3 link banana strength question

[TexasAviator]

I have read that the banana can turn on the axle if not welded to the tube. Definately not hard to do and may come sooner than later but I was curious as to what you all thought.

It has an arm that comes off the banana and goes under the 8.8 and gets bolted to the diff. Is this a new part that was added to later 3 link kits? Other threads made no mention of it. Now I am wondering if i need this 3 link brace kit from here. http://www.vintageperformancemotorcars.com/

What do you all think?

[RoadRacer]

I haven’t welded but have got the VPM brace - I figure it’s cheap insurance. Perfect fit and nicely made.

[Boydster]

Moser unit is welded. I suggest welding because the first time you find out whether it needs to be welded or not, well, it's too late.

Whats the "arm that comes off the banana and goes under the 8.8 and gets bolted to the diff."? Supplied by F5? Got a picture?

[wallace18]

It is a brace from Vintage Performance Motorcars. Only works with 8.8 that has 4 link ears next to diff. Will not work with Moser. I use it on all my 3-link builds. Cheap insurance, IMO.

75985

[CraigS]

The arm under the diff is part of the FFR banana bracket. It has always been there. I like the VPM reinforcing struts myself. If you do decide to weld it, weld to both the diff center housing and the axle tube. Otherwise it can eventually rip apart on a diagonal tear of the split tubes that are bolted around the axle tube.

[NAZ]

It looks like you're planning to run a T5 M7003-Z trans with a 2.95:1 1st gear ratio. That trans is rated at 300 ft lbs of torque so you're not likely going to put much more than ~3,100 ft lbs of torque on the axle housing (assuming 300 ft lb at the flywheel and 3.55:1 rear gears). Welding the UCA bracket (banana bracket) to the axle tube with a couple of .12" x 2" fillet welds with ER70S-2 filler would seem to me to be sufficient. Making the beads linear with the axle tube rather than radially would lessen the chance of warping the rather thin axle tubes. If you tie the welding into the cast steel center section (not my recommendation on this application) I would advise you to use the TIG process with 99% nickel filler and small beads immediately stress relieved while cooling to prevent cracking the casting.

[TexasAviator]

I haven’t welded but have got the VPM brace - I figure it’s cheap insurance. Perfect fit and nicely made.

That is my thoughts as well.


Moser unit is welded. I suggest welding because the first time you find out whether it needs to be welded or not, well, it's too late.

Whats the "arm that comes off the banana and goes under the 8.8 and gets bolted to the diff."? Supplied by F5? Got a picture?

The only pictures I have are in my build thread but they are not really focused on that and I am out of town at the moment.

75993


It is a brace from Vintage Performance Motorcars. Only works with 8.8 that has 4 link ears next to diff. Will not work with Moser. I use it on all my 3-link builds. Cheap insurance, IMO.

75985

I am running a mustang 8.8 with the ears. It will work, but I think I would rather weld it.


The arm under the diff is part of the FFR banana bracket. It has always been there. I like the VPM reinforcing struts myself. If you do decide to weld it, weld to both the diff center housing and the axle tube. Otherwise it can eventually rip apart on a diagonal tear of the split tubes that are bolted around the axle tube.

Thanks for that, I believe that to be the right way as well.


It looks like you're planning to run a T5 M7003-Z trans with a 2.95:1 1st gear ratio. That trans is rated at 300 ft lbs of torque so you're not likely going to put much more than ~3,100 ft lbs of torque on the axle housing (assuming 300 ft lb at the flywheel and 3.55:1 rear gears). Welding the UCA bracket (banana bracket) to the axle tube with a couple of .12" x 2" fillet welds with ER70S-2 filler would seem to me to be sufficient. Making the beads linear with the axle tube rather than radially would lessen the chance of warping the rather thin axle tubes. If you tie the welding into the cast steel center section (not my recommendation on this application) I would advise you to use the TIG process with 99% nickel filler and small beads immediately stress relieved while cooling to prevent cracking the casting.

NAZ, yes I am running the T5 M7003Z gear set. In my 3.35 geared foxbody I would have to shift almost immediately after launch. It would chew through blocker rings (syncro) and would not put me in the ideal rpm. With this gear set it wont torque the car as hard, allow me to stay in first gear longer off the line and keep me from going immediately to second. This alone can save transitions on the blocker rings from 1-2 helping longevity. As you said it will be a little gentler on the axle as well. Its a street car but would definitely like to heed your advice to allow for some occasional track days with out worrying about this part.

[CraigS]

It looks like you're planning to run a T5 M7003-Z trans with a 2.95:1 1st gear ratio. That trans is rated at 300 ft lbs of torque so you're not likely going to put much more than ~3,100 ft lbs of torque on the axle housing (assuming 300 ft lb at the flywheel and 3.55:1 rear gears). Welding the UCA bracket (banana bracket) to the axle tube with a couple of .12" x 2" fillet welds with ER70S-2 filler would seem to me to be sufficient. Making the beads linear with the axle tube rather than radially would lessen the chance of warping the rather thin axle tubes. If you tie the welding into the cast steel center section (not my recommendation on this application) I would advise you to use the TIG process with 99% nickel filler and small beads immediately stress relieved while cooling to prevent cracking the casting.
This is another reason I don't really like the welding. Different techniques needed, that I for one don't have, (stress relieve while cooling?) and the possibility of warping the axle tube and wrecking the rear wheel alignment.

[cgundermann]

I didn't weld mine because I had my axle powder coated silver vien, but was worried about the strength where it attaches to the axle tab. Didn't know VPM made this support brace, - just ordered it!

Thanks,

Chris

[BEAR-AvHistory]

Are the "ears" the two round loops with the rubber donuts in them?

[cgundermann]

Are the "ears" the two round loops with the rubber donuts in them?

Yes, that is correct.

Chris

[cobrajj]

I didn't want to weld mine, and installed the support brace from VPM.76004

[BEAR-AvHistory]

Yes, that is correct.

Chris

Thanks.

[TexasAviator]

I didn't weld mine because I had my axle powder coated silver vien, but was worried about the strength where it attaches to the axle tab. Didn't know VPM made this support brace, - just ordered it!

Thanks,

Chris



Your welcome man. I found out about from just scanning builds on this site.

[BEAR-AvHistory]

Brace just came in. Next down day (bad weather) will do the install. Is there any load on the banana if I support the car with jack stands under the axle?

[totem]

Brace just came in. Next down day (bad weather) will do the install. Is there any load on the banana if I support the car with jack stands under the axle?
Yes. Support the car with stands on the frame and slightly lift the axle with a jack. Still be careful as the axle might rotate.

[BEAR-AvHistory]

Yes. Support the car with stands on the frame and slightly lift the axle with a jack. Still be careful as the axle might rotate.

Thanks, will do. :)

[cgundermann]

Yes. Support the car with stands on the frame and slightly lift the axle with a jack. Still be careful as the axle might rotate.

Just installed mine and that's what I did. Even then, once the third link bar is detached from the banana bracket - it will move. When you re-connect with the new brace, you can roll/push/jack it back in to get the third link bar into place. Very nice piece in terms of price, quality & engineering. Money well spent!