

I'd be wary of driving it with a wobbly fan. It would be a pity to lose that fairly new Behr radiator.

Sometime back I noticed the fan went off kilter (but not loose). The bolt that holds the tensioner arm to the timing chain cover came loose. I made a special tool to tighten it. Consisted of a bolt with a 12mm head and two 12mm nuts jammed againt the bolt and eachother. Fit the head into the 12mm hex of the tensioner bolt and use whatever wrench you can get on the jammed nuts to tighten.

Man, sorry about that.

Sixto

sixto · #3 05-01-2006, 03:07 PM

On the matter of other clutches fitting, note that some engines have fans that spin the other way. The M103 is one such engine. I don't know if clutches are directional but if they are then M103 clutches are ones to avoid.

One thing I considered was going with an electric puller fan. There's not a lot of positive sentiment around that idea but I don't think very many have actually done it. Maybe the compromise is to fit the electric clutch from a 190E 2.3. Dave can probably find one for you in one of his scavenger hunts

Sixto

mj_sid · #4 05-01-2006, 07:33 PM

Quote:

Originally Posted by sixto

Man, sorry about that.

Sixto

It's the nature of the beast.

My first thought when I noticed the problem was that I wanted to put electric fan(s) in. We have a couple of them sitting in the garage and I figured that this would be a perfect application. I will have to investigate this some more. I figure that it should be as easy

as welding a frame, putting the fans in said frame and then wiring them to a 12 volt source (AC Fan??) with a temp switch inbetween.

Luckily I will have access to a spare car starting Wednesday and will be able to take the SDL down and make the necissary repairs.

Have you (Sixto) bought another silver star yet?? Any replacement vehicles??

--Matt

sixto · #5 05-01-2006, 07:37 PM

Still MB-less.

There's a white over gray SDL in San Jose for $4800. My ideal color combo. I don't have time for the next few days to see it, though.

Sixto

mj_sid · #6 05-01-2006, 09:34 PM

Yeah but you still have to deal with that wood

.
--Matt

Hit Man X · #7 05-20-2006, 02:46 PM

I'm searching for another thread regarding SDLs, but I have an M103 clutch on mine and it's still working fine. I made a good thread about this far less expensive clutch.

For what it's worth...

Brian Carlton · #8 05-20-2006, 09:25 PM

We've had a lot of discussions about that clutch.

One of the members was in the identical situation and replaced the clutch. He found the same symptoms with the new clutch and concluded it was defective. So he returned the clutch and received a second new clutch that performed the same way as the first clutch.

Apparently, the clutch won't fully couple until the temperature of the bi-metal spring is in the area of 105°C. This is a very high temperature and would require the coolant temperature to be higher than this value because some heat is lost in the radiator.

It seems that the calibration of that clutch is much higher than what we would consider "normal". Understand that replacing it may not provide you with any better results.

dieseldiehard · #9 05-21-2006, 12:17 AM

Quote:

Originally Posted by Brian Carlton

We've had a lot of discussions about that clutch.

One of the members was in the identical situation and replaced the clutch. He found the same symptoms with the new clutch and concluded it was defective. So he returned the clutch and received a second new clutch that performed the same way as the first clutch.

Apparently, the clutch won't fully couple until the temperature of the bi-metal spring is in the area of 105°C. This is a very high temperature and would require the coolant temperature to be higher than this value because some heat is lost in the radiator.

It seems that the calibration of that clutch is much higher than what we would consider "normal". Understand that replacing it may not provide you with any better results.

Except getting one that doesn't wobble should be a priority!

mj_sid · #10 05-21-2006, 09:17 PM

My final decision was that the fan was probably ok; if there is no way to test it and if it doesn’t work until it's way to hot for my liking. I figure that the wobbling in probably mostly in my head since I cannot wobble it when it is stopped. So for now I'm going to close my eyes and hope all is well in this department. (It should be noted that I’m doing this with great arm twisting).

Many thanks to those who helped and if anybody has any other ideas please let me know.

Matt

Jason SVO · #11 06-08-2013, 11:43 AM

Hello,

I had a knockoff water pump start leaking from the inner seal after 1.5 yrs. I have replaced with a German part. But I noticed the fan has a lot more resistance on it when cold. It used to spin freely when engine was cold, now it won't free wheel.

Think it's bad?

Thanks,

Jason

sixto · #12 06-08-2013, 12:42 PM

It's common for a clutch to not freewheel for a few seconds right after a cold start. The fluid settles while the clutch isn't spinning and takes a few moments to redistribute so the fan can freewheel. If it goes a couple of minutes without disengaging, look into it further. A feature of the clutch is that it disengages above 3000 rpm or so so the fan doesn't spin itself apart. Make sure you don't hear the clutch still engaged at higher rpms.

Sixto
87 300D

Jason SVO · #13 06-09-2013, 11:27 PM

Yeah, the clutch is bad. It doesn't engage anymore, and has a lot of resistance to turning when the car is off and cold.

It's an ACM, only 2 yrs old. I bought a replacement, also ACM, and noticed that it is coming apart at the seam.

Behr replacement has been ordered.

Jason

VA-Merc · #14 06-10-2013, 10:36 AM

In response to the original post...is it the metal fan or a plastic fan? I have a metal fan and clutch I pulled off my 87 300d with the om603 that is just sitting around. I replaced it with an 11 blade plastic fan from a newer car and have no use for it. There was still some resistance in the clutch, although it could probably use a top-up with some silicone fluid. It did not wobble or have any noticeable issues. If you want me to send it to you just PM me and I can find out how much shipping will cost. I live on the east coast.