drive shaft nuts and bolts (1 Viewer)

[FJCowboy]

Took the bolts to Napa and they did not have replacements but said they were M8 1.0-30. My limited knowledge says that are Grade 8, thread pitch 1.0, 30mm in length. Which I believe is the OEM standard, correct? I think the 13mm head was throwing me off. Based on that size, does anyone know which year that would fall into? As mentioned earlier, this is titled a '69, but lots of upgrades were done and not sure if/how to know if the driveshaft/flange is from newer FJ. I was able to find some bolts at Home Depot, but not the nuts or washers. They were Zinc plated and I'm not sure what they are supposed to be.

@RAGINGMATT Really appreciate all the insight. I would prefer to support one of the vendors on here and saw SOR and Cruiser Corps had on their sites. I need to email them to make sure I get the right year based on the bolt size. It is interesting you mention the parking brake as they is on my list as well plus new pads. This vehicle was given four wheel disc brakes, so I will need to figure out how to tackle that with the upgrades.

 

[sfab]

Trying to revive this thread as I have a question on some pinion side flange bolts. ToyotaMatt, your chart above is AWESOME, so thanks for that!!. Totally answered some nagging questions for me, as well as confirmed my measuring came out right. According to the chart, the flange sizes and spline counts are the same between the 63 to 8/69, and the 1/74-7/78, but the older flange uses 8mm bolts vs the 11mm bolts on the later. So I was wondering if anyone ever switched out from the earlier to the later, assuming the pilot diameters are the same (which I do not know)? That gets you some nice, fresh, beefy 11mm bolts to work with. I am getting a new driveshaft made and would rather have new holes all around, vs perfect on the new stuff and potentially ovalized on the old stuff.

 

[ToyotaMatt]

 

[65swb45]

There is not enough meat on the stock flanges to safely drill them out that large. The heads on the 11mm bolts are not only bigger across, but taller. Quite a bit taller.

And on the small bolt pattern of a pre ‘69 flange, I’d have to wonder how close they’d be to to the fixed yoke on the driveshaft tube???

 

[ToyotaMatt]

There is not enough meat on the stock flanges to safely drill them out that large. The heads on the 11mm bolts are not only bigger across, but taller. Quite a bit taller.

And on the small bolt pattern of a pre ‘69 flange, I’d have to wonder how close they’d be to to the fixed yoke on the driveshaft tube???

mark is 100% correct

and ill add this is TOTALLY Unsafe to MOD this idea too .........

 

[sfab]

I think I wasn't entirely clear. There is a pinion flange made by Toyota or others (1/74-7/78) with the 11mm bolt holes already accounted for. This flange bolt pattern matches the 66 bolt pattern that I have (63-8/69 with 8mm bolts), even with the same spline count. I DEFINITELY get the drilling memo- would not want to do that. But if the flanges are made that way, then a matching flange yoke has to be made to match it. Since all the elements of the driveshaft will be new (and yes, probably NOT Toyota), then I don't see why one couldn't proceed that way. Make sense?

Please have some latitude with my parts vernacular. In other words, put the 1/74-7/78 pinion flange on my pinion output shaft, get a matching flange yoke and fab up the bottom end of the driveshaft. The upper section all seems fine, using Toyota #'s, and I would obviously need to keep the flange yoke on the transfer case brake the same. What Mark said about the taller heads on the 11mm bolts could come home to roost on this one, and no real way to test this until it's built. Also to solve is whether or not the pilot sizes can all play nice.

Anyway, thanks for listening.

 

[sfab]

PS, all this is BECAUSE my splines are out of tolerance, so I need to replace the driveshaft anyway. I definitely would not throw away a perfectly usable unit just to switch to 11mm bolts.

 

[sfab]

OK, so I had too much pie for dessert. That 1/74-7/78 bolt pattern is NOT the same, at all. End of scenario.

Still may be possible with the 8/69-1/74 and 10mm bolts tho... Add in to the equation, angle of driveshaft, u-joint type, bolt head height, yada yada yada...

 

[cruisermatt]

Cruiser Outfitters sells round drill coarse spline pinion flanges that have plenty of material to drill if that helps.

 

[65swb45]

Cruiser Outfitters sells round drill coarse spline pinion flanges that have plenty of material to drill if that helps.

As do I.

 

[65swb45]

OK, so I had too much pie for dessert. That 1/74-7/78 bolt pattern is NOT the same, at all. End of scenario.

Still may be possible with the 8/69-1/74 and 10mm bolts tho... Add in to the equation, angle of driveshaft, u-joint type, bolt head height, yada yada yada...

The 69-73 shafts are a great compromise if you’re staying OE. The more compact ujoint is still hella sturdy behind the 6, and takes a steeper angle than the 74 up.

And if you relief grind the yokes (a cool idea I have @Mark W to thank for), the angle is approaching what you can get out of a Spicer.

 

[archie73]

The 69-73 shafts are a great compromise if you’re staying OE. The more compact ujoint is still hella sturdy behind the 6, and takes a steeper angle than the 74 up.

And if you relief grind the yokes (a cool idea I have @Mark W to thank for), the angle is approaching what you can get out of a Spicer.

Is there a write up on this grinding for angles? Maybe it’s pretty obvious, but I’ve mucked things up before. I’m not in need of d/s work at the moment, it it’d be good to know.

 

[sfab]

I was going to ask the same question.

 

[Mark W]

Just popping into the conversation real quick here, this may have already been suggested. If you are considering swapping to new flanges and redrilling them and you need to make a new driveshaft anyway... Consider using a mini-truck shaft and ujoints. The joints themselves are the same size as the ones in the three speed Cruisers. I've never seen one actually fail from overloading... and the ears on the minitruck shafts are a LOT taller. Like the FJ55 front shafts... but not nearly as rare. That gives you a LOT more clearance for ujoint deflection. More than you can get by grinding the standard Cruiser driveshaft.

Mark...

 

[sfab]

Mark,

I have multiple people telling me about mini-truck drivelines, and it is an interesting direction. If I may ask, do you mean just mini truck, or are you pointing towards a double Cardan style driveline? Are they synonymous? Thanks.

 

[EWheeler]

What this guy said. And I'm not saying it because I've bought parts from him.

I feel like an ass asking, but with the new Toyota hardware suggested on page 2, does the flat washer go on the bolt head side, or the nut side with the 10mm prop shaft hardware? If it was a split lock washer, I'd put the washer on the nut side. With the flat washer, I'm thinking it may just be a spacer and goes on the bolt head side? @OGBeno

 

[brian]

nut side

 

[EWheeler]

nut side

One would think. But what is the purpose of a washer that is the same diameter of the flange of the nut?

 

[brian]

One would think. But what is the purpose of a washer that is the same diameter of the flange of the nut?

what purpose would it serve under the head of the bolt, vs the nut, which is what you are supposed to tighten?

 

[Engineer8000]

It is probably a hardened washer to prevent the nut embedding in the surface of the flange and losing preload.