TKO 600 whine in 4th and 5th

[k72nova]

I've been restoring a '72 Nova, and took it for it's first drive out of the neighborhood today. All was going well until 4th gear, I immediately had a loud whining sound, I'm not 100% sure that it's the transmission but it makes the most sense, I shifted into 5th and same thing. This wasn't a low whine that was hard to hear, it's loud. It only happens under some kind of load, if I'm in gear with zero accelerator into it then the whine isn't there, if I barely touch the gas then the whine is there. below is a video of the incident, you can hear me shift from 4th to 5th, and give it a little extra gas in 5th to see if the whine increases... I put the car in the air and put it in 4th and 5th to try to recreate it but I couldn't recreate it at low speeds ( I didn't want to get the wheels going too quick while the car was on jacks).

A bit more info about the setup, TKO-600, Quick Time scatter shield (dialed in), LS-7 Clutch, RAM Throwout bearing (78131)


https://youtu.be/eAUOFXnbsZI

[67nova]

Sounds Exactly like the whine I get. Comes on around 50 and fades around 60 under load no matter which gear I’m in. I believe mine is in the rear end. T56 magnum trans, 9” rear end with trutrack posi.

[k72nova]

Sounds Exactly like the whine I get. Comes on around 50 and fades around 60 under load no matter which gear I’m in. I believe mine is in the rear end. T56 magnum trans, 9” rear end with trutrack posi.

I'm also running a 9" Tructrack Posi, I've heard others say the truetrac can be noisy but this just seems louder than I'd expect

[eville]

my tko600 has a little "singing" in 5th. But I appreciate it as I would have never heard it with the m22 at 3300 rpm on the freeway.

[k72nova]

Transmission fluid was low, filled it up, checked the rear end to make sure it was full too. Took the car for a test run down the highway and it's still whining, got up to 65 and it just whines louder the faster the car goes. It's only when I have a little throttle into it which is what's throwing me off the most, I feel like it would make be noisy no matter what that's just not the case. Any other ideas of what it could be? It's loud enough that I'd have to raise my voice to have a conversation. Thanks again.

[CTK]

Gear noise can vary, on, off and part throttle(cruise). It is important that for the first tank or 2 of fuel you treat a new gearbox or diff like a set of rings. All metal needs to be work hardened. However it may just be built wrong?

[another69]

What rear suspension do you have?

[andrewb70]

My money is on the rear gears and not the transmission. The TKO600 is in direct drive in 4th, which means the input shaft and the output shaft are locked together and nothing is going through the gears.

Andrew

[k72nova]

My money is on the rear gears and not the transmission. The TKO600 is in direct drive in 4th, which means the input shaft and the output shaft are locked together and nothing is going through the gears.

Andrew

I think you're right, after more driving around I'm almost positive it's the rear end now.

I've been doing some light driving around and notice that I can also barely hear the whine in 3rd gear as-well. The whine get's louder the faster I'm going and everything I've been able to find shows that when you're only hearing the whine during some form of acceleration, it's pinion related.

[67nova]

My Currie F9 rear end With truetrac posi came assembled from Currie. I would think that they set it up correct. I’ve got 2500 miles on it and the whine is the same as day one.

[k72nova]

My Currie F9 rear end With truetrac posi came assembled from Currie. I would think that they set it up correct. I’ve got 2500 miles on it and the whine is the same as day one.

My truetrac came assembled straight from quickperformance, and while I didn't measure the backlash, the markings on the gears look like it was setup correctly.
I keep hearing mixed reviews about the truetrac some people say it's just a noisy unit, others say theirs is dead quite. When I put in my order to quickperformance, I ordered 2 of the exact same third members. The other one is sitting in a friends garage waiting to go in his '70 Camaro, I guess I need to get over there and help him get that thing finished so I can hear if his is noisy too!

[andrewb70]

It's not necessarily the set-up as much as what type of gears the vendors use. Some are notoriously noisier than others.

Andrew

[k72nova]

It's not necessarily the set-up as much as what type of gears the vendors use. Some are notoriously noisier than others.

Andrew

That's something I hadn't thought of, my gears are Motive Performance that I opted in for REM finish on.


While driving the car last night I noticed that the more throttle I put into it, the quieter the whine seems to be. initially I thought it was just being drowned out by the exhaust volume but now I'm starting to notice that it seems to be noisiest when I'm barely into the throttle, like when I'm maintaining speed.

[andrewb70]

That's something I hadn't thought of, my gears are Motive Performance that I opted in for REM finish on.


While driving the car last night I noticed that the more throttle I put into it, the quieter the whine seems to be. initially I thought it was just being drowned out by the exhaust volume but now I'm starting to notice that it seems to be noisiest when I'm barely into the throttle, like when I'm maintaining speed.

Having noise under light throttle or decel is pretty typical with hear noise. Under heavy throttle they tend to be quiet.

Andrew

[another69]

Some rear suspension designs amplify gear noise more than others. My torque arm transmits way more gear noise than my old leaf springs.