The description on the chunk in that link says full spool. Is that different than trac loc?

 

Yes, a spool locks both axle shafts together 100% of the time. Absolutely no differentiating or slipping. Most of the time, they are used only in racing applications, and on some off road vehicles. They are very aggressive on the street because you will always be dragging the tires around corners.

 

Not sure where you're getting the 'full spool' reference from...that unit is a Trac Loc limited slip style differential. And just like he stated - a full spool is too aggressive for street driving.

 

That's weird. The words complete 9 inch were highlighted and when clicked took me to ebay listings which I assumed were the seller you were referencing. Anyways, you are right, full spool is not for the street.

 

Gear lube will eventually seep out around them. You can use 3/8" copper washers for brake banjo bolts available at your local auto Parts store or hardware store.

 

Thanks for the tip on using the brake banjo washers...I thought the overhaul kit would come with new washers.

What's the best brand of oil and friction modifier to use with this limited slip? I was planning on using Royal Purple synthetic, but I called the seller and they said not to use synthetic.

 

No don't use synthetic. Honestly, I used the store brand 75-140 and LubeGard additive. Works very well. Smoooooth and strong! If I didn't know it was back there, I wouldn't notice it under normal driving. But it's there when I need it and I'm very glad it is.

 

Oil is one of those things that is mostly opinion. I'm of the opinion that I don't need to run high dollar oil in low dollar equipment. (And the low dollar oil does just as good in that situation)

Now if I had a tight tolerance, high performance race car, you can bet I would run Castrol GTX in it. (If it's good enough for the funny cars, it's good enough for me)

 

I put 80W-90 GL-5 (non-synthetic) gear oil in my truck's rear end with the Ford Traction-Lok (clutch type) differential and 3.50 gears. I also put 4oz of Motorcraft XL-3 friction modifier in.





My stock C7AW-E 28-spline, 3.50 ratio, single track differential, 9-inch 3rd member on the left. Heavy duty Ford Nodular iron 9-inch 3rd member on the right.



You'll need (3) bottles of gear oil and the friction modifier. Pour the friction modifier in first. It will take all of the first two bottles of gear oil and most of the 3rd bottle to fill the rear end.

Ford Daytona 9-inch N-case, 4-pinion, 31-spline, Traction-Lok differential, 3.50 ratio 3rd member in place of my old C7AW-E 3rd member.

 

I need to stamp out a new tag for my pumpkin. Same as the original, only with 4L11 and the date I did it.

 

The tag was missing from the N-case, at the time I pulled it from the '75 F150 4x4 truck that the N-case came from.

The tag on the N-case is bogus --I just transferred it over from my C7AW-E single track 3.50 ratio 3rd member. The only thing on the tag that's correct is the ratio.

The 3rd member just looks more 'complete' with it on there.

 

Thanks for the oil recommendations...oil is a slippery subject. The different brands all use different additive packages and that's what makes the most difference. I'll check to see what's available locally.

Adding a tag does seem like a good idea. If I make one I don't think I'll put it in code, just stamp out Yukon LS 4.11 and a date. Then there's no need to look up anything.

 

I received the Yukon Trac Loc and got it over to the shop.
I should have the differential back sometime this week but I don't have time to put it in until the following weekend. This weekend is full because my woman is competing in a snow shoe race...LOL...not sure what anyone does that.

The box says "Assembled in the USA" and the differential is stamped USA...does that mean it is MADE in the USA? Or just that some of the parts are and that it's built here?

 

That means one or more of the components is "made" outside of the U.S. Some of it may be but if part of it isn't then the final assembly can't be advertised as "Made" In America.

 

That's what I was thinking...kind of like they are trying to sneak it by as if it is made in America. I'm guessing that the largest part, the carrier, is made in the USA since it has USA stamped on it next to the part number.

Only time will tell how many burnouts it can withstand