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Diff backlash and shims question.

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Old 09-19-2018, 01:49 AM
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stascom
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Default Diff backlash and shims question.

Spec is 0.10mm-0.15mm. I'm at 0.28-0.30mm. Stock side shims are 2.15mm and 2.45mm. They're about $40 a set. Would like some advice on what sizes are likely to get me into spec, so I don't have to buy more than 1 pair. I'm leaning toward 2.05mm and 2.55mm.
Old 09-20-2018, 12:16 PM
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guitman32
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Hard to say exactly. Definitely err on the loose side, especially if your pattern is already good. How is the pattern?

Did you add gears, lsd?
Old 09-20-2018, 02:35 PM
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Tomei LSD, new side bearings. Same gear set. Haven't checked the pattern, yet
Old 09-21-2018, 01:50 PM
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Giving the pattern a check couldnt hurt, although the pinion depth should be ok. Which side is the 2.15 side on?
Old 09-25-2018, 03:14 PM
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stascom
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Originally Posted by guitman32
Giving the pattern a check couldnt hurt, although the pinion depth should be ok. Which side is the 2.15 side on?
2.15 is opposite of the pinion. Swapping them would increase backlash. Looks like I'm waiting until October for the shims to ship :/
Old 09-25-2018, 05:11 PM
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Opposite of the ring you mean...the smallest they make is 2.0 so at most you should only need a second set. Another $40 isnt that bad to get it right.
Old 09-26-2018, 04:53 PM
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Originally Posted by guitman32
Opposite of the ring you mean...the smallest they make is 2.0 so at most you should only need a second set. Another $40 isnt that bad to get it right.
It is opposite of the ring. But I did mean pinion. I pictured it wrong; it's on the side closest to the pinion. The odd thing is that backlash was excessive when I broke it down the first time. Wasn't this far out though.
Old 09-26-2018, 05:10 PM
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If it was an OEM setup on the diff, it could be wear that resulted in the excessive lash as you measured on the way out. If that is the case it may be wise to aim for what it was rather than the OEM specs since you are reusing the same gears.
Old 12-14-2018, 12:26 AM
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stascom
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So this is how much play there is in the shaft after all said and done. Does it seem excessive?

https://mega.nz/#!9TYRzQzR!tT_wQoKbJ...UpZVL_oSjdjheU
Old 12-14-2018, 06:25 AM
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It looks fine, but looks fine is not how you determine if your backlash is correct. What was it as measured at the gears with the new shims?
Old 12-14-2018, 03:54 PM
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BigBlue
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Originally Posted by stascom
Spec is 0.10mm-0.15mm. I'm at 0.28-0.30mm. Stock side shims are 2.15mm and 2.45mm. They're about $40 a set. Would like some advice on what sizes are likely to get me into spec, so I don't have to buy more than 1 pair. I'm leaning toward 2.05mm and 2.55mm.
I've got a few unused shims available from when I did a FD build; 3 pinion shims: 3.20, 3.24, 3.25 and a side adjust shim that is 2.55 (all from Nissan). *wish I could help with more side adjust shims.
Old 12-15-2018, 12:57 AM
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Originally Posted by guitman32
It looks fine, but looks fine is not how you determine if your backlash is correct. What was it as measured at the gears with the new shims?
0.26

Originally Posted by BigBlue
I've got a few unused shims available from when I did a FD build; 3 pinion shims: 3.20, 3.24, 3.25 and a side adjust shim that is 2.55 (all from Nissan). *wish I could help with more side adjust shims.
Thanks. It doesn't matter for now. I have 3 other vehicles to deal with. I'll get the pinion bearing replaced at some point, so I'll worry about it then. Just wanted to get this thing out on the road after letting it sit for a year.
Old 11-26-2021, 10:23 PM
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hughtol
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did you ever find out what shims were needed? Also how much miles were on the diff?
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