Oil Filter Cover, why studs?

[spray____]

Went to do an oil filter change on the weekend and totally screwed it up. This is the first one I've done where I actually had a torque wrench, so I thought why not use it and do things right. Set it to 12 ft/lbs and the nut just kept spinning, until... well you know what happened after that. After 3 hours I still couldn't get the damn broken stud out so I had to wheel it down the street to a shop where it's still being worked on. Hopefully I'll get it back tonight.

This whole ordeal got me thinking, what the heck is the point of those studs anyway? Couldn't they just as easily be replaced by bolts going in through the outside of the filter cover? There's a hole, and the threads are forward unless I'm wrong.

[BockinBboy]

They don't need much tightening as the O-ring does the work of keeping oil in there for you.  Those oil filter cover nuts are probably the most often over-tightened thread on the bike, and the studs save you from stripping your threads in the engine.  Better to strip a stud than strip the thread in the engine, right?

Some folks do replace the a broken stud with a bolt for a quick temporary fix, but I would not advise leaving it like that and I would especially advise against replacing all of them like that.

- Bboy

[adidasguy]

Studs: They stick out so you can get the cover on them.

Bolts: Hold cover on, TRY to locate where the bolt goes n way down there a few inches inside the oil filter place.

And there it is: studs make it so much easier to get the cover on.

You can strip and break bolts or studs.  Oil cover, as mentioned, needs very little torque because the o-ring makes the seal.

[sledge]

Its an engineering design principle and the same reason why cylinders and heads (and sometimes big-end bearings) are always clamped down with studs.

If a bolt was used, when tightened it would be subject to rotational force as well as tension. With a stud and nut its the nut that provides the tension and rotational force in the stud is practically non existent as the nut is tightened. Upshot is a more evenly distributed torque load and less stress on the stud than you would see with an equivalent length bolt at the same torque value. However this situation only really becomes an issue when the fastening is way longer than its diameter and under a lot of stress, a good example being, as mentioned........cylinder head studs.

From a stress perspective the use of studs on the filter cover is overkill, M6 high-tension bolts or cap-heads could easily provide enough torque to clamp the faces together effectively .......but there is another factor to consider.

Threads in aluminium alloy are very weak in comparison to threads in steel and a cycle of removing, refitting and re-torqueing bolts in alloy will over time compromise their strength further. On the basis the filter cover is intended to be removed and refitted on a regular basis I believe this is why Suzuki went with studs over bolts. They could have put an insert in there to strengthen them up but studs and nuts probably worked out cheaper and as we all Suzuki are known for being cheap asses.

[jboogie13]

I don't have a manual, but im willing to bet the necessary torque on those nuts are closer to 40-50 in lbs.

[adidasguy]

Can't locate the oil filter cover torque spec.
It can't be much.
Oil drain is 16 ft-lbs
Case 6mm bolts like 4.5 ft-lbs
I can't imagine the oil filter cover being anything more than one ft-lb. Basically hand tighten. One manual cautions not to over tighten them. Check various Suzuki manuals, and Haynes and no spec on the oil filter cover torque.


TIGHTENING TORQUE ENGINE
ITEM N·m kgf-m lb-ft
Cylinder head cover bolt 14 1.4 10.0
Cylinder head nut 38 3.8 27.5
Cylinder head bolt 10 1.0 7.0
Cylinder stud bolt 15 1.5 11.0
Camshaft journal holder bolt 10 1.0 7.0
Cam sprocket bolt 18 1.8 13.0
Cam chain tensioner mounting bolt 10 1.0 7.0
Conrod bearing cap nut 32 3.2 23.0
Generator mounting rotor bolt 120 12.0 87.0
Starter clutch bolt 18 1.8 13.0
Signal generator bolt 20 2.0 14.5
Crankcase bolt (6 mm) 11 1.1 8.0
(8 mm) 22 2.2 16.0
Counter-balancer shaft setting bolt 40 4.0 29.0
Oil pump mounting screw 10 1.0 7.0
Oil pressure regulator 19 1.9 13.5
Oil drain plug 23 2.3 16.5
Oil pan bolt 14 1.4 10.0
Clutch sleeve hub nut 50 5.0 36.0
Clutch spring set bolt 5 0.5 3.5
Oil cooler hose bolt (crankcase side)
(For GS500F)
* 26 * 2.6 * 19.0
Exhaust pipe bolt 10 1.0 7.0
Muffler mounting bolt 23 2.3 16.5
Engine mounting bolt 66 6.6 47.5

[sledge]

Suzuki got something wrong when they quoted those figures in the manual.

12lb/ft  is about 16Nm.

4-5Nm is enough.



Forget about spanners, sockets and torque wrenches, if you use a nut runner you wont shear anything.......unless you spend hours on the weights.

[sledge]

Can't locate the oil filter cover torque spec.
It can't be much.

They are specific figures, there is a table in the Suzuki shop manual somewhere that quotes general figures based on size.

[spray____]

sledge: That makes a lot of sense, very helpful insight.

I actually just realized where I went wrong while writing this post....

I've seen that table before, although I couldn't find anywhere when I went looking for it. I only have a PDF version of the service manual and it wasn't coming up anywhere when I searched for torque, not sure if it's in the one I have.

I did find the video GS500 Oil Filter Cover Stud Repair, where they break the studs and at about the 1:00 mark they say "It took about 130in/lbs, which is more than double the recommended torque".

I took 130in/lbs, converted it to 10.8 ft/lbs (forgetting to divide by 2) and said "I'll make sure it's good and tight", and rounded up to 12. Oops.

Bike is still in the shop for now. I mangled the stud pretty badly in trying to twist it out with vice grips. It really just fell apart. Tried cutting a slot in the end and using a screwdriver but that' didn't work any better. At the shop they tried to take it out with an extractor bit, which broke. They'll hopefully get a new one and have some success tomorrow, and fingers crossed I'll get my bike back.

[gsJack]

Torque Chart from Suzuki Shop Manual:



3-5 lb-ft for M6 bolt.  I put chart in wiki a couple years ago, should still be there.

[BockinBboy]

Thanks for the detailed comments, sledge. 

...you covered what I was gonna' say         

Now everyone remember this thead for the next filter cover stud thread... knew its been gone over, but nothing covered quite like the above that I'm aware of, so thanks again!



- Bboy

[0Bw4n]

The torque listing is all well and good until your torque wrench doesn't work (and you still over torque the little buggers). I 2nd the idea of just hand tightening with a nut runner or maybe a palm ratchet. The less additional force via lever (such as a traditional ratchet or a torque wrench) the better.

On a side note, I tried a torque wrench (1/4" drive) from Harbor Freight. Set it to the proper setting, and still stripped the studs. I've heard rave reviews of their larger torque wrenches, but I can't say that I was impressed with their smallest.

[BockinBboy]

On a side note, I tried a torque wrench (1/4" drive) from Harbor Freight. Set it to the proper setting, and still stripped the studs. I've heard rave reviews of their larger torque wrenches, but I can't say that I was impressed with their smallest.

...Great, and I literally just purchased their smallest!

- Bboy

[jboogie13]

On a side note, I tried a torque wrench (1/4" drive) from Harbor Freight. Set it to the proper setting, and still stripped the studs. I've heard rave reviews of their larger torque wrenches, but I can't say that I was impressed with their smallest.

...Great, and I literally just purchased their smallest!

- Bboy

All you need is a 1/4" drive ratchet (short-about 6 inch handle) and make the nut snug. Once the cover is run down to the mating surfaces, you can feel when it is tight enough. You only need to squish an o-ring.

Once the o-ring has begun to squish, tightening the nut further will do absolutely nothing. If you are worried about it vibrating off, then use a new nut so the locking features are in proper working order.