Axle rebuild help. How badly did I screw up?

[simps80]

how often?

I think its very common.

When I went to slee's to buy the marlin seals

I was asking Ben about pointers/pitfalls

he mentioned this one specifically, he said "one of the more common mistakes is people threading trunnion cap bolts into caliper holes and vice versa"

and then....I went home and did that

 

[simps80]

i was actually thinking about taking pictues of the two bolts
and then writing a blurb about putting the caliper bolts back into the housing after removing the caliper to avoid this issue on re-assembly.

and then sending it to Romer to see if he would add that to the FAQ.

(which btw that was really really helpful, that axle FAQ, thanks Romer!)

 

[Barmanus]

I just called Slee Offroad to see what they thought about just running the caliper bolts in the trunion for a few months. Of course they would never say anything that isn't installed correctly was ok. They actually recommended that I find a used knuckle. I guess I will pull the bolts out and see just how damaged they are go from there.

 

[IdahoDoug]

Mike,

I'm positive I did not make this mistake because I label stuff, but if you posted these pictures I'd be one of perhaps dozens who would be grabbing a flashlight and heading to the garage. Even if there's only a .001% chance it's a critical set of bolts to make mistakes on. I suspect the bolt is tougher than the material the knuckle is made of in terms of which part will damage the other.

DougM

 

[wxm]

I just called Slee Offroad to see what they thought about just running the caliper bolts in the trunion for a few months. Of course they would never say anything that isn't installed correctly was ok. They actually recommended that I find a used knuckle. I guess I will pull the bolts out and see just how damaged they are go from there.

I would switch it back now for a peace of mind (I am sure your friend will understand), different pitch implies different strength.

 

[cruiserdan]

As far as chasing the holes in the knucle is concerned, I would remove the knuckle and thread the tap in from the back-side of the hole(s) so that you are lined up on good threads for the cut.

 

[Barmanus]

I am picking up a thread chaser kit from Sears on my way home. The main thing I am not looking forward to is removing all of that fresh grease!

 

[cruiserdan]

Use a 12 x 1.5 mm tap, not a "chaser".

 

[wxm]

Use a 12 x 1.5 mm tap, not a "chaser".

Dan, correct me if I am wrong. Will 1.5 make it weaker?

 

[Barmanus]

I think I am just going to take it to a machine shop. I can't afford to mess it up any further.

 

[cruiserdan]

Dan, correct me if I am wrong. Will 1.5 make it weaker?

The correct pitch for the trunion cap bolts is 1.5 mm.

 

[simps80]

Mike,

I'm positive I did not make this mistake because I label stuff, but if you posted these pictures I'd be one of perhaps dozens who would be grabbing a flashlight and heading to the garage. Even if there's only a .001% chance it's a critical set of bolts to make mistakes on. I suspect the bolt is tougher than the material the knuckle is made of in terms of which part will damage the other.

DougM

I will get some pics up later tonight (at work now)
of the two bolts, clean up the heads if IIRC, there are different markins on the top of the two bolts.

 

[Barmanus]

Ok, I found a machine shop nearby that said it would be no problem to fix the threads however they need to be. I have new caliper bolts on the way so it seems this isn't going to cost me much more than a lot more time and messy work.

Thanks for everyones help!

 

[simps80]

check w/ cdan!

Ok, I found a machine shop nearby that said it would be no problem to fix the threads however they need to be. I have new caliper bolts on the way so it seems this isn't going to cost me much more than a lot more time and messy work.

Thanks for everyones help!

just fyi, not sure what the machine shop will charge, probably not much,
but you might be surprised that the housing, while relatively expensive, is not really all that bad if you ask cdan (and he stocks them)

just another option, maybe worth your time depending on the machine shop charges.

 

[Barmanus]

As I understand if I get a new knuckle I would have to get new bearing shims as well to properly set the preload. I think I would also have to seperate the steering links also. I bet the machine shop will only charge me an hour labor or so. As always though, I am new to this so I am not too sure. The machine shop just seems like the quickest and safest option.

I orginally hoped I could pull out the bolts and find minimal thread damage. Doesn't sound like that is possible now.

 

[wxm]

The correct pitch for the trunion cap bolts is 1.5 mm.

Sorry, I was thinking about the one on the caliper.

 

[nicholas]

Probably a little late, but I actually replaced the caliper bolt into the caliper after I took it off the knuckle. I also but the trunion cap in a baggie with it's bolts.

But reading this is making me paranoid and I want to go home and check.

 

[Cruiser804]

I have never used a tap.

Just line it up and screw it in the knuckle and then back out?

It couldn't be easier to use a tap. You can get a set at Sears for less than 50 bucks. Yes, you need to make sure the tap is straight but I have done many times on all areas of my trucks, its very easy.

You'll want to start it slowly and back it out a quarter turn every turn or so. This will clear the threads. You can really feel it as it picks up what is left of the treads. They are directional so you want to start on the side the bolt will be entering.

I realize the shop probably has a minimum but this is 5 minute job, if that.

I basically tap and die every nut, bolt and stud I take apart. There is almost nothing nicer than a fresh set of threads.

 

[simps80]

pics of bolts/stats/partnumbers

Mike,

I'm positive I did not make this mistake because I label stuff, but if you posted these pictures I'd be one of perhaps dozens who would be grabbing a flashlight and heading to the garage. Even if there's only a .001% chance it's a critical set of bolts to make mistakes on. I suspect the bolt is tougher than the material the knuckle is made of in terms of which part will damage the other.

DougM

Here are the pictures

the trunion cap bolts have a 10 on the top (you could identify them with that alone on the truck) the caliper bolts have an 11
this represents class 10T and class 11T respectively. According to the FSM:
an 11t 12mm 1.25 bolt (caliper bolt) 'specified torque' would be 110 ft lbs, now the fsm also calls for 90 ft lbs for the spec on the caliper bolts themselves...so that tells me the bolt is probably harder than the housing.

and yes the higher the 'class' the more torque it can handle/called for.

Anyway, I think that's the best way to identify them on the truck,
trunnion cap bolt has a 10, caliper bolt has 11 on the head.

the next picture shows thread and size, they are identical length with previously stated thread differences.

part numbers:
cap bolts: 90101-12166
caliper bolts: 90101-12144

of course this is all from my 97, doubt it changed from 95-97
but dan or someone could probably answer the year question definitively

don't make fun of the microsoft paint labels

 

[Barmanus]

It's a good thing this mistake couldn't be easier to avoid. I think these might be the only bolts you can mixup during the axle rebuild. I even had things labeled in bags and just looked at the bolts not the label!

I took the knuckle back off. Just as expected the the threads in the knuckle were damaged. They weren't that bad though. I ran tap through them and they looked fine and the correct bearing cap bolts went in smooth and tight and torqued down properly. I think everything is fine now. I am glad this wasn't a more costly mistake.