Water pump replacement / crank pulley

[pickupcentral]

So, last week my 88 Quad developed a serious engine vibration. After looking on this board and asking a few people I determined it was a dying water pump. If it's not, well, hey, I'll have a new water pump!

Worked on it Sunday but stalled at the crank pulley nut. I got me a 36mm socket and today managed to remove the nut on the crank pulley. There was no tab to bend back as stated in the shop manual, but I needed an extension on the breaker bar to get it loose. Good advice elsewhere to put the car in 5th gear and chock the wheels. Also used copious amounts of PB Blaster. (That means lots of it.)

So anyone have a tip on pulling the pulley? Rubber mallet? C4? It is my last disassembly hurdle, and I don't want to hurt this key part.

While I'm in there, I am going to replace the alternator with a new (rebuilt) from Vick. Might save me a trip under the hood soon. I have had the car since July and really don't know what the PO might (or might not) have done. Also have a new thermostat. And some cool patches for my denim jacket.

Thanks!
-Phil
88 Quad

[Tifosi]

If you're gonna go as far as pulling the crank pulley and are in an preventative maintenance mode anyway, why not change the front seal while stuff is out of the road?

[Alfajay]

If you have gotten the nut off, they you have completed the hard part of the operation. The crankshaft pulley pretty much just slides on. Tap it with a mallet, pry it with a big screwdriver - it shouldn't require a lot of effort. These pulleys are pretty beefy, so I don't think you will fracture or bend it - again, it shouldn't require that much force.

Note that I've never removed a pulley on an engine still installed in the chassis - I presume there's enough clearance between the front crossmember and the front cover.

[pickupcentral]

Thanks, Jay. I give it a shot (ha!) tomorrow.

Tifiosi - I hadn't really thought about it. I got the parts for the plan, but not more. I am anxious to get the thing back together, and have all the parts for the current job. Now that I have done a lot of it, I am not as nervous about having to do something like this again. And I have experienced situations where I fixed more than I needed to and mucked up things (not on a car, though). I was ambivalent about even doing the alternator, working on that theory, since the current unit seems fine.

Feature creep is a danger! I have trailing arm bushings that I will do soon, and the "while I'm at it" bug wants shocks and springs, too.

Thanks for your help. The more I do, the more I can contribute back to the forum.

-Phil

P.S: I sure hope the water pump was the problem!

[ghnl]

Quote:

Originally Posted by Alfajay These pulleys are pretty beefy, so I don't think you will fracture or bend it - again, it shouldn't require that much force.

[ghnl]

Quote:

Originally Posted by pickupcentral P.S: I sure hope the water pump was the problem!

[pickupcentral]

I have a new fan, too. The old one didn't show any breakage, but I was strongly advised to replace it since we didn't know how old it was. The shroud was so brittle you could break pieces off with your fingers.

[Alfajay]

Tifosi had written: "If you're gonna go as far as pulling the crank pulley and are in an preventative maintenance mode anyway, why not change the front seal while stuff is out of the road?"

This is good advice, but I think it would be hard to change the seal with the engine in the car. I'm sure that professional shops, with lifts, do this operation all the time. Still, as a home mechanic, I would be hesitant - there isn't a lot of room to work with the engine in the car. Also, the detail of the front seal mounting is a little odd - there is no lip at the back to stop the seal as you tap it in. It is possible to knock one edge in so far that it falls out the back of the hole. Installing a new seal is an easy operation to do on a disassembled engine, with the front cover on your workbench. It is pretty easy on an assembled engine sitting on a stand. But, in the car? I'd be cautious unless there was a severe leak.

Do check the smoothness of the sealing surface on the front pulley. A groove can develop there, as grit in the oil wears into it. If you find a groove, smooth it with fine emery cloth.

[Art Vandelay]

Hmmm, I've had several 4-cyl. Alfa water pumps fail in the last few decades, but never felt any engine vibrations. The pulley will wobble a bit as the seal and bearings go, though, so hopefully that's your issue. Also never seen a bad pump that wasn't leaking. Is yours leaking, and/or can you feel any wobble in the pulley?

[pickupcentral]

No leaks, but I could feel a small movement when I grasped the fan and push/pulled it.

[ghnl]

If you run the engine with the fan belt removed is the vibration gone? If NOT, the problem lies elsewhere...

[pickupcentral]

Quote:

Originally Posted by ghnl If you run the engine with the fan belt removed is the vibration gone? If NOT, the problem lies elsewhere...

[ghnl]

Quote:

Originally Posted by pickupcentral If it isn't the water pump, where else might the problem lie?

[pickupcentral]

The engine vibrates at idle, out of gear. It isn't constant, but regular, cyclical. When it started, I pulled into a gas station and opened the hood. Under the flourescent lights, the fan apeared to "strobe" backwards when the engine vibrated. The engine feels and sounds good, and revs well. There also developed a metallic clank. The effect seemed to be diminished when I turned on the A/C.

Shortly before I noticed it, we had to brake hard for an idiot, but did not hit any bumps. The motor mounts are new (August) and appear sound. Also new are the rear tranmission mount and center driveshaft support, all replaced at the same time.

Thanks!
-Phil

[ghnl]

Have you removed the crankshaft pulley? If so, did you carefully inspect for damage/cracks of the hub near the key way? If you haven't removed the pulley, with the belts off, does the crank pulley wiggle at all (it shouldn't).

Peruse this thread - I hope it is NOT a cracked crankshaft pulley.
What the?!?