woodruff key(s)
Discussion
Now entering my fourth week off the road for a "simple" water pump replacement. The full story is too long but vindicates my previous banned comments.
For those that don't know, if your water pump leaks you have to send it back to the factory for a rebuild. Its integral with the power steering pump and also bolts up to the sump (which carries some cast in water ways). O yeah... and its an engine out job.
So what used to take me 15 minutes in the car park on an MGB now takes, um, longer. Such is the price of progress. But here's the thing.. the factory lost my woodruff key. So after another week, they sent two more because they weren't sure which one would fit.
And the answer was...
neither (you were way ahead of me there weren't you)
So now they say we have to grind the key to fit. But if the key is case hardened, then grinding it is just going to wreck the hardening and lead to an inevitably expensive water/power steering pump failure. And what do I tell the warranty company then?
So does anyone know if the key is case hardened or if it is really safe to grind the key to fit (should have said.. its too thick)? Help please?
For those that don't know, if your water pump leaks you have to send it back to the factory for a rebuild. Its integral with the power steering pump and also bolts up to the sump (which carries some cast in water ways). O yeah... and its an engine out job.
So what used to take me 15 minutes in the car park on an MGB now takes, um, longer. Such is the price of progress. But here's the thing.. the factory lost my woodruff key. So after another week, they sent two more because they weren't sure which one would fit.
And the answer was...
neither (you were way ahead of me there weren't you)
So now they say we have to grind the key to fit. But if the key is case hardened, then grinding it is just going to wreck the hardening and lead to an inevitably expensive water/power steering pump failure. And what do I tell the warranty company then?
So does anyone know if the key is case hardened or if it is really safe to grind the key to fit (should have said.. its too thick)? Help please?
Beej
Well if I were designing a keyed pulley / shaft assembly then I would not case harden it. I would rather the key were damaged in the case of failure than the shaft or pulley. I really doubt it is case hardened, easy to tell though, just take a file to a corner and see if it cuts, if it does the key is not case hardened. If the file wants to bounce off of the key rather than cut then it is hard.
Cheers
Bob
Well if I were designing a keyed pulley / shaft assembly then I would not case harden it. I would rather the key were damaged in the case of failure than the shaft or pulley. I really doubt it is case hardened, easy to tell though, just take a file to a corner and see if it cuts, if it does the key is not case hardened. If the file wants to bounce off of the key rather than cut then it is hard.
Cheers
Bob
Thanks, I haven't had chance to check whether the key is case hardened - I just assumed it would be. But as you rightly say, there is a good engineering reason for it not to be.
Joolz, the water pump and power steering pump run off the same jack shaft don't they - water pump behind, PAS in front? But I guess you are right in the sense that they are seperable.. what i meant was they sit as a unit sandwiching the timing cover and with the water pump bolted into the sump. To get the water pump off you need to remove the PAS pump - the factory insisted that the whole lot was sent back to them to be rebuilt - thats when they lost the key. The keys they have sent aren't even close in size to the slot in the jack shaft/pulley - they are closer in size to the crank shaft front pulley key. It would take a fair bit of grinding to get it to the right size.
I just find it incredible that the factory can't supply the correct size key. What serious car manufacturer sends you a part and says "we know its miles too big but just file it to fit.. it'll be ok"
TVR.
Joolz, the water pump and power steering pump run off the same jack shaft don't they - water pump behind, PAS in front? But I guess you are right in the sense that they are seperable.. what i meant was they sit as a unit sandwiching the timing cover and with the water pump bolted into the sump. To get the water pump off you need to remove the PAS pump - the factory insisted that the whole lot was sent back to them to be rebuilt - thats when they lost the key. The keys they have sent aren't even close in size to the slot in the jack shaft/pulley - they are closer in size to the crank shaft front pulley key. It would take a fair bit of grinding to get it to the right size.
I just find it incredible that the factory can't supply the correct size key. What serious car manufacturer sends you a part and says "we know its miles too big but just file it to fit.. it'll be ok"
TVR.
beej said: Thanks, I haven't had chance to check whether the key is case hardened - I just assumed it would be. But as you rightly say, there is a good engineering reason for it not to be.
Joolz, the water pump and power steering pump run off the same jack shaft don't they - water pump behind, PAS in front? But I guess you are right in the sense that they are seperable.. what i meant was they sit as a unit sandwiching the timing cover and with the water pump bolted into the sump. To get the water pump off you need to remove the PAS pump - the factory insisted that the whole lot was sent back to them to be rebuilt - thats when they lost the key. The keys they have sent aren't even close in size to the slot in the jack shaft/pulley - they are closer in size to the crank shaft front pulley key. It would take a fair bit of grinding to get it to the right size.
I just find it incredible that the factory can't supply the correct size key. What serious car manufacturer sends you a part and says "we know its miles too big but just file it to fit.. it'll be ok"
TVR.
see what you mean now .. yep the power steering pump comes off the back relatively easily, the pumps are driven by a jackshaft from the timing cover.
So now they say we have to grind the key to fit. But if the key is case hardened, then grinding it is just going to wreck the hardening and lead to an inevitably expensive water/power steering pump failure. And what do I tell the warranty company then?
So does anyone know if the key is case hardened or if it is really safe to grind the key to fit (should have said.. its too thick)? Help please?
Hi Beej,
Sorry to read about your woes, sounds a right pain in the A
SE. As far as my engineering knowledge goes. Key steel used to be made from EN6 steel (not sure of the ISO number) been out of the front line for some time. It is not a case hardening steel and should be fitted in it's natural state. All "keys" are designed to shear under load, thus preventing excessive damage to the components that its locking together i.e. shaft and pulley. Key steel (EN6) in its normal state can be filed, ground, chiselled or machine to shape. If you need any more information on the steel, give me a shout and I’ll look up my old specs.
Hope this helps.
Regards,
BigAl.
Thanks to everyone for your help on this. It sounds like it would have been safe to grind/file the key to fit but it really was so far out I have entrusted the job to an engineering firm who are making one from scratch.
Guess what. Warranty Holdings are refusing to pay for the water pump replacement.
This is really putting me off the idea of a 440.
Guess what. Warranty Holdings are refusing to pay for the water pump replacement.
This is really putting me off the idea of a 440.
Byff, I haven't touched it. Its at a Warranty Holdings approved garage with considerable experience of TVRs (especially Cerberas). It just happens that I get on very well with the mechanics and not being mechanically inept myself, they involve me in the decisions. These guys at least managed to track down the water pump problem - which is more than can be said for the dealer.
I will not name them of course, but having asked the dealer to check over the car on two seperate occasions and explain where the coolant was going, I got the usual - they all do that sir. I am sure you will understand my frustration with them and why I opted to have the work done by someone whose judgement I trust.
There are some really good non franchised/dealer mechanics out there. Joolz clearly knows his stuff and I would personally recommend Andy at APM. It just happens that the guys I am using for the current job are 100 yards from my place of work.
But hey.. loads of people are really happy with their dealer. Each to their own. I wouldn't want you to think I was actually pulling this engine part by myself though!
I will not name them of course, but having asked the dealer to check over the car on two seperate occasions and explain where the coolant was going, I got the usual - they all do that sir. I am sure you will understand my frustration with them and why I opted to have the work done by someone whose judgement I trust.
There are some really good non franchised/dealer mechanics out there. Joolz clearly knows his stuff and I would personally recommend Andy at APM. It just happens that the guys I am using for the current job are 100 yards from my place of work.
But hey.. loads of people are really happy with their dealer. Each to their own. I wouldn't want you to think I was actually pulling this engine part by myself though!
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