Drive Shaft Flange Question (1 Viewer)

[srgould41]

I have a '71 FJ40 that I swapped in a newer 4speed transfer case. Some drive shafts came with the tcase when I bought it. The tcase and shafts had been mated to chevy axles so the drive shaft flanges at the pinion end won't work on my 40. The shafts are custom made long splines with spicer 1310 ujoints.

I want to mate these up to my '71 pinion flanges with the least amount of work and expense. The early pickups (8/78 - 7/83) have the same bolt pattern of 64mm x 56mm using 8mm bolts. The '71 pinion flanges are also 64 x 56, but use 10mm bolts.

I have found drive shaft flanges for the older pickups that will hold the 1310 ujoints. However, not having ever had a set of early pickup flanges in my hands I don't know if the bolt holes can be drilled out to 10mm, or better yet 11mm and still have enough boss area to stay strong.

Does anyone know if this can be done?

Thanks,

Steve

 

[2ndGenToyotaFan]

Do you mean the pinion flange, or the drive shaft flange? The pinion flange would probably be fine, but I think you might be rolling the dice on the drive shaft flange...

 

[srgould41]

I do mean the drive shaft flange.

I know the pickups have a round pinion flange, but I dn't know about the drive shaft flange. I suspect it is rectangular, but I never saw one before.

So from your comment I assume the drive shaft companion flange doesn't have a lot of room for drilling up the hole diameter?

 

[2ndGenToyotaFan]

The drive shaft flange is overall a rectangle shape, but each hole is out on it's own little peninsula so to speak. So it's not an ideal set up for drilling out. That said, I have not measured to see how much room there may be. if no one else pipes in I can measure my 85 in a few days.

 

[Chop Shop]

replacing baddass superior toyota joints with spicer 1310 garbage!!

(PUKE)

What a waste of time

 

[srgould41]

The joints in a '71 are about the same as 1310's so I'm not trading down. I am also looking at some 4speed shafts this weekend and may decide to go that route for the rear at least. Problem is clearance in front since I have a 700R4 with a stupid wide pan to clear. I have about 1/4" clearance with 1310's.

 

[Dingman]

Picasa Web Albums - Jon Paul - Toytota CVDC

Here's a couple pics I have laying around... don't know if it helps you or not. (pickup\4runner shafts here)

on the left is a IFS front shaft, on the right is a SFA shaft. You can see how the SFA CV has a greater operating angle.

 

[srgould41]

Thanks for your reply Dingman. I am not positive from your pictures, but mine looks more like the IFS one in your pics.


Edit: Never mind. I just noticed the ears on the flanges on the IFS shaft. Mine does not have those which suggests I have the SFA shaft instead. That is what I thought I had. This helps to validate that.

I'll be taking my drive shafts to a shop for shortening next week. I ordered flanges from Tom Woods to mate the 1310 ujoints up to the stock '71 diff pinion flanges.


Here is a pic of my CV shaft

Picasa Web Albums - Jon Paul - Toytota CVDC

Here's a couple pics I have laying around... don't know if it helps you or not. (pickup\4runner shafts here)

on the left is a IFS front shaft, on the right is a SFA shaft. You can see how the SFA CV has a greater operating angle.

 

[Chop Shop]

The easiest way to tell a SO shaft froma n IFS shaft is the "tittys" on the side of the CV flange.

All the CV shafts will have a protrusion of sorts on the side of the flange while a solid axle shaft will be flat on the sides.

IFS shafts/CVs are worthless.

 

[srgould41]

Mine aresans the "titties" so I think I'm good

 

[Chop Shop]

If I have thos correct you have a GM motor/tranny and a pair toyota axles in your rig correct?

If so why order custom flanges? Just get a dana spicer cv shaft or noncv sjaft and put a toyota slipyoke/lower end on it and have NO custom parts?

 

[Chop Shop]

if drilling out the ears is the easy fix but not ideally strong them why not run the larger mini truck lower yoke (10mm holes) and drill out the pinion flange to match the new yoke instead of drilling out the ears on the old yoke?


Marlin has a new 5 pattern flange also.

Do ya need a CV on top? Is the front axle cut and turned or does it have some angle on the lower driveline joint?

 

[srgould41]

I do have a SBC, 700R4, 1980ish 4speed tcase and '71 axles. The tranny/tcase came with custom long spline shafts (CV rear and straight front). They were orignally connected to Dana 60 axles. The flanges wouldn't do me any good so the PO kept them. So rather than have all new shafts made, or mine heavily modified, I choose to get new ends that will mate the 1310's to my '71 diff pinion flanges. Then all I need is to have the shafts shortened.

I have been going around in circles on this for weeks and getting every opinion under the sun. This seems to be the easiest and cheapest route for me with what I have in hand. It may not be the best way forward possible, but it's the best I can do for now.

If I have thos correct you have a GM motor/tranny and a pair toyota axles in your rig correct?

If so why order custom flanges? Just get a dana spicer cv shaft or noncv sjaft and put a toyota slipyoke/lower end on it and have NO custom parts?

 

[srgould41]

I skipped the minitruck flange idea.

I ended up purchasing 2 yoke flanges today from Tom Wood. They will mate the 1310 ujoints to the '71 56mm x 60mm diff flanges. This way I don't need to replace my diff flanges. Since I have 10 spline pinions I am limited to this pattern or the newer 60 x 68.5mm pattern.

The newer pattern pinion flanges would let me run pure LC 4 speed shafts, but they are kind of limited in spline length and the only ones I can find need a full rebuild anyway. That would cost more than the route I chose.

if drilling out the ears is the easy fix but not ideally strong them why not run the larger mini truck lower yoke (10mm holes) and drill out the pinion flange to match the new yoke instead of drilling out the ears on the old yoke?


Marlin has a new 5 pattern flange also.

Do ya need a CV on top? Is the front axle cut and turned or does it have some angle on the lower driveline joint?

 

[2ndGenToyotaFan]

This is far too much tech... we need some pics of this ride!

 

[srgould41]

I have a build thread.

https://forum.ih8mud.com/40-55-series-tech/304599-green-71-frame-off-mild-build.html

 

[2ndGenToyotaFan]

Very nice!!!