Sunday afternoon, I noticed oil on the garage floor and I knew exactly where it was coming from.

Before I get into details, some of you know the transformation I've done in my CELT4 back in Dec, I installed the roller chain setup but, because I saw the OEM water pump gear/shaft looked the same size I DID NOT CHANGE the old part with the new one.

I finished engine work and I started the Vette, it started like a champ but there was a "duck noise" coming from the engine. I was concern so I bought a stethoscope and the noise was coming from behind the water pump. I knew this was going to end bad (Sunday afternoon). I posted a thread and I started to search on Roller Chains and few CF mentioned about the water pump gear issue.

So, I was already done and now, again, the whole front of the engine is out. Here are some pictures for you future modificators to ensure you install the water pump gear even though it looks the same.



The noise was gear grinding and it destroyed the O-Ring, that was where the oil was coming from.



Now, IAW the FSM I have to buy a puller to pull the water pump gear (J39243) and (J41546) to install it. If any out there has a DIY way to remove and install it at home with basic tools shoot me a post or PM.

So far, this roller chain issue is reaching $400+ and likely I'll need the water pump gear shaft (another $90).

 

Just a thought. 1) is the pump gear rear bushing worn out? 2) is it possible to simply shave a few thousands off of the face of the gear and reinstalling it? 3) isnt the OEM chain plenty strong?

 

Ouch - man, that is a bummer!!

 

omg

 

I was wondering the same thing. Other than a little less friction what advantage does a roller chain give?

Anyway, I hope you get it all back together without anymore problems and no leaks this time. I hate an oil leak!

It did sound like a duck........

 

An electric water pump would solve all your problems, and can be had for about $200. Then you can remove the water pump gear completely, seal the hole in the timing cover with a 18mm freeze plug and right stuff, put it all back together and enjoy the five extra horsepower you freed up while removing the duck from behind the water pump and eliminating the oil leak. It's a win-win.

 

though I may be going back to a mechanical for road courses.

 

Good point,

How long an electrical water pump lasts?

 

I run the WP118HD - Electric Water Pump its 55 gpm and keeps my car cool in the Mississippi heat. (kept it cool in colorado too)
From the Mez site:
American made with quality far superior to any other performance aftermarket company, we build our water pumps with pride right here in the USA. Don't be mislead by inflated flow numbers and competitors' outlandish claims. We say what we mean and mean what we say. Our 2 year, unlimited mileage guarantee and full satisfaction money back guarantee should convince you that buying Meziere is buying value!
This water pump model features:

•Fits GM LT-1 / LT-4 engines as an insert into the factory pump housing
•Suitable for street or drag strip use – 3000+ hour life expectancy
•Show quality black finish
•Heavy duty motor provides 42 gallons per minute free flow rating
•All stainless steel hardware included
•Light weight. Complete unit weighs only 3.6 pounds!
•Stainless steel large diameter main shaft with high performance ceramic seal
Technical Specifications:

•Finishing The System: This pump is supplied complete with gaskets and hardware. Factory hardware is reused. There are no other necessary items.
•Amperage draw: Under normal use the pump will draw 6-7 amps.
•Overall Height Dimension: The heavy duty pump is 3.50" long from the mounting surface to the tip of the pump.
•Pump Weight: This application weighs 3.6 lbs.
•16 volt systems: When purchasing a pump for a 16 volt system we recommend the 16 volt optional motor on our pump. The 12 volt pump will work for limited use applications.

Additional Notes:
The standard 42 GPM pump is suitable for normally aspirated engines up to 650HP. Supercharged, turbocharged and high compression, high horsepower applications should use the 55GPM High Flow pump only.

Installation Instructions:
Download installation instructions HERE

Accessories for GM LT-1 / LT-4:
Relay Wiring Kit upgrade WIK346

Mike

 

What exactly caused the problem?

Are you saying there is noise due to not replacing the waterpump drive gear? And an oil leak because?

It looks like a GMPP Extreme Duty timing set.

I've put two sets on my LT4 and have never had an issue. I also purchased a new waterpump drive setup at the same time... My theory is this is a pain in the rear area to reaccess and since we are talking a fairly high stress area that I turn over 7000 rpm...new parts are a good investment.

WP Drive assembly...10219554
Cost $45 a few years ago from Superior Chevrolet (CF discount) and came equipped with all the gears/bearings ready to install.

The bushing was probably caused by incorrect installation. It 'stretches' ever so much over the shaft and requires a special tool to do it or the black membrane reverses and is very effective at leaking oil. My special tool is a shaved nozzle to RTV tube. I believe there are easier ways now...something like a marker cap. A search should turn up the solution.

Electric waterpumps have their own issues. Some have returned to mechanical for heavy duty work. Fix the problems rather than patching it with a band aide unless something else is involved.

Good Luck!

 

I ordered a new timing kit and the shaft GM 12551727 It is discontinued but GMpartsdirect.com sells them. The shaft is a bit loose and I never took it apart. It is my fault, bought the new part and I took a shortcut. Lesson learned

 

 

sorry to hear about your timing chain/water pump drive misfortune.

First, as to your inquiry as to removing the water pump drive gear without a puller: if you remove the intake manifold, the water pump drive gear can easily be driven out from the rear (lifter valley). As an added bonus, when you reinstall the drive gear assembly you can easily verify that it is fully seated in the recess in the block.

The importance of the bearing in the water pump drive cannot be overstated; essentially it supports the entire water pump drive and if worn out it could easily allow the shaft to "wobble" radially and destroy the seal just as happened to your engine.

I replaced the stock roller chain in my LT4 with an extreme duty roller timing chain; the extreme duty chain links and rollers are noticeably larger than the stock chain; the crank sprocket and cam sprocket are correspondingly larger in diameter to accomodate the chain; as a result
clearance between the timing chain and the water pump drive shaft are minimized. Any 'wobble' in the water pump shaft could contact the timing chain.

Check the water pump drive bearing; mine was worn out needed to be replaced (120,000 miles); I doubt that there could possibly be enough slack in a new timing chain set to allow any contact between the chain and the water pump drive shaft.

Good luck; the second time will be the charm.

 

My electric water pump suggestion was based on the idea that the OP installed an aftermarket timing set that was bigger than the original and interfered with the water pump drive mechanism, causing the noise and excess wear on the seal.

If this is the case, and the OP wants to keep his aftermarket timing set, then the water pump is not a "band aid," but a legitimate solution to keep the timing chain from rubbing the water pump drive shaft, since the drive shaft would be removed.

The way it reads, it seems like the new timing set came with a new drive shaft anyway, machined to allow clearance. But it would need the gear pulled from the old and installed on the new. That would be the other option.

 

Information on parts:

The dealer no longer sells the water pump cam but I was able to order it thru http://www.newgmparts.com The roller chain water pump gear is 0.05mm smaller in diameter than OEM.

The new water cam bolt comes with the bearing, cam and gear but due to the fact I had to remove the bearing to install the new roller gear I oredered a new water pump bearing thru http://www1.mscdirect.com/CGI/NNSRIT...MT4NO=65151552

 

No Go
Is correct about that WP seal it is in the wrong orientation right now. The black seal faces toward the motor and the yellow toward the radiator they are very tight and hard to stretch when new , good luck
with your repair.