r34's love to squeal

[Nizzy_R34]

Hello all

I have 2 r34 sedans , one turbo one na, only recently aquired the na 34. 
Man what is with these things.... My turbo 34 started sounding like a super charger, it was screaming at anything above 4000rpm , I took the alternator apart and replaced the front bearing which is the only one I think you can access and it did not fix the issue so presumably the bearing in the rear of the alternator is gone. ( diagnosed it was the alternator by taking off the aux belts one by one to figure out which pulley or bearing it was ) 
My friend gave me one he had lying around, Installed it , it did not squeal for maybe 500kms and now its started to squeal again briefly on startup 

Recently got an na r34 and I replaced the timing belt, water pump + all the auxillirary belts. Runs amazing but it suddenly developed the same squeaking problem but significantly worse, Ive had my neighbour come down screaming at me because it was waking her up everytime I moved the car. It takes a good 2 minutes before it quietens down.  Im yet to diagnose where its coming from but im fairly sure its coming from the alternator aswell.

My question isnt about how to fix it but rather where can you get a new alternator for an rb25 neo??? Ive searched everywhere but I havent been able to find a direct fit oem type replacement thats not genuine.

All the automotive stores sell an oex one - BXA035 - which I picked up for cheap through a friend with staff discount , got it home only to find the connector is completelty different.... As far as im aware bxa035 is for rb20/30's and after a bit of figuring out the bxa035 has an ev14 type connector, which is tiny compared to the rb25 connector.

I actually had an ev14 connector lying around which I was considering just replacing the bigger plug with to get the alternator working but the bxa035 is rated for 70amp vs the rb25 alternators are 90amp ( or so ive been told ? ) That paired along with the fact im about to install an amp + sub in the back and I have the stock sized small battery Im not sure itll do the job unless anyone has another opinion? 
I know and have seen all the websites selling the ls1 alternator conversion kit but I am not going down that route, nor do I have the money to. Hopefully I can figure out how to get 2 brand new alternators for both cars. I would buy second hand which there seems to be many of but considering how common this seems to be im sure If I installed a second hand one it would start squealing in no time 

Or even better if anyone knows how to fix the issue directly with the alternator itself...

Any input appreciated

Thank you  

 

Link for bxa035 connector picture

[GTSBoy]

18 minutes ago, Nizzy_R34 said:

My question isnt about how to fix it but rather where can you get a new alternator for an rb25 neo???

Use an LS1 or similar, via kit like Frenchy's. But....

It's probably not the alternator. It sounds like belt squeal, which would be because the pulleys are glazed. Rub every groove on the pulleys with 120 grit paper. Report back. Oh, and new belts afterwards too. The old new ones will be shitted up already.

[Nizzy_R34]

12 minutes ago, GTSBoy said:

Use an LS1 or similar, via kit like Frenchy's. But....

It's probably not the alternator. It sounds like belt squeal, which would be because the pulleys are glazed. Rub every groove on the pulleys with 120 grit paper. Report back. Oh, and new belts afterwards too. The old new ones will be shitted up already.

Ye good idea , would have never thought of something like that. Might aswell do it to every pulley and the balancer while I’m there 

[MBS206]

And make sure the belts are tightened appropriately too.

[luke gtr]

If you're dodgy you can try using a slightly finer grit (2-300) sandpaper on the belts ribs to remove the glaze from the pulleys. 

Worse case scenario, you still need new belts and wasted an hour scuffing them up.

 

To confirm its the belts, if you have access to some, you can try dry lube.

If they shut up for a minute or two, it's most probably as above.

[silviaz]

On 12/05/2025 at 11:28 PM, GTSBoy said:

Use an LS1 or similar, via kit like Frenchy's. But....

It's probably not the alternator. It sounds like belt squeal, which would be because the pulleys are glazed. Rub every groove on the pulleys with 120 grit paper. Report back. Oh, and new belts afterwards too. The old new ones will be shitted up already.

Jaylec sells brand new alternators for r34's. I wonder if they are better than the oem version. I was considering getting that if I have to tighten this belt 1 more time. Been fine for months but I expect it to happen again eventually. 

Edited June 13 by silviaz

[Nizzy_R34]

just an update to this, poor man pays twice 

Tried sanding down the pulleys but it didnt do the trick. Chucked another second hand alternator in the na car which I got for free off my mate and its fixed the squelling. Must have been unlucky with the bearings. 

 

As for my turbo car, I managed to pick up a cwc rb alternator conversion bracket + LS alternator for 250 off marketplace, looked to be in really good nick. Installed it , started the car and its not charging the battery.... ( Im not good with auto elec stuff so im not sure if this was all I needed to do but I verified such by using a multimeter on the battery when the engine was running and I was only getting 12.2v )  

I had to modify the earth strap for the new LS alternator , factory earth strap was a 10mm bolt which did not fit the bolt on the LS alternator which was double the size so I cut it off , went to repco bought some ring terminals that fit, crimped it onto the old earth strap and bolted it up to the alternator , started the car and same issue. Ran like shit and was reading 12.2 at the battery. 

For a "plug and play" advertised kit thats not very plug and play but alas. 

My question is , am I missing something ? Ive been reading that some people recommend upgrading the stock 80 amp alternator fuse to a 140 amp but I dont see how that would stop the alternator charging especially at idle not under load. 

Regardless ive pulled it out and am going to get it bench tested by an auto elec tomorrow but it would be handy to know if ive missed something silly or have done something wrong.