Transaxel question.

[Fast Freddy 944]

When I drive my 86 951, all gears are quiet except 4th and 5th gear, I hear a little noise when I accelerate, when I lift off the throttle it quiets down. I think its worn syncros, any thoughts?

[944 Ecology]

Nope, synchros that are worn cause clashing when shifting (due to their lost ability to synchronize the gears).

The whine when you accelerate that disappears when you decelerate is caused by worn bearings, probably the pinion bearing. You should replace it before the rest of the transaxle is damaged by the worn bearing.

[kevingross]

I would agree with George. Fourth and fifth gears are separate, actually at opposite ends of the gear carrier. If the noise were happening in third and fourth, maybe a different diagnosis.

How many miles on the car? When was the transmission fluid last replaced?

[Fast Freddy 944]

Originally Posted by kevingross

I would agree with George. Fourth and fifth gears are separate, actually at opposite ends of the gear carrier. If the noise were happening in third and fourth, maybe a different diagnosis.

How many miles on the car? When was the transmission fluid last replaced?

It was changed 4 yrs ago, this car has always had that noise, mostly in 4th gear, and I only drive it on weekends, 130k miles on it, it runs great, has all maint. records, the noise isn't really loud either, but enough to make me pay attention.

[Fast Freddy 944]

Did tranny flush, and the fluid level was indeed low, now it runs great with fresh gear oil, thanx for the input gang!

[pfarah]

Question...
Has the torque tube been rebuilt? It could be those bearings as they spin faster in the higher gears. I've read that TT bearing last about 125k miles or so... Just a suggestions.

[944 Ecology]

Originally Posted by pfarah

Question...
Has the torque tube been rebuilt? It could be those bearings as they spin faster in the higher gears. I've read that TT bearing last about 125k miles or so... Just a suggestions.

Bzzzzt! Wrong! The torque tube spins at the same speed as the engine and clutch. The gear selected inside the transaxle makes no difference.

[dgcantrell]

Mine has lasted over 250K. Mine has made a little bit of noise every since I got it with 50K miles on it 24 years ago. But yes, they rotate the same speed as the engine speed as it is a direct connection between the clutch disc and the input shaft on the transmission.

[pfarah]

Ok then, I stand corrected... Thanks.

[Fast Freddy 944]

Originally Posted by pfarah

Question...
Has the torque tube been rebuilt? It could be those bearings as they spin faster in the higher gears. I've read that TT bearing last about 125k miles or so... Just a suggestions.

As far as I know they haven't been replaced, it has 130 mi on it total, but the noise was from 4th gear when I was driving highway speeds, I became quiet when I did a gear oil change, so mabe I dodged a bullet?

[pfarah]

Fresh oil tends to quiet things down some... Good luck!