Rear-end, what hardware is 1 time use?

[Cubieman]

I plan on installing a Vincebar over the winter and the list of items keeps growing.

I plan on installing CMP subframe bushings and SDW RTABS, beyond that I want to tear down the rear-end and replace all bushings with stock pieces and replace nuts/bolts where necessary.

What bolts must I replace once removed?
Off the top of my head I'm thinking diff mounting bolts as well as diff OPF bolts as I want to install new diff seals.

If anyone can come up with any other one-time use hardware it would be much appreciated as I'm aiming to make as few orders as possible.

Thanks.

[Tbonem3]

I would reuse everything. Unless you don't have the updated diff bolts yet.

[WestBankM4]

I've completed my rear-end rebuild just recently including the epoxy-rivet Vincebar, did you buy the Hardware kit and the gusset cups?

[cobra]

The only time you need to replace hardware is
-they are torque-to-yield fasteners that plastically deform when you tighten them (chassis reinforcement bolts, rod bolts, vibration damper bolts)
-the old ones are rusty and corroded (depends where you live and which bolt it is)
-the bolt has been replaced with a new design (eg. diff bolts)

For your job this might include the V-shaped reinforcement bar bolts (3 of them). That's all I'm aware of.

[heinzboehmer]

I recently learned that TIS calls for the replacement of both the washers and bolts on the output shafts of the diff.






I'll let you decide if you want to spend $300 replacing those though:



I've reused mine a couple times (as have others) and they've been fine. But, the plural of anecdote is not evidence.

[oceansize]

When I installed a new driveshaft I saw that as well and replaced them since I could tell it wasn't the first time they had been off. However, they were no where near that expensive, dang.

[Cubieman]

I recently learned that TIS calls for the replacement of both the washers and bolts on the output shafts of the diff.






I'll let you decide if you want to spend $300 replacing those though:



I've reused mine a couple times (as have others) and they've been fine. But, the plural of anecdote is not evidence.

Ouch, I think I will re-use mine or find maybe try and find a suitable alternative.

I would imagine it would be OK to replace with a bolt of the same size and strength yes?


I had thought I would replace all hardware just for aesthetic purposes however this job keeps adding up, so I'll skip that wherever possible.

[Cubieman]

The only time you need to replace hardware is
-they are torque-to-yield fasteners that plastically deform when you tighten them (chassis reinforcement bolts, rod bolts, vibration damper bolts)
-the old ones are rusty and corroded (depends where you live and which bolt it is)
-the bolt has been replaced with a new design (eg. diff bolts)

For your job this might include the V-shaped reinforcement bar bolts (3 of them). That's all I'm aware of.

Ah yes, the v-shaped bar bolts, I forgot about those, added to cart, thank you!

[Cubieman]

I've completed my rear-end rebuild just recently including the epoxy-rivet Vincebar, did you buy the Hardware kit and the gusset cups?

I did buy the Epoxy kit w/tools and gusset cups. I sure as shit hate to hack up my car, I don't like the idea or lowering it's resale value, however I don't intend on selling it either.

You're really getting some experience on your M3 as of late! I haven't done anything in a while and need a project so it's time.

[Sharocks]

The urge to make jokes is strong.

But I shall remain a legal adult for this lol

I'm with T Bone, I wouldn't re-use anything.

Hardware especially, it's a couple extra bucks, why not.

And to add to this, I've had to replace parts that I didn't replace when I did my subframe like my driveshaft, both axles, rear camber arms etc.

So it's better to get all of it done at once and be at peace.

[DoubleSidedTape]

I did buy the Epoxy kit w/tools and gusset cups. I sure as shit hate to hack up my car, I don't like the idea or lowering it's resale value, however I don't intend on selling it either.

You're really getting some experience on your M3 as of late! I haven't done anything in a while and need a project so it's time.

I don’t think something like a vincebar would lower resale value at all. If anything it would increase it since that’s an issue that no longer needs to be addressed.

[Cubieman]

The urge to make jokes is strong.

But I shall remain a legal adult for this lol

I'm with T Bone, I wouldn't re-use anything.

Hardware especially, it's a couple extra bucks, why not.

And to add to this, I've had to replace parts that I didn't replace when I did my subframe like my driveshaft, both axles, rear camber arms etc.

So it's better to get all of it done at once and be at peace.

I plan on doing all that needs to be done at once and not half-ass this job, but just interested in what hardware is 1 time usage only.
My OCD will very likely end up forcing me to buy all new hardware, although the $300 etorx are a bit hard to stomach.

I plan to repaint the subframe etc. so all new HW may be the ticket.

Also, I do believe Tbone suggested to reuse everything..

[Casa de Mesa]

If you repaint everything, chances are you'll not like puting a rusty or corroded bolt back in its place. I replaced all hardware, every last bolt.

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/36443-bushing-pre-load-question-reassembling-rear-suspension

Depends on your level of OCD I suppose...

[maupineda]

Ouch, I think I will re-use mine or find maybe try and find a suitable alternative.

I would imagine it would be OK to replace with a bolt of the same size and strength yes?


I had thought I would replace all hardware just for aesthetic purposes however this job keeps adding up, so I'll skip that wherever possible.

since the torque spec is a straight torque value and there is no stretch, as long as the heads are not stripped you can reuse them.

[JustAWhisper]

I agree that the manual seems a bit overzealous when calling for hardware replacement. I know for a fact that many independent shops don't bother replacing a lot of those hardware pieces. However, there are some cases where it's important, and it's better to safe than sorry if you have any doubts or concerns about the age of the hardware in question. I generally make a judgment call on a piece by piece basis based on what it's holding and known age (if age is unknown I generally replace).

One thing that hasn't been mentioned is you should always replace Nylock nuts (the ones with the nylon collar at the top). I see some people reuse those (especially the one connecting the steering knuckle to the front control arm) and strongly advise against that. BMW uses Nylock nuts for a reason.