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Discussion Starter #1
At least I think that's what it is. Took my 1750 out this weekend, and noticed that the bottom radiator hose was covered in oil, as was the front face of the sump.
On closer inspection, it seems to be coming from behind the bottom fan belt pulley on the front of the crank, as the back face of the pulley is very oily.
My questions are:

- Is this a likely source? Given the pattern of oil I think so, it doesn't seem to be coming from the dipstick/top end of the engine etc?
- If it is the crank seal, how long can I just keep driving the car and topping up the oil? Is it a full pressure seal that's likely to let go completely and dump all of the oil onto the road, or will it just gently dribble? I'm also a bit worried about the bottom radiator hose which I think is original, and is probably not being improved by being soaked in oil - its allready looking a bit baggy.
- Finally, how much of a job is it to replace the seal. I assume I can do it with the engine in situ, but does the rad neet to come out, or can I just take off the plastic cowl? Is the the pulley on a taper? Do I need a puller to get it off? How easily should the seal come out?

Thanks
 

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It does sound very much like the front oil seal and to get at it you will have to remove the radiator.
The pulley is keyed and held on by a 36mm right hand thread nut with a tabbed lock washer under it. You need a fair bit of room to get at the nut, hence the necessity to remove the radiator.
For safety reasons, disconnect the battery before you start all of this.
You will need a compressor and 'rattle gun' to get the nut off the front of the crankshaft and you will have to 'lock' the crank somehow - probably the easiest way, if your clutch is OK, is to put the car in 4th gear, pull on the handbrake and chock the rear wheels while you 'rattle' the nut off.
Once off, you'll need a puller to get the pulley off as it is a very snug fit (I can't remember the torque - maybe someone else can help).
The oil seal itself can be gently prised out and replaced (#46 in the photo) - it is a standard seal with a 40mm OD / 28mm ID. You can just see the markings in one of the photos.
This is also a good time to clean the front of the engine. Check the water pump while you are at it and replace if necessary because you'll have to repeat all of this if it fails in future. Also get your radiator cleaned and pressure tested before you reinstall it. Finally, replace the dud hoses.
Hope this helps. I'm never really sure how much detail to go into with these answers - I don't want to be seen to be telling people how to 'suck eggs' ...
Let us know how you get on. BTW, you can continue to drive the car with a leaking seal so long as you check the oil regularly but it does get very messy.
Regards,
Chris
 

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Discussion Starter #3
Thanks for the very comprehensive answer! All very helpful, unfortunately I don't have an air compressor, maybe a socket with a long bar on it might work?
 

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I replaced the front seal without an airtool.

It might be easy to loosen the crankshaft pulley nut . . . . or it might be a real bear. Mine was a really large Kodiac Bear in a foul mood. I had to remove the starter and install a flywheel lock in order to get enough torque on a 3/4" socket, a breaker bar with a long steel pipe used as an extension. You'll need to remove the radiator and injection pump drive belt, of course. Other than getting the pulley nut off, it was quick and easy.
 

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I did this very job on my Alfa a couple of years ago and like you John, my pulley nut was just about welded on. I grunted and groaned with a socket/pipe and just got frustrated, so I hired a compressor for the day. Once I got the nut off, the rest was a doddle.
I've since helped a few other people replace these seals on a few different cars and have used a compressor (I bought one) each time.
I know not everyone can go to this expense, but it is a very handy device to have lying around the shed, particularly, if like me, you own and run a number of ageing autos.
I'll try to get the torque setting for the nut sometime.
Chris
 

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Tom, you're doing this at home right? If you have access to a friend's shop with an air supply and an impact wrench, the job is a no brainer. I needed to install a new water pump on my 1750. My friend's shop was busy so I did the job at home in my driveway. You'll need to take the radiator out and the front grille/side pieces. This will give you easy access to the front pulley. Most tool rental stores have 1/2 inch electric powered impact wrenches so you'll need one of these if you don't have an air supply at home. You'll need a good quality 36mm 1/2inch socket, an impact quality extension and, if memory serves, an impact wobble extension. I used a SnapOn socket (expensive) and the store's impact extension that came with the wrench. Be sure to bend the tab up, hit it with the impact wrench and it'll come loose on the first try. At least you can hope it will.

A caveat: You really should use a thick walled 36mm impact socket. These are hard to find and it's unlikely that a rental store (or anybody else other than SnapOn or Cornwell tool guys) will have one. I took a chance using a standard, high quality, socket rationalizing that a one time use wouldn't do any damage. It didn't because the nut came off quickly. However, if the nut is hard to get off (it shouldn't be) and you really have to work on it there's a good chance that you're going to ruin a standard (expensive) socket. Needs must. :)
 

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Discussion Starter #7
thanks, will be doing this at home, I've got a fairly well equipped workshop. Might try and hire an electric impact wrench - I've heard of 12v ones for sale for not too much money - has anyone got any experience of them?
Will probably do the water pump at the same time, the car has done about 50k miles, are they known to fail?
 

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Had same issue on my '88 Spider. The seal was actually destroyed (chipped off, slowly but certainly) by a broken crankshaft pulley!! :eek: (Heard that the broken pulley is a known issue for A/C cars). So while you're at it, you might want to check the pulley. I did not do this job myself, though :eek:
Good luck :cool:
 

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You want to check for grooving on the pulley made by the old seal. If bad, a new seal will leak. There are sleeves that you can slip over the sealing surface to correct a bad groove.
 

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1) a thick walled 36mm is available at several parts counters actually. (I got one at Advance Auto, though AutoZone and Napa also both had them)

It's used to change the halfshafts/CV shafts in I believe Ford Tarus'. (if not that, then another make and model, but the point is they do have them in 'impact grade' 6 point right on the shelf for about $15-20 USD)

If by some chance they don't have one for sale outright, they likely do have one they use in thier 'lend a tool' program (if they participate anyway)


2) If you're not interested in renting or borrowing a compressor or scrounging up whatever flywheel lock or electric whatsisjigger, just get a breaker bar with said socket on it, brace the bar against the floor or frame on the left side (right side when standing in front looking back) disconnect the coil wire, reconnect the battery and crank the engine.

It'll take all of 2 seconds or less to break loose and spin the nut off. You won't even strain your fingers or break any blood vessels.

Definitely a tried, true and viable method of doing it, unless you really do wanna fart around with it all day of course.... ;)
 

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Discussion Starter #11
I'd thought about using the starter motor to undo it like that, but assumed that it was a bit dangerous, otherwise people wouldn't bother with impact wrenches etc...

Or are they just wimps?
 

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I can't find a value for the torque setting for that nut. Just do as an old mechanic mate of mine used to say - tighten it up until the thread strips and back off half a turn ....

As to the other - I guess that is why the starter motor is called just that and not the 'help to loosen the pulley nut' motor. Caveat emptor, as they say.

Let us know how you get on,
Chris (wimp)
 

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Definitely a tried, true and viable method of doing it, unless you really do wanna fart around with it all day of course.... ;)
Thanks for posting this method, Darren. Many pro mechanics (and me as an ex-pro) have used this method since forever.
 

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Hi,guys. I'm working on crank shaft pulley and front oil seal refering this thread. Regarding the tightening torque for the pulley, I have a question. In my service manual the torque value is shown with the description of the "oiled". What does "oiled" means? Sorry for my very general question.
Takeshi, Japan
 

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Takeshi, it means to add a few drops of oil onto the threads of the bolt or nut and then torque it down.
 

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Torque value for a 2L is 138-144ft/lbs. 1750 shouldn't be much different I imagine.
That's not always correct as there are 3 different thread sizes on the cranks thru the years. Try a search here on Alfabb, we've had that topic several times.

It's not the issue for a mech to get the nut off, it's more important to get it correctly fixed. WITHOUT creating a hair line on the pulley boss when tightening with an imoact tool!

Do check your pulley boss accurately first when off.
 
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