Messed Up taking my balancer off

[Aprules2]

I have a 75 coupe Deville and I had to change the water pump. I have never done one on a 500, and it turns out you have to remove the balancer pulley to get to the bottom bolt of the water pump. I forgot that the timing marks are on the pulley not on the balancer on the block. I also saw there's some spots drilled in it for balance so I have to imagine it has to be lined up where it was. What can I do to get it re-aligned?

[russ austin]

There has to be a key way involved here. 

[Aprules2]

OK, if this was a regular gm set up, the balancer would have a keyway on it, with a bolt and washer retaining it, and the timing mark would be ground on the balancer, then a pulley would bolt to the balancer.

My 500 has something that looks like the regular gm balancer and its pressed on and has a keyway, but does not have a center bolt retaining it. Then there is a huge metal pulley that looks like it doubles as a balancer, and it has the timing mark notch in it. There is no mark or notch on the part that's still on the engine. That's how I messed up, I'm so used to the crank pulley just being a pulley I didn't mark where it was or anything, then I realized it when I went to bolt it back on.

[Aprules2]

here is a picture I found on the web of what is still on the block

[Bob Hoffmann CLC#96]

First, I'm not sure why you removed the pulleys. There is no water pump bolt hidden.The part in the picture is the "balancer". No need to pull that. You will find that the mounting holes for the pulleys are offset. It can only go on one way. You really didn't mess up.
HTH, Bob

[Aprules2]

I couldnt get the ratchet onto the bolt at the bottom, the giant pulley was blocking it. I was going to try and rotate the engine to top dead center in the morning to put the pulley back on at the right position. Ill look tomorrow to see if the holes are offset. They almost looked like they were spaced evenly.

[The Tassie Devil(le)]

There is no problem with reinstalling the harmonic balancer as it can only go on one way.

A bit like the Flex Plate.

Bruce.

[35-709]

As has been noted twice already the balancer will only go on one way, even though the holes look evenly spaced, they are not.  You won't have a problem getting it on correctly.  I have heard of them being forced on incorrectly but you really have to work at that.

[Scot Minesinger]

I am doing this very same job this weekend, where I will be replacing the timing chain on my 1970 RWD 472 which is quite similar.  I did this before and because of the mark on the edge of the pulley and my lack of experience with this engine I did mark it (so I don't know about only goes on one way concept although that makes good sense), but never tried to install any other way.  Will check it out when I do this and report back.

The shop manual may mention reinstallation of this pulley and how it goes on only one way -check it out.

Also I have replaced the water pump before too and it is better to use a wrench in lieu of a socket to get to the ones under the pulley, although I agree, they are no picnic either with the pulley on.

Hope it all goes well.

[35-709]

Things I've learned to do from the shop manual and others here ----

Be sure to put sealer (per the shop manual) on the 1/4-20 bolts (screws).  For first timers working without a shop manual ( ?), be very careful tightening those 1/4 inch bolts, even the factory recommended 70 INCH pounds may be too much.  If/when you strip them you can use a metric bolt which will be slightly larger (forget the number) to replace the ones that strip.  OR, I weld a 14/-20 nut on the inside while I have it apart to negate future problems with those troublesome bolt threads stamped into the cover.  Grind the stamped holes flat and carefully align the nut on the inside with the hole and hold it in place with a 1/4-20 bolt.  Weld the nut in place (don't weld the bolt!), a good tack in 3 or 4 spots should be sufficient.

[mgbeda]

Yeah the shop manual says you have to take off the pulley, but you can use a wrench (not a socket) to get that last bolt loose, then sort of wiggle the pump out with the bolt still in the hole.  Reinstalling is the reverse of removal.  Whole lot wiggling goin on.

Of course that doesn't help the original poster now.  But it might help someone else.

-mB

[Aprules2]

I went out there today, and you guys were 100% right the balancer pulley only goes on 1 way. I tested it with a timing light just to be sure. Oddly enough changing the water pump got rid of the vibration Ive had for months between 40-70 mph.

Scot, honestly if it wasn't for my lack of knowledge about the balancer pulley it was one of the easiest water pumps I've ever done. Don't sweat it. Make sure you pick up some gold silicone for the pump. My timing cover had some groves by where the gasket went from rust. After cleaning it, I put a thin layer of silicone on the gasket then stuck it to the pump and let it set for 10 mins. Then I put a slightly thicker bead on the side that goes against the timing cover to make up for the grooved areas. Then just bolt it up where the bolts are just tight. The next day I give them like a little turn, don't torque them.

If I had planned this better I would have changed my timing chain too. But I hear you have to take the oil pan down too, and that wasn't happening in the snow on my back.

[Scot Minesinger]

Yes, it is funny people say, well if you are changing the water pump, might as well change the timing chain -no not on a Cadillac 472/500.  To change the timing chain you have to drop the oil pan and remove the distributor.  To remove the distributor on a 472 1970-72 you also have to remove a solenoid to clear the vacuum advance.

To drop the oil pan - read my other post, you have to remove the exhaust y-pipe, starter, flywheel cover, and center link.  I'm doing a mechanical restore and the y-pipe was just changed, so that was not difficult.   

[The Tassie Devil(le)]

Yes, it is funny people say, well if you are changing the water pump, might as well change the timing chain -no not on a Cadillac 472/500.  To change the timing chain you have to drop the oil pan and remove the distributor.......... 

You are lucky the engine isn't in an Eldorado as you HAVE to pull the engine to drop the pan.

Bruce.