Replacing axle leaf spring ubolts questions

[gba88]

Never did this before so bunch of dumb questions.... found a nut with a busted bolt in the driveway...inspected underneath and it was the passenger side outer ubolt on the rear axle for the leaf spring. I will have new bolts tomorrow, but was wondering about some details of doing the job.

1. getting weight off the springs: I assume if I lift it under the differential then jack stands on the end of each tube, is that the way to go? How do you tell if enough weight is off?

2. I figure it only makes sense to replace all 4....my fear is if I just change the one that broke or one whole side that it will affect height and then affect alignment and i really don't want to have to get an alignment done. I'm sure the other 3 are ready to break too if one broke...

3. Should I put the new bolt on without removing the one that is still in place or do they both need to go on at the same time? It would make sense to me to leave one in to keep it held together while you put the good one in.

Is it dangerous to drive it with a broken bolt? What if both were broke?....I'm definitely replacing them but just wondered because I was driving about 70 on the last trip I took before getting home to the driveway and finding the broken bolt. Please post any info any write ups that may be around. I really only found one video on youtube of a guy doing it, and it didn't really answer my questions.

 

[gba88]

1. getting weight off the springs: I assume if I lift it under the differential then jack stands on the end of each tube, is that the way to go? How do you tell if enough weight is off?

I think I may have this completely wrong after watching videos on other cars...I think I need to get jack stands under the frame rails so that the hubs drop and all tension is off the springs, is that right or can it be done with stands under the axle?

 

[lawsoncl]

If both broke on the same side, the axle would stop being centered under the spring when you hit the breaks. Not good.

Being paranoid about dropping heavy things on myself, here's what I'd do - Jack under the tube until the tire just lifts off. Put jack stands under the frame. Pull the tire and slide it underneath as an extra fail-safe. Ease the jack down so the jack stands touch and support the body, but keep some weight on the jack pushing the tube upwards into the spring so it doesn't slip out of place.

Put an alignment mark on the spring just in case it moves. It shouldn't as there is a centering pin on the spring that goes into a hole on the spring perch. With the weight of the vehicle pressing down, the spring shouldn't move out of place. Do one bolt at a time.

An impact wrench and a deep socket are really most helpful here. If the u-bolts are badly rusted,you may need a cutoff wheel or nut splitter to cut them off.

 

[gba88]

If both broke on the same side, the axle would stop being centered under the spring when you hit the breaks. Not good.

Being paranoid about dropping heavy things on myself, here's what I'd do - Jack under the tube until the tire just lifts off. Put jack stands under the frame. Pull the tire and slide it underneath as an extra fail-safe. Ease the jack down so the jack stands touch and support the body, but keep some weight on the jack pushing the tube upwards into the spring so it doesn't slip out of place.

Put an alignment mark on the spring just in case it moves. It shouldn't as there is a centering pin on the spring that goes into a hole on the spring perch. With the weight of the vehicle pressing down, the spring shouldn't move out of place. Do one bolt at a time.

An impact wrench and a deep socket are really most helpful here. If the u-bolts are badly rusted,you may need a cutoff wheel or nut splitter to cut them off.

Thanks for the reply! Yeah I read that running with broken bolts can break the center bolt in the leaf pack too. I'll bet the clunking I've been hearing for months was related to this (thought it was maybe the transmission mount).

I'm kind of afraid to put the stands under the frame rails for fear of bending/crushing as it's pretty well rusted underneath after 23 years in the rust belt. I was trying to find a picture of the best point to place the stands. I read something about directly to the front of the shackle mount. Maybe I'll put wood blocks to distribute the weight better than just the top of the stands.

 

[gba88]

Sorry I didn't have this in the first message but I also need to know the torque specs for the bolts. I've read that it's 55ft pounds for the half inch, but on the replacements I bought it says on the box 78ft pounds. I read a post online somewhere about a guy denting his axle tube with too much torque and I don't want to do that. Logically I would think to follow the specs on the box since they apply to the new hardware, but the info about denting the axle tube makes me think maybe I should just follow the FSM spec of 55.

 

[Anak]

Wood blocks should be fine.

Just replace one U-bolt at a time and nothing should move.

Regarding getting the old ones off, odds are your best bet is to hope they break. If they don't break then plan to cut them. You will probably need to cut the new ones down a bit anyways (extra threads above the nuts). Might as well get those tools out at the beginning of the job.

Note that you will need to re-torque after a hundred miles or so. After re-torquing I like to double nut the U-bolts with upside-down lug nuts (cones pointed up). Extra insurance to keep things from loosening up, plus I know where I can find a spare set of lug nuts should something happen during a tire change.

 

[gba88]

Wood blocks should be fine.

Just replace one U-bolt at a time and nothing should move.

Regarding getting the old ones off, odds are your best bet is to hope they break. If they don't break then plan to cut them. You will probably need to cut the new ones down a bit anyways (extra threads above the nuts). Might as well get those tools out at the beginning of the job.

Note that you will need to re-torque after a hundred miles or so. After re-torquing I like to double nut the U-bolts with upside-down lug nuts (cones pointed up). Extra insurance to keep things from loosening up, plus I know where I can find a spare set of lug nuts should something happen during a tire change.

Thanks! Yeah, I figure I'll be cutting the other ones off so I'll have the angle grinder ready. I have an impact that will hopefully break them but I probably won't get that lucky. I saw a video where a guy partially cut the bolt then broke it by torquing it after getting about 3/4 way through...it was a "safety tip" video to prevent the bolt shooting up after cutting it. I'd imagine it has to do with how much or how little tension you have on everything though.

 

[Phil]

Don’t jack anything up unless you can’t physically fit under the Jeep. One is already removed; replace with a new u-bolt. Then remove and replace the adjacent. Move to the other side, repeat process.

 

[gba88]

Don’t jack anything up unless you can’t physically fit under the Jeep. One is already removed; replace with a new u-bolt. Then remove and replace the adjacent. Move to the other side, repeat process.

I can physically fit under it, but although I didn't try... I can't imagine working on those bolts with the wheel on. It's not lifted or anything, pure stock. What If I jacked it up just enough to get the wheel off and why shouldn't it be jacked up? Everything I've seen shows people jacking it and supporting it on the rails. Thanks, for the reply!

 

[maxbraketorque]

I can physically fit under it, but although I didn't try... I can't imagine working on those bolts with the wheel on. It's not lifted or anything, pure stock. What If I jacked it up just enough to get the wheel off and why shouldn't it be jacked up? Everything I've seen shows people jacking it and supporting it on the rails. Thanks, for the reply!

Do that. Jack the axle near the u-bolts just high enough to be able to remove the wheel. Then replace u-bolts on that side.

 

[gba88]

Do that. Jack the axle near the u-bolts just high enough to be able to remove the wheel. Then replace u-bolts on that side.

Thanks! This will be my plan then, I guess. I won't try to get the whole thing off the ground at once, I'll just very slightly raise one side at a time. Not sure when I'll get to it but probably not until tomorrow afternoon at the earliest due to work. I'll keep watching the forum for any more info or torque spec input.

 

[XJI6191]

Can't help but think OP is over-thinking this - or perhaps I didn't think about it all when removing the rear ant-sway bar from my parts Jeep. Applied usual rules, only jack it up enough to do the job, don't remove any more than essential to do the job. So - crack lug nuts (no rattle gun then), floor jack under diff, lift 'til can see daylight under one tyre, remove that wheel, put to one side (never seen the point of placing it under the vehicle (certainly not a 4x4), reach under fender & remove U-bolt nuts, then bracket, replace nuts & wheel, raise jack a little more, repeat on other side. Was I was lucky? This was a couple of years back, it's a '96 that's been standing maybe 8 years, only a couple of miles from the ocean - & it all came apart with an 18" breaker bar.

No, I didn't mention jack stands;never felt comfortable using them (so only use them when I need the jack for something else) probably 'cos seldom had the luxury of working on level &/or flat ground & chances of coming off stands seem to outweigh a jack failing suddenly. Not advocating it as good practice, just explaining my thinking & what I'm happy with.

 

[gba88]

Can't help but think OP is over-thinking this - or perhaps I didn't think about it all when removing the rear ant-sway bar from my parts Jeep. Applied usual rules, only jack it up enough to do the job, don't remove any more than essential to do the job. So - crack lug nuts (no rattle gun then), floor jack under diff, lift 'til can see daylight under one tyre, remove that wheel, put to one side (never seen the point of placing it under the vehicle (certainly not a 4x4), reach under fender & remove U-bolt nuts, then bracket, replace nuts & wheel, raise jack a little more, repeat on other side. Was I was lucky? This was a couple of years back, it's a '96 that's been standing maybe 8 years, only a couple of miles from the ocean - & it all came apart with an 18" breaker bar.

No, I didn't mention jack stands;never felt comfortable using them (so only use them when I need the jack for something else) probably 'cos seldom had the luxury of working on level &/or flat ground & chances of coming off stands seem to outweigh a jack failing suddenly. Not advocating it as good practice, just explaining my thinking & what I'm happy with.

I agree 100% on overthinking it....I have a bad habit of researching the crap out of anything I've never done before. The biggest thing I've done is change the front axle ujoints and the track bar. I also fear having to take it to someone for something I can't do so a big part of this job was thinking that if something goes wrong or shifts too much I might need an alignment..I kind of don't think that is the case though with this job.

Although my dad is in his early 70's, he still helps me with projects now and then. He cannot BELIEVE I want to go by torque specs! He's always saying that he never used a torque wrench in his life and the guys at the garage next door never use them. I'm just like ok.....the main reason I started using one was because I had a tendency to over tighten bolts to the point of breaking them.

I do appreciate the reply and observation!

 

[gba88]

One last question.... I think the bolts I got may not work. They are 2 7/8" not 3". I went by a video I saw on youtube of a guy that bought some dorman bolts and after watching again it looks like he may have the dana 35 which is why he said they were "bigger". I have the 8.25 chrysler.

I crawled under and tried to push one onto the axle near the differential and it was very tight. I didn't try to hammer it on or anything but I was wondering if anyone knew if the 1/8" difference would be enough to not allow them to go completely against the axle? What a pain...now it looks like I may have to postpone and order online!

 

[gba88]

Really wish there was a way to edit posts on here instead of creating new ones. Found 3 1/8" at a local oreilly's I'm going to get. I really don't think the 2 7/8" will go without beating them on.

 

[jeep ride]

You need 3 x 8 with 1/2 thread for the Chrysler 8.25 we had them in stock at all the Napa store I ever worked at.

 

[XJI6191]

Do so agree about editing, afaIk, unique to this forum.

If you've done front axle ujoints and the track bar, this should be a walk in the park.

Given my attitude to jack stands you won't be surprised that I think torque settings are for head bolts/nuts, mains caps, con. rods & not much else. As a rule of thumb, I'd say U-bolt nuts should be as tight as a good pull on a standard length 1/2-drive ratchet.

Good luck - but sure you'll be fine. :yelclap:

 

[gba88]

Do so agree about editing, afaIk, unique to this forum.

If you've done front axle ujoints and the track bar, this should be a walk in the park.

Given my attitude to jack stands you won't be surprised that I think torque settings are for head bolts/nuts, mains caps, con. rods & not much else. As a rule of thumb, I'd say U-bolt nuts should be as tight as a good pull on a standard length 1/2-drive ratchet.

Good luck - but sure you'll be fine. :yelclap:

Well, it's done, but it was a s*!t show. Let's start with the basics...I used 1/2 by 6.5" x 3 1/8" bolts, grade 5 from the local auto parts store. They SHOULD have been 3", but I just "had" to get the job done and couldn't wait to order online so I paid the price. The 6.5" matched the ones that came off perfectly, no way 8" would have worked here, I would have had to chop 2" off.

I had to bend them in somewhat due to the extra 1/8", but OMG the inner ones that needed to clear the shock mounts!!!! Had to keep f'ing around and try to bend just the one leg of the rear of the passenger one. Then, got it all together and torqued to 55ft lb (even though package said 78ft lb).. WELLL.. one of the GARBAGE auto part store bolts decided to destroy it's threads under the nut and it would not loosen or tighten!

I started using a torque wrench so that I wouldn't break bolts. I have NEVER seen this happen before. Luckily a different store had another with same specs so I ran and got that with my dad then started to cut the old/new SOB off. It's all together now and I went to 45ft lbs on those and when I check it in 100 miles, I'm gonna set it at 45.

And to think I was all worried about the alignment and how to jack it up and all that BS... ridiculous. I'm gonna say 90% of my problem was using GARBAGE parts. Yeah they weren't 3" but like I said, but I was able to bend them and make them work since it was only 1/8".

Now I'm afraid the others are gonna let go or something but hey...whatever. If they do, I know the job is NOTHING like I thought it would be though. The only issue I ran into is I couldn't torque the one under the sway bar link because a deep well on the ratchet wouldn't fit. I just went by "feel" of the others and used a gear wrench.

 

[maxbraketorque]

If your axle needs 3" u-bolts, I suggest ordering those and ditching the 3 1/8" u-bolts.

 

[gba88]

If your axle needs 3" u-bolts, I suggest ordering those and ditching the 3 1/8" u-bolts.

It's the chrysler 8.25 and I've seen the 3 or 3 1/8 specified on different sites so I think it will be just fine. I cannot find any clear website that has what I would need precisely.

Does anyone have a link to suggestions? I REALLY don't want to have to replace them again since I just spent about $60 on these, but if it would be some kind of safety concern?

We bent them in enough to get through the plate holes, and they seem fine. It's only 1/16" more on either side so I don't think it will really affect anything, will it?