Shredding power steering belts
#1
Shredding power steering belts
My track-mostly MSM has a predilection for consuming power steering belts, starting earlier this track season. The first time it happened, I found the 17 mm bolt behind the pump pulley finger tight and thought that might have been the cause. Since then, I've lost a belt about every second track day, initially falling off and most recently shredding to bits. At the last track day, I lost a belt in the morning and its replacement a couple of sessions later. I finished the day using "power steering by Armstrong", which was, er, interesting.
Anyway, when the belt is installed and with the engine running, there is no visible wobble or lateral movement. When I got home after the last event, I put a ruler across the main and power steering pulleys and found that the upper pulley is approx. 1 mm further out (towards the front of the car). Is this acceptable in terms of tolerance? If not and the root cause of my woes, how does one actually adjust for this? As far as I can tell, there's no adjustment possible short of pulling off the PS pump mount and machining 1 mm off of it. Anybody have any ideas?
Thanks.
Anyway, when the belt is installed and with the engine running, there is no visible wobble or lateral movement. When I got home after the last event, I put a ruler across the main and power steering pulleys and found that the upper pulley is approx. 1 mm further out (towards the front of the car). Is this acceptable in terms of tolerance? If not and the root cause of my woes, how does one actually adjust for this? As far as I can tell, there's no adjustment possible short of pulling off the PS pump mount and machining 1 mm off of it. Anybody have any ideas?
Thanks.
#2
Are you sure it's just the PS pump that's shifted, and not the harmonic balancer having slipped/shifted slightly?
How's the alignment for the water pump belt?
I'd also try and check alignment using a metal ruler / straight edge
Timber ones aren't as accurate since they easily deform, as well as expand/contract/warp with humidity.
How's the alignment for the water pump belt?
I'd also try and check alignment using a metal ruler / straight edge
Timber ones aren't as accurate since they easily deform, as well as expand/contract/warp with humidity.
#4
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I used to have this very problem. Kept going through PS belts.
The PS belt would knock the SC belt off, too, and that was no fun.
I researched it as best as I could. Very little info on this issue, mostly in passing. Meaning, people talk about this problem as part of some other thing or other, and there are very few/no dedicated discussions on PS belts.
Turns out our engines are not used to revving up very quickly under load.
Even though the pulleys look perfectly aligned while the engine is off, apparently they flex and otherwise manage to move outside the alignment plane, enough to throw the belt off.
I did everything I could imagine before giving in.
Played with belt tension, removed and fiddled with all PS mounting hardware, had stuff machined, and resorted to harsh language even. No dice.
That's when I decided to go electric.
https://www.miataturbo.net/general-m...version-72689/
Never looked back.
The PS belt would knock the SC belt off, too, and that was no fun.
I researched it as best as I could. Very little info on this issue, mostly in passing. Meaning, people talk about this problem as part of some other thing or other, and there are very few/no dedicated discussions on PS belts.
Turns out our engines are not used to revving up very quickly under load.
Even though the pulleys look perfectly aligned while the engine is off, apparently they flex and otherwise manage to move outside the alignment plane, enough to throw the belt off.
I did everything I could imagine before giving in.
Played with belt tension, removed and fiddled with all PS mounting hardware, had stuff machined, and resorted to harsh language even. No dice.
That's when I decided to go electric.
https://www.miataturbo.net/general-m...version-72689/
Never looked back.
#6
Godless Commie, I love what you did with EPS but, unless there's an affordable turn-key conversion available, I have neither the time nor the fabrication skills to cobble together my own version. I am coming around to your conclusion that it's just "one of those things" with no easy fix.
So, per sixshooter's suggestion, depowering: I managed to drive the car for a couple of sessions sans power steering but the effort was extremely high (in that I had to invert my grip on one side of the wheel and pretty much put all my body weight into things in high-g turns). There was also a lot of chuddering (probably a made-up word, but trying to describe how the effort would randomly change during a constant radius corner) and excessive kick-back. I'm sure all of that can be ascribed to having to move fluid through the unpowered pump. So what's the process that will create the best return on time invested (meaning, can I get it done before the next track day). Is looping the fluid lines sufficient?
From what little knowledge I have, this is the best way to depower a rack, but that's maybe a winter project. Anybody done one or the other. Feedback on steering effort and feedback?
Thanks.
So, per sixshooter's suggestion, depowering: I managed to drive the car for a couple of sessions sans power steering but the effort was extremely high (in that I had to invert my grip on one side of the wheel and pretty much put all my body weight into things in high-g turns). There was also a lot of chuddering (probably a made-up word, but trying to describe how the effort would randomly change during a constant radius corner) and excessive kick-back. I'm sure all of that can be ascribed to having to move fluid through the unpowered pump. So what's the process that will create the best return on time invested (meaning, can I get it done before the next track day). Is looping the fluid lines sufficient?
From what little knowledge I have, this is the best way to depower a rack, but that's maybe a winter project. Anybody done one or the other. Feedback on steering effort and feedback?
Thanks.
#7
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My rack is simply drained completely and the lines looped. No complaints.
Btw, the easiest way to get the fluid out is to put the front end on jackstands and disconnect the lines and drain what you can. Then, unlock the steering wheel and from outside of the car grab the driver's side wheel and steer it left to right slowly at first and then getting faster as you get down to that last little bit of fluid in the rack. It will sound something like air rushing out and then at the very end of the stroke a little spurt. Then reattach the lines and loop them and you are left with just enough oil to provide some lubrication inside the rack but no resistance to movement.
Btw, the easiest way to get the fluid out is to put the front end on jackstands and disconnect the lines and drain what you can. Then, unlock the steering wheel and from outside of the car grab the driver's side wheel and steer it left to right slowly at first and then getting faster as you get down to that last little bit of fluid in the rack. It will sound something like air rushing out and then at the very end of the stroke a little spurt. Then reattach the lines and loop them and you are left with just enough oil to provide some lubrication inside the rack but no resistance to movement.
#10
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Even if the whole thing slips, it still stays within the same plane.
The pulley needs to move out of its plane to throw the belt off.
My guess at the time was, it was the PS pulley that was getting out of whack. Otherwise, I would be having problems with the alternator belt, too.
#11
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At high RPM the mass of the belt causes it to orbit. If the leading edge indexes even slightly off track things can go down hill in a hurry. It only takes a mm or so longitudinally or a few degrees off-plane to be problematic. Use the precision metal edge from the ps pulley side, make sure the edge spans the entire pulley, measure the offset between the pulley face and the bottom of the first groove. Apply the same offset on the crank side, eyeball how parallel it is with the groove. Try to span the entire vrank pulley for best reference. If it looks even a little out of parallel or off longitudinally, it could be a problem.
#12
I have the same situation with the power steering belt on the same car - canadian MSM without A/C.
It started right after PS belt replacement, i never expirienced this problem before, so I suspect an operator error.
I have tried the Bando, Continental and Gates belts, the different tension gauges, inspect a shafts and puleys play.
All seems correct and nothing helps.
It started right after PS belt replacement, i never expirienced this problem before, so I suspect an operator error.
I have tried the Bando, Continental and Gates belts, the different tension gauges, inspect a shafts and puleys play.
All seems correct and nothing helps.
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