fx4life79

I ran 4.88 Yukons in my 09 running 38" tires and they performed great for daily driving.

SnowDawg

It looks like I'm going to go with Motives. After talking to them more they seem to know their stuff so I'll see how it goes. I'm taking it in the 27th, I'm looking forward to getting rid of these 3.55's, that's for sure.

PerryB

Give us feedback when its done. I really want to put 4.56's in mine, but I have a few too many financial irons in the fire right now. I'll have to re-gear vicariously through others for the time being.

SnowDawg

Yeah, will do. Like I said, it'll be a couple weeks bc it's not going in until the 27th but I'll check back in with the results. If it is anything like my last truck, it'll be a welcomed change.

LILRaptor5.0

I put 4:56 in September.Front and rears are Nitro Gears no problems.There was a bearing design change in the 9.75 diffs for 2010-11- up.I got mine from Just Differentials and I delt with Murph he was very helpful.The link below is what you will need for your truck.
http://www.justdifferentials.com/For...0-2-select.htm.
G2 will work in the front but for the rear you will need bearings from Timken.I was going to put in Yukons which I ordered in June and was told by the local supplier(end of Aug) they would not be here till late Oct.I had the gears from Just Diffs by 3 days.
Hope this helps.

traxiii

According to a long time off-road truck builder I talked with, he says that freeway miles are toughest on gears as heat builds up and cheap gears can loose their strength and fail when loaded later, and to go with the highest quality gear and lube you can get, and a finned aluminum cover to transfer heat. Slow moving crawlers can make due with cheaper gears unless they get lots of highway miles between crawls. Heat kills, and 3 quarts of gear oil isn't much to carry it away from the ring and pinion.

SnowDawg

For an update, I got the truck back with the new R&P. I'm loving the 4.56's, after driving with the 3.55's for so long it is a welcomed improvement. I got the Motives and thus far they are silent without any problems. 4.10's would have been a huge mistake. Now if I can get my SCT X4 to work.

PerryB

Thanks. I did this swap on a previous truck and upon driving it for the first time, it was like releasing the parking brake, for lack of a better example.

Z7What

I had Yukon 4.56s in my 2003. It was daily driven for 6 years then was retired as a DD and became a weekend toy. The truck currently has roughly 120K on the gears and NOT a single noise what so ever and in those 120K miles the truck has done any burnouts, many 600+mile(one way) trips to vacation, many trips down the quarter mile, plenty towing. Changed fluid and friction modifier every 25K with MotorCraft Oil and Modifier.

Can't say how true it is but I was told when purchasing the Yukons that Yukon is the maker of rearend gears for GM.

Wayne