hey guys
so after doing some research on here I've decided I want to upgrade my rear diff. I'm not sure how soon I'll have it installed with work getting busier but I'd like to have the parts handy just in case theres a slow day.
I have 3.42's and the 6 speed and from everything i've seen on here, doing 4.10's will barely effect highway rpms by like 350rpms and sounds like city MPG actually gets better. and this will help with future mods ie stall cam etc

I'm looking to order this Detroit Locker and the reason I went with a locker is because I want guranteed lock up and I still have differential action allowing me to turn in parking lots etc etc.

for a ring and pinion 4.10:1 ratio; I decided I want the Motive Gear Set I've had good luck with Motive Gear on previous diffs in other vehicles so I figured why change whats worked 3 times before.
HOWEVER the thing Im a bit confused on is summit has another listing for a motive gear 4.10 set, that looks the exact same but is $20 more...so can anyone verify why there is a different set listed? this is that other set

as for bearings and seals, I left a price quote with the parts guy at the shop cause I know there'll be a better deal to be found here in town.

Do all these parts seem right? what do you guys think of this setup? while looking for parts I went with a GM 8.6" 30 spline

so now for my real questions. I am a canadian (red seal) 3rd year apprentice so I have set diffs at school, and did pretty good at it. but school isnt the real world. at school I had access to the GM pinion depth gauge and a wall of every shim i'd ever need. here at a real shop...i'd have to order shims!
my question is, for the guys who've changed carriers and gear sets....how often have you had to change shims? does the factory pinion shim usually work if the pattern is good? what about the carrier shims to mantain case preload and backlash?

what I was planning to do, if I cant find a pinion depth gauge to borrow from a gm friend...I was going to take my old pinion bearings and kinda grind out the middle so i dont have to press it onto the pinion and assemble the diff without the crush sleeve and check the pattern...then from there at least its easy to take back apart and I dont wreck any new parts if I need a shim change.
what do you guys do when your setting up your diffs?

 

That's exactly what I do. Create "setup bearings". You will probably need to shim it some. But always start with the original shims. Your best bet is to get a master install kit. Comes with all the bearings, pinion seal, and shims.

 

Are you sure you want that Locker? thats the hard core off road locker. Daily Driving its gonna act like a spool.

Have you looked at the Detroit Trutrac or Eaton LSD?

 

I've had an Eaton lsd in another diff and a auburn cone style posi that's what made me hate clutch pack diffs. It would constantly let go during a burn out or donut and I'd end up doing a 1 tire fire. So that's why I was like I want the gear locker.
What can you tell me about the tru trac?

 

well technically one of those is 4.11 and the other is 4.10...not that you'd notice a difference performance wise but if you look at specs one on has 37 ring gear teeth and 9 pinion teeth, the other is 41 and 10 and also mentions accepting the factory ABS reluctor and the other one says nothing about it.

Eaton TrueTrac:
Performance Products | Detroit Truetrac Differentials

 

Isn't the abs off the hub on this truck though? I'll check out that website. Thanks

 

Locker is for race only go with the true trac it has worm gears no clutches

 

Also I had bad luck with motive gears, got Richmond excel now to try just my 2cents man

 

Hmm I need to do some research then.
What happened to your motive gears?

 

would this tru trac be the one i'd want. it would be about $250 cheaper, and I have seen a few people on here using it and im sure anything is better then the g80 I currently have now. im just paranoid i'll be like mid fish tail or donut and itll unlock ...thats embarassing haha