On another note, I thought I would try manually shifting to see what
happens. So I put it in 2nd and when I get up to 20mph it stars bucking,
like it does not want to go faster than 20. I can manually shift to 3 and it runs fine but I did not accelerate to see if it would buck and sputter at higher rpm.

But when the shift lever is put in 2, and I drive, it will not go above 20 and then starts this bucking that I experience when it automatically shifts.

Any advice would be greatly appreciated.

David in Florida

Hello Mr. Cattaneo. I was wondering if you could give me some insight? I could not find my answer through the forums.

I have a 1986 928 with 60k miles on it. The problem is hesitation in upshifting at high rpm. The vehicle starts fine, and idles at about 750-800. The fluid level is normal and replaced. There is vacuum at the brake booster. If I accelerate normally, the vehicle shifts perfectly. But when I push the pedal to the floor, it starts hesitating and does not want to upshift. If I back off the throttle, it will shift. If I do not aggressively accelerate the vehicle shifts. If I am at 60 mph, and mash the pedal it kickdowns, but sputters, hesitates but will not downshift. It will only shift if I back off the throttle.

I have readjusted the bowden and throttle and pedal cables dozens of times. Interestingly, it seems to run fine, even at full throttle, when it is cold.

Hi Steve, It's been a while, hope you & your family have been well.
I have a question. On my 86.5 928, what would the symptoms be if my control pressure cable was broken?
By the way, I may be needing a higher stall converter soon. Is that something you may have?
Thanks, Hammer

Hi Steve,

My apologies for the blind PM.
About 2 years ago, you helped me with a B2 piston and K1 spring replacement on my Porsche 928 A28 transmission. That helped the trans last awhile longer; however, it will not shift at all now. I have pulled the unit and have been directed to a local MB trans shop by the local third party Porsche shop.

They have not looked at the unit yet; however, they quoted $2850.00 for a fully rebuilt and dyno tested transmission. Obviously, they will need to look to get a better idea; however, I wanted to ask you if this sounds reasonable to you for a quality rebuild?

Kooler kleen - A pro wrench on a forum suggested I use this to flush the cooler lines as I can not get access to a flush machine. If you are familiar with this product - what is your opinion?

Any other things I should be aware of or check into?

I really appreciate you all your help,
Tom Whiteley