Correct Torque For Rb26 Crank Bolt

[Duncan]

VFT is a fair bit tighter that FT.

[Shaun]

Im freaking out about all these stories of balancers coming off now!

I got mine off fairly easily the other day. I tried cranking the engine with a 300mm bar resting on the radiator mount, but that didnt work. So then i fit my trolley jack handle over the breaker bar (making a 1 meter long handle), put the car in fourth with the brake on and really leant on it. It came off ok, but i could feel the stretch in the timing belt (i think thats what it was anyway). Just waiting for my ATI balancer to arrive now.

I think ill definately use a bit of loctite in the thread. Maybe the blue semi permanent stuff, rather than the red permanent.

Is there any point in replacing the bolt and washer if the original is undamaged? Theyre only $8.50 from Nissan, but i was wondering if the older (work hardened and stretched) bolt would actually be better than a new one that might stretch or move and maybe loosen as a result. Maybe im becoming over paranoid now.

Shaun.

Edited July 10, 2008 by Shaun

[den001]

i have tried to get mine off and had no luck, this must be the hardest bolt ive ever tried to get out, i had a 1 meter breaker bar and was cranking the engine whilst the bar was on the floor, and all it did was lift the car....

im going to try cubes method, 4 gear, handbrake and massive massive 2 metre pole....

[Cubes]

I usually use a square galvanised fence post/stake; only just slides over the breaker bar and is fairly easy on the hands as it has a flat surface. Then rock hard/bounce against it and before you know it its off.

I've also used a dewalt 18v rattle gun; removed the std rb20 one that was impossible to get off when the motor was out of the car.

[Shaun]

So, when i go to do the bolt up again, am i right in thinking that i should use my 1 meter long handle and just put as much force on the thing as possible. When i say that, i mean put my entire body weight, swing off the bar type of force?

Im just trying to figure out how much torque up to 500Nm is. I mean, is it possible to snap gears in the gearbox, or break a timing belt, or strip the thread on the bolt or crankshaft???

Makes me shudder thinking about it. What do you guys reckon?

Shaun.

[Cubes]

Shaun; You'll never break the cam belt as all the cam belt does is spin the cam shafts..

The rubber band feel is the driveline and most likely the IRS rear forcing the arse end down. Which is why I drop it in 4th 1:1 as I'm not keen on placing so much load through the drive line even though it should be able to handle it.

I've placed a hell of a lot of load on mine without breakage; the leverage I've had I had to shorten as it was hitting the bonnet. It should qualify for VFT

I've always hit the bolt with a wire brush to clean up the thread and then applied red loctight.

[Shaun]

Shaun; You'll never break the cam belt as all the cam belt does is spin the cam shafts..

The rubber band feel is the driveline and most likely the IRS rear forcing the arse end down. Which is why I drop it in 4th 1:1 as I'm not keen on placing so much load through the drive line even though it should be able to handle it.

I've placed a hell of a lot of load on mine without breakage; the leverage I've had I had to shorten as it was hitting the bonnet. It should qualify for VFT

I've always hit the bolt with a wire brush to clean up the thread and then applied red loctight.

Ok, thanks Cubes.

Thats exactly what i wanted to know. Yeah, when i think about it logically, there's very little load on the cam belt. Feel like an idiot now, but it kinda looks like a rubber band, and thats what it felt like!

Shaun.

Edited July 10, 2008 by Shaun

[Duncan]

yeah its amazing how much slack there is in the driveline. I think its mostly a little bit of movement in every joint comes out as 30o or more at the balancer bolt

[Swiper the Fox]

So, when i go to do the bolt up again, am i right in thinking that i should use my 1 meter long handle and just put as much force on the thing as possible. When i say that, i mean put my entire body weight, swing off the bar type of force?

Im just trying to figure out how much torque up to 500Nm is. I mean, is it possible to snap gears in the gearbox, or break a timing belt, or strip the thread on the bolt or crankshaft???

Makes me shudder thinking about it. What do you guys reckon?

Shaun.

Croydon uses a massive torque wrench, and unfortunately i was present when they did my torque bolt. It was a bit 'disturbing' to witness being done up. Teeth gritting stuff.

[Bumblebee]

Childs play... i dunno why ppl do that shit for.. i did mine to 14xnm and ive never ever had any problems with it.. infact, when i had to take it back off again to build it, i couldnt.. had to get it off with the 1" rattle gun @ work..

500nm+ is just stupid and has nothing to do with how much torque ur car makes.. u could put the bolt through a 900nm rattle gun and ur driveline wont feel any of it

[Cubes]

So your saying if you applied 900nm to the crank the usual single plate clutch would not slip? Or have I misunderstood.

I think the problem is a fair amount have had their balancer come loose and let go. Most likely due to track use?

[Shaun]

Childs play... i dunno why ppl do that shit for.. i did mine to 14xnm and ive never ever had any problems with it.. infact, when i had to take it back off again to build it, i couldnt.. had to get it off with the 1" rattle gun @ work..

500nm+ is just stupid and has nothing to do with how much torque ur car makes.. u could put the bolt through a 900nm rattle gun and ur driveline wont feel any of it

I know the torque of the bolt has nothing to do with the torque my car produces; i was just trying to put it in perspective.

Shaun.

[Swiper the Fox]

I know the torque of the bolt has nothing to do with the torque my car produces; i was just trying to put it in perspective.

Shaun.

If Mark Jacobsens GTR which has the most power out of any GTR in this country, that sees a lot of ignition cut rev limit and high revs, cannot shake a bolt loose using the same method as I described, then i dont think you will have anything to worry about.

Just use a moly based lube to get the correct torque when assembled. I wouldn't recommend Loctite or any other anerobic compound.

Edited July 13, 2008 by DiRTgarage

[Bumblebee]

as an engine builder, i agree with dirtgarage and i wouldnt recommend those either.

[Swiper the Fox]

as an engine builder, i agree with dirtgarage and i wouldnt recommend those either.

make sure the washer has moly lube on both sides of it as well

[WantGTR]

So what's the verdict here? How many ftlbs is VFT?

[burn4005]

329-344 ft lb

 

[BK]

How about just go off the 440 - 466 Nm as is in the manual ? We use an rb26 starter motor that is cut in half and welded up locked to lock flywheel and a 3/4 inch drive torque wrench, and go to 460Nm. Pretty easy when flywheel is locked properly,

And the right length torque wrench.

[WantGTR]

I do have the workshop manual and I have read this thread. Just wanted to confirm. It's a huge amount of torque

[BK]

yes it is when all other rbs are around 150Nm. You'd be surprised when doing it that its easy to get to say 200Nm, then to get to the 460Nm it was around 1/4 of a turn more. Took notice the last couple of times to confirm this. Hardest part is getting a good quality 3/4 inch drive torque wrench as they are worth heaps.