Does anybody know of a reliable source for a fan clutch for a '78 F-150 with a 400 engine. I have tried several auto parts stores, but they either stop working(don't engage) or they engage at too high of a temperature. The NAPA one I have now engages at 228 degrees. I tested this by covering the radiator and measuring the temp at which it engaged. I have also tried a new old stock motorcraft fan clutch that didn't seem to engage at all. I want to stay with a fan clutch if at all possible.

Also has anybody had any success with "adjusting" the spring on the front of the clutch to change the engaging temp? I currently have a severe duty clutch and the pitch on the fan blades is between 2 1/4 and 2 1/2 inches.

Anybody have the same problem?

 

Would it be possible to move this thread to the 73 - 79 forum for a little more exposure?

 

I find it interesting that you used a NOS Motorcraft fan clutch on your 1978 F150 w/a 400 engine.

There isn't any such thing!

No 400 engine used in 1977/79 F100/350's had a fan clutch = none.

The only fan clutch used was on the companion 351M engine and only when A/C and/or the Trailer Tow Package was present.

No Ford passenger car with either a 351M (1975/79) or 400 engine (1971/79) used a fan clutch = none.

1977/79 F100/350 351M = D4TZ-8A616-A > > replaced by > > E1TZ-8A616-A .. Fan Clutch / Marked: D5TA-CA or EDD5TA-CA / use with A/C and/or Trailer Tow Pkg only.

There is NO Motorcraft part number for this fan clutch.

Bottom line: You have the wrong fan clutch.

What fan are you using with this fan clutch? If genuine Ford, it will have an ID number on it.

D8TZ-8600-A .. Fan-5 Blade / Marked: D8TA-AA / 19 1/2" diameter / 2 5/8" center hole / Application: 1977/79 F100/350 351M / Use with A/C and/or Trailer Tow.

 

Bill,

The only number I can find on the fan other than the "ford" insignia is a "TX1". It is a 19 1/2 " diameter fan with a 2 5/8" hole.

The fan clutch was ordered by a ford dealer. I wished I still had it and the motorcraft box that it came in.

What is this engine supposed to have on it, if it didn't come with a fan clutch.

 

I am curious to know why the 1978 Ford repair manual lists a fan clutch on both the 351 and 400. Is this a mistake also?

 

Find me the fan clutch part number for a 400 engine in the 1973/79 Ford Light Truck Parts Catalog. Good luck, there isn't one.

I have three of these catalogs, they're on Ford microfiche slides and are the exact same catalogs the dealers used: 1979/1981/1988 editions, no part number is listed.

Only the 351M fan clutch part number is listed.

1980/82: Now, that's a different story.

Both the 351M & the 400 engines used in F150/350's have fan clutches listed.

 

So what am I supposed to have on this engine? Just a 7-blade fan with a fan spacer and no clutch?

 

Are you trying to stay stock or are you having a overheating problem?

 

There's no 7 blade fan listed for a 1977/79 F150/350 with either a 351M or a 400.

D7TZ-8600-A .. 5 Blade Fan ~ 18 1/2"

D9TZ-8600-A .. 5 Blade Fan ~ 19 1/2"

That's it!
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Please take the following into consideration.

This was 1978, not 2008.

There were less ppl and therefore less traffic back then.

The Ford warranty period was 2 years, 24,000 miles.

There was no 5 year/50,000 mile power train warranty available, even as an option.

There were several extended warranty plans available, good for an additional 1 or 2 years.

But...the prices for those plans were between $400 and $700 1970's dollars, which seems a trifle today, but was a lotta money back then.

Because of the cost of the extended warranties, very few ppl added one.

Where does Ford get most of their profits from (then and now)?

Vehicle sales? Heck no!

All the auto manufacturers are in the partsbiz, where over 90% of the real profits come from.

If parts don't wear out, Ford profits go down...simple as that.

These vehicles weren't built to last a lifetime. Think "planned obsolescense."

Vehicles back then had an average life span of SEVEN years.

 

Ultramagdan,

The engine overheats on grade and when pulling an 18' camp trailer. This is a new rebuilt engine, new radiator for a 460 engine, new shroud, and numerous fan clutches. Problem also occurred before engine was rebuilt. It is a stock rebuild.

Thanks for the info, Bill.

 

Was the water pump replaced? Checking the timing and using premium may help. I use e-fans on my truck and putting a pusher on the front of yours would not hurt it.

 

Yes, the water pump was replaced with a new motorcraft pump. Timing is @ 8 BTDC. The EGR is still on the engine and functioning.

 

How come I just pulled an OEM fan clutch off of a 1979 F-150 2wd with an original 400 in it then?

I also own a '78 F-150 with an original fan clutch in it, and it has a 400.

Maybe I am mis-understanding your post.

Anyways, you should consider using the 7 blade AC fan with the YB-427 motorcraft fan clutch, which was offered on the 1980-1982 351M's in the truck. I got mine here:

MOTORCRAFT Part # YB427

It was worth EVERY last penny. The replacement fan clutches from the auto parts stores are total, and utter garbage.

Good luck.

 

Hmmmm.... my '78 F150 Explorer with 400 and A/C still has the ORIGINAL FACTORY fan clutch on it(I know for a FACT it's the factory clutch bacause I know the history of that truck since it was bought new in '78).

Maybe A/C came with fan clutche and non A/C didn't...?

 

Anybody know were to get one of the 7 blade fans that can be used on a 1978 F150 with 400?


will 7 blade Flex-a-light fan be a good choice?