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Crankshaft toothed pulley  Rating:  Rating
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 Posted: 03-07-2006 07:07 pm
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colinw59
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Joined: 02-14-2006
Location: Bloomfield/Hebron, Connecticut USA
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74 JH # 15851 (see CT gallery pics) was anxiously turned over for the first time in 15 months last Friday. New engine loom, Petronix Ignitor, Petronix Coil, Plugs, leads, new Lucas alternator in favor of the original Delco unit, rebuilt carbs. I turned the key and the engine turned over slowly, very slowly. Ah poor ground, I'd forgotten to attach the engine ground wire! Second turn, and there she goes, lumpy and rough but running non the less. The timing was 30 deg off (Petronix ignition will do this)! Carbs need to be balanced and a few other thing before she can deliver the 140HP she's supposed to.

Oh yes, and oil on the floor!! The crankshaft front cover oil seal had given out. Ok put car in gear and e brake on, radiator & hoses out, loosen alternator, fan and belt out, crankshaft V belt pulley off, marked position on aux pulley, timing belt tensioner removed (will replace bearings now along with belt, which I was going to do later as the belt looks good), timing belt off. Remove bolts from front cover, oh dear the toothed pulley wont budge! Of course not this thing is keyed and has to be on there tight without any radial movement. I checked the parts diagram to make sure I wasn't missunderstanding something which I wasn't.

Jim at Delta had suggested I pry it off by using a Ladie's shoe between the front cover and the rear face of the crank pulley flange (which is really a large washer). I don't have a ladies shoe (nor any other articles of women's clothing for that matter!)and I'm getting impatient. I sprayed anti sieze fluid all over the area and then used a dent puller with an L shaped pulling attachment on the end in lue of that ladies shoe. A dent puller works in the same way as a sliding hammer, so this may work also. I measured the position of the front face of the pulley, (it was 11mm (OK I'm European and it is a metric engine!) to the end of the crankshaft) to see if all my pulling resulted in any forward movement of the pulley. I was just able to get the L shaped puller in the front cover's timing belt guide slot and behind the pulley flange. And then I began working the puller. I rotated the cover/puller thru 180 deg each time to prevent the pulley from locking into the crankshaft. After 20 minutes I started to notice some movement! It took me an hour, achieving very small increments by slowly crabbing the pulley of the shaft. The last 6mm were easy though. I inspected the pulley and crankshaft and rust had siezed the two together. I think it would have been impossible to have pryed this pulley off in any other way.

I have a new cover oil seal and a replacement front cover gasket is on its way from Delta, along with the timming belt tensioner bearings and a new crank pulley flange. Disassembly time was 2 1/2 hours, assembly should be qicker and earier, correct!!!!!

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 Posted: 03-07-2006 08:28 pm
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jcdean
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Joined: 02-22-2006
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While in the Navy I had the opportunity to watch a few propellers come off and go back on submarines.  I do believe some methods that I saw would have been applicable in your case.

 

1.   When at all possible, have a crane on the dock.  This provides adequate leverage

2.   Improvised tooling.  If step one is not enough, weld on a 20 ft. I-Beam.

3.   Explosives.  After the nut breaks loose, this will free the siezed part.

4.   Navy Seals.  Read three above.

 

Hope this helps next time.

 

Joey

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 Posted: 03-09-2006 02:47 pm
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Judson Manning
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The later sprockets have threaded holes to attach a puller - much easier.  I have had to use a 20' cheater pipe and dynamite on some of my early sprockets....

Make life on yourself easier, use some 400-grit sandpaper on the shaft, clean the crank, sprocket, etc., and put some anti-sieze compound on the shaft prior to re-assembly.

Also, use a non-hardening gasket sealant on the front cover.  There is considerale slop with the mounting bolts, so be careful in the tightening sequence.  The cover needs to 'float' on the shaft or else it will pull to one side and continue to leak.

 

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 Posted: 03-09-2006 03:54 pm
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colinw59
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Thanks for the tip Judson, especially regarding centralizing the front cover. I should be putting the assembly back together next week when the gasket & flange arrive from Delta. Jim at Delta had also told me about the tapped holes in the pulley on later models. This is a case hardened item so I won't try to drill & tap it for future removal. I don't have any dynamite here, I just used a lot of offensive language and shamed it of the crankshaft!

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 Posted: 03-11-2006 01:39 am
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Esprit2
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There is a special tool for centering the front seal during installation (and another for the rear seal).   It takes all the guess work out of centering the seal and ensures a dry seal.   I highly recommend using one.   Ask your favorite parts supplier if they have a J-H/ Lotus tool rental program.   If not,  Jeff at JAE does rentals (?  it might be tied to buying the part from JAE...  I'm not sure ?).

Without the tool,  be really anal retentive about getting the seal centered accurately.   I've used a long-jaw vernier caliper to measure the gap between the housing ID and the crank journal OD.   Measure top & bottom and left & right,  tweaking the housing position until the dimensions are equal.

I've also used plug gauges (drill bit shanks).   Measure the housing ID and crank journal OD,  subtract,  divide the difference by two.   Buy three drill bits (or actual plug gauges) that diameter and place them at 120 degree intervals around the journal so they also pick up the housings OD.   Hold everything while you tighten the bolts with your third hand.

Boy,  that seal centering tool takes all the time and frustration out of installing the seal.

The original front seal has a 67.71mm OD.   I don't know if they've in short supply now,  or if the Lotus prices just got way high;  but most independent Lotus/ J-H parts suppliers are now selling a non-Lotus seal that is very similar but with a 68.00mm OD.   It's an SOB (!) to get into the front housing.   I've ruined more seals than I've managed to get in properly.    Considering my success ratio and the expense of replacing damaged seals,  I don't see the value of an economically priced alternate seal.   If you can find an original Lotus seal,  buy it.

The diameter difference may not sound like much,  but when you start with a negative fit,  going tighter by  0.29mm (0.0116")  is a lot tighter !

Original seal  =  51.81mm ID,    67.71mm OD,    7.92mm Thickness

Tim Engel  (Lotus Owners Oftha North)

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