Jump to content
SAU Community

Ross Metal Jacket Harmonic Balancers For Rb25Det Neo's

JustinP

By JustinP,
in Engines & Forced Induction

 Share

Recommended Posts

JustinP Mentor

JustinP

Posted
Posted

Has anyone used a Ross Metal Jacket harmonic balancer for a Neo yet?

I contacted Ross a while ago and he said they had a new part to suit the Neo (#306204) which is not yet listed on their website. I ordered one but the box I recevied said part number #306517 on it (Neo with 10% under driven alternator and 7% under driven power steer). However when I opened the box the part number on the balancer is #306200 (RB20DET) and is missing 3 of the 6 bolts.

I rang them last week (Ross has been away for a while) and they didn't seem to think that they did any parts for the Neo. Then they worked out that they did do a Neo part, but they only did an under driven model for the Neo, and that it is made out of parts of other balancers (i.e. RB20DET, hence the wrong part number printed on it). They said that one was normal to be missing the 3 bolts. They seemed pretty confused and unsure about what they were saying.

If anyone is familiar with Ross balancers for Neo engines could they please have a look at the pictures and let me know what they think? I have the OEM and Ross balancers side by side for comparison. I have also attached a picture from the Ross website of the R33 RB25DET for comparison too, it looks completely different again.

I will call Ross next week and I'm sure I will get it all sorted out, but I just wanted to check to see if anyone else has used these before for a Neo.

Also one more question, have people had problems with under driven pulley's before on cars that are used for a mix of street and racing duties?

Cheers :cheers:

Justin

post-31977-0-33012300-1344660330_thumb.jpg

post-31977-0-61050900-1344660350_thumb.jpg

post-31977-0-06911200-1344660437_thumb.jpg

kitto Mentor

kitto

Posted
Posted

Interesting.

Myself, along with Garage 7 were the people who organised ROSS to start making a balancer for the NEO. I sent my old original balancer to them and then they designed one to suit.

The only difference between a standard RB25 and NEO harmonic balancer is the power steering pulley. Different offset and the NEO uses a 4PK belt where as the normal RB25 uses a 3PK. They make the NEO balancer by using a standard RB25 off the shelf under driven balancer and fitting up a power steering pulley they the would have designed.

When i received mine i was very much like WTF in regards to there only being 3 bolts holding the power steering pulley and timing disc on. I rang ROSS and spoke to Ingrid. She told me they had employed a new head designer and that he believed 6 bolts for the timing disc and power steering pulley was overkill. They may well be overkill but honestly i'd prefer they use 6.

Your NEO balancer does look very different to mine. Mine has a specific NEO part number engraved as well as 'RB25 NEO' engraved as well.

I can also see that the engraving stating the Torque for the balancer bolt is incorrect. Thats the torque spec for an RB26. RB25 balancer bolts are torqued to 152Nm. The stuffed the engraving up on mine as well. They engraved 235Nm on mine, Ingrid confirmed this was wrong. Apparently the operator typed it in wrong into the laser engraver.

I can't take any photos of mine to show you just yet. Its currently back at ROSS getting some modifications done to it to make it correct and the way it should be.

If i was you i would ring up on Monday and ask. Speak to either Ingrid or Ross himself (if he is back) and complain. I am getting a bit frustrated with them. They are SO vague and not really sure whats going on. Their products are good and at the end of they day i'm hoping this will turn out to be a good thing. But its just a bit all over the shop at the moment.

In regards to the weight of the ROSS vs Genuine i'm not sure i can't help you. Havn't weighed mine, i would ask as well. To be honest i dont think its much of a deal.

kitto Mentor

kitto

Posted
Posted

Oh, to add. under driven is really good for flat out race cars, or cars that spend a lot of time at the track at really high revs.

Street car, hmm you might notice the power steering is a bit heavier at idle.

Hopefully the balancer spins the alternator and water pump quick enough.

JustinP Mentor

JustinP

Posted
  • Author
Posted

Thanks Kitto - your info is much appreciated!!!

I will speak to Ross next week, hopefully I can get some clearer info and get this sorted out. And yep I noticed the printed on RB26 torque setting for the main bolt too, which worried me further!

In regards to the under driven pulleys, I'm not worried about steering effort at idle but I am a little worried about the alternator. I won't be running a mechanical water pump, but the extra load from the electric water pump, thermo fans, WMI etc is a bit of a worry.

kitto Mentor

kitto

Posted
Posted

Well an alternator doesn't put out bugger all current at idle, let alone if its under driven.

For your setup, this could not be good.

Speak to ROSS, find out if they are doing a 'standard' type balancer yet. Did you order an under driven or a standard? Or you were under the impression you were getting a standard balancer?

If they don't do one yet and you'd like to use a ROSS balancer still, you could fit a larger alternator pulley.

JustinP Mentor

JustinP

Posted
  • Author
Posted

I did order the standard, non under driven one, which was supposedly part number #306204.

Seeing as your's actually has RB25 Neo printed on it, do you remember if the part number printed on it #306504?

Cheers

Justin

kitto Mentor

kitto

Posted
Posted

Well if you ordered a standard then you should receive a standard.

I had a look on my phone and i took two pics. Mine has 306517 engraved on it.

What you can do is check the circumference of the alternator and power steering pulleys on the OEM one and compare it to the ROSS unit.

See if the ROSS pulleys are slightly bigger.

kitto Mentor

kitto

Posted
Posted

Ok so i just compared an OEM NEO bskancer with an OEM R32 RB20DET balancer.

The offset of the power steering pulley is identical. Both being 4PK.

The NEO ever so slightly under drives the P/S pump.

The NEO drives the alternator and water pump a fair amount quicker. R32 alternator pulley has a circumference of approx 465mm where as the NEO is approx 515mm. I measured this by wrapping 1mm2 wire around one of the belt grooves.

Air con pulley has the same circumference on both.

Circumference of the P/S pulley on the NEO is approx 375mm.

If the ROSS balancer underdrives the P/S pump by 7% i would exoect thr ROSS bslancer to have a circumference of around 349mm. If the ROSS balancer underdrives the alternator by 10%, i would expect a circumference of 464mm.

I think the reason the OEM NEO balancer has a larger circimference alternator pulley is because the RB25 doesnt rev as hard or need to rev as hard as an RB20.

JustinP Mentor

JustinP

Posted
  • Author
Posted

Thanks for checking kitto. I finally got in touch with Ross. He has assured me it should all work well, so I will give it a go. Also the idea of the under driven pulleys has grown on me. I will make it work one way or another :)

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • JC71
      new 1.5 LSD issues/concerns

      By JC71 · Posted

      looking for some help and maybe some insight on others experience with a new LSD. R34 GT ran and drove beautifully, but always alot of grip loss due to the open R200 rear end, so I just installed a new 1.5 LSD way into the stock open R200 for a ER34. Simple. Everything seemed right. I test drove for the first time this weekend. as I started to back out the garage the first time slowly with tires straight it sounded and felt like I had a loose or half disconnected drive shaft...that was clucking around loose and shaking entire vehicle, and making it feel like the trans clutch was spontaneously slipping then grabbing very roughly while just letting out pedal slowly. I backed it out went to pull forward with the same noise, shake and slip grab feeling with hesitation, I turned the tires to back out more and then pulled ahead some same thing but worst because of added wheel resistance (which that I expected) puzzled … pulling it back in checking everything over and finding nothing wrong, I tried it the next day. same thing, couldn’t believe how it shook everything again making a terrible noise and making it feel like the trans clutch was slipping and grabbing, but I got it out of garage into the driveway, got it straight, drove forward and then reveres a few times in a straight line everything shaking , causing what felt like clutch slip and grab every time, sounded like right behind front driver tire and I could feel it in the floor board with my feet,... worst right when beginning to let clutch pedal out to engage slightly, shuttering and sounding terrible along the way…I managed to slowly get down the road, babying it the whole way, once I was rolling (out of 1st) seemed to be better and between shifts, then clutch felt closer to normal…not slip/ grab etc., but back down to any stop, straight road or turning, same thing. Made no difference if all tires were straight or if I was turning. All other gauge read out correct. with in 2 miles as planned I reached the empty parking lot and performed the break in procedure that came with lsd, essentially to drive in a figure 8 a bunch.  Did this, binding chattering, and shaking the car the whole way. I drove it back home seemed somewhat normal once I was in straight line and past 10 mph or so, and I know it will “bind” on corners and cause some tires squeal when turning especially from a stop, but when I begin to move it still causes what feels like the trans clutch to slip and jerk badly as well as shaking the entire car, and sounds terrible, that I didn’t expect. I used the fluid they supplied with LSD kit and did the breaking, planning to change fluid as they suggest after breaking, but wondering will it get smoother or less aggressive with use? maybe a 1.5 is just too aggressive for normal road driving?   I have a LSD that I put in my 71 cuda when I restored it, with amazing smooth , quite yet effective results. Different style LSD but that ones a joy to drive. maybe expecting too much from this R200?
    • Matt Z
      SAU NSW - Archies Flame Grille Meet & Cruise to Kurnell

      By Matt Z · Posted

      Join SAU NSW for a flame-grilled feed & flame-spitting cruise! Sunday 17th August 2025 3:30PM Meeting Archies Flame Grille Sylvania Waters 4:45PM Cruise Departure 5:15PM Arrival at Cape Solander Kurnell Meet Location: Archies Flame Grille Final Destination: Cape Solander Kurnell *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
    • Ozdavroz
      WTAC 2025

      By Ozdavroz · Posted

      Yeah good luck out there! Will be good to see a mighty GTST going harder than the GTRs
    • bcozican
      WTAC 2025

      By bcozican · Posted

      i will be there 😁
    • patrickxdf12
      Squeaking clutch/throw out bearing

      By patrickxdf12 · Posted

      Hello!  i just finished manual swaping my r34 skyline with a r33 rb20de box(RB71C)box  When the car is running it squeaks crazy loud and it was smoking from the gearbox area. The gearbox is fine it was tested. The clutch slave cylinder seems like it doesn't fully releases the clutch. I want to ask if this noise is from the throw out bearing or could it be the clutch assembly or disk att.xFliq87Gzw6kImKBVqDebXkj0fBqymk0JaYeP3_3SlM.mp4
×
×
  • Create New...