IFS Birfield vs 8" Minitruck Solid Axle Birf (picture)

[Jetboy]

Just thought I'd share a picture comparing the two. The IFS joint on the 5th gen is really strong compared to the older truck's joints. Of course it also has to handle greater angle and more weight, but it's pretty impressive in size. I don't want to cut the band off my trail spare to compare internal parts, but I assume they're equally large in size.

 

[(none)]

Great demo. Any idea how much larger an 80 series birf is?

 

[Jetboy]

The picture doesn't totally do it justice on size. I'll measure it when I get back to my shop. I don't have an 80 birf, but I've had them in my hand in the last 6 months so I think I can say that 5th gen is bigger than an 80 I'm almost certain. Is have to measure to be sure. Of course material is important too. I'd love to do a destructive test to see how a 5th gen birf does.

 

[wfo9]

The size is not the only factor that matters all that much. The materials are big part of it. The original min-truck birfs were weak and would break on anything over 33s. The tests showed failures at 4k tq. Then longfields came along and doubled the strength having a failure point around 8.5k. Now you see people running 40s on those birfs without issue. Same with the aftermarket cheap CVs, they fail under very light loads compared to the Toyota ones....

RVC is producing chromo CV axles again for our trucks which should eliminate all failures there.. but the problem wil just move down to the front diff. I would rather break a CV than a diff at this point.

I've got both sitting bare in my garage now. (although the CV is a cheap aftermarket one). I'll take a pic tomorrow. There is grease on them...

 

[jrandom]

RVC is producing chromo CV axles again for our trucks which should eliminate all failures there.. but the problem wil just move down to the front diff. I would rather break a CV than a diff at this point.

gees that right there, chasing the breakage points. Agreed CV's are cheap, fast, and easy comparatively speaking.

I am still more concerned with the rack. Glad I only recall seeing one person post about it so far.

 

[wfo9]

The size is not the only factor that matters all that much. The materials are big part of it. The original min-truck birfs were weak and would break on anything over 33s. The tests showed failures at 4k tq. Then longfields came along and doubled the strength having a failure point around 8.5k. Now you see people running 40s on those birfs without issue. Same with the aftermarket cheap CVs, they fail under very light loads compared to the Toyota ones....

RVC is producing chromo CV axles again for our trucks which should eliminate all failures there.. but the problem wil just move down to the front diff. I would rather break a CV than a diff at this point.

I've got both sitting bare in my garage now. (although the CV is a cheap aftermarket one). I'll take a pic tomorrow. There is grease on them...

30 spline original longfield mini truck on left, cheap auto parts store 120/150 CV on right.

 

[jrandom]

Complete with tempering.