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4th broken spring center pin! Who makes a stronger one?

JEEPZZ

JEEPZZ

NAXJA Forum User
Location
In front of my PC
I just broke yet another rear leaf center pin. It's the second one since 3 months. The kicker is, I haven't been offroad since the NAXJA Oct run. It's possible (but unlikely) that I broke it back then and never noticed it until now. I replaced the same pin just the weekend before Moab and now it's broken again. All the U-bolts are still tight but the axle shim has just started to work it's way out.

The local shops around here tell me that center pins are all the same, is this true? If not, where can I get a stronger one that's made from unobtainium or the like?

Thanx,
Todd
 
What size is it? There was a discussion about upgrading to 3/8" center pins a couple days ago.

Ary
 
I'd check the axle perch for size. If the pin hole is sloppy you might be working that pin pretty hard.

You ARE using 4 ubolts right? ;)
 
Thanks for the link. I'll check the pin hole in the axle perch for slop. (I didn't think about that one) Looks like I'll try the 3/8th pin conversion too. Now I'm starting to wonder if my Alcan springs were supposed to have 3/8 pins all along? I doubt it though as the last broken pin was a pain in the ass to replace with the standard 5/16.

BTW, the axle is a locked XJ D44 with no axle blocks, just spring and shim. (and broken pins) Would a traction bar help or will the pins break regardless. I'm on 35's with 4.88's.
 
I just bought spring perches from RE, and 3/8" center pins. Drilled the RE1462 out, no slop inside the springs, no slop in the new spring perch, I'm very happy about it. Also put the perches at the right angle to rid the shim. Every time I removed my u-bolts, I could see how bent up my center pin was...I've replaced them 3 times before, hopefully this is one of my last. I think you should just drill your spring to 3/8" and see where that gets you.
 
Shims are hard on center pins. The center pins are hardened and as such are brittle. By adding a shim, you place the load on the pin all on one side, instead of distributed around the shaft. Use a couple of soft washers to help even up the load, Ideally you should use a washer that is tapered the same angle as the shim, and mount it in the reverse direction. The other big reason my be that you need to retorque the Ubolts at least once after installation. They stretch. Never use Ubolts over again more than one time. Manufacturers recommend using new ones every time. As they stretch, they allow the spring to move under the spring plate.
 
Never use Ubolts over again more than one time.
Click to expand...

Holy cripes, if this was adhered to, there would be a lot of rich U-bolt manufacturers!

I think my U-bolts have been on and off about a dozen times.

I understand the concern, but you RARELY ever see broken U-bolts. Without a traction bar, the spring usually bends before the U-bolt gives. With a traction bar, they see very little load.

Original question: Get a 3/8 pin, it will solve the problem.

CRASH
 
Know someone with a lathe ? Have some made with a longer head.IIRC we used drill rod turned and threaded to size.
The legnth of the head is important so it reaches thru the shim and into the spring mount.
Wayne
 
I know you're supposed to use new U-bolts, but I've had my springs apart so may times that I've used U-bolts over and over again. If you're breaking center pins, and the shim is moving around without even wheeling, your U-bolts aren't tight enough....period. Tighten the hell out of them and check them regularly. I check mine every couple of trips.

It is good to get one size bigger center pin, but it can be a pain drilling a bigger hole through the leaf pack. It also is a good idea to get one size larger U-bolts. MIne are 9/16" rather than 1/2".
 
Do you guys running shims bolt the shims to the leaf packs? or do you rely upon the head of the bolt to locate the shim and the spring on the perch?
 
Safari Ary said:
Do you guys running shims bolt the shims to the leaf packs? or do you rely upon the head of the bolt to locate the shim and the spring on the perch?
Click to expand...

Always run the pin through the shim.

Good shims have a flat spot machined into the bottom where the head of the pin should ride, thereby avoiding the unequal pin torque issue.

Always use steel shims.

CRASH
 
Go and get a grade 8 bolt, grind the head down to fit in the perch hole and you shouldn't have any problems. Ask the guys that were at NACFest 01 if this works :D

Sean
 
OneTonXJ said:
Go and get a grade 8 bolt, grind the head down to fit in the perch hole and you shouldn't have any problems. Ask the guys that were at NACFest 01 if this works :D

Sean
Click to expand...

Been running the "Grade 8 grind-to-fit" (not a Rose Ginding exclusive mod ;) ) setup for 2+ years with no problems, I agree......the pin is loose or the u-bolts or both. Bolt the steel shim to the spring.
 
OneTonXJ said:
Go and get a grade 8 bolt, grind the head down to fit in the perch hole and you shouldn't have any problems. Ask the guys that were at NACFest 01 if this works :D

Sean
Click to expand...

haha, it was quite funny driving around and seeing your jeep abandoned on the side of the road with one side of the axle just kinda....somewhere under your jeep.
 
Call it hack if you like, but on my dana 60 front under my Xj Im running Xj rear leafs with a 4 degree case aluminum shim (all they had in town). The xj pack has a 5/16in pin, but standard pins are not long enough or wide enough to fit well with the shim, pluss a dana 60 leaf perch has a much larger hole then a dana 35 rear...

So what I did was get a 24in piece of better then grade 5 equivalent all thread, Its black all thread, strong stuff, its less then grade 8 but better then grade 5, and 3 grade 8 nuts for each center pin. I have two nuts welded to the all thread at the bottom and one nut on top of the leaf pack. My U-bolt plate is VERY tight fit with the grad 8 nut and have had no issues yet. only like 600 street miles and afew trail runs so far...

its cheep and works good.

I think having such a large u-bolt plate with a tight fittign pin really helps..
yes the U-bolts were cut down...

download.php
 
Hows this for a shocker - pull the pins, replace with new spring centerpins - buy some new perches and cut your old ones off - set the angle properly and get rid of the damn shim!

Total cost in parts is about 25$ - one afternoon with the grinder and some welding...

Matt
 
Matt said:
Hows this for a shocker - pull the pins, replace with new spring centerpins - buy some new perches and cut your old ones off - set the angle properly and get rid of the damn shim!

Total cost in parts is about 25$ - one afternoon with the grinder and some welding...

Matt
Click to expand...
You're not the first to suggest this. :doh:
Here's the friggin' update, the pins are/were already 3/8th as per the Alcan springs. (no I wasn't the original installer of the leafs) If I break another pin, I'm going to have the perches cut and rotated to eliminate the shims. Also I'm going to check the torque on the U-bolt monthly myself; and yes they we're all still tight when the pin broke. The pin on the drivers side was bent at least 20 degrees also so I replaced that one too.
I've never broke a pin on my 87 and I wheel it much harder than my (Limo Cruiser) 97 and I've owned it since 91. So what in the heck in causing this?? 35's, 4.88's or the taller Alcan springs?? (the 87 is at 6", 33's w/4.56's and tapered blocks instead of shims)
 
all I can say is make sure that the centerpin takes up the COMPLETE hole in the springs. No slop at all, and then tighten them after a little while of driving..........then get new spring perches:)
 
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