Crank pulley nut is 38mm?

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bran100
Posts: 155
Joined: Thu Feb 08, 2007 12:34 am
Your car is a: 1982 Spider
Location: Draper, Utah

Crank pulley nut is 38mm?

Post by bran100 »

I've seen a couple references that the nut on the crank pulley is a 38mm. Is this true? I went to Sears for a 38mm socket and they don't even have one that big.

I'd like to change the timing belt this weekend on my 82 Spider. Is it necessary to pull the crank pulley?

Where do I get such a monstrous socket?
HawaiianSpider

Post by HawaiianSpider »

I can't remember what size it was exactly, but I got mine at NAPA auto parts. You will probably also need a impact wrench to get it off. If you don't have a compressor, they sell electric impacts at Sears.

Have fun,
Mike
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manoa matt
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Joined: Thu Oct 26, 2006 4:28 pm
Your car is a: 1978 Fiat 124 Spider 1800
Location: Honolulu, Hawaii

Post by manoa matt »

A 1 1/2 inch socket is roughly equivelant to 38 mm, and it works well and is avilable at Sears for about $10.

Depending on the crankshaft oil seal casting, you may, or may not need to take off the pully. On earlier years, I have a 78, the belt can go on and off without taking the pully off. I have heard that on later years there is a flange that might prevent this. I have posted pictures of the process for my 78 in the "engine and tuning" section, look for a post on the top of page 2 that says " replacing the cam belt--how to get the front pully off"

If you need to take the pully off, then you'll have to drain and remove the radiatior and fan, to get adequate and unrestricted access to the nut. It is on there pretty good, and you don't want anything in your way when it breaks free, or you could get hurt. If you don't have one, rent an electric impact wrench.

If by chance, you think you can get the belt on and off without taking the pully off then all you have to take out is the fan.

A socket that big will have a 3/4" drive, so you might have to buy a step down adapter to 1/2", if you don't have a 3/4" drive wrench. But by the time you get the socket and the adapter on there is no room for the socket wrench, unless you take out the radiatior.

To simplify this I took a piece of flat stock steel, 1 inch wide by 10 inches long and put about 3/4 " in a vice and bent it at a 90 degree angle. Now I only have to take out the fan. If you take out the fan there is enough room to get the socket on.

The socket has a hole that is 3/4" by 3/4" square. The hypotenuse of that square is slightly over 1 inch. So the part that you bent will fit in the diagonal of the hole. Sounds confusing, I'll take some pictures tonight or tomorrow to show you, as I have to turn the engine over by hand this weekend.

If you take the spark plugs out, as you should, it will be much easier to turn over by hand.

Once you get all your timing markes lined up, and you are shure your timing is correct, make a mutual mark on each timing pully and the belt.
Take the old belt off and lay it next to the new belt. Transfer the marks directly, noting how many teeth are between each mark. Put the new belt on so that the marks on the belt line up with the marks on the pullys.

The old belt could stretch durring its life, and when you put on a new belt that is slightly smaller, you may have a timing wheel whose teeth don't exactly line up with the belt. You would have to turn the wheel one way or the other, then your timing could be off by as much as two teeth.

By making mutual marks you'll always have the same number of teeth between each wheel, and the slack will be taken up by the tensioner.

I'll post pictures of the wrench later tonight.

Matt
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manoa matt
Posts: 3442
Joined: Thu Oct 26, 2006 4:28 pm
Your car is a: 1978 Fiat 124 Spider 1800
Location: Honolulu, Hawaii

38mm nut

Post by manoa matt »

Here are the pictures of the wrench. Remember that this wrench is only used to turn the engine over. It is NOT used to remove the nut.

http://www.flickr.com/photos/38097470@N00/408514319/

http://www.flickr.com/photos/38097470@N00/408514320/

http://www.flickr.com/photos/38097470@N00/408514321/

http://www.flickr.com/photos/38097470@N00/408514325/

If you look at the picture where the wrench is installed on the pully nut, my radiatior fan is still installed, its red. Now that I think about it you still have to drain the radiatior a little bit in order to get the cooling system "T" off, so you can get the timing belt cover off.

I hope you can get the belt on and off without taking the pully off, good luck

Matt
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bran100
Posts: 155
Joined: Thu Feb 08, 2007 12:34 am
Your car is a: 1982 Spider
Location: Draper, Utah

Post by bran100 »

Dumb question, but I have to ask as the freakin' crank nut is killing me......

Righty tighty, lefty loosey, right?

Using a 1/2" impact that's rated to 250 ft/lb and I can't get it broken free. I'm using a pancake compressor that is probably delivering too little CFM, but it seems like I could at least break it with short bursts. Guess I'll have to rent a larger compressor.

Thanks,
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manoa matt
Posts: 3442
Joined: Thu Oct 26, 2006 4:28 pm
Your car is a: 1978 Fiat 124 Spider 1800
Location: Honolulu, Hawaii

Post by manoa matt »

Yep, righty tighty, lefty lucy. If your compressor has a regulator, open it up to 90psi. The compressor may go higher, but the air reaching the impact wrench should stay below 90psi. Try some PB Blaster, or penetrating oil on it. Let it soak in.

matt
124cso

Post by 124cso »

If you have an 82, you WILL need to remove the pulley ( assuming some previous mechanic has not left the sheilds off) ( and I've seen a car like this), and it is a Bas###d of a job - until you know how.

I had the same problem and suggest you look at my posting - "Tool for removing front pulley" listed under 'spider related ' forum and last entry date about 14th Nov. I gave a quick run down on how i did it and link to pic of the tool we made. If you want any more detail - email me.
Remember to put a smear (only) of antiseize paste on the thread when you reinstall - for next time, but ONLY on the THREAD.
All the books say torque up dry but a well known engine reconditioner told me always lube the thread. It is head friction you want, not to try and shear off the thread.

I was able to get it off & do timing bely with the radiator still in place. Cannot now recall if I had to lift out the fan or not ?

good luck
Last edited by 124cso on Tue Feb 05, 2013 6:52 pm, edited 1 time in total.
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SLOSpider
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Your car is a: 1973 124 Spider 2.0FI
Location: Lompoc, Ca USA

Re: Crank pulley nut is 38mm?

Post by SLOSpider »

Harbor freight is my best friend when it comes to bigger sockets and impact wobble extensions.

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narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: Crank pulley nut is 38mm?

Post by narfire »

bran100 wrote:I'd like to change the timing belt this weekend on my 82 Spider. Is it necessary to pull the crank pulley?

Maybe... if the metal shields are still in place, yes as there is a 10 mm bolt tucked in behind, so the nut has to come off.

If the metal shields are missing then I don't have a problem changing the belt in my 80.
You will notice just below the water pump the timing pointer. That has a threaded bolt and a pressed in bolt. Remove the threaded bolt, and the pointer will swing up and away enough for the timing belt to fit through..
Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
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