1977 CJ7 304 overheating

[swrogers]

535000

The 1977 Jeep that I just acquired overheats.
Sometime in its prior existence, someone took
off the fan clutch and bolted a 15" flex blade in its place. I believe that the 15" blade is way to small. Can some one tell me what the diameter of the origional blade was and also did the Jeep come with a two or three core radiator?

 

[sillsmack]

536000

I'll have to go look at my 77 7 304 to get those numbers for you.

My 304 does not have a fan clutch. I thought that odd and thought about buying one.

Before i did tho, I kept wondering why it did not. I've also wondered why the rear axle has grease wheel bearings instead of oil.

It turns out the reason is the same for both.

The AMC model 20 axle, and all dana's for Jeeps are the same, grease.

Finally it hit me!

Your 20 miles off pavement working some tough trail strewn with rocks & boulders. its about 90 degrees & your making maybe 3-5mph or less.

Your getting NO airflow so the radiator fan has to do all the work. You can't afford for the fan clutch to malfunction or quit at this time.

Hence, no clutch.

The same is for the grease wheel bearings. Most vehicles rely on the ring gear spinning fast to sling enough oil up into the axle tubes to get lube to the bearings, but, if your going S L O W you get no lube & a hot dry bearing siezes.

20 miles off pavement.

I'll look at my '7 tonight for you when i get home.


I have 2 12" electric fans in front of my rediator to help out when things get hot.

 

[sillsmack]

537000

OK, My 77 '7's fan measures 18 1/2" tip to tip. It is a steel flex fan with NO clutch, hard mounted to the pulley.

My radiator has 3 rows of tubes in it.

I replaced my radiator a few years ago and I bought a brand new one. I remeber the parts man asking : You got AC ?
HELL Yeah, I got AC ! I told him because AC cars need more cooling and hence a bigger rad with more rows.


Good luck to you