Rear subframe 19mm bolts reusable?

[Hudson456]

I removed the 2 rear 19mm bolts on the subframe to install a cusco brace, and according to this diagram the bolt are supposed to be replaced - are these torque to yield bolts that should not be reused? I've never seen anyone on the forum mention this.

Also, should these bolts have loctite on them? Mine had red substance on them - I'm not sure what this is. Are these bolts supposed to be lubricated when reaching the 107 ft/lb torque spec?


Thanks

[maslin]

If the torque spec is just 107ft/lb they are not torque to yield.

The one time use is due to that red substance. The applied “loctite” is one time use.

Same with any pinch or locking nut and any bolt that is torque to yield.

Very few bolts are lubricated prior to installation, I believe I’ve only seen that on head bolts.

[Ultramaroon]

Originally Posted by maslin

The one time use is due to that red substance. The applied “loctite” is one time use.

Would you use red, or blue if it was yours? In some cases I feel like red is overkill.

[maslin]

Originally Posted by Ultramaroon

Would you use red, or blue if it was yours? In some cases I feel like red is overkill.

It’s not Loctite specifically. It’s a coating they apply to hardware that keeps the bolts in. Colors don’t match the known purple, blue, red, green scheme.

I would never apply loctite in a tube to any of those bolts. I would either run them back in and assume you’re never going to have a problem, or replace the hardware as specified.

[new2subaru]

Originally Posted by maslin

I would never apply loctite in a tube to any of those bolts.

I’ll bite, why not?

[Ultramaroon]

Originally Posted by maslin

It’s not Loctite specifically. It’s a coating they apply to hardware that keeps the bolts in. Colors don’t match the known purple, blue, red, green scheme.

Ooo, good point.


I mostly switch between the blue, green, and white. I'd probably just clean and reuse the screws for those subframe mounts.

[maslin]

Originally Posted by new2subaru

I’ll bite, why not?

Because I have no desire to glue bolts into a car. The stuff that comes on new bolts is dry, it tightens up the tolerance between the fasteners, keeping everything tight along with the tension on the bolt.

I’m not a big fan of liquid loctite. It certainly has its place, but I wouldn’t try to outsmart the engineers that designed the car. If they wanted them loctited in they would specify loctite. Instead they specified a bolt with a coating. I’d either replace the bolts or reinstall and forget about it.

I’ve replaced thousands of one time use fasteners, I doubt I’ve used one of the little tubes of loctite in 10 years.

[Ultramaroon]

The main reason factory screws come pre-coated is for quality control in the assembly process. IRL, a properly-chosen, carefully-applied liquid adhesive is just fine. That being said, I have a couple tubes that are probably 20 years old. Should probably just toss them.

[new2subaru]

I agree, nothing wrong with a liquid adhesive used sparingly.

[Tristor]

As @maslin pointed out these are not torque to yield, they are marked one-time use due to the pre-applied coating. I re-used mine, just cleaned them up on a wire wheel and applied liquid blue loctite prior to torquing to spec. I no longer have the link handy but had read a spec sheet showing the pre-applied coating is most similar in specifications to blue loctite, despite being red in color. Do NOT use red loctite on your subframe bolts.

If you are installing something like the whiteline KDT922, if you can get them you want the subframe bolts from the TS. They are identical except having a slightly longer overall length to ensure full thread engagement between the subframe and body when running bushing inserts. The TS comes with the STI bushing inserts (which look identical to the whiteline KDT922) pre-installed, so has a lengthened bolt. I tried to acquire them and found it impossible because the parts counter people at the dealership are borderline retarded and refuse to order on part numbers and I didn't have a valid TS VIN number to give them. The TS bolts aren't essential, thousands of people have installed subframe bushing inserts and reused their factory bolts, but since you seem concerned, this would be a route to replace the bolts with OEM spec bolts that have pre-applied coating and also get the longer length killing two birds with one stone.

[soundman98]

Parts counters are almost as bad as the DMV

[ZionsWrath]

Originally Posted by soundman98

Parts counters are almost as bad as the DMV

Their prices are much worse.

[Tristor]

Also, I realize you didn't ask, and the instructions don't say, but just to clear it up you should definitely get an alignment after installing the bushing inserts. The inserts will forcibly realign your subframe to be centered on the body, which may not be where it was positioned from the factory and this will affect both camber and toe in the rear.