Hey all,

Been putting more highway miles lately on my 330,000km+ 1989 240 automatic.

Had car for a few years, it's been fantastic.

I noticed one day on deceleration from highway speed...a howl starting...sounded like was coming from the back of the car.

As you would come down through speed, 50, 40, 30, 20mph, it seemed to get louder and more prominent.

As I'd get to the light it would get QUITE loud, and I could FEEL the like the tranny wasn't disengaging from gear.

(I must say that I screwed up and have been using Type F and not Dexron III for the past year or so, hopefully haven't destroyed anything there)

Anyway, did a basic checkout of the driveline, and everything seemed really tight and good except the tailshaft bushing, does have play in it.

Talked to a tranny shop to see if they had the quickchange tool, they said if that bushing was gone at all, fluid would be leaking out of there like CRAZY. (then again, they probably don't know the tailshaft housing is actually long and tall...meaning that the oil probably pools in bottom)

Anyway, I chalked it up to the bushing, but they are saying that even tho it has play, if it had a bad bushing, fluid would be gushing out.

It does hold fluid but the tranny does leak. I need to top it up every few months etc.

Tranny mount is in bad shape too.

hint: when I am decelerating, and getting the howl, if I shift to neutral, it makes no difference. The howl remains.

What makes a difference is if I 'two foot' it: applying a tiny bit of gas, while I brake, so as to reduce full rotational torque load on the output shaft...the sound definitely goes away a bit.

Also, I find if I am slow and steady on the brakes, and let the harmonics build up, they REALLY build up.....but if I pump the brakes hard a number of times instead...the harmonics don't build up.

The fact it's heavily speed sensitive and does not come and go directly with braking....but more when I disturb the harmonic resonance....it makes me think driveline. Tailshaft bushing was the first thing that jumped out at me....but maybe it's not that after all.

Tranny shop also told me to definitely drop the entire drive shaft and check out all the u-joints like that. Can't really check it in vehicle if it's binding somewhere.