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Maniacal Motorist
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Discussion Starter #1
My end-play measurements show that I need a 1.75mm shim, but the smallest shim from Lotus is 2.00mm. Has anyone else com across this? All bearings and races are seated fully. The Quaife must be slightly longer than the stock diff? Do I just have the old 2.10mm shim machined-down?

Thanks for the input!
 

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Assuming you have measured everything correctly and you do need a 1.75mm shim. Get a piece of 1/2" think glass or a scrap of granite (need a hard flat surface, about 12"x12"), put 1000 or 1500 grit wet/dry sandpaper on your glass/granite. Wet the sandpaper and lap the shim, rubbing it in a swirling motion. Wet the sandpaper frequently. Measure the thickness often and in multiple places to make sure you are removing material evenly. Take your time.
 

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Assuming you have measured everything correctly and you do need a 1.75mm shim. Get a piece of 1/2" think glass or a scrap of granite (need a hard flat surface, about 12"x12"), put 1000 or 1500 grit wet/dry sandpaper on your glass/granite. Wet the sandpaper and lap the shim, rubbing it in a swirling motion. Wet the sandpaper frequently. Measure the thickness often and in multiple places to make sure you are removing material evenly. Take your time.
interesting.... that's some precision craftsmanship
 

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Maniacal Motorist
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Discussion Starter #4
Great tip! Glad it’s memorialized on here for anyone who might encounter the same issue. I ended-up taking to a machine shop, and they took it down to 1.85. The 1.75 was a mistype. It worked great and got the turning torque into spec.

Thanks for the thoughts!
 

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Hmmmm. Never seen that before and I've installed a ton of these. Must be a bad one or lot.
 

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Hmmmm. Never seen that before and I've installed a ton of these. Must be a bad one or lot.
I was wondering when you were going to chime in on this one. Makes me wonder if the bearings are fully seated in the housing. When I switched from the TRD to the Quaife, I had to change the shim but it still was withing spec.

Later,
Eldon
 

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Assuming you have measured everything correctly and you do need a 1.75mm shim. Get a piece of 1/2" think glass or a scrap of granite (need a hard flat surface, about 12"x12"), put 1000 or 1500 grit wet/dry sandpaper on your glass/granite. Wet the sandpaper and lap the shim, rubbing it in a swirling motion. Wet the sandpaper frequently. Measure the thickness often and in multiple places to make sure you are removing material evenly. Take your time.
You are talking about sanding off 0.010", you will be there for days. 🤣
 

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You are talking about sanding off 0.010", you will be there for days. 🤣
I took .020" off of some standard washers once to make shims. Yes, it took a long time, a few hours to do 4 of them. Definitely not days.
 

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A quicker way to do this is something I've done with valve shims for a shim-and-bucket engine (a Fiat 128 engine, but the principle holds). I did a post over in the Esprit boards a few months ago about this. Basically you put a grinding wheel in a drill arbor, chuck it up in a drill press, adjust the table tilt carefully to get just a smidge of off-level (so you have a very slightly conical grind) Use bolts, nuts, and washers through the table to make a jig to hold the shim in place, and then start grinding (use oil). The shim will rotate in the jig because the off-level table setting, resulting in a very, very shallow auto-leveling grind. Works quite well once you figure it out. You can even change out the grinding wheel for a finer/slower grind as you get close to the desired dimension.
 
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