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Discussion Starter · #1 ·
I took the easy way out and hired out the timing belt on my 94. He found the small oil leak I have was the front main seal. So we decided to change it. The new seal is such a tight fit its rolling. He is checking to make sure he received the correct seal. He said he is using the proper tool to seat the seal.

Is there any special guidance or other issues (common to receive the wrong seal) that might shed light.

Did Lotus change the seal around that time? Thinking this is related to why I had the leak in the first place.

Thanks!
 

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If he is using the Lotus tool to install the front main seal, it really can't be used with the engine in the car - the handle is too long. That would lead to the seal not going on square to the crank. If he's not using a tool - well there's your problem.
 

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Lotus 9XX Front Main Seal

It's normal Lotus procedure to remove the front main seal housing from the engine (easy with the timing belt off). Then work more conveniently at a bench to remove & replace the front main lip seal in the housing. Re-installing the seal & housing on the engine requires the use of a centering tool. That's the Lotus Special Tool Mike referred to as being too long to use in the Esprit. True. The tool was designed in Elite-Eclat days, before the Esprit was in production. It's handle is just too long to use in any of the mid-engine Esprits.

Lotus also made a special front seal extraction tool. I have one, and IMHO, it doesn't work... don't bother. The theory was that you could easily remove the front main seal without first removing the seal housing from the engine. Then use a standard seal driver to tap the new seal into the housing. That's another Elite-Eclat theory that doesn't work well in the mid-engined Esprit. There's not enough room in the Esprit for mallets and tapping.

The best bet for an Esprit is to remove the seal housing from the engine, then R&R the seal at a work bench. Then modify the Lotus front main seal centering tool by cutting it's long handle down to about 2.25" long. With the seal housing securely bolted to the engine, extracting the centering tool can require a pretty strong pull. Now the short handle combined with poor access in the Esprit means you may not be able to pull it out.

So, back when you cut the handle short, also make an insert to plug the hollow handle. Either a press-fit with Loctite, or a threaded insert. Also bore and tap the insert for a long bolt that will be used as a jackscrew. BEFORE installing the seal housing on the engine, screw the front V-belt pulley retaining bolt into the crank. That plugs the hole, and the bolt's head gives the jackscrew bolt something to bear against. When it's time to withdraw the centering tool, just install the jackscrew (ie, long bolt) and use a ratched to screw the bolt in... removing the centering tool.

SEALS ~~~~~~~~~~~~~~~

Lotus' OEM front main seal was a GACO INC52004
Engraved around the front face of the seal was...
"INC52004 GACO 1 ANGUS Shaft --> Rotation"
It's dimensions were:
51.81 mm (2.0398) -- ID
67.71 mm (2.666) ---- OD
. 7.92 mm (0.3118) -- Thickness

The following are two other commonly sold seals that have the "same dimensions" as above OEM seal. They have the following engraved around their flat faces:
AS-LD. . 1. . D>> . 51.81 . 67.71 . 7.92
and
AS-RD. . . . . D>> . 51.81 . 67.71 . 7.92

All three of the above fit the way Lotus intended.

Another seal that's commonly available has slightly different dimensions, but it usually goes in with a minimum of fuss. Engraved around it's flat face is:
TTO F3159 2
Dimensions:
50.749 mm (1.998) -- ID (slightly smaller)
67.89 mm (2.673) ---- OD (slightly larger)
7.97 mm (0.3148) -- Thickness (about the same)

Two commonly sold seals are significantly larger in OD, and very difficult to push into the seal housing's bore. Difficult on a workbench, and a royal pain in the but in an Esprit. Engraved around their flat faces are:
1 . NAK . TGR . 52 . 68 . 10 . 1 . 47404 . . ---> (that's an arrow)
Dimensions:
52 mm (2.0472) -- ID (larger bore/ looser 'seal')
68.00 mm (2.677) ---- OD (larger OD/ difficult fit)
10 mm (0.3937) -- Thickness (much wider)

and
TTO F4187 2 HTCWR 52 68 10
Dimensions:
52 mm (2.0472) -- ID (larger bore/ looser 'seal')
68.00 mm (2.677) ---- OD (larger OD/ difficult fit)
7.67 mm (.302") -- Thickness (a little narrower)

Those last two, with 68mm Outside Diameters, are very difficult to install in the seal housing without damaging them. I've screwed up several of them, even working at a bench. I had an opportunity to practice my 4-letter vocabulary.

~~~
The FRONT main seal is on the front end of the crankshaft, behind the V-belt pulley and timing belt sprocket.

The REAR main seal as on the back end of the crankshaft, hidden by the flywheel & clutch.

Regards,
Tim Engel
 

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Discussion Starter · #6 ·
Thanks Tim - I will pass along to the mechanic.

He told me he got it Tuesday. He had the front main seal housing off and the seal was not going in nicely and he mentioned that he damaged the seal during the process. He ordered two more seals to experiment with and was successful with one of those. I wonder if the first seal he received was one of the larger ones that you describe? He orders from JAE so I would hope they had the right seal - but they have to keep up with millions of parts. Who knows if a supplier sent them the wrong seal?

Thanks again for your priceless contributions.
 
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