Engine Mounting Bolt Sequence and Specified Torques

[VTRDark]

Engine Mounting Bolt Sequence and Specified Torques

The workshop manual is a bit confusing to follow due to bad layout and makes it all sound a lot more complicated than it actually is. Hopefully this makes things a little more clear and easier to follow.


Notes:
a) It's a good idea to apply some lock-tight to all parts.
b) Be careful with the inner adjuster bolts as the castle type ends are easily broken.
c) Depending on what tools are used, it is not always possible to lock of the inner adjuster bolts while torquing up the outer castle lock nuts. In this case be aware that the inner adjuster may tighten up slightly off spec as the outer castle nut is torqued up. In this case you just have to do the best you can.

Start with getting everything installed hand tight.



1. Loosen off all threaded adjuster bolts that are fixed in the frame. This just allows some clearance space for the frame sliding over the engine.

2. Loosely install the front and rear engine bolts (These are the long ones with the allen type head) from the left side through to the right, not forgetting to slip the front inner spacer collar in place between the engine and threaded adjuster bolt. Note the allen head is squared off to slide inside the threaded adjuster bolts. Loosely fit the outer castle type lock lock nuts over the top. These screw onto the ends (castle type) of the threaded adjuster bolts.

3. Loosely install the left centre hanger bolt through the threaded adjuster bolt in the frame, not forgetting the inner spacer collar. Then loosely fit the outer castle type lock lock nut over the top..

4. Loosely install the right side centre hanger bolt and front and rear hanger nuts.

That's everything hand tight and loosely fitted which assures that you have all the required parts. Also with everything being loose and free moving, this makes it simpler to get all threads started with a bit of wiggling and jiggling.


On to the tightening/torquing up sequence

Torque Values
Centre Engine Hanger Bolts = 39 N.m - 29 lb ft
Centre Adjusting Bolts (threaded part through frame) = 3 N.m - 2.2 lb ft
Outer Castle Type Lock Nuts = Indicated: 49 N.m - 36 lb ft and Actual 54 N.m - 40 lb ft.
Engine Hanger Nuts = 64 N.m - 47 lb ft.

1. Starting with the right centre engine hanger bolt, Torque to 39 N.m - 29 lb ft. This goes directly into the engine casting so go easy and don't over-tighten.

2. Move onto the left centre adjusting bolt. This is the threaded part that goes through the frame up against the spacer collar. Torque to 3 N.m - 2.2 lb ft. If possible holding the centre adjusting bolt move onto the outer castle type lock nut which is done in two stages. An indicated torque and and actual torque. Tighten to the Indicated Torque of 49 N.m - 36 lb ft. Once this is done, tighten the centre hanger bolt and Torque to 39 N.m - 29 lb ft. This also goes into the engine casing so go easy and don't over-tighten.




3. Move onto the rear adjusting bolt and from the left hand side If possible holding the centre adjusting bolt tighten the castle type lock nut which is done in two stages. An indicated torque and and actual torque. Tighten to the Indicated Torque of 49 N.m - 36 lb ft.




4. Move onto the front adjusting bolt. This is the threaded part that goes through the frame up against the spacer collar. Torque to 3 N.m - 2.2 lb ft. If possible holding the centre adjusting bolt move onto the outer castle type lock nut which is done in two stages. An indicated torque and and actual torque. Tighten to the Indicated Torque of 49 N.m - 36 lb ft.




5. Moving onto the right hand side tighten the rear engine hanger nut to a Torque of 64 N.m - 47 lb ft.

6. Tighten the front right engine hanger nut to a Torque of 64 N.m - 47 lb ft.




7. Now finally go around and tighten up to actual torques starting with the left centre castle type lock nut and Torque to 54 N.m - 40 lb ft. Then the left rear castle type lock nut and Torque to 54 N.m - 40 lb ft. Then the front left castle type lock nut and Torque to 54 N.m - 40 lb ft.

Done.

And for your convenience, a copy you can print out and get all greasy.
PDF Download Zip 194 kb

(:-})

[lloydie]

Thanks Carl I will print that out for reference when I do mine

[VTRDark]

I will sort out a downloadable PDF shortly. I expect Tony or someone may have something they may like to add or change, but I think I have pretty much got it. The one bit that confuses me a bit, is the Indicated and Actual torques that the workshop manual mentions. I figured what they really mean is that it's a two stage tightening sequence. So used my common sense (wherever that may be ) and figured the Actual torque figures would just be to nip it all up once the initial tightening of everything has been done.

(:-})

[AMCQ46]

Carl, soory to correct you.

the actual torque is the real torque you would apply if you have a conventional socket and are driving the 1/2" square in the center of the socket. the indicated torque is a corrected value are if you are using the official tool which has an offset 1/2" drive so you can put the allan key down the middle to stop the adjuster bolts moving.

As I dont have the special honda tool I used a pipe wrench on the outside of my castle nut tool to get enough torque on them while I had the allen key through the center and this allowed me to stabalise the joint so it was unlikley to keep moving when I fully torqued it up. Then I marked the position of the adjusters to the frame with a felt tip pen, and used a normal torque wrench to set to the "Actual" value on the castle nut socket, the n I checked the felt tip marks to see it the adjuster had moved. it didnt move so I was happy

[VTRDark]

Don't apologise mate, I feed on constructive criticism. I'm just trying to get my head around what you have said. So which should it be if using a torque wrench and holding the adjuster bolt from turning more. Surly the the final setting would be the higher of the two. Unless it's tightened to the higher then backed off. Whether the adjuster bolt is being held to stop it from moving or not it can only have one final reading, so which is it, the higher or the lower.

It's the terminology they use makes it confusing. Actual suggests that, that is what it actually is, but then Indicated suggests that's what indicated on the torque wrench. it don't make sense. Whatever my torque wrench reads is what it is actually torqued up to as long as the torque wrench is calibrated properly. Whether the inner adjuster bolt has moved or not is irrelevant. Well, not irrelevant, but that has either moved or not from the required torque, which is separate from the one being torqued up.

Once I got this worked out I shall edit it as appropriate.

(:-})

[tony.mon]

OH GOD OH GOD OH GOD it's horribly complicated.
I definitely have a torque wrench somewhere, not sure where. Maybe I don't have one, not sure.

I just sort of do them up tight enough, not too tight and don't distort the frame. Now I know how complicated it is I'm never taking an engine out again, ever.

The Haynes manual is accurate enough when your merely use it for the tyre pressures and cold valve clearances, anything else and I just make it up as I go along.

Is that so wrong??

[AMCQ46]

If you look in the Honda manual this is what the proper tool looks like



So with the torque wrench acting about 2" away from the true centreline, the effect will be to generate a higher torque than it is displaying. So they assume you have the official tool and the "indicated" setting is calculated to compensate for the added advantage of the 2" offset.

[VTRDark]

So with the torque wrench acting about 2" away from the true centreline, the effect will be to generate a higher torque

Argh, got it Now that makes sense. I understand now. So with the Honda tool when it reads 36 lb ft it is actually 40 lb ft. So the final torque is at 40 kb ft then.

And yes I know what the tool looks like, it's a crowfoot what I did not think of, because I'm not an engineer is the effect the crowfoot would have on the leverage. I bet you could really blow my mind and throw me some maths, length times diameter divided by py or something or other and this how Honda worked that out.

Back to my first post. Where I have gone wrong then, is that rather that initially torque to 36 ib ft and nip it up to 40 ib ft at the end. It should just be done to 40 ib ft in the first place, unless using the Honda tool in which case only torque up to 36 lb ft. No biggie then! but something to be aware of if using the Honda tool or equivalent rather than a torque wrench that attaches directly over the top.

Now I see why they call it Indicated and Actual. It makes sense now.

Phew, there endeth my lesson for today. I need to lay down now.

(:-})

[VTRDark]

I didn't see your post there Tony. It's a difference of 4 bags of sugar 4 lb ft. So I sort of agree, it's no biggie really. If a torque wrench is not calibrated properly it could be out by 4 kb ft anyway. I quite often just do things up as tight as I feel and don't bother putting the right torques on every nut and bolt, but I think the engine mounts are pretty crucial as the frame is a torsional part of the suspension. I'm guessing your just kidding though.

Talking about doing things up to feel. When I was torquing up the right centre bolt on Marty's, I felt it was going to strip the thread. You now how you can just feel these things! So I stopped and did not tighten any further. I guess someone had overtightened it in the past. I figured once the opposite side was torqued up it would pull it the other way which would give it the extra it needed. This is why I mentioned going easy as they go straight into the engine cast.

(:-})

[tony.mon]

I didn't see your post there Tony. It's a difference of 4 bags of sugar 4 lb ft.

(:-})

Aren't they normally 2lb (actually probably 1kg now) bags?

[AMCQ46]

actual and indicated Sugar weight?

[Jamoi]

Great info & super clear

Anyone know where I can get one of these... but one that hasn't been stood on!



Note: This wasn't a result of following Carlos instructions, merely me and my clumsy feet in an untidy workshop!

[turbo_billy]

Should still be available from Honda. Bought one for the SP not long ago, around £15-17 if I remember correctly

[VTRDark]

Now there's a good question. Super fragile those tips, they wont like being stood on.

(:-})

[lloydie]

Yep I need two too ! But keep one for the frame when it's being blasted and powder coated :-)