Diff Drop Brackets

[tom4bren]

"I think all said and done I paid $50"

OK, let us in on your little secret. Did you buy em or make em? Joe indicates $200 plus shipping & my welder is estimating $150 plus shipping.

[JHarris1385]

bought the brackets from someone parting theirs out and got a welder to fab it basically free.... Its not that hard of a job, but I am no welder either, just what I have heard.

[tom4bren]

'Bout what I figured. You owe your welder friend about $100 in favors I prolly could've done the same but I was trying to get it set up to help others out. Rekin humanitarians never get rich

BTW - you have to go back to page 4 of this thread to find out why it got bumped.

[JHarris1385]

Not sure where the bump took place.


$100 yeah right. Its no more than an hour of work.

[tom4bren]

Ida know. I'm not a welder. He fab'd inserts, then cut out a section & welded in the new. Since he prefab'd the inserts, maybe he had to take the time to ensure alignment. I think he said that he used 7 welding rods since he welded both sides. Since Joe charges $200, I don't think this guy is too far off.

The alignment issue does bring to mind one thing I was curious about: since we are dropping the diff to ease the CV angle at the expense of U-joint angle - would it have made sense to rotate the mounting features on the bracket to relieve some of the angle we are imposing on the U-joint?

The comment on the bump was just to let others know to look back a page to see why this thread became active again after several weeks.

[ZEUS]

Ida know. I'm not a welder. He fab'd inserts, then cut out a section & welded in the new. Since he prefab'd the inserts, maybe he had to take the time to ensure alignment.

The alignment issue does bring to mind one thing I was curious about: since we are dropping the diff to ease the CV angle at the expense of U-joint angle - would it have made sense to rotate the mounting features on the bracket to relieve some of the angle we are imposing on the U-joint?

I am more or less guessing on this one based on things I have heard and read over the years... I wonder if rotating the housing would throw the joints on the driveshaft out of alignment, causing vibration. In stock form, the joints on the shaft are at equal angles; of course even with dropped brackets the joints are at equal angles. After rotating the axle housing in order to position the pinion closer to it's stock location though, the angles would no longer be equal, so they may not "phase" during rotation anymore - causing vibration. Like I said, just a guess... people shim the rear axle after adding a lift to leaf sprung rigs to minimize driveshaft angle. Screw it! I just found this: http://www.pirate4x4.com/tech/billav...ft/index2.html

1/3 the way down talks about all this, maybe it will help explain.

[tom4bren]

Thanks Zeus - I forgot to consider the phase aspect.

[LittleBeast]

Interesting read. I now am certain I have drive line vibration due to the increased angles of the lift but I still don't know how to fix it.

[tomdietrying]

Ryan,
What speed do you hear the vibration? I'm hearing a little something around 63 mph. I'm not sure if it's the normal vibration since the lift or a new one.
Peace.
Tom
012009

[tom4bren]

Tom - tried to pm you & your box was full. Tried to email you but it was rejected.

Ryan - since your vibration started after you lifted, I'm guessing that your best be will be to do the diff drop soon (you'll be wanting to do that anyway to save your CVs). Try shooting some grease in the U-Joints as well. If the vibration continues after that, move on to the next likely culprits.

BTW - have your wheels balanced - you may have thrown a weight. Sometimes it's the simplest of things that cause the biggest problems.

[tom4bren]

Just got 'em.

Pix are in my gallery

[ZEUS]

Tom, WTH! Did you coat those things with black chrome or what?! Sparkle from Hell!

[tom4bren]

It's an anti friction coating that is supposed to provide me with 0.01% increase in throttle response.

Actually, the guy who welded them runs the spray booth in our big machine shop so I rekin he's kinda anal about making sure everything is well painted before he delivers. I was thinking about shooting them Proton with a rattle can before install but haven't decided. I've never been concerned with how the under side of my vehicles look but thought that if I wanted it nice looking later ... now was the time.

[tom4bren]

Still haven't installed the brackets yet. Was planning on doing it tomorrow but weather isn't cooperating. I did manage to clean things up a little so that I can take some pix of the CVs before & after. Things were pretty dirty down there since the inner boots came loose & tossed grease everywhere.

I dropped off the crossmember to the welder. I'll post pix of the drop brackets when available.

[LittleBeast]

Ryan,
What speed do you hear the vibration? I'm hearing a little something around 63 mph. I'm not sure if it's the normal vibration since the lift or a new one.
Peace.
Tom
012009

I hear the vibration only when I get off the throttle, or am on steady/no acceleration, normally around 2300 rpms or yeah right around 55-64mph.

Ryan - since your vibration started after you lifted, I'm guessing that your best be will be to do the diff drop soon (you'll be wanting to do that anyway to save your CVs). Try shooting some grease in the U-Joints as well. If the vibration continues after that, move on to the next likely culprits.

BTW - have your wheels balanced - you may have thrown a weight. Sometimes it's the simplest of things that cause the biggest problems.

Yeah I have been greasing the U-joints ever since lift and it does decrease the noise slightly, but it comes back in one day of driving.

Here is where I explained it when I 1st noticed it:
http://www.vehicross.info/forums/sho...t=13537&page=2