AWD shutter, vibration, rumbling when under load

[madmader]

Well i have a 91 GSX and wondering about a problem it has.
Well under load/boosting, it will tremble (rumble/vibrate/shutter or what ever you wan to call it). It seams to be coming from behind me. It is very consistant (like a back massager at low speed) and respons to RPM in any gear as long as there is a load. And it is dependent on the amount of load also, more load the more violent it is.

Clutch in it will not happen.
Clutch released and in neutral will not happen.
I can rev it up in neutral and it will not happen.


I might have a missfire but i don't think it could make a vibration so server like it is.

U joints? Carrier support bearings, or Rear Diff is what im thinking it could be.

Anyone help me out.
would be nice if i can get some prices for replacement parts also/ part numbers. The local parts stores don't have anything i listed up there. I think i need to go to dealership.

 

[Rob10_99]

sounds like what my car is doing sort of, not really speed dependent. But high load/low rpm on the awd is from the lobro's(yeah the 15 u-joints) under the car. There is an article on the forum about how to fill them with silicone I think it was. I felt mine and they seem in fairly good shape, but they are able to move quite a bit, so that should help on worn ones.

 

[madmader]

Well hell, the ECu that is in it is not the right one. I bought the car from a guy who got a ECU off ebay.
Anyways a long story but the ECU # match that of a 1990 Galant 2.0 SOHC non turbo.

So no I'm looking for e-prom 91 GSX ecu. DSMlink i hope.

 

[Lazer RS]

sounds like a howlin differential to me....

 

[Jason84]

are you talking like trying to go uphill in 4th gear doing 30 mph or are you talking like just normal driving?

the AWDs you usually have to stay in a lower gear then the FWDs. my friends can almost cruise through town in 5th gear.. while i stay in 3rd sometimes 4th if its about 40 mph..