DIY axle flip kit question, Pinion angle?

[amodedude1]

So I am about to buy some leaf spring perches to to do an axle flip. I am planning on taking out all the 4wd stuff in my 79 k20 and putting in the front cross-member out of a c20 and using drop spindles and coils.

I want to keep my 8-lug all the way around so I am keeping my 14ff rear. No one makes kits for this truck and as to weather or not the c30 1ton flip kit would work or not is debatable.

On to the new question of the day:

-If I buy a new axle perch to weld on do I have to consider the pinion angle? If I just weld the new perch in keeping the surface of the new perch parallel to the old one won't that retain the correct angle? I'm a bit confused about this.

-If the pinion angle is such a concern does that mean that all the kits you could buy for these trucks have a new pinion angle already accounted for in the design of the perch?

-Lastly, would you recommend reusing the old perch by cutting it off or would buying a new perch be best?

[maskale]

simply, ur output shaft and ur pinion shaft need to be parallel, UNDER LOAD OR NORMAL DRIVING, the angle of the shaft doesn't matter, except in extreme angles.

So typically u want ur pinion angle to be 1-3* lower then ur output, that way under normal driving, just pushing the truck down the road you will get slight spring wrap and that will bring it in closer to parallel.

If u can get the perches off with out much damage there is no problem reusing, in this case the 14 is a 1/2" thick, if I had to remove material off the perch or axle to get the welds ground out, then I would grind into the axle a bit, save the perch, and fill in the grind marks on the axle and grind smooth.


I doubt most kits take pinion into consideration, to many variables, most drivers probably don't.

[amodedude1]

Okay, I think I get it now, thanks. So as long as the trans and diff outputs are parallel, then I'm good.

To me it looks like most of the kits I see just basically flip the perch 180deg keeping the old perch surface parallel to the new surface. Do you think I would be good if I just knock off the old one and flip it 180, basically doing the same thing?

If so, then I'll just give that a shot.


I thought the pinion angle was going to be a huge factor I had to take into consideration.

[maskale]

Angle is a factor, but not complicated to know where u need to be. What can make it difficult is getting ur set up right to give u what u need.

for info if u like

http://www.4crawler.com/4x4/CheapTri...line-101.shtml


the 180 should be fine like u say. The angles should stay the same. What does change things is when u do shackle chages, takes quite a bit of change in shackle lenght to make a significant change in angle though.

[amodedude1]

Great info, thanks!

I'm keeping the stock shackles, so I'm going to go ahead and try the 180 flip of the perch. Hopefully I wont have any drive line vibrations. I'll be as precise as humanly possible when doing it to make sure I get an exact 180 flip.

I was a bit confused after reading this thread as to why he needed to spend so much effort and time in setting up his pinion angle??

http://67-72chevytrucks.com/vboard/s....php?p=4762089