Lost Rear End Shim in Diff?

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Hello TDR Brothers!

Question: How do you know when a Dana 70 has lost a shim in a First Generation truck?

The reason I ask is that I have just installed a Mag-Hytec & Amsoil 75W-90 Series 2000 in the rear differential. When I pulled the OEM rear cover there was a suspicious looking ribbon of metal attached to the OEM magnet. This strip of metal resembled thin 'gage stock' material that had been coiled.

I don't have much experience with what the actual shims look like in the differential. Could someone provide some potential insight on this unidentified metal?

The rear end seems to perform well with no noise or excessive slop.

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1992 W250 5spd. 3. 54 gears, LSD, Banks "Stinger Plus" consisting of a 14cm2 wastegated housing, 3 1/2" exhaust/muffler, pyro/boost gage, K&N, Skyjacker 2 1/2" front suspension lift to clear 305/70R/16 Goodyear MT's, Mag-Hytec, Amsoil

 

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That strip may have been in there since new. I couldnt imagine a large piece falling out and not making a racket or getting caught up in the ring gear. Be worth keeping an eye on though.

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1999 2500 Cummins w/4spd auto,3. 54s,Quad Cab,SWB,4x4,Flame red ,all options less leather and radio controls on steering wheel,OEM color matched runningboards,DeeZee bedrails painted black,Power Vision Mirrors,OEM ventshades,Oem sill covers,OEM underrail bedliner,Isspro pyro,Westach temp,Painless wiring,RadioShack CB,Westin Black brushguard

 

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The stock shims are about 1/2" wide. It could be that a sliver from the OD broke off--often the outer 1/8" or so of the diameter is unsupported and I suppose a piece could vibrate and break off.

 

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Might have been dropped,and not picked up by the orig assembler, on Friday at 2:15PM just prior to the weekend, cover installed oil added first time the gears turned bent it up and the magnet caught it. never a problem since it did??


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95-2500-ExtCab-LB-4x4-Auto-AMSoil Air Filter, Bypass Oil Filter by others, AMSOIL and Mobil Synthetics, TST 255HP and TransGO Shift kit .

 

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Keeno, Yes that metal is part of a shim. Take it to a rear end shop and within 20 min the mechanic can show you where either one or both of your inner bearings are spinning where they shouldn't be.
You just described exactly the same thing that I expierenced with mine. The shop explained to me that this was not uncommon with the Dana 70 and if caught early you would save money on rebuild. Mine made NO noise at all and was totally undectable while driving. I had it rebuilt with Timkin Bearings and all new Seals for a little over $800. 00. DON'T LET IT GO!
Walt

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91 D350,New style BD Brake,Gear Vendors O/U Drive,Gauges-Pyro,boost,tach,trans,rearend,brake,
Airbag rear,Transfer flow tool/tank, Exh. sys,Rino lined bed, Alcoa Mags,SS runningboards.
16cm.

 

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Thanks Gang, for the replies!

I'll do some research an find a reputable shop and take her in for a diagnosis. My concern is that I don't know how long the suspected shim has been loose or out. The strip of metal is about 1/2 in width and extremely thin.

What should I do with the $60. 00 of Amsoil & friction modifier I just put in? Should I consider straining & reusing it or just take the loss?

Thanks again! Keeno

 

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When I bought my 92 used, it had 18,000 miles on it, the rear end was set up with 4. 10's and the best it would due was about 68mph so I took it to the rear end dude and had them throw a set or 3. 54's in and when I picked up the bill he said it was a good thing that I had this done because the bearings were real bad - Funny thing is that I never heard a groal come out of it. That musical Cummins can cover up a lot of sounds/noises.

 

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Keeno, Bite the bullet and buy some more lube. No telling how much material is ground up in your new fluid. Not worth taking a chance on it.
Walt

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91 D350,New style BD Brake,Gear Vendors O/U Drive,Gauges-Pyro,boost,tach,trans,rearend,brake,
Airbag rear,Transfer flow tool/tank, Exh. sys,Rino lined bed, Alcoa Mags,SS runningboards.
16cm.