80 Series Pitman on 70 series Box

[gifu]

this is a HZJ79 built from parts.
The steering box is from a 1985 BJ70.
the axles are 1994 80-series
The pitman arm is a 1994 80-series pitman.

Because of a twisted sector shaft, I am replacing the box. Sent the new box to West Texas put a new sector and input shaft in. I noticed the pitman's splines were ugly. So, new (used) 80 series pitman.

Here's the problem. The 80 series pitman will not go on all the way. I don't know what it looked like before... but this doesn't look right. Maybe this is how it was and I never noticed it. Seems wrong to me.

 

[gifu]

Can you re-explain that?
This is an 80 series pitman on a Bj70 steering box.
I guess I'm surprised that an 80 arm spline/taper is different than a BJ70. I mean... it kinda goes on there. Sorta. Mostly.

 

[gifu]

so i need a FJ60 or BJ70 or IFS pitman. OK, that makes sense. Now where the heck did I put my extra pitman?

 

[OGBeno]

Winner winner chicken dinner!

 

[sadam_husain]

that looks right mate, the shaft is tapered so the pitman arm will pull up the shaft when you wind the nut up, I've got a BJ70 box with a 80 series pitman arm sitting in the shed and it fits fine

 

[OGBeno]

that looks right mate, the shaft is tapered so the pitman arm will pull up the shaft when you wind the nut up, I've got a BJ70 box with a 80 series pitman arm sitting in the shed and it fits fine

If he says so!

 

[sadam_husain]

If he says so!

 

[gifu]

To be clear; these pictures are after using a 500lb impact to drive the arm on.


This is the Marlin IFS arm.
Seems about the same.

Neither as snug as a stock 70 arm

 

[Tapage]

for your reference I just did sorta the same .. replace my stock pitman on my 60 series ( Tencha ) box with a Marlin unit ( pitman arm ) with the one Ton TRE tap which I did ..

Long story short .. more less the same as you .. I believe mine did better and travel bit more on the splines .. in my case I'm not too worried about it coz I have RAM assist .. so not all the effort / impacts are going in to my pitman / box ..

 

[gifu]

So... what's the consensus? It just seems weird that I can't get the pitman all the way on. It's about... 90% of the way there...

 

[sadam_husain]

Looking at your picture in the first post the pitman looks pretty close to me if you compare how much spline is visible above the pitman arm when you compare it to the 70 series boxes in both of my trucks, once you torque the nut up the pitman arm should pull up and seat a little higher, I don't know about your marlin IFS pitman I'm guessing that's an aftermarket part so not necessarily machined to the same tolerances as the Toyota pitman's? My pics are RHD if they look a bit different

 

[gifu]

So... Again, those pictures are after it was torqued.
I painted the splines and torqued both the 80 series and the IFS Marlin arms. The IFS arm meshed the sector shaft nearly 100% (of the 90% that I could get it on).
The 80 arm only meshed about 25%!!!
This explains why the 80 arm I pulled off had nearly stripped the top 25% of the splines! This explains why my steering wheel was off 90 degrees last Rubicon run. I'm pretty sure the pitman actually moved.

So, to be clear: while the 80 arm fits on the spline of a 70 steering box... It does not actually fit correctly and could be extremely dangerous.