I have a quick question, hopefully. I'm going to pick up some parts this weekend and stumbled across some supposedly new FJ rotors from an 81 and up that fit the SFA from a mini truck using the IFS minitruck calipers.

How can I tell the difference between and IFS rotor and the FJ/LC rotor that I'm referring too?

From what I've been reading, the height of the FJ rotor is less than the height of the IFS rotor (if you were to lay it flat on the table. I looked up rotors on rockauto for each vehicle and there were some specs mentioning the "height" of the IFS one is about 64.4mm and the height of the FJ is 48mm.

Is this the best way to tell the difference between them or is there a quicker way then having to bust out the calipers (the measuring instrument, not brakes) and check the height?? I want to be sure they are actually the right rotors.

 

it's all a moot point of you don't have the correct calipers.

I don't know about an "fj/lc caliper", but the way to tell if you have '86 and up 4runner/truck(?) ifs calipers is to compare the piston diameters... the stock sfa has one bore bigger than the other, ifs calipers have matched bore sizes.

what calipers do you have now?

http://www.marlincrawler.com/brake/d...rotor-standard

when you swap the rotors on the axle hub, you'll have to use a press or a hammer and a brass drift for the studs... it's a real hassle.

 

the other thing is, if you upgrade to the ifs caliper, and you still have the small bore master cylinder/single brake booster, your brake pedal action won't be optimal... so you'll want to upgrade that as well.

 

I know this. I have it all taken care of. I was curious about the differences between the rotors I mentioned.

 

your post is confusing... you have a rotor question, but you ask to compare calipers that don't need to be compared, then say that it's all taken care of?

see if this helps:

"FJ40 fronts, say off an 81. They are the same width as the IFS rotors. They measure in at 11.890 diameter. About 1/2" larger than the IFS rotors."
http://www.pirate4x4.com/forum/toyot...-diameter.html

 

My apologies, that was a mistake. It should have said rotors. I can admit my own mistakes. I will get that corrected asap.

Thanks for the info. I'll take a look through it.


edit: I cleared up the post, thanks. I have SW13B calipers off of a 92 or 94 4runner (I'd have to look at my notes).

 

I remember going through this when I upgraded my front brakes, lol

here is what it looks like when the rotor diameter is too small for the pads, that "1/2" larger than the ifs rotors" can make a difference:
http://forum.ih8mud.com/60-series-wa...-question.html

I think that you have the right calipers(?)

 

Thanks, I picked up some parts today and they appeared to be the LC rotors. I do have the right calipers. They are the "largest" (piston wise) that you can slap on to the SFA with the LC rotors. I got the master dual booster with aluminum mastery cyl. I'm going to run the man. prop. valve and do a full float conversion on the rear with the sfa stock disc and calipers on the rear. It should have no issues stopping at all now.

The guy that I bought the parts from says that he uses the IFS hubs on the SFA, machines it down a little so a tacoma rotor will fit then uses an IFS caliper. This is no new information. Along with getting the additional 1.5" on each side without spacers, you also achieve something that I never realized when researching. You can practically just pull the caliper off, unbolt the hub from the knuckle and remove the whole damn assembly!! You don't have to disassemble hardly any of the hub or wheel hub. SO MUCH QUICKER! I have all the parts for what I'm doing now, so I will stick with the typical SFA wheel hub setup, however in the future I may change over to the IFS wheel hubs for the two obvious added benefits.

 

I looked hard at that swap, the bigger Tacoma rotor is also tempting... and sign me up for that full float!!

discs and the parking brake situation...

your rig sounds pretty hard-core, if you are still running the factory sfa housing, you'll probably bend it, and have to get a real axle housing... I ended up with the trail gear housing, so I didn't want the extra width of that axle conversion... a sad tradeoff for sure.

 

Just get an all pro type of tcase brake. Simple solution and you don't have to think too hard for it. ha ha.

Mines an 84 housing. It is gusseted pretty well and has the TG gusset. I'll probably do the ball joint gussets when I pull the axles next. I think it should be ok. I've been building the truck for a few years. I work on it here and there when I have time. If I have issues with my axles, I'll go with entirely different axles. Probably FJ rear and not quite sure for up front.