I need to swap the driveshaft pinion flange between an '83 and '85 Toyota 4x4. I'm swapping the front and rear axles between the two trucks and I am keeping their driveshafts where they are. Need to swap them because the bolt holes are larger in the '85 flange VS the '83.

From what I can tell, I knock the dimple out of the retaining nut and remove it, and slide out the flange on each differential, swap them with a new nut, torque it and punch the retaining edge down to hold it. Is this all there is to it? Are these flanges identical between these two year trucks with the except of those four bolt holes, i.e. flange to pinion splines?

 

This type of thing is a little sketchy in my opinion. There are several factors to consider. Pinion flange depth, diameter, spline count, spline diameter, etc. If the old pinion flange and newer pinion flange are just a couple thousandths of an inch different, this can affect pinion preload. The crush sleeve was set to each pinion flange and bearing, respectively. And if there are variances, things can get out of whack. Why not just swap the whole third member? Are you going for different gearing? 3.90 vs. 4.10? Not much change there...

On the other hand, you could be one of the lucky ones... Change it out and if it just kinda fits, it'll last forever. But that not how it is for me, unfortunately...

 

Swapping front and rear ends for several reasons. The '83 is the truck I'm keeping, the '85 I'll sell later, needs an engine. I need the '85 rear because it has a limited slip unit in it, and good brakes, lines. I need the '85 front because my springs and steering are all worn out on the '83, and also someone cut the bottom part off one dust shield on it. Second option would be swapping the driveshaft ends I guess, new ujoints. Think that'd be a better plan? Thanks for your help.

 

Triple drilled flanges would probably be ideal. It can't hurt to try the driveshaft-end swap, if the different years use the same joint. I would suggest getting the shaft balanced afterwards. If your u-joints are fine, maybe you can have a driveline shop just cut off the end and weld it to existing shaft? I'm just throwing out ideas, since I'm not sure what the drivelineparts differences are between 1st and 2nd gen trucks.

But I think triple drilled flanges would allow you to use most any proper Toyota shaft you get your hands on.

 

Why don't you just drill your existing flange either bigger or with a new shifted pattern? Same idea as a triple drilled flange.

Worst case you kill a couple of drill bits..