69 Power Steering Pump pulley and belt alignment

[Grahame M.]

I hope everyone had a great Christmas and New Year.

I'm afraid this problem is doing my head in and I need all the help I can get from the much brighter minds on this forum.

I have been toiling with this alignment issue for some months now, waiting for new parts to arrive from the states which due to COVID were taking up to 6 months to arrive in Oz. After fitting the new parts (from Paragon) and then due to the misalignment reverting to refurbishing the old parts. I thought I had this problem licked but, I still have a slight misalignment of the PS pump pulley and belt as you may be able to see in the attached pics. The pump has been refurbished and tested but I think the problem lies with the adjusting bracket or the lower bracket that attaches via the bolt at the front and the nut and stud at the rear.

When fit everything (hopefully in the right order) and nipping the bolts it looks ok but the pulley alignment is off just a fraction toward the front of the car. Once I adjust the PS belt and then tighten the lower nut and bolt the pulley moves toward the engine and almost hits the new idler pulley I've fitted. The idler look pretty well aligned in the attached pics so I don't believe this is the cause.

I understand that tolerances are tight in this area of engine bay but I also would have though that fitting these brackets (and new ones I purchased) would just fit. What am I missing in all of this? Will I have to bend the adjusting bracket at the adjusting slot to ensure the PS pulley is aligned and a little further away from the idler pulley? What should the distance be on either side of the idler, between the pulley and the PS body? Do I need to use spacers to push the pump out a fraction of an inch? I don't think this would fix the misalignment, only move the pump toward the front but still be on an angle.

I'm missing something so any help would be very much appreciated if you have experienced this or a similar issue.

Cheers
Grahame

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Quick update if it helps identify the reason for the this issue.

Today I loosened all the nuts and bolts that hold the PS pump to brackets. Once this was done the pump pulley was much better aligned and the gaps on either side of the Idler (PS pulley and pump body) were more like i would expect. Once I tightened the adjusting bracket nut it pulled the pump back toward the motor but still seemed aligned. The problem seems to be the lower mounting? I have a new one I purchased so I'll try that to see if it fits better. It seems to have a more pronounced bend (toward the front of the car) at the nut anchor slot.

My observation is that I need to place a washer against the pump at the adjusting bracket and if the new lower mounting bracket doesn't fix this I'll need to place some washers on the nut side (between the pump and the bracket) to push the pump toward the front of the car.

Any comments would be very much appreciated.

Cheers
Grahame

[Bill M.]

Re: 69 Power Steering Pump pulley and belt alignment

Grahame. I do not own a 69 but I have a ps 67 and looking down at the pump it looks slightly pitched towards the front of car probably from engine tourque. With all of the bolts tight and the belt snug does the pump look more in line? Is it possible that you are over tightening the belt?
bill

[Edward J.]

[Mark E.]

Re: 69 Power Steering Pump pulley and belt alignment

Grahame,

I went through this a couple of years ago with my '70 454 with PS, which has a similar (if not identical) pulley arrangement (sans AIR pump). The assembly process was a bit of a mystery for me. None of the pulleys aligned during the first trial fitment, so I tried a variety of spacers and washers to get things lined up. Not happy with stacks of washers in various places, I removed then reinstalled all the pulleys and brackets without any extra spacers or washers. For some reason, that did the trick... everything aligned fine. This design is an exercise in stacked tolerances, so pay attention to washer thickness, bracket condition, order of bracket installation.

Looking at your photos, your assembly looks correct. The alternator and PS brackets are stacked properly where they attach to the cylinder head (the bolt near the PS filler cap). And it looks like you have the correct cast PS double pulley.

It appears all you need is for the PS pump to come forward a fraction of an inch. As suggested above, double check the alignment of the PS bracket. Is it bent? Or perhaps the strategic placement of a washer will tilt/orient the pump just enough... it doesn't take much. Are the bracket bolts all torqued down in your photos? Just tightening everything down can change alignment. Again, it doesn't take much to correct this.

Attached are a few photos of my '70 454 as reference, and as encouragement that if I can fiddle through this so can you.

P.S. How did the battery box installation turn out?

IMG_20210103_104221132.jpg

IMG_20210103_102717728.jpg

IMG_20210103_102619883.jpg

IMG_20210103_102605772.jpg

[Joe L.]

Re: 69 Power Steering Pump pulley and belt alignment

Quick update if it helps identify the reason for the this issue.

Today I loosened all the nuts and bolts that hold the PS pump to brackets. Once this was done the pump pulley was much better aligned and the gaps on either side of the Idler (PS pulley and pump body) were more like i would expect. Once I tightened the adjusting bracket nut it pulled the pump back toward the motor but still seemed aligned. The problem seems to be the lower mounting? I have a new one I purchased so I'll try that to see if it fits better. It seems to have a more pronounced bend (toward the front of the car) at the nut anchor slot.

My observation is that I need to place a washer against the pump at the adjusting bracket and if the new lower mounting bracket doesn't fix this I'll need to place some washers on the nut side (between the pump and the bracket) to push the pump toward the front of the car.

Any comments would be very much appreciated.

Cheers
Grahame

Grahame------


Are the brackets and supports you used for the pump installation original GM or reproductions?

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Thanks for responding Bill,

I adjusted the belt in line with normal belt settings so i think that's fine. My theory is that there is a gap on the stud side lower mount which allows the pump to turn when i tighten the nut. Next check is the bracket opening to pump housing measurement.

Cheers
'Graham

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Thanks for the tips Edward,

I refurbished the brackets by stripping all the paint and applying a coat of DTM POR 15 so this shouldn't be a problem. I also scraped the block around the bolt holes as well. I've checked the AIM about 10 times and there are no spacers used other than what came out from a previous repair. There were washers everywhere in the Alternator brackets so it wasn't a very good job previously trying to mask a problem.

All pulleys are aligned until I tighten the lower mounting bolts, then the pump pulley tilts toward the engine about 1/8". I have another bracket so I'll check opening measurements of both and the pump housing to see if one fits better than the other. I have also test fitted the Alternator which appears fine, it seems like the PS is the only problem.
Cheers
Grahame

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Hi Mark,

Thanks for the photos, comments and words of encouragement. I'm trying to work everything off the new idler pulley I installed as its perfectly aligned with the belt when tight. With the PS pump mounting and adjusting bolts/nuts loose it lines up perfectly, about 1/8" - 1/4" gap between the PS pully on one side and the pump housing on the other. Yours looks a little more than this? Its only when I tighten the lower mount that everything goes pear shaped, so as I mentioned previously the next check is pump to lower bracket gap. I think this is the issue, as you said bent brackets could be the issue.

Unfortunately this has consumed my time (plus waiting a while for parts to arrive) so the battery box will move back to the next job. I'll definitely be contacting you on that one.

Cheers
Grahame

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Hi Joe,

The one that's on there at the moment is the one that came off the car, can't say its original as it appears to have some signs of welding when I stripped the paint off brackets. The other one I have is a reproduction form Paragon. I'd like to know the opening gap, from an original part, for that lower bracket if anyone has it? Also a pic of an original part would also help me understand the slight inward bend (toward the front of the car if any) for that lower stud mount. I think that's the issue so I'll take it apart again this week and check everything for the best fit. I think I'll have to space the lower stud mount on the pump side of the bracket to fix the alignment.
Cheers
Grahame

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

Sorry Mark,

One more question, I noticed that the Idler pulley adjusting mount stud doesn't have washers against the pump. Is this correct?

Cheers
Grahame

[Mark E.]

Re: 69 Power Steering Pump pulley and belt alignment

I don't know if no washer is "correct" or not, but adding one pushes the idler pulley too far forward.

Water pump bolts don't have washers, so I suspect no washer is typical.

[Grahame M.]

Re: 69 Power Steering Pump pulley and belt alignment

I also wondered if the PS pulley has been installed to far on to the shaft when refurbished, hence closing the gap. Your gaps are twice that of mine after looking more closely. The funny thing is the idler seems to be aligned perfectly with the belt. Do you know of any way to measure where the pulley should be, as I've read on some forums it shouldn't be pressed all the way and i think mine is?

Cheers
rahame

[Joe L.]

Re: 69 Power Steering Pump pulley and belt alignment

I also wondered if the PS pulley has been installed to far on to the shaft when refurbished, hence closing the gap. Your gaps are twice that of mine after looking more closely. The funny thing is the idler seems to be aligned perfectly with the belt. Do you know of any way to measure where the pulley should be, as I've read on some forums it shouldn't be pressed all the way and i think mine is?

Cheers
rahame

Grahame------


The 1963-74 power steering pumps used a shaft tapered on the pulley end. The nut draws the pulley, also with a slightly tapered orifice, to seat fully on the shaft. If, for whatever reason, the pulley were not seated fully on the shaft, the pulley would be loose. So, there is no way that the pulley can be pressed too far on the shaft. If the pulley orifice or the shaft's tapered end were damaged in some way, I suppose a problem could result.

[Joe L.]

Re: 69 Power Steering Pump pulley and belt alignment

Hi Joe,

The one that's on there at the moment is the one that came off the car, can't say its original as it appears to have some signs of welding when I stripped the paint off brackets. The other one I have is a reproduction form Paragon. I'd like to know the opening gap, from an original part, for that lower bracket if anyone has it? Also a pic of an original part would also help me understand the slight inward bend (toward the front of the car if any) for that lower stud mount. I think that's the issue so I'll take it apart again this week and check everything for the best fit. I think I'll have to space the lower stud mount on the pump side of the bracket to fix the alignment.
Cheers
Grahame

Grahame-------

I know of no weld of any kind that was present on original pump brackets. So, if yours shows any signs of welding it would indicate some sort of repair. Such a repair could also have resulted in some distortion of the bracket or otherwise rendering it out of spec. In addition, the bracket, even if un-repaired, could be in some small way bent. It would not take very much to create the situation you have.

I have no experience with reproductions of this particular bracket. However, I do have a little experience with other "reproduction" brackets and have found some to be out-of-spec, some far enough to be unusable.

Attached is a link to an eBay ad for a GM #3946002 bracket which offers several photos (saves me the trouble of trying to dig one of mine out to photograph):

https://www.ebay.com/itm/1968-TO-1974-CORVETTE-BIG-BLOCK-427-454-POWER-STEERING-CRADLE-NOS-GM-3946002/253221522205?epid=669800574&hash=item3af52dcb1d:g:LiQAAOSw7z1Z7QJP