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Discussion Starter · #1 ·
My sons 68 has the limited slip and it is making a clunking sound when engaging, I was told by a few that this is normal, is it? Thanks for the replys Joker.
 

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You sure it's not a u-joint that's going bad?
Also, what type of limited slip? Does he have Ford's "friction modifier" additive in it? If so, the stock ones shouldn't make any "clunking" sounds.
Daniel
 

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Discussion Starter · #3 ·
Yes, I do have ford additive in it, and it is a original Detriot locker for a 68. Joker
 

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If it's a locker, it will "pop" and "clunk" as it engages and dis-engages, particularly around corners. Just the nature of the beast. ::
Daniel
 

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Discussion Starter · #6 ·
Ok, here it is more information, door code for axle is "H" the Trans code is "5". The axle tag code is WFD-F/981 and it is the origanal Traction-Loc rearend that came in the car. The car is a 1968 Shelby gt500kr.Thanks for the info so far. I have not driven this car in 15 years and am having problems remembering all the little things about it. I remember a clunk but it sounds louder now or I'm just older and less forgiving. Joker
 

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WFD-F is for a 3.50 geared limited slip type rear, but tag wouldn't specify type. My guess if a 68 would still be an equa loc, just had an original N case 68 4.30 drag packed geared rear with original tag that I sold, it had the equa loc and it was an early June built 68.5 CJ fastback.Earliest trac loc unit I have ever seen was the C9 part number, which with Ford doesn't really mean much at times.The 981 (hopefully )is code for a 68 9 inch Mustang housing type (I don't yet have all specific but it should match build sheet under "axle" ), there should be a date code on tag itself in form of a number/letter/letter (ie. 8FA= first week of June 1968). The build sheets I have are for 390 cars with 9 inch 67/68 and 67/68 8 inch cars- they show 996 for 67/68 9 inch housing type and 930 for 8 inch. On build sheet the three digit number will be displayed with a model year digit before and a suffix type afterwards (I don't have all the facts yet on suffix's). But a 67 build sheet for a nine inch in a 390 shows 7996A, while a 68 shows 8996A etc.. I add this info because my source shows the WFD-F as a 69-71 only code, not 68, but I know there were exceptions.
 

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Are you sure it's the original rearend for that car? I'm thinking the "981" you see is actually "9 B1." This would translate to a build date of Feb 1, 1969. This would appear to make sense since the axle code (WFD-F) is supposedly for 69-71 Mustangs. If that's the case, it should have a traction lok in it. I don't when the first traction loks were used, but the earliest one I've ever found was in a 68 station wagon. I remember it because it was an odd one. Nine inch, 3.25 gears, 31 spline TWO-PINION traction lok.
 
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