1990 2Wd Calipers

[OneOverZero]

If it's kosher for me to crosspost from my project thread, I've run into an issue that has reassembly at a standstill and hope it can get some more visibility in Tech.  I can't find the correct calipers for my '90 2WD Pioneer, but I foolishly returned the pieces on the truck as cores before checking the replacements.

 

At this point, I've exhausted local supplies (listed below) and am going to start ordering online.  RockAuto lists Wagner L123602 and L123603 as correct for a '90 2WD, so it's my next option, though not one easily (or cheaply) returned.  I can't find an image of them anywhere, though the other calipers they list for my application appear to be the same incorrect casting as the SE4892 shown below.

 

Does anyone have experience with this setup?  Tracking down the correct calipers is the last big step to getting my truck out of the garage for the first time in over a year.

 

 

MJ now has rear brakes!  What an odd setup on the Dana axles.

Still no luck tracking down calipers.  Calipers shown in 1990 microfiche are 05252985, 05252984 (oddly enough, appear to be shared with my Dart):

 

And boy howdy, does that ever look like the SE4892 from NAPA:

 

Not even close.  See also: why I'm replacing the rotors and wheel bearings, and why I shouldn't apply grease in the dark.

 

Based on a few trips back and forth, here's a group of NAPA calipers that don't appear to be correct, along with their respective applications (according to NAPA interchange, at least):
SE4892, SE4893 ('90-'92 XJ/MJ, 2WD, pictured above)
SE4890, SE4891 ('90-'92 XJ/MJ, 4WD)
SE4732, SE4733 (pre-'90 XJ/MJ)

 

What exactly do I have here?  And what am I doing so horribly wrong?  I wish these had the same unit bearing & hat rotor setup I'm familiar with from later XJs.

[1987Comanche]

  What you need is someone with a mid-90 through early -92 2WD to take some measurements and check their calipers for factory P/N stampings.  Georgia is a late '92 build and she uses the 4WD brake hardware so no help there. 

  Are the caliper retaining brackets bolted on to the knuckle or is it a 1 pc forging? 

  Maybe someone has a 2WD front axle laying around from a 4WD conversion that could be a donor?

[Keyav8r]

The caliper brackets look pretty much like those on my 88 2WD. I would think the calipers for 2WD trucks would not have changed over the years. I'll take a photo of the 88 caliper on the truck and send it later today. PM an e-mail address and I will send it from my phone. That's easier than posting the photo.

[mvusse]

Later 2wd models used a dummy axle tube with the same knuckles, rotors, calipers and unit bearings as 4wd models with a dummy shaft holding the unit bearing together. Don't know what year the changeover was, though.

 

The only difference between early 4wd and later 2wd/4wd calipers was along with the caliper bracket bolting onto the knuckle  and the caliper bracket being part of the knuckle casting. Don't know anything about early 2wd parts.

[Rockfrog]

I believe the 2wd format changed in '93 so the MJ's should still be a bearing in rotor assembly with bolt on caliper bracket for 2wd still.

 

Have you tried looking at pre 90 4wd calipers?

[HOrnbrod]

At this point, I've exhausted local supplies (listed below) and am going to start ordering online.  RockAuto lists Wagner L123602 and L123603 as correct for a '90 2WD, so it's my next option, though not one easily (or cheaply) returned.  I can't find an image of them anywhere, though the other calipers they list for my application appear to be the same incorrect casting as the SE4892 shown below.

 

Yes, those Wagner calipers are correct for your application. I have them on my 91, bought them new, not rebuilt, from O'Reillys when they were phasing out some of the Wagner products. They came with new pins, but not the anti-rattle clips for the pads. Check out this thread too:  http://comancheclub.com/topic/33716-anti-rattle-clips/?hl=brake+squeal&do=findComment&comment=339049

 

[nitroxsteve]

I don't understand is the picture what you have or what you want? That looks correct to me.

[Rockfrog]

Yeah looking at it again ... the calipers looks fine ... the pads ride on the "ears" not the calipers. If that is what you have now (pictured) have you added pads? The picture shows the caliper unloaded ... so there is no way they will fit as they are incomplete. Or is the issue that the bolt spacing is incorrect where the pins go into the bracket? Or are we talking about the caliper not being centered over the rotor (but it being a sliding caliper ...). There should really only be two types of caliper available .... more or less, pre 90 Bendix calipers and 90+ Chryco calipers (similar situation with 4wd knuckles - only two types) ... My '00 XJ uses the same calipers as a 93 does (but the wheel hub and rotors differ greatly). The 2wd should only have two flavours and use the earlier Bendix caliper for the bolt on bracket with bearings in rotors, and the later Chryco caliper for the unit hub style (but as mentioned I don't think the MJ ever got the later unit hub/Chryco caliper style front end as production was halted prior to the changeover).

 

Also ... I have more often than not received the wrong parts in the right box.

[OneOverZero]

Whoa, just realized I never replied back with the results and it's been a whole month.

 

All of you folks are right, of course.  :cheers:  I again swapped on the calipers shown above, and although the machined ears on the calipers don't appear to match the casting, it's correct.  I just overthought it and second-guessed everything when the machining (particularly that inboard ear) sat so far out.  I did receive at least one set of calipers that were mislabeled, but hey, the above ones were correct anyway.

 

The fact that machining on left and right calipers isn't mirror still strikes me as odd, though.  Good thing calipers slides aren't put under shear because these things sure have a good bit of angular slop. :rotf:

 

Thanks again!