6”lift, Front Diff Angle?

I’ve lurked this forum for ideas and help for a long time, just signed up today because I’m in a jam. I figured it’s time to ask the experts.

Rough Country 6” lift. Less than a year old and front diff is destroyed. The shop that installed the lift said I need to rebuild the gears. I got a second opinion from a mechanic friend and he said the front diff angle is different and is headed uphill toward the T-case. So much so, that the drain/fill plug is below the pinion gear. He thinks the gears wore out quickly cause they ran dry.

called rough country, they said the front diff angle should not change from stock and should not be angled uphill at all.

I’ve yet to hear back from the shop that installed he lift as I let them know the differential angle may be too steep and cause the damage.

so my question is to all you 2nd Gen owners, with or without a lifted truck. Does your front diff sit level or is it pitched up toward the T-case. And most importantly, those who have a Rough Country 6” lift, is your pinion gear above your drain/fill plug on your front diff? If so, how do you make sure this is properly filled with oil?


Thank you for any and all input on this, as my truck now needs a new front diff or a rebuild.

 

did they cut the subframe and install the drop bracket? Something is off. Snap a couple of pictures.

 

Driving to work one morning during a massive storm, no one on the road, in 4 whee drive. Lots of snow, ice, slush.. driving about 35 tops. Front end locked up and slid down the road and got stuck. Felt like I ran into a tree! Got out of 4 wheel drive, drove fine in 2 wheel. So I had the shop that installed the lift check the truck, they said the front diff gears need to rebuilt. They’re chewed up, mentioned it was due to the front drive shaft being loose at the front diff connection.

after having them check the truck it now grinds slightly while driving in 2 wheel drive, which it did not do prior to them checking it.

 

Geometrically speaking, it only makes sense that your diff would be angled upward relative to level ground if you have a Carolina squat. If your rear is also lifted 6”, the angle of the diff relative to the ground could not have changed.

 

Ya something fishy is going on, the whole point of a DB lift is that it keep all the drive line angles the same. Who filled and maintained the diff?

 

Correct. The diff mounts in the new Rough Country crossmembers. There are no spacers or other provisions to adjust the diff angle.

Looks like you're running 35" tires. Did you regear?

 

It appears the rear axle sits level and doesn’t not angle upward at all. So oil fill levels will contact all gearing. Shouldn’t the drive shafts take care of angles with the u-joints? I thought that both the T-case and Differential needed to be angled level with the ground.. and if there’s an angle put on a drive shaft, it should have an equal angle on both connecting ends, no?

 

The diff fluid was filled by them at lift install. They popped one of the axles out and damaged it on accident. So they replaced it and had to have re-filled the diff fluid at that time. I had a full T-case & Diff service done after this happened as I wanted to check for metal shavings or damage. The fluids were good and there were no shavings or metal chunks.

I am running 35’s. Yet have not re-geared. I’d rather not if I don’t have to.

 

Angle of the diff, for purposes of lubrication doesn't matter that much. The ring gear acts as a giant slinger ring and throws oil everywhere. As long as the ring gear is in the oil is should lubricate correctly. Look up a video of a clear diff cover and you will see what I mean.

 

Heres a good video of a diff in action
https://www.youtube.com/watch?v=9-yG3D3JBRs&t=304s

 

If I were you I would check the front diff fluid. If it’s really fried you’ll have a mess in there of metal and such. There’s really not that much gear oil in there, like 1.6 quarts so if you been had a slight leak it could be about dry. As for the drop bracket angle, It should have no effect on your issue whatsoever. It looks like your front driveshaft is correct from what I can tell. Kinda stumped on this one but here’s a pic of my front driveshaft at the drop bracket/cut in the frame. Best of luck.

 

There’s a massive difference in height between these two drive shafts. Interesting. Are you in a 3rd gen?

 

Thats what I was thinking, they cut the subframe but it doesn't look like the diff was dropped down into the gap. Did you have any vibrations or weird noises?

 

This is fishy, a loose front drive shaft should have made a lot of noise especially if the 4x4 was on and it was loose. I think they mat have screwed up the install or something.

 

What does this mean?
Maybe there’s more to it than “angles”.

 

2nd gen 2015. Zone 6” for my brackets. Is it possible your diff relocation brackets are installed incorrectly? I’ll try to get some better pix. Now I’m wondering if somehow someway they improperly installed your diff and relocation brackets on your kit. I just ran outside to try to get better pix.

 

Think it means the drive shaft bolts are loose or the pinion nut is loose.

 

Sounds like the DS wasn't tightened properly when the lift was installed

 

I've had the RC 6" lift on my truck for several years now and never ran into that issue. My front diff is straight back. Sounds like an installer error. Maybe they put the passenger side diff bracket in backwards.

 

I'm not a smart man but...