Brandon587

So Friday I finally went to 4.10s in the rear after years of saying I would. I went with Yukon gears, a Detroit truetrac differential, and all new bearings. Carrier, pinion, and wheel bearings. Timken. And obviously seals. I love it all. The truetrac is a beast, and the truck moves pretty good with the 4.10s. I've driven it 450 miles since Friday (not a typo) and so far so good. I'm about done with my break in, Ill change my oil sometime this week and recheck pattern. But gears are quiet, (other than a slight wine on coast from 45 to 40 but it has become quieter during break in) and axle runs cool. First run I ran about 15 miles and parked it, the diff cover was about as hot as my hand could stay on it for extended period of time. Drove it the next morning about 30 miles and it ran much cooler. Ran again that afternoon for about 10 miles and the next day I went on a road trip. After 45 mins of driving at 70 mph I checked it, it was cool enough to put your face against the cover. Drove another two hours and still no warmer. Drove 7 hours total (Yes I was actually going somewhere) through mountains down to flat land at all speed ranges. I got on it pretty good towards the end of the trip a couple of times and its goes with no problems. I averaged 13.5 mpg vs 15 or so with my 3.55s. But I can accelerate up an 8 percent grade in overdrive slowly, but 8 percent is pretty steep. before it would kick down. Normal hills I can pass in the left lane without downshifting. So, now in a few weeks ill do the front. Overall I'm extremely pleased. Truck is a 96 5.8 extended cab 4x4 with 217,000 miles on stock original engine and trans.

Brandon587

Oh and my tire size is a 265/75/r16. It is a 31.8 by 11.3 tire, but I call it a 32 by 11.5.

Brandon587

I would like to know one thing though. This was present before and after axle build. I can do a hard launch or brake stand and get a vibration. But only at a stop or on a heavy acceleration from a stop. I also hear it too. My engine mounts are new, old ones were bad. Trans mount appears good, but I may have to unbolt it to find a problem. Any ideas would be appreciated.

Brandon587

bump

Martian

You'll probably get better results if you repost #3 as its own thread.

Brandon587

I'll probably do that but first I'll poke around at it more. Haven't looked a ton into it. Anyway, here are some pics from the project

Chris_1

iTrader: (1)

What pictures ? Since you didn't post them we're stuck picturing you on the side of the road under the truck with your face pushed up against the diff cover ! LOL
Vibration could be anything from spring wrap up or old spring bushings or shocks to ...well the list gets long. You'll just have to crawl around and look for loose stuff.

Brandon587

Haha sorry, I tried uploading from the app but it wasn't working and I gave up and forgot. Anyway, I have them on my computer now so they will be up in a minuet. The fact that it does it while under a load and not moving made me thing it was weird. At last in my mind, that eliminates u joints and leaf spring bushings because if it were them I feel it would just clunk and stop. But it will vibrate as long as your on it. I have stuck my go pro under there watching it, I noticed the cab seemed to flex a good amount off the frame. I do need new cab mounts, but doing it while stopped I feel it wouldn't be them. Ive been wrong before. I tightened them up some, no change though. Also tightened trans mount and cross member. I will check u bolts on the rear axle. Ill get to the bottom of it eventually, its just annoying right now. I was just looking for ideas. I have a new trans mount to put in just because the old one has a small crack in the metal part of it. And I also have new front and rear sway bar bushings to put on. Ill get to it later this week.

Brandon587

Still having troubles but her are a few


Maybe not, its not inserting into the post.

Brandon587