Ok, so I want to install 4.10s in my 2008 AWD Sierra Denali. Anyone know what else I need other the the ring and pinion sets for the front and rear? I'm going to go with GM factory gears. Do I need a shim set to get these to mesh right, do they use a crush collar for preloading the pinion bearing, etc.?
Also, what do you all guess this will give me in terms of 1/8 mile ET reduction, going from 3.42s to 4.10s in the AWD?
Any input would be greatly appreciated...

 

why go with 4.10s!! that's gonna be a crazy first geat, too much it might make it useless... the srt8s have 3.73s and they're crazy outta the hole... 3.73s would be good for acceleration and top end...

either way let us know what u do, im thinking bout doing this mod as well

 

Yeah I'd be hard pressed to spend the grand or so it will take to make it 4.10s. I would spend 1K on go fast parts, cam, exhaust should do more then 4.10s.

 

You will need a crush sleeve for both front and back. You may need shims for the rear too. I would definitely throw the shims back in and see what you have for backlash and tooth pattern and go from there. You'll have to be gentle with bearings when you press them off the pinion otherwise you will need to replace them. I would put a pinion seal in both too while it was apart.
I was also thinking of throwing 4.10's in mine too so I would say go for it.
I don't know about the GMC's but the Chevrolet came with 3.73 or 4.10 gears.
I bet it will pull alot harder and won't make to big of a change at cruising speeds on the highway.

 

Thanks for your input guys.
I know it will be crazy in first (I hope!), but that's what this 5500lb sucker needs to get out of the hole. First in the 6L80E is low (4.03:1, I believe), but the other gears are relatively high, especially with a 31.8 inch tire diameter. It dead hooks now with the AWD (as long as I don't touch the spray button).
In any event, highway speeds down here are 50MPH max (when there's cops around), with most roads at 40MPH, and right now the truck almost lugs in 5th and 6th gear at those speeds. I figure the 4.10s will help with that, and, after all, we only have a 1/8 track down here, so I need all the gear I can get.
My truck definitely has the 3.42's so I'm hoping to pick up at least a couple of tenths in the 1/8th. Right now it spins on the Nitrous in 1st anyhow (no progressive control as yet), so I figure I can use either a progressive in first or just spray from 2nd on. I think it will probably still have as good acceleration in first w/ the 4.10s without the spray, as it does now with it.
I'm gonna do a cam too, as soon as I figure out which one to go with. I don't think there's anything else I can do to the exhaust tp pick up power, since I already have ARH 1 17/8" Long Tubes, 3" Y w/ no cats and a 3 1/2" cutout.
Thanks again for all your input.

 

Where are u running the 1/8 in Cayman?

When I lived there,they only raced 1/4 mile....left a few years ago when the hurricane struck.

 

Breakers Speedway.
We used to race 1/4 mile on the High Rock Quarry road in East End, back in the old days, but we now have a 1/8 track at Breakers. It was in fact operational back in 2004 before Hurricane Ivan hit, but some guys used to still race on the road. The track isn't the greatest, mainly because the surface is pretty crappy, but it is better than running on that old 25ft wide road. It has a Port-a-Tree timing system and everything, but it still needs some work to bring it up to spec.

 

They never ran Breakers in the 5 years I was there,or at least I never heard of em,I heard friends mention it but didnt know it was 1/8.....If the track prep at Breakers is anything like it was in East End,your truck is MOVIN even with awd.Im sure alot of sand gets blown across the track...

I ASSume you are local?You live in West Bay,East End,or SMB?

I worked for Don Fosters.And since youve lived there a minute,I am sure we know alot of the same people...a really good friend of mine,Roy Bush,works for Licenseing...several other friends are expats with status.I have visited since Ivan but the island isnt the same and I dont think it ever will be I lived on Palm Heights Drive on Snug Harbor and that has been blocked since after Ivan!!!

I have a 2005 Escalade and was thinking of going from the 3.73's its got to 4.10's or even 4.56's.I would be happy to gear it where it would red line in overdrive at 120mph.Thats as fast as my speedo goes too and big trucks arent to steady at high speeds.

Also,you say you want to use GM gears,anyone know where would you be able to buy GM gears online?

 

id go for it i think the old body style denali's came with 4.10's. it will make a big difference out of the hole. I'm wanting to do 4.10's in mine but i have to do front and rear also and its only one size up from what i have now so dont know if it will make enough difference to justify all the money

 

I am local, used to live in WB but now live on SMB.
I think I know who you are. Did you live near Talledega? Roy is a friend of mine and I think I met you through him, before you left Cayman.
If I remember correctly, you had an issue with a ***** called Rafe that I helped you sort out? Small world (and smaller Island), ain't it?
You should see the Island now, it's built back bigger and better than before the hurricane.
You get what I'm saying with the gears, right? These trucks aren't safe above 120 anyhow and the gears they have are way taller than they need to be for maximum performance in the 1/4, let alone the 1/8. And, in the sort of start and stop traffic we usually have down here, it doesn't make sense to have tall gearing anyhow.
I'm definintely doing the gears, because I found a thread on HP Tuners forum the other day by a guy with an AWD truck like mine and he said that with the 4.10's it was a beast out of the hole and that it was quicker stoplight to stoplight than his 2002 Heads Cam and 4.10 geared LS1 T/A.
I am going to order them through Gene Culley at gmpartshouse.com. This guy is excellent when it comes to customer service, and he is very meticulous about getting your order right - checks your VIN in the GM database and all, and his prices are so good that even with international freight and import duty it works out at less than half of what the local Chev dealer would charge me.
I'll let you all know how it goes...