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View Full Version : Brody T case mount repair



Brody
August 22nd, 2009, 08:14 AM
This probably shouldn't go under Build Threads, but should go under carnage. I put it here as I also show the fix.

I was replacing the rotor and spindle assembly on my rig and decided to do my every couple of weeks 'Let's take a look under the heap and tighten or fix anything that needs it." It was a good thing to do as I found a broken T case mount.

This is an after market item made by Front Range Off Road and is a stout unit. It is made from 3/8" plate and has a reinforcing bar that adds considerable strength to the unit on both sides. It doesn't look as though it would break and I am sure seldom does. Well, my was broken as you can see.

Since I was in the middle of doing another project and had limited time to fix this, also because soon I am going to raise the T case and carrier bearing, I decided to fix this in place rather than take the whole unit out.

What I did was to clean off and reweld the basic bar first. Then I welded a piece of 1/4" plate to the bottom, making this piece now 5/8" thick. I then cut a piece of 3/8" stock to reinforce the slightly weak design of the bracket, spanning the break and welding it on both sides. I will probably do the same thing on the other side when I re vamp the T case since I will have to take the whole case and mount off.

If you wheel your rig, you should always take a little time to double check all your critical torques, and look hard at the underside for anything that doesn't look right. I do this on my on a regular basis as I really don't like doing trail repairs. This broken T case mount could have been fixed on the trail, at least enough to get down to the road provided it wasn't under a heavy load when it finally let go. If it was under a heavy load, it probably would have taken out at least one drive shaft and possibly caused damage to the T case itself...a whole different scenario. For those of you who have a fondness for mud, keep the underside of your rig clean so that you can see what is going on under there. Mud hides a lot of potential problems.

1freaky1
August 22nd, 2009, 08:32 AM
Good catch Pete repair looks good too!

4Runninfun
August 22nd, 2009, 08:32 AM
looks good pete. you sure have an affinity for breaking HD stuff.

Patrolman
August 22nd, 2009, 09:53 AM
I just can't get over that you even broke it to begin with! What it does look like though is that it is at the weakest point. Looks like each section is narrowing down approaching that area. I bet if you measured out the width at that point of each piece and combined them (2+2=4) that you wouldn't come up with another section within the entire unit that is as "narrow". Everything has to have its "weakest" point.

Brody
August 23rd, 2009, 05:35 AM
Certainly the weakest point and I wouldn't be a bit surprised to see that Front Range Fabrication, whose mount this is, has changed their design. They are getting a copy of my repair fix pictures so they have a heads up.

Anyone would have been hard pressed to bend this piece (except Randy maybe) if they wanted to. It was a super clean break, too, with no signs of bending stress, indicating that it simply snapped.

1freaky1
August 23rd, 2009, 05:55 AM
After looking at the pics closer and seeing how straight the break was that is a sign of one or two things, metal Fatigue or molecular stress in the steel especially on the 3/8ths plate, which would cause it to just snap clean like it did. From the looks of the stepped break I would say it was the latter.

colomil
August 23rd, 2009, 10:02 AM
Wow that 3/8 plate broke like it was hardened tool steel. I can see from the last photo that the area that broke was dealing with an obscene amount of torque. Your fix looks very beefy though. If that T-case mount had some engineering calcs/finite element done on it I am sure they would have seen that the torque would have created enough force to overcome the stress/strain limits of the cross section in that area of the "beam".
When is the next overhead welding clinic...? :thunb: