1G Vibration in the driveline that starts around 3k rpms

[blakkat]

I have a vibration somewhere in the driveline that starts around 3k rpms and only goes away when I get into the throttle quite a bit, or put the clutch in and let the rpms drop.

thinking either the rear diff or driveshaft carrier bearing. Any experienced dsmer's know what this could be

 

[Deadspool]

Part of me wants to say balance belt. If its based on rpm, It would have to be located in or around the engine, up to and including the clutch, anything past that would be speed dependent.

because, if it were the drive shaft, or rear end, it certainly would get worse the more you got into it.

I know my poly filled carriers are rumbly at 50-55 kmp/h and again at 100-110 kmp/h. Shittly, these are the most common speeds on my streets. not terrible, just noticeable.

Then again, a shitty harmonic balancer could do the trick too.

 

[blakkat]

Well I just ordered an intercooler, fixed all the oil leaks on the car, the timing belt looks recent, but I suppose it's possible the balance belt could be toast. What all parts would I need to refresh while I'm in there doing the timing?

 

[immortalmcf]

water pump, tensioner and get the tensioner pulley set: (includes the tensioner pulley, iddler pulley and balance belt tensioner) and might as well switch both belts. it depends on your budget

 

[Deadspool]

Take the time to remove the cover and inspect it before ordering parts. IMO.

 

[Wildside22]

Better yet do a balance shaft delete and forget about those pesky things.

 

[mattiouti]

Agree on the balance shaft delete. You said the timing belt may have been done recently. Might want to check and see if the balance shafts are in time. If the balance shaft belt is broken it would be pretty obvious. Usually when they are out of time you get a pretty good vibration at 3k. Let us know how it turns out!

 

[blakkat]

Definitely will do, ill remove the timing cover when Im doing the vrsf intercooler install and post pictures of what I find. How critical is the balance shaft? Is there any damage that could occur from it being out of time?

 

[DSM1G90]

Take the BS stuff off and get used to the vibration is the results.

Could be that the BS belt did a jump, throwing the front balancer to be off-phase with the rear balancer, which could be causing your vibration.

If that belt did take a hop, it's getting ready to bust and go into your main timing belt and you're not going anywhere, anymore soon when that happens.

 

[white92talontsi]

The front balance shaft usually won't cause too much vibration if its off but the rear will. The rear shaft is driven by the timing belt so the timing belt will have to come off.


You can set the front shaft out of phase without any ill effects but if the rear is off it will cause the issue you are having.

 

[blakkat]

Ok well that will be my next step, then I was going to do the timing belt anyway. Should I order the Kevlar one? Which do you guys recommend?

 

[white92talontsi]

Ok well that will be my next step, then I was going to do the timing belt anyway. Should I order the Kevlar one? Which do you guys recommend?

No need to waste money on a high dollar Kevlar belt unless you just have money to waste or like the blue or purple.

Get yourself an OEM 2006 Evo IX belt and call it a day, just as good as any $200.00 Kevlar belt.

 

[DSM1G90]

OEM is tons cheaper . Get one from the Mitsu dealership - Belt Model Number: MD326059

 

[1995 talon]

have you looked at your tires? are there any lumps in it ? or hows the cv axles? any tears in the boots? tires out of balance

 

[AUTOMODSGST]

I had something similar with my car after taking my timing belt off and double checking everything twice I still have the vibration it turns out to be my transmission mount thast was loose I never touched the damm thing but it was loose but that was the problem

 

[white92talontsi]

Evo IX belt is cheap as well!
https://www.extremepsi.com/store/product.php?productid=23832

 

[DSM1G90]

I tagged mine at a dealership for less than 60 bucks along with getting the rest of the kit also at the local dealership ... bit of a markup there for that 3rd party.

 

[blakkat]

Engine mounts are kinda cruddy but those will be replaced soon, and tires are new and freshly balanced. The vibration is more rpm dependent rather than speed

 

[blakkat]

Ok, so I've noticed it doesn't do it in neutral, only when it's in gear over 3k. So I'm assuming its something in the driveline. Either transfer case, driveshaft or rear end.

 

[SleepingTSI]

Like they said above, rpm based vibrations tend to be motor related... Double check the transmission and transfer case mounting bolts as well, bought a 2g once that the genuis hadn't tightened all the bolts and it had a similar vibration...

 

[jtmcinder]

Ok so I've noticed it doesn't do it in neutral, only when it's in gear over 3k. So I'm assuming its something in the driveline. Either tcase, driveshaft or rear end

You are being a tad frustrating. You keep saying that the problem is engine-speed-related and, yet, probably in the driveline. Please go and drive the car at the speed at which you first get the vibration and then up-shift. Tell us if it goes away.

 

[blakkat]

You are being a tad frustrating. You keep saying that the problem is engine-speed-related and, yet, probably in the driveline. Please go and drive the car at the speed at which you first get the vibration and then up-shift. Tell us if it goes away.

Ok ,I will try to make it more clear what I mean. When the car is in any gear above 3000 rpms there is a vibrating\grinding noise emanating from what sounds like the middle/rear section of the vehicle.

 

[blakkat]

Sorry for the double post, tapa talk is messed up.

 

[jtmcinder]

When the car is in any gear above 3000 rpms there is a vibrating\grinding noise emanating from what sounds like the middle/rear section of the vehicle.

I'm not very good at diagnosing via internet, but I can tell you this much: If the problem really is engine-speed-dependent and ground-speed-independent, then it is almost certain that the problem is not post-transmission, regardless of where you think the sound is coming from (which can be very misleading). Also, 3000 rpm is one of the harmonic frequencies of the engine (as anyone with either no balance shafts or a mis-clocked balance shaft can tell you). So I'd start with the engine mounts, given that you also said that it's load-dependent.

 

[blakkat]

I understand, I am pretty confident in my abilities. Here are some additional noteworthy conditions that this occurs under:
1. Under acceleration in any gear
2. When decelerating in gear at an rpm above 3,000
3. It goes away when I put the car in neutral when coasting even if rpms at the time are above 3,000.

So I suppose it would be an accurate statement that it is load dependent.It vibrates slightly when free revved but it's much less violent almost like interior plastics making noise so I believe they are unrelated now.

Also it might be useful to note that the rear diff is caked in old oil. This is what initially led me to believe it was a differential problem.