I got a 90 f150 4x4 and the bolt that goes through the leaf springs and rear axle between the u bolts is sheared off on the passenger side. As a result, the axle Has moved and isn't sitting square under the frame and truck doesn't track straight going down the road. No parts store or dealer knows the part number or description of this bolt. Anyone know?
Dealer drawings show the holes but not the bolt. U bolts may also need replacement. No shop will ale the bolt out to measure it.

The u bolts are either m14x2.0x218 or m14x2.0x274, which no parts store carries metric either....(I got that much out of the dealer.)

One shop told me that my sway bar linkage on the drivers side is missing and that fixing the passenger side bolt/axle problem won't do any good unless I fix the sway bar first? Is this true? One buddy thinks that is BS since his truck doesn't even have easy bars and is fine.

 

Only need to know the dia of the hole through the spring pack to get the correct center pin, tighten it down cut extra off after doing so.

Search: leaf spring center pin | Spring Center Bolt | AutoZone.com

And yes replace the U bolts, they are single use can't be retightened.

Easier/faster to just cut them off too!

 

Sae u bolts seem to be more common. I can't find the metric. Is there an sae size that will fit?

 

You can just replace the missing bolt with a hex head (preferably grade 8) SAE of (I believe) 3/8" or 7/16", length determined by number of leaves in the pack. I rebuilt a pair of spring packs a few months ago and broke one of the bolts during disassembly. In order to get the head to fit down in the recess of the spring perch you will need to grind off a bit of the head's edges. It worked like a charm! Be sure to use a type C lock nut.

"Fixing the sway bar first"? I don't think so. You could actually drive the truck for a time without the sway bar though handling could be adversely affected - especially if carrying or towing a heavy load or trailer.

Yes, it is a good idea to replace the u-bolts when R&Ring an axle. Check online if you cannot locate any locally. Check here first - there may even be an advertiser here on FTE that makes them and can coach you through measuring to get the correct length.

dn.

 

9/16"x4"x 8-1/2" ruffly?

Best bet just take a tape measure and measure one out a minute, I know you can buy them "SAE" on blister pack at NAPA for example. Individual blister pack, cheaper have them bent up at spring shop but only if not to far away. For me its a 50 mile round trip to a spring shop.

I had to drill out the hole to fix SAE U bolts on the front of my truck, slightly enlarge the hole it had metrics. Bought SAE U bolts at napa slightly larger the originals rather then smaller swim in the hole.

NAPA/local auto parts did not have them in stock no, got them later same day, always do if order early enough believe before noon or one pm?

 

9/16", I believe, is the replacement equivalent.

dn.

 

I was going to take it to a 4x4 specialty shop that has a salvage yard and as them to pull the bolt off a truck from the yard and put it in mine. Advisable?

 

Ya can for the center bolt but why go through all that, get it all at one place. Center pin and u bolts, can use a grade 8 yea but then need grind head down to fit into center pin pocket. A actual center pin doesn't cost much more then a grade 8 bolt.

Another issue with "used" center bolt while not a drastic one it will already be cut down to finished length. If you have same number of leafs no extra to work with to get the bolt started.

You'll need fairly decent clamps to compress the springs together tight enough to get the nut started on the bolt. Part reason a new bolt is extra long to start with. Fits packs with varying number of leafs and provides for extra length beyond that to draw those leafs together in a pack.

 

Ok, so it is 2 u bolts and a pin, not 2 u bolts and another threaded bolt?

 

Yea 2 u bolts and 1 center bolt.

"Center bolt" / "center pin" same thing sorry if using both names in posts was confusing, I see I was doing just that.

"Pin" is actually the correct name I believe rather then bolt, the head of the center pin is different then a bolt has, not a "hex head" its round and tall.

Taller "head" on the pin then say your standard allen bolt would have, IIRC near twice as tall to positively locate the axle with the spring pack.

 

I see this mentioned a lot on here, is there a reason the u-bolts are single use? As far as I know they aren't torque to yield and the factory service manual doesn't say anything about using new u-bolts when the axle is installed.

 

Heres some info on that very subject, probably plenty more too.

(link will open in PDF)

http://www.google.com/url?sa=t&rct=j...,d.aWc&cad=rja

I can understand the reasoning behind use a new u bolt each time. Keep in mind no bolt/nut expert here!

U-bolts stretch further then a straight bolt of same leg length. Process of tightening a u bolt will pull around (amount dependent on dia and over all length), an 1" of rod conforming to load. More on smaller dia extremely long u bolt.

loosen that u bolt after had been tighten once, not going to get that inch back when the load on it is released (again, using 1" figure as a reasonable example but would vary).

A straight bolt on the other hand will contract back to pretty close to its original length, torqued to spec then released again it'd fully contract. Not 100% no but close enough again vary by dia and total length.

A bolt that does that can be used again, re torqued "stretched" over and over again (more then once) to hold rated yield repeatedly.

Re using a U bolt it would have to be stretched again to attempt hold the same clamping force for a second time, it already stretched an inch first time it couldn't get back, now going beyond that point weakening it in the process.

 

do you really want to try and reuse 23 year old bolts? ubolts and center pins are cheap, do it once, do it right. id do both sides to be safe. you just need a c clamp to hold the leaf packs together

 

I'm still not convinced. It makes sense that a company that sells u-bolts would say not to re-use u-bolts because that sells more u-bolts. They compared the clamp load in two very different cases. If the used u-bolt would have been cleaned and threads lubricated, the clamp load would have been much closer if not the same as when the parts were new. Now if the 23 year old u-bolts were rusty and damaged, then absolutely replace them because it is a safety issue.