Strange noise coming from TH350

[454 blazer]

I have a noise like a clunk as im deselarating , its strange it doesnt do it when im accelaratingAny ideas what it could be ? I have just changed a bush that sits inside the rear of the NP205 t/c (Kinda looks like a cone)As there was a hell of alot of play there before , so i thought it was that but no luck.Ive also noticed a really loud CHING noise when i put it in drive,it sounds strange but could it be a bearing in the rear axle ? Hope someone can help as its doing my head in

 

[Fordum]

KaChing! is usually a U-joint. The slop resonates in the hollow driveshaft and makes it ring like that.
Could cause the clunk too.
J.

 

[Greg Ducato]

I agree, there is a strong chance it is a u-joint. Pull the shaft and check the joints, you may not be able to tell when they are "loaded" in the vehicle. The 350 may have some case wear at the low sprag housing which will cause a bit of slop on engagement and decell, they also will wear at the high drum to sun shell contact point and can cause a clunk or ring when engaged. It is a pretty common problem on both of these and when combined will induce a lot of drive line slack.