center pin

[buddy208]

what size is the center pin of the leaf springs of a 2.5l d35 Comanche pioneer

[jpnjim]

I've always used ground down 5/16" bolts (spin a nut up tight to the bolt head, then grind them both till they're round, like the pin),

so I'd say 5/16" :D

[Eagle]

XJs use 5/16" pins. I haven't disassembled or rebuilt any MJ spring packs but didn't someone post awhile back that they are 3/8"?

[jpnjim]

XJs use 5/16" pins. I haven't disassembled or rebuilt any MJ spring packs but didn't someone post awhile back that they are 3/8"?

 

I'd like to say I'm 100% sure on MJ's = 5/16" (especially since I'm running XJ leafs below my MJ main leaf right now),

but I've had more important stuff than this slip my mind, so :dunno:

 

I can remember drilling out a set of leafs for a 3/8" pin (it actually went through allot easier than I thought it would),

but I can't remember why I did it. :dunno:

[Pete M]

been too long for me to remember the size, but I just wanted to chime in that you should use nothing weaker than grade 8. :thumbsup: just in case.

[CWLONGSHOT]

Mine are 3/8". Thats with the RUSTY's leafs and the current MOTION leafs. I Run the Mopar perches and those have even a bigger hole. I also made my own as jmpjim mentioned. the one thing most centering pins use is a fine thread.

 

CW

[mvusse]

I can't remember. All I know is I used actual center pin bolts, but needed to have the heads ground down because the Ruffstuff perches use the same size hole as the stock ones, which is 1/16" smaller than the common head on the proper sized pin.

[HOrnbrod]

Usually the center pin for the standard XJ/MJ springs are 5/16". The HD springs (Up-Country, Metric Ton), etc. are 3/8". But throughout the years there were many optional spring packs offered, sometimes as many as 6-7 annually. :eek:

[HellCreek]

MJ center bolts are 3/8", but they have a 12 mm head diameter. We use standard 3/8" spring center bolts and turn the 9/16" heads down to 12 mm in our lathe.

 

Don, I sent you prints on these springs. Shame on you for not looking. :no: :rotf:

 

-Tom

[HOrnbrod]

Yeah, but guess what Tom. The 52003676 3+2 MT springs I purchased long ago (copies from another vendor) had 5/16" center pins. Everything else was correct according to your print (3-leaf w. 2 overloads, free arch, load, etc.) except the pins. I've since drilled them out and used 3/8" pins when I inserted shims for the lift. :hmm:

 

I don't think anything is written in stone for these rigs Tom. :D

[CWLONGSHOT]

Here is a shot of my centering pin in the MOPAR perch.

 

 

Here is a shot of what I made up to compensate:

 

 

CW

[HellCreek]

Yeah, but guess what Tom. The 52003676 3+2 MT springs I purchased long ago (copies from another vendor) had 5/16" center pins. Everything else was correct according to your print (3-leaf w. 2 overloads, free arch, load, etc.) except the pins. I've since drilled them out and used 3/8" pins when I inserted shims for the lift. :hmm:

 

I don't think anything is written in stone for these rigs Tom. :D

 

That's true, Don, but a lot of aftermarket guys use 5/16" center bolts just because they don't want to go to the trouble of turning down the 3/8" heads to the correct diameter. The factory bolt should be 3/8". The head diameter on a stock 5/16" center bolt is 1/2", which is a little tight in the 12 mm hole in the factory axle saddle, but it will work.

 

CW, Mopar probably uses the same axle saddle on several different vehicles, so they most likely drilled the hole to the larger bolt size - just my guess.

[89mjpioneer]

Mine were 3/8 when I rebuilt my factory pack.

[jpnjim]

Here is a shot of my centering pin in the MOPAR perch.

 

 

Here is a shot of what I made up to compensate:

 

CW

 

 

Maybe I'm :nuts: ,

but I run those Mopar perches on my MJ's rear axle,

and never gave the slop a second thought. :dunno:

 

To take it even further, when I had to drill new holes to alter the wheelbase,

I went slightly bigger than the Mopar holes, to get the pins in/out easier.

(previous bad experience trying to get a tight pin in & pop rust-welded pins out).

 

My thoughts on this have always been:

 

1)The U-bolts hold the axle in place, the pin is just for location

2)My trail junk is usually so beat, even if there was a combined 1/4" of slop on both sides (there's not), the axle will still probably be the straightest thing on the whole Jeep. :yes:

 

 

 

I'm not saying one way is right, or wrong (yours is obviously more precise then mine :yes: )

just weighing in from the opposite side of the curve. :dunce: