looks like 5mm would be optimal increase in water pump pulley height to be correctly aligned with crankshaft pulley BUT I'm going to go a little less - like 4mm so the pulley will still be secured by being (just barely) on the tip of the main 5/8" shaft of the water pump - at 5mm it's kind of loose cause it's is tapered by the top of the shaft   .. and also the stock studs end up being too short at 5mm - (even with them turned forward in the hub) so 4mm height extension is my safest compromise I think.  Here's the problem with water pump pulley on the bottom, crank on the top

 

Of course I wish somehow I could have moved the crank pulley back BUT it only has barely 2mm clearance from the timing belt covers!..and I have my timing belt cogs on the crankshaft stacked in the correct order, so that's not causing this problem..

 

so I really need about 114mm hub / deck height - 4mm taller than the stock "tall" version, which is 110mm

.. sounds like an easy simple job, right? .. as long and it stays together and the pulley doesn't wobble..

this solution by Steptoe's photos  from Australia  would probably be the best.

https://www.ultimatesubaru.org/forum/topic/142209-water-pump-has-me-confused/page/2/#comment-1457136

Quote

Down under, we have metal supply shops with round discs for sale, to be used for whatever - plugging ends of pipes, weld in, weld on style etc. 5mm thick flat steel, punched out at 57mm The 57mm fits perfectly inside the water pump pulley of the V belt style, pressed steel pulley. I set about marking out the centre hole and four holes for the mounting bolts/studs. Job done, a 5mm spacer..

but I'm hoping a "stack of 3 of these washers on each stud.." will suffice, cause I don't have easy access to any good metal shop tools and would at least want a good drill press and vice.

https://www.homedepot.com/p/Everbilt-10-Stainless-Steel-Flat-Washer-50-Pack-800032/204276382

I found #10 washers at Homedepot that should work with a stack of 3 on each stud, going to blue loctite the studs & nuts. 1/2" O.D. x 7/32" I.D. x .049 thickness 304 Stainless steel  - I just need to make the hole a little bigger and a stack of 3 of them is 3.81mm  probably a safe compromise..  I'll add some pictures tomorrow if time permits and maybe Ill have the car back up and running in a couple of days - and hopefully the fan and the pulley stay happily attached.. will see..

If it starts coming apart then maybe try some 2" O.D x 1/2" i.d "fender washers" that could work if I open up the center hole to 5/8" and drill 4 holes for the studs  - and I'd use 4 or 5 of the and it would be way more work and probably overkill.

 

 

Edited August 21, 20241 yr by Craigar
typos, brainos & more Details

shoot me if I am wrong, but I swear i saw a listing for a water pump with a deck height greater than 110mm and I think it was not a rounding of 5 , so 114mm ??

Going in to rock to have a bit of a look, out of curiosity

That would have been good - before I installed & put all the rough stuff back together - 4mm would have probably been OK with a standard length shaft  BUT it's a little "shakey" to go out 5mm with a stock length shaft cause the centering hole in the pulley won't be on the shaft, it will just be catching the tapered section right before the top/cut off of the shaft..

so I shimmed mine with 2 different washers to get a "safe" max height and want to make sure I get enough threads on the hub's studs, used one of each on all 4 studs - and used a micrometer to get all the heights the same - there is a LOT of variance in the thickness of washers even though they all came from their same packages.

 

 

I put the larger one against the backside of the pulley , which is completely flat and th smaller on against the water pump hub, and got 3.6mm or .140" additional height and I think it will be OK, but not "perfect" in this image I lined up the  (top) power steering center ridge with the (middle) crankshaft pulley center ridge , and we can see the water pump pulley center ridge  (bottom) is still slightly offset. 

 

time will tell - but probably won't have time to be able put everything else back together and test drive for at least 3 weeks - unless my schedule changes again...

 

 

Edited August 22, 20241 yr by Craigar

That pulley can be slide out on the center shaft, by using a hammer and a holding device for the pulley, so that you pound on the center shaft protrusion and push the water pump away from the front of the pulley.  Also there are water pumps for pulleys with two different heights.  The shorter one is for the GL.  The taller one is for the GL10.