69 427 water pump, pulley and fan clutch problems

[Don W.]

69 427 water pump, pulley and fan clutch problems



The fan clutch went out and I ordered a GM replacement from Paragon. The current fan clutch is an aftermarket model.







Thanks for your assistance,

Don

[Grant W.]

Re: 69 427 water pump, pulley and fan clutch problems

69 427 water pump, pulley and fan clutch problems



The fan clutch went out and I ordered a GM replacement from Paragon. The current fan clutch is an aftermarket model.







Thanks for your assistance,

Don

Hi Don
Joe Lucia has mentioned many times on the forum that there is a replacement fan Clutch from GM or the GM parts direct or GM restorations or from GM dealerships themselves. Correct fitment but just looks different from originals. I don't have the part number but it only cost 99.00 or 119.99
I have many original 69 fan clutches but some need restoring or I don't even know the date code you need.
Anyways as to your question buying a 74.... it won't fit. You will have to change the water pump pulley, pullies to make it fit. Spending 3 times the amount rather than buying a correct one. My opinion.
Thanks, Grant

[Don W.]

Re: 69 427 water pump, pulley and fan clutch problems

Grant,

If you read my post above, you will see I did buy a correct one and it does not fit. The GM part number is 3916141. That is the GM replacement model and it has a 5/8" opening for the water pump stud to go into. My car has a 3/4" stud and the correct part will not fit.

Don







Paragon Number: 714
GM Part Number: 3916141
Engine fan clutch unit, 5/8" arbor hole, 1 3/4" bolt center. Visually, this part does not look exactly like the original style, but it is quite close.
Years 1960 - 1970 Condition: New

[Don W.]

Re: 69 427 water pump, pulley and fan clutch problems



The fan is a universal fit 5 blade with 8 holes to fit different clutch assemblies; also incorrect

I will replace everything in the future when the water pump fails.



Thanks,

Don

[Dick W.]

Re: 69 427 water pump, pulley and fan clutch problems

Get a fan clutch for a '71-'74 Corvette with 454 engine. This should solve your problems. Maybe Joe Lucia will chime in with the part number

[Don W.]

Re: 69 427 water pump, pulley and fan clutch problems

Dick,

Thank you very much. It always amazes me, if some previous owner needs to fix or replace something; why put a complete setup (pump, pulley, fan & fan clutch) from a different year on the car.

Don

[Jack H.]

Re: 69 427 water pump, pulley and fan clutch problems

When these changes happened, the typical solution was to make replacement parts 'downward' compatible. That was accomplished by installing a sleeve over the tip of the water pump shaft to absorb the extra space in the later era fan clutches.

Here, the problem is one of being 'upward' compatible (making an earlier version of the fan clutch fit on a later version of the water pump). Seems to me the simple fix is to take the fan clutch you've got to a machine shop and have its center hole widened out...

If/when you eventually replace the water pump, you can always solve the issue by sliding a sleeve over the pump's front shaft!

[Joe L.]

Re: 69 427 water pump, pulley and fan clutch problems

The fan is a universal fit 5 blade with 8 holes to fit different clutch assemblies; also incorrect

I will replace everything in the future when the water pump fails.



Thanks,

Don

Don-----


ALL 1955-70 Corvette V-8's used a waterpump with a 5/8" pilot. No exceptions, whatsoever. So, your 1969 was originally fitted with a waterpump with a 5/8" pilot. That means it originally also had waterpump pullies designed for 5/8" pilot and a fan clutch for 5/8" pilot. Someone has installed a 1971-74-style Corvette waterpump on the car. These will easily fit to a pre-1971 big block; no problem, at all. The ONLY Chevrolets through at least 1982 that used waterpumps with a 3/4" pilot were all 1971-82 Corvettes as well as some MD and HD trucks.

If you wish to maintain your current waterpump and pullies, then you need to use a 71-74 Corvette fan clutch. Here are the ones that will work:

GM #88961768, aka Delco #15-4950 (This one comes with my HIGHEST recommendation. The successor to the absolute best fan clutch EVER installed on a Corvette);

GM #88961763, aka Delco #15-4946

GM #88961765, aka Delco #15-4317

[Dick W.]

Re: 69 427 water pump, pulley and fan clutch problems

Thanks Joe, could not remember the # for the clutch. I took your advice and installed this on our car, made a world of difference in slow moving traffic

[Don W.]

Re: 69 427 water pump, pulley and fan clutch problems

Joe,

Thank you very much for the information. I called around yesterday morning and ended up buying a Hayden fan clutch from Checker auto for $39. It will delivered to their store this morning and go in tonight.

Since my fan, fan clutch, pulley and water pump are all incorrect, what are the most nearly accuarate replacement parts and where should I look to find them. I figure I'll start aquiring the correct parts over the near-term so I can do a correct replacement sometime in the future when the water pump goes out.

Thank you for all your help and assistance.

Don

[Joe L.]

Re: 69 427 water pump, pulley and fan clutch problems

Joe,

Thank you very much for the information. I called around yesterday morning and ended up buying a Hayden fan clutch from Checker auto for $39. It will delivered to their store this morning and go in tonight.

Since my fan, fan clutch, pulley and water pump are all incorrect, what are the most nearly accuarate replacement parts and where should I look to find them. I figure I'll start aquiring the correct parts over the near-term so I can do a correct replacement sometime in the future when the water pump goes out.

Thank you for all your help and assistance.

Don

Don------


Finding a correct waterpump is the easy part. You need a GM #3856284 casting if the car is a VERY early build 1969 or a GM #3940960. The 3856284 casting is easy to find; the 3940960 is a little more difficult. A source like Bill Mock or Arthur Gould can do a first class rebuild and can even supply you with a rebuilt pump of the correct casting number and date if you can't find a core. These pumps are dated, so if you want the most "correctness", you'll want one with a date 6 months or less prior to the car's build date. However, I don't think the dates are judged in NCRS Flight Judging.

For a fan clutch, the Eaton-manufactured GM #3916141 is the closest thing to original that you can get in a NEW fan clutch. In fact, the GM #3916141 was actually used in PRODUCTION for some 1969 Corvette big blocks. However, the configuration of it has changed slightly over the years so a current example is not 100% correct in every bit of detail.

For a fan, you need a GM #3888366. This is a 5 blade fan which has "66" stamped on the hub section. It's difficult to find and VERY expensive when you do find it. I've seen originals with asking prices of over $1,000. It is reproduced, though, and available for about $200.

For a waterpump pulley, you need a GM #3889372 to be 100% correct. Difficult to find and expensive but available in reproduction for about $200. You can also use a GM #3995644. It replaced the aforementioned pulley for SERVICE. However, it was discontinued quite awhile ago and is difficult/expensive to find NOS.

[Don W.]

Re: 69 427 water pump, pulley and fan clutch problems

All,

How do the correct service replacement/current GM restoration parts score in NCRS judging vs. Actual original correct parts?

Don

[Jack H.]

Re: 69 427 water pump, pulley and fan clutch problems

They receive originality deduction(s) to the extent that they differ from known factory originals along the lines of Finish, Date, Installation, Configuration and Completeness. That's standard judging policy...