Body mount bolts, bushings and rust

[skrelnik]

I ordered and received my new front and rear bumpers from KD Fabworks, and while the front install was a breeze, the rear install is more complex since it ties into the two rear body mounts.

My concern is rust, since I live in New England the jeep has a bunch of rusty bolts, including these body mount bolts. Since I need to loosen or remove some of the bolts I intend to replace them, but wanted to see if anyone had a recommendation to source the bolts. I found this site which seems like a good price but would like to hear what others have done.

Also, the bushings appear to be fine but is replacing the bushings recommended since they are almost 15 years old? Is there a stock kit available that is the same quality as mopar, or better? Not looking for Daystar, Crown or Energy kind of mounts, regular stock rubber mounts? Maybe there is a complete refresh kit with stock parts (bolts and bushings) that someone may know of?

Also, would you recommend removing the bolts by hand or with an impact wrench, due to the rust?

Thanks in advance?

https://www.jeepbolts.com/collectio...y-mount-bolts-full-set-11-grade-8-beefy-bolts

 

[Goatman]

Looking forward to this. Any stainless options? Or is that a poor choice. I'm in NY so have the same rust issues.

 

[chino1969]

Before spending that kind of money for bolts I would check any number of industrial suppliers like McMaster Carr or Grainger. A grade 8 bolt is a grade 8 bolt that must meet certain physical properties to receive that classification like tensile strength. That price is exorbitant. Check the size and TPI (threads per inch) and search these two sites. They also have metric bolts in different strengths.>>> https://www.mcmaster.com/grade-8-bolts
https://www.grainger.com/search?searchBar=true&searchQuery=grade+8+bolts

 

[matkal]

There are a couple local fastener suppliers that sell small quantities to walk-ins. Maybe you can find someplace like that.

 

[chino1969]

Looking forward to this. Any stainless options? Or is that a poor choice. I'm in NY so have the same rust issues.

Stainless is typically a weaker bolt as far as strength. There are high strength bolts available with a zinc finish to resist damp environments. Check out McMaster Carr or Grainger Supply. You will find any fastener you can think of in every grade and finish a hell of alot cheaper than those.

 

[Mike_H]

Careful with Grade 8 bolts in your body mounts. The strength isn't necessary (I think the torque spec is only 35 ft-lbs) and you'll play hell trying to drill them if it becomes necessary. Grade 5 will be MORE than sufficient. They are just regular, standard Hex bolts.

As far as body mounts are concerned...I replaced all of mine when I did my lift. Bought this kit off amazon

https://www.amazon.com/gp/product/B009XUZ8QY/?tag=wranglerorg-20

They are not Poly bushings, they seem to be just like the originals.

 

[chino1969]

Careful with Grade 8 bolts in your body mounts. The strength isn't necessary (I think the torque spec is only 35 ft-lbs) and you'll play hell trying to drill them if it becomes necessary. Grade 5 will be MORE than sufficient. They are just regular, standard Hex bolts.

As far as body mounts are concerned...I replaced all of mine when I did my lift. Bought this kit off amazon

https://www.amazon.com/gp/product/B009XUZ8QY/?tag=wranglerorg-20

They are not Poly bushings, they seem to be just like the originals.

Good point about the strength of Grade 8 bolts. How hard was it to replace body mounts?

 

[F Troop]

Go to a local hardware store. Not a box store. They’ll have a wide selection of bolts , washers and, nuts.

 

[Mike_H]

Good point about the strength of Grade 8 bolts. How hard was it to replace body mounts?

I live in the rust belt, so it took me a bit. I had a few bolts fight me on the way out. It isn't hard... Just do one side at a time.

 

[skrelnik]

Before spending that kind of money for bolts I would check any number of industrial suppliers like McMaster Carr or Grainger. A grade 8 bolt is a grade 8 bolt that must meet certain physical properties to receive that classification like tensile strength. That price is exorbitant. Check the size and TPI (threads per inch) and search these two sites. They also have metric bolts in different strengths.>>> https://www.mcmaster.com/grade-8-bolts
https://www.grainger.com/search?searchBar=true&searchQuery=grade+8+bolts

Good call but they only had one of the two bolts needed, did not offer the one bolt in the length needed. The one bolt they did have was sold in packages of 5, and 6 are needed.

I do agree the prices are expensive, but they are similar in price as Crowns bolts.

Bolt depot on the other hand has the stainless steel 316 available, and with shipping the cost comes out to about $40 vs the $57 from jeepbolts which are alloy steel, and quite possibly the Crown bolts.

Stainless is typically a weaker bolt as far as strength. There are high strength bolts available with a zinc finish to resist damp environments. Check out McMaster Carr or Grainger Supply. You will find any fastener you can think of in every grade and finish a hell of alot cheaper than those.

Boltdepot has the bolts in stainless steel but didn't have both sizes of these bolts in zinc plated or other materials. The stainless steel option was $15 cheaper but as you said is typically a weaker bolt.

Careful with Grade 8 bolts in your body mounts. The strength isn't necessary (I think the torque spec is only 35 ft-lbs) and you'll play hell trying to drill them if it becomes necessary. Grade 5 will be MORE than sufficient. They are just regular, standard Hex bolts.

As far as body mounts are concerned...I replaced all of mine when I did my lift. Bought this kit off amazon

https://www.amazon.com/gp/product/B009XUZ8QY/?tag=wranglerorg-20

They are not Poly bushings, they seem to be just like the originals.

I want to stick with the grade 8 bolts since that is what's called for and stock replacement bolts are grade 8. I hear what you are saying and will use lots of anti-seize.

Thanks for the tip on the bushings, I was thinking Crown or Dorman but I just looked at my bushings and they appear to be okay so I am not going to change them.

I live in the rust belt, so it took me a bit. I had a few bolts fight me on the way out. It isn't hard... Just do one side at a time.

Did any bolts break on you, or did you just slowly go back and forth until they broke free? What did you use to remove? I am debating using a 3/8 or 1/2 sized breaker bar, impact drill or impact wrench.

 

[Mike_H]

I had one break off in the nut, one broke off just under the head, and one I was able to get unstuck after some heat and patience. I used my impact gun...they are half inch bolts, they can take it.

To get my stuck ones...The one that broke in the nut was the rear corner on the Driver's side. I cut into the cross member to get it. The other one that broke was the front mount on the tub, Driver's side. I welded a nut to that one. The heat of welding was enough to break it free...Took a couple tries though.

I'd check your references on the body bolts being Grade 8. I really don't think they were...but I'm not sure so I'm not saying you're wrong. If I get a free minute, I'll check the parts list I have saved...I will say this, just because replacement parts are grade 8, doesn't mean OEM was...

 

[glwood]

First I've heard of a bumper needing to use body mounts. Why is that, and do you have any pics of that?

I know some armor uses body mounts, but I thought bumpers were strictly mounted on the frame...

 

[skrelnik]

J

I had one break off in the nut, one broke off just under the head, and one I was able to get unstuck after some heat and patience. I used my impact gun...they are half inch bolts, they can take it.

To get my stuck ones...The one that broke in the nut was the rear corner on the Driver's side. I cut into the cross member to get it. The other one that broke was the front mount on the tub, Driver's side. I welded a nut to that one. The heat of welding was enough to break it free...Took a couple tries though.

I'd check your references on the body bolts being Grade 8. I really don't think they were...but I'm not sure so I'm not saying you're wrong. If I get a free minute, I'll check the parts list I have saved...I will say this, just because replacement parts are grade 8, doesn't mean OEM was...

Awesome, thanks for the tips on the busted bolts.

I cant even check my OEM bolts to determine the specs, but the Crown bolts are grade 8 alloy, same with these jeepbolts, but I did read the JKS and Savvy body lift bolts are grade 5....

 

[skrelnik]

First I've heard of a bumper needing to use body mounts. Why is that, and do you have any pics of that?

I know some armor uses body mounts, but I thought bumpers were strictly mounted on the frame...

Kurt makes an awesome bumper and ties it into the body mounts for additional strength. They look awesome and the powerdercoating is great, great welds and everything. Once I get them installed I will post some pics, but for your reference here are the details:

Bumper Features Include:
3/16" formed steel construction for strength
1" thick D-ring tabs welded through the bumper fits standard 3/4 D-Rings with a 7/8" pin.
2" low profile receiver (Not rated for towing. To be used as a recovery point)
10 Grade 8 bolts for mounting (2 more are included but optional)
Ties into the back body bolts for strength.

http://www.kdfabworks.com/TJ-Rear-Bumper-no-tire-carrier_p_276.html

 

[tworley]

The strength isn't necessary (I think the torque spec is only 35 ft-lbs)

I believe the JKS instructions told me to torque them to 55 ft/lbs

 

[Mike_H]

In the interest of providing correct information I went and looked at the JKS instructions since @tworley and I posted conflicting information...Here is a screen shot. (not doing this to be "right", I just like to make sure that I'm posting correct information)

and a link for those so inclined.

http://4x4media.info/instructions/jks/JKS9904.pdf

 

[tworley]

In the interest of providing correct information I went and looked at the JKS instructions...Here is a screen shot

View attachment 92797

and a link for those so inclined.

http://4x4media.info/instructions/jks/JKS9904.pdf

Yep--you're right. I now realized I was thinking of the skid plate bolts. Sorry for the confusion all.

 

[glwood]

Kurt makes an awesome bumper and ties it into the body mounts for additional strength. They look awesome and the powerdercoating is great, great welds and everything. Once I get them installed I will post some pics, but for your reference here are the details:

Bumper Features Include:
3/16" formed steel construction for strength
1" thick D-ring tabs welded through the bumper fits standard 3/4 D-Rings with a 7/8" pin.
2" low profile receiver (Not rated for towing. To be used as a recovery point)
10 Grade 8 bolts for mounting (2 more are included but optional)
Ties into the back body bolts for strength.

http://www.kdfabworks.com/TJ-Rear-Bumper-no-tire-carrier_p_276.html

Thanks for the info and the link. I had tried to find a rear TJ bumper on their site, but either my search skills suck big time, or for some other reason, could not. I see now what you were referring to, how they incorporate the body mount bolts. A first for me.

Looks like a stout bumper.

 

[chino1969]

Good call but they only had one of the two bolts needed, did not offer the one bolt in the length needed. The one bolt they did have was sold in packages of 5, and 6 are needed.

I do agree the prices are expensive, but they are similar in price as Crowns bolts.

Bolt depot on the other hand has the stainless steel 316 available, and with shipping the cost comes out to about $40 vs the $57 from jeepbolts which are alloy steel, and quite possibly the Crown bolts.



Boltdepot has the bolts in stainless steel but didn't have both sizes of these bolts in zinc plated or other materials. The stainless steel option was $15 cheaper but as you said is typically a weaker bolt.



I want to stick with the grade 8 bolts since that is what's called for and stock replacement bolts are grade 8. I hear what you are saying and will use lots of anti-seize.

Thanks for the tip on the bushings, I was thinking Crown or Dorman but I just looked at my bushings and they appear to be okay so I am not going to change them.



Did any bolts break on you, or did you just slowly go back and forth until they broke free? What did you use to remove? I am debating using a 3/8 or 1/2 sized breaker bar, impact drill or impact wrench.

Exactly what size (length) bolts are you looking for and how many threads per inch?

 

[skrelnik]

Exactly what size (length) bolts are you looking for and how many threads per inch?

These I believe are the OEM specs, meaning grade 8 although aftermarket kits sell grade 5, like Savvy and JKS.

I dont know if these companies choose grade 5 because it is less expensive or if they do the job and grade 8 is overkill.

Grille Mount & Rear Body Mount Bolt;
5 Required;
7/16″-14 x 2-3/4″ Flanged Grade 8 Bolt.

Front Body Mount Bolt;
6 Required;
1/2″-13 x 3-3/4″ Flanged Grade 8 Bolt.