Builds 86 Xtra Cab Build (4Wheelunderground 3 link front, 4 link rear and 3.4 swap) (6 Viewers)

[aztoyman]

It's ground and polished to close tolerance, stress proof rod. Often used for cylinders or linear actuators and such. Usually hardened.

Most of the kits available for Dana, Ford and GM axles are 1 1/2" rods.

I have seen guys use generic stuff but checked it on V blocks first.

 

[ntsqd]

For the diy guy who wants to build his own I'd look at linear motion shafts. An easy although not necessarily lowest cost vendor: McMaster <- those are all straight within .002" per foot of length. Sometimes you're ahead to just buy it and move on. Other times it's worth sifting thru the vast net to find the most ideal vendor.

 

[toyotaboy80]

I guess it falls along the lines of you can only be as good as your tools... ground hardened etc would probably pay for itself after a couple housings...

 

[aztoyman]

I still haven't found my axle alignment bar so messed with the 2017 4Runner brakes today. I got the IFS hubs turned down so the rotor hats can fit down over them.

The instructions I saw online for the Sky and FROR kits say to turn them down to "ABOUT" 6.680" Do NOT turn your hubs to that spec. WAIT until you have your rotors in hand. Measure them first!

I don't know if the spec given fits Tacoma rotors or what. My rotors would be loose at that spec. They don't really center on the studs. They MIGHT if using the next longer stud with the longer shoulder?? The shoulder may be too long though?? See image. https://forum.ih8mud.com/attachments/wheel-stud-sizes-jpg.3057705/

I haven't read anything about the 6.680" spec in the instructions being a problem. But if I cut mine to that spec, the rotor would be able to move around a little. May be a non issue? I'm just mentioning it.

The 2017 4Runner rotors I bought are Raybestos 980784R and I have a snug slip fit on them with my hubs turned to 6.730"

 

[aztoyman]

Here's some pics of the hub and rotor with some measurements in case anyone wants them.

 

[aztoyman]

These M10x1.25 holes align with the two M8x1.25 holes in the rotor.

If there is a loose fit between the hubs and rotors I would think if a pair of M10x1.25 bolts were modified to thread into the hub as a long setscrew with the tip turned down to 8mm (like a dowel) they would center a loose fitting rotor.

I also thought about just using an M10 counter sunk Allen head bolt but it's pretty thin around the holes?

Both methods should properly locate the rotor until clamped on by the lug nuts. Just a thought.

 

[aztoyman]

It looks like the stock IFS hub wheel studs would probably still be long enough for a steel wheel. I'll try a fit tomorrow and update this if not.

 

[aztoyman]

Here's the calipers. I don't have pads or the mounting brackets yet so I'll probably be working on steering tomorrow.

 

[toyotaboy80]

Thats pretty cool. Do the calipers deliver more cowbell than the ifs/v6 calipers used or is the primary benefit the larger rotor?

Seems strange that theyd say to just cut the hub to X" if it wasnt even close. Hard to tell from the pics, but is the rotor hole bigger than the hub body?

 

[gnob]

i think your o.d. is going to vary depending on rotor. mine appear to be turned down smaller as im using 3rd gen 4R brakes. neither set of mine are tight by any means and its been a non issue. the 312 studs are also what im using f/r with oe wheels/nuts without issue.

 

[gnob]

Thats pretty cool. Do the calipers deliver more cowbell than the ifs/v6 calipers used or is the primary benefit the larger rotor?

Seems strange that theyd say to just cut the hub to X" if it wasnt even close. Hard to tell from the pics, but is the rotor hole bigger than the hub body?

there is much less fade even vs fj60 vented.
the real advantage, imo, is the ease of teardown and replacement. its frigging irritating having to pull down the bearings for a rotor service.

 

[ntsqd]

......

View attachment 3203301

View attachment 3203302

These two pics show it best. Design intent of the rotor is to pilot on the wheel hub just inboard of the locking hub. Notice the smoothly machined section adjacent to the face the studs protrude thru in the lower pic. Also notice how the OD of the wheel hub gets slightly smaller and rougher a little further outboard of the stud face. This is so that you're not having to fight the fit all of the way down, and since it's clearance rather than location it's surface finish isn't as important. What is needed is a thin band between this surface up against the wheel stud flange and the ID of the rotor. Can see the small gap where the shim would go in the upper picture.

The way that I would make these parts is to make the ID of the shim to be a shrink-fit on the wheel hub and an over-sized OD. Heat one, freeze the other and then assemble. Then turn the OD of the shim to be a slip-fit in the ID of the rotor.
The other way to make these, and what the kit mfg's should be doing, is to make the ID of the shim a tight locational slip-fit and the OD the same OD as the pilot on a Taco's hub; and then supply some Lock-tite red or stud & bearing mount green to hold the shims in place.

Choosing to pilot the rotor the way they have is easy for them and completely incorrect because the mating surface of the rotors are not held to a tight tolerance. I'll bet not every rotor mfg even machines that surface. So some rotors will locate correctly, some won't fit at all, and others will be sloppy. To locate the rotors the way that they were designed to be located would require more effort on the part of the kit mfg and they're basically just being cheap. Irritates me when I see stuff like this done so poorly when the correct way is so obvious but incurs more cost to them and they opt to put their customers in a bind instead.

Without a good piloting of the rotor it will be eccentric and it will behave like a badly out of balance tire. If you're running 40's or TSL's you may not notice this. If you're running 33's you very likely will notice it.

 

[aztoyman]

The conversion kits have to be cost effective for the seller and the buyer. What you said is about the fit on the hub is correct. Too much work for most people I would think.

The most important thing to make this work as is, is to change the instructions. Measure before machining.

I don't have an inside micrometer so I typically get by with dial calipers. My 8" calipers don't fit down in there so I could only barely contact the edge.

I could clearly see that the spec given was too small so I cut to 6.700 and was "planning" on taking small cuts to get to size. I was pissed when it dropped right in. I have another hub but I'm not wasting this part. I'm going to put some tack welds around it and re cut it. It's .030 too small.

I took more measurements and found the longer shoulder wheel studs will not center the rotor. The hub HAS to be cut to fit the rotor hat.

The other solution to at least center it if the hubs are cut too far is my setscrew idea. The only possible problem I see is it shearing off under heavy braking IF the rotor rotates on the wheel studs.

Here's a factory Toyota bolt I found in my stash that at least shows what I'm talking about.

Basically an M10x1.25 bolt with the tip turned down to .266" could screw in two opposite holes in the hub and center the rotor. Easy fix for anyone that has hubs turned too far. The clamping force from the lug nuts would "hopefully" keep them from shearing off. Wouldn't hurt anything if they did.

I don't know if there would be room to back them out from the rear once assembled.

I found that a 17/64" drill bit or an H drill bit is a snug fit in those two M8 holes in the rotor.

Here's another pic with it installed. It could even be a long setscrew with the end turned down.

UPDATING THIS ALIGNMENT SCREW IDEA:

I found another one of these screws in my Toyota bolt stash so I made two of these to try it out.

THIS DOESN'T WORK.

The two bolt circles are slightly different. You can't get both bolts in.

 

[aztoyman]

@ntsqd, I measured that area on the hub that you want to sleeve. On my hubs its 4.173".

The bore of my particular rotors is 4.250".

Best I can get with a dial caliper. No inside mics on hand.

 

[aztoyman]

The stock IFS hub wheel studs are long enough for a steel wheel. These Dorman studs are barely 1/8" longer.

I don't know about thicker alloy wheels. Here's a pic to give an idea.

 

[aztoyman]

The calipers are going to be tight on these steel 17" Race line bead locks. I think 3.5 BS.

I won't know for sure until I get it assembled.

 

[gnob]

whats the od of the rotor ?

 

[aztoyman]

With tape measure roughly 13 5/16" across.

 

[aztoyman]

@toyotaboy80, The 13WL calipers used from the Tundra or Tacoma? (I don't know all the applications) have 45mm pistons. 12.5" x 1" rotor

I was already using an upgraded brake setup from a 1995 T100 with S13WB calipers with 45mm pistons and 11.5" dia x 1" thick rotor so the Tundra brakes weren't really much of an upgrade. I could maybe use IFS hubs and a slip on rotor for that benefit??

These 14WA calipers have 48mm pistons and a rotor 13 1/4" x 1 1/4" thick so more cow bell I'm hoping. Ha ha,

My ORIGINAL 1988 stock calipers were S12+8. There was a large and a small piston. 34mm and 43mm. The rotors were 11.3 dia x .787" thick. The stock brakes sucked and were scary even when I had 31" tires on it.

 

[ntsqd]

@ntsqd, I measured that area on the hub that you want to sleeve. On my hubs its 4.173".

The bore of my particular rotors is 4.250".

Best I can get with a dial caliper. No inside mics on hand.

It looked like it was about that size gap, which is why I'd turn a ring that was a heat-fit (say 4.170"+.000/-.002 ID) and get them in place before turning the OD to the Taco hub's pilot diameter (say 4.240" +/-.005 OD). I'd make them from something like two of these: 4140 Steel Discs

If wheel studs are loaded in shear we're done. There aren't enough of them and they aren't in a big enough circle to take stock gear reduction, never mind a doubler + deep diff gearing + .....
It's all about the clamp load that the lug nuts & studs can generate against the wheel hub's flange. That friction is what transmits the torque. Putting the rotor's mounting flange in the stack changes nothing.