I bought a used trac-loc off Ebay to use with my 4.10 gear swap and I noticed that the spider gears on the cross pin have a small amount of play in them. Is this a major issue, and if it is can I use either the gear or cross pin from my old open diff?

I also bought two master install kits to put in the gears and they have this little case of white greasy substance in them. I was just curious what this is, and what it's purpose is.

Thanks

 

Play in the gears is normal, "greasy stuff" is gear marking compound to check gear pattern after install. I suggest letting someone who knows what they're doing install the gears. It can go really bad if you don't know how to do it.

 

I thought that it was gear marking compound I just wanted to make sure.

I took the cross pin out of the LS this morning and the pin isn't worn at all and neither are the centers of the spider gears. I'll bet that the play is coming from the reduced thickness of the clutch packs in either side allowing the gears more freeplay as they mesh I have the remedy for this in the clutch rebuild kit I got from Ford Racing.

I'm going to tackle the gear swap myself as I have all the tools required even a dial indicating inch pound torque wrench to set pinion preload, and a dial indicator for backlash. I rebuild atv and motorcross engines occasionally so I'm a little mechanically inclined:o This is just my first foray into the differential world. I've been reading up on the Web and this Forum for months and I've got a pretty good idea what a proper gear pattern should look like. We'll see

 

I finished the 4.10 LS install tonight. All I can say is WOW! What a huge difference these gears make on my truck. It's so nice to have both back wheels grabbing traction instead of the dreaded one-wheel-peel.

Getting the speedo calibrated was a breeze with the Flash Programmer I got from Troyer. Glenn and Anita are very helpful and great to deal with.

A few tips to those who read this and are contemplating tackling this job themselves. Having the special tools everybody says you need is no joke...it would be near impossible without them. The Pinion preload and backlash is something that HAS to be right if you want quietness and longevity out of your new gears. I set my backlash at .012 and they make NO noise. Pinion preload at 10 in/lbs seemed to work well also. Ths pattern has to be centered or as close to it as you can possibly get it. I ended up removing my pinion and carrier no less than 4 times for both front and rear axles before I was satisfied with all the tolerances and the pattern. You simply can't settle for CLOSE ENOUGH on this job.

To anyone installing a trac-loc. I rebuilt the used one I bought with a new clutch kit. I used the alternating friction disk setup for an extra friction disk on either side and used the thickest shims I could fit and still be able to install the spider gears. I also soaked the friction disks in the modifier fluid for a good 2 hours prior to installation. The end result is a LS that hooks pretty hard when needed but is very quiet under normal driving, virtually no popping when it slips. Very happy with this carrier for the money.

Having said this, I think that anyone with good mechanical skills and an even better set of tools can do this job. Patience and perserverence are the key in my opinion. Also you simply can't read enough on the subject of gear installs before you tackle the job yourself. This forum among others was a great source of information for me and I probably couldn't have done it without all the great info. Thanks guys.