Coilovers - replace nuts?
 

The shop manual says a lot of the suspension nuts are "non-useable parts".

What is the reason for that? As a preventive measure against rust? Are they Locknuts? Or what is the reason?

1) What is the consensus on that? Do you really replace all of the nuts?


Speaking of nuts and coilover change, 2 more questions:

2) I read somewhere that you shouldn't put grease on suspension bolts as it change the torque characteristics when fastening. What about loctite?

3) Any other parts that greasing, top mounts against the frame?

Thanks!

I usually change out the nuts to new ones if they have the teeth on them or the nylon inserts on the end. they're relatively cheap so it doesn't bother me.

if you have a bearing on your tophat like some coilovers do, I would make sure that is fully greased up so that it doesn't squeak. most of the time those come pre-greased already though. I don't do anything special such as locktite or grease on bolts.

Non re-usable nuts are torque nuts. There's all different types but the most common two are Elliptical and the Nylock style.

Elliptical nuts are deformed into an elliptical shape during manufacturing. When they're torqued onto the thread they retain a little of their shape and lock onto the thread, These types should always be replaced as they loose their original shape and wont lock the same a second time around, they can even weaken and break.

The Nylock style typically has a thread like a normal nut except at one end has a band of nylon which prevents the nut from backing off once torqued. Theres debate as to wether these can be reused or not. Some say yes, others no. I say it depends on quality and age of the nut.

Torque nuts generally don't need grease or locktite. You should only grease where the good book says to grease :thumbup:

Thanks for the replies and sorry for the newbie questions, but I have a few more.

1) Are the Elliptical and Nylock types interchangeable? I.e. if I take an Elliptical off, can I replace it with a Nylock?

2) Should I get them from my Toyota dealer? Or if get them from a hardware store/amazon/ebay, what should I look out for (material etc)?

Best to replace like for like, ellipticals are used in critical applications such as head studs, where it's essential that the nut stay locked exactly where it is to ensure the head is locked down even and doesn't loose compression. Nylocks aren't so critical.

Pretty much all of the aftermarket suspension pieces I have on my car have Nylock nuts. Hrdware stores and shops that specialise in nuts and bolts are the best place to go, Ebay not so much because you can't confirm fitment and quality.

Thanks again.

What about material? I found 3 kinds (are there more?), galvanised, stainless and steel. I suppose stainless is too brittle for suspension parts?
Are galvanised okay?

Is it correct that there are different grades of Nylock? During google search there was mention of e.g. grade 5 and 8.

Haha yeah nuts and bolts aint just nuts and bolts! lol you'll find that the deeper you go the more you realise that there's quite a science to it. Theres different materials then different grades of those materials then different threads etc. etc. the list goes on and on. Usually the information about the nut and bolt is marked on it. What I usually do when I want to replace one is just take it to a specialist who can identify it straight away and give me a suitable replacement

Thanks again. Yes it seems complicated.

Just for the record, it's not like I never worked on a car before. Previous cars were all junk though, and I would just put back what I took off. So I never put much though into it. With my GT86 it's different though :wub::wub:

I think I'll have a word with my dealer before getting started on the coilover change.

If you're getting new gear it'll come with nuts/bolts etc. But not usually the main bolts at the hub, I'm still using the same ones and I'm on my third set, still going strong.

Just use the ones that come with your coils. I've never gone to the dealer for a bolt that didn't require a weird length neck or otherwise couldn't be replace with simple parts from the hardware store. Even nylocks can be reused a couple times before the nylon gives out. I wouldn't grease anything that doesn't call for it though. Thread lock never hurt but I feel is generally unnecessary

I would replace the rear lower strut bolts with new oem bolts and nuts. I Torque them to factory specs+15% to keep them from banging around.