Jump to content
SAU Community

Recommended Posts

Hi,

Im just about to install an ATI harmonic balancer on my RB26, and i was flicking through my engine (workshop) manual and discovered that there were two vastly different torque recommendations for the 30mm crank bolt.

There is an exploded view diagram of the RB26, and it has 446 - 544Nm (45.5 - 55.5Kg-m) with an arrow pointing to the crank bolt. However, when you read through the step by step instructions, it says "Tightening torque: 142 - 152Nm (14.5 - 15.5Kg-m)" in relation to the crank bolt.

My manual also has the instructions for the RB20 and RB25, and the recommended tightening torques are all 142 - 152Nm.

I cant see why the torque for the Rb26 should be any different, let alone almost 3.5 times that of the other engines. Its a massive amount of torque; that means you've gotta apply about 27Kg of load on the end of a torque wrench with a two meter handle!

Im wondering if its a typo in the manual, and the correct torque is the lesser of the two. If anyone could shed some light on this it would be appreciated; especially those who have had experience in installing these balancers on RB engines. Its a pretty important topic i reckon, as its an engine destroying problem if anything fails down there.

I wish i could supply some pics, but if anyone else has a manual could you verify this for all of us. I got my manual off a forum member who sold me a disk; i cant see why i wouldnt have originated from a Nissan maunual.

Thanks,

Shaun.

Edited by Shaun
Link to comment
https://www.sau.com.au/forums/topic/226987-correct-torque-for-rb26-crank-bolt/
Share on other sites

Yeah, thats the same diagram as mine. You'll notice that in subsequent pages it recommends the 142-152Nm. It would be good to clear this up, as im a bit nervous about putting that much torque on the bolt.

Ive heard that you've gotta put the car in 5th and have someone with their foot hard on the brake, then use a stupid long handle to get the 500Nm. Apparently it sounds like the gearbox is going to let go under the load!

We need some engine builders to shed some light.

Shaun.

Edited by Shaun

Permanent Threadlocker + big breaker bar and hang off it is how I've always done it.

I drop mine in fourth gear with the hand brake on; never had issues with it moving.

I've always figured 4th would be the strongest gear 1:1; Don't like the idea of forcing 5th even though I'm probably only able to get 200-250nm in to it and no doubt the motor makes more at peak torque.

the last time i took the bolt out of my rb26 when i did the timing belt, it was on so fkn tight... ridicuous..

i put it back on and tightened to 156nm.... and then when the turbo popped and killed the motor... i STILL couldnt undo the bastard! lol

its like it tightened itself!

Why no threadlocker?

Doing mine up to basically as tight as I can. 200nm or so with thread locker its fairly easy to remove with a normal breaker bar.

Onyl reason I've used threadlocker is every crank bolt I've pulled has had some on it. Be it from factory I'm unsure; Multiple RB30e, 2 x rb20det's. Given the age I'd say they have all been apart prior.

im an engine builder and mechanic by trade

500nm+ is very wrong...

u would snap the bolt or the destroy the thread.. 142-152nm sounds about right and i wouldnt use threadlocker either

Im with you mate. Over 500Nm just sounds too much. I dont think my 350Kw engine even makes 500Nm of torque. Imagine if you snapped or stripped the bolt inside the crank! What a fcuking nightmare!

As for undoing it, ive heard that you can use a 300mm breaker bar and rest the handle on the radiator support, then crank the car (with injectors disconnected or something like that), so that the engine turns but the bolt doesnt. Do you think thats dodgy?

Anyone else with opinions or experience?

Shaun.

I would invest in a decent impact gun and compressor guys. You will end up using it for lots of other jobs so its worth it

That way you can even have the car in neutral and crack a bastard tight crank pulley bolt without the engine turning one bit. When it comes to tightening just a few seconds with the gun and its all done. Should always double check it with a breaker to be sure however.

I was thinking of doing it this way for my build. what PSI would you set on compressor? also would you use a torque wrench to test the bolt afterwards?

threadlocker?

cheers

rob

I would invest in a decent impact gun and compressor guys. You will end up using it for lots of other jobs so its worth it

That way you can even have the car in neutral and crack a bastard tight crank pulley bolt without the engine turning one bit. When it comes to tightening just a few seconds with the gun and its all done. Should always double check it with a breaker to be sure however.

  • Like 1

there will not be many regular impact wrenches that can deliver 500Nm. some people use a special gun with a reduction gear to get the required torque. as for whether or not it's correct, I'm not 100%, but lots of people that I know, who are 'in the know' tell me it is. I do also know I've seen a fair few RB26 balancer bolts come loose, no doubt they were not tightened 'enough'. mine has been one of them. :P

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Even with the piston at TDC there was room for it to drop, but I don't think it can drop fully into the cylinder, the problem you have is that you need something pushing against the valve to hold it up so you have enough room to put the new stem seal on and the spring etc.  I used compressed air only because putting rope in the cylinder seemed a bit risky to me, I know people have done it countless times before like this. Overall it's a pain in the ass job. Honestly you'd probably be better off taking the head off because the risk of dropping something in the engine and the finicky-ness of it all is very stressful. If you are going to attempt it though i 10000% recommend a 36050 valve spring/keeper tool. I had both the traditional lever type and after doing 1 cylinder it was absolute pain to get those valve keepers in place, even with 2 people. That 36050 is amazing, you do have to push hard to get them in place but it works perfectly almost every time. Back to my actual issue I think my engine is just tired and old and the rings have gone bad. The comp numbers (cold, no oil) were: Cyl 1 -129psi Cyl 2 - 133psi Cyl 3 - 138psi Cyl 4 - 137psi Cyl 5 - 157psi Cyl 6 - 142psi   Cylinder 5 and 6 having the most carbon on them.
    • Who did you have do the installation? I actually know someone who is VERY familiar with the AVS gear. The main point of contact though would be your installer.   Where are you based in NZ?
    • Look, realistically, those are some fairly chunky connectors and wires so it is a reasonably fair bet that that loom was involved in the redirection of the fuel pump and/or ECU/ignition power for the immobiliser. It's also fair to be that the new immobiliser is essentially the same thing as the old one, and so it probably needs the same stuff done to make it do what it has to do. Given that you are talking about a car that no-one else here is familiar with (I mean your exact car) and an alarm that I've never heard of before and so probably not many others are familiar with, and that some wire monkey has been messing with it out of our sight, it seems reasonable that the wire monkey should be fixing this.
    • Wheel alignment immediately. Not "when I get around to it". And further to what Duncan said - you cannot just put camber arms on and shorten them. You will introduce bump steer far in excess of what the car had with stock arms. You need adjustable tension arms and they need to be shortened also. The simplest approach is to shorten them the same % as the stock ones. This will not be correct or optimal, but it will be better than any other guess. The correct way to set the lengths of both arms is to use a properly built/set up bump steer gauge and trial and error the adjustments until you hit the camber you need and want and have minimum bump steer in the range of motion that the wheel is expected to travel. And what Duncan said about toe is also very true. And you cannot change the camber arm without also affecting toe. So when you have adjustable arms on the back of a Skyline, the car either needs to go to a talented wheel aligner (not your local tyre shop dropout), or you need to be able to do this stuff yourself at home. Guess which approach I have taken? I have built my own gear for camber, toe and bump steer measurement and I do all this on the flattest bit of concrete I have, with some shims under the tyres on one side to level the car.
    • Thought I would get some advice from others on this situation.    Relevant info: R33 GTS25t Link G4x ECU Walbro 255LPH w/ OEM FP Relay (No relay mod) Scenario: I accidentally messed up my old AVS S5 (rev.1) at the start of the year and the cars been immobilised. Also the siren BBU has completely failed; so I decided to upgrade it.  I got a newer AVS S5 (rev.2?) installed on Friday. The guy removed the old one and its immobilisers. Tried to start it; the car cranks but doesnt start.  The new one was installed and all the alarm functions seem to be working as they should; still wouldn't start Went to bed; got up on Friday morning and decided to have a look into the no start problem. Found the car completely dead.  Charged the battery; plugged it back in and found the brake lights were stuck on.  Unplugging the brake pedal switch the lights turn off. Plug it back in and theyre stuck on again. I tested the switch (continuity test and resistance); all looks good (0-1kohm).  On talking to AVS; found its because of the rubber stopper on the brake pedal; sure enough the middle of it is missing so have ordered a new one. One of those wear items; which was confusing what was going on However when I try unplugging the STOP Light fuses (under the dash and under the hood) the brake light still stays on. Should those fuses not cut the brake light circuit?  I then checked the ECU; FP Speed Error.  Testing the pump again; I can hear the relay clicking every time I switch it to ON. I unplugged the pump and put the multimeter across the plug. No continuity; im seeing 0.6V (ECU signal?) and when it switches the relay I think its like 20mA or 200mA). Not seeing 12.4V / 7-9A. As far as I know; the Fuel Pump was wired through one of the immobiliser relays on the old alarm.  He pulled some thick gauged harness out with the old alarm wiring; which looks to me like it was to bridge connections into the immobilisers? Before it got immobilised it was running just fine.  Im at a loss to why the FP is getting no voltage; I thought maybe the FP was faulty (even though I havent even done 50km on the new pump) but no voltage at the harness plug.  Questions: Could it be he didnt reconnect the fuel pump when testing it after the old alarm removal (before installing the new alarm)?  Is this a case of bridging to the brake lights instead of the fuel pump circuit? It's a bit beyond me as I dont do a lot with electrical; so have tried my best to diagnose what I think seems to make sense.  Seeking advice if theres for sure an issue with the alarm install to get him back here; or if I do infact, need an auto electrician to diagnose it. 
×
×
  • Create New...