Tweet
This transmission is known to have problems with cold 1st and 2nd gear shifting. In my case, the first sign of trouble was ocassional gear scraping shifting into 6th gear in addition to the typical chronic problems.
The first sign there was a serious problem was when a gear whine developed after a boosted run that sounded like cupped tire noise at first but coincided with acceleration load in 1st through 3rd gear.
On one particular evening the 6th gear scrape became more pronounced and shortly after that a loud whine occured that was aggravated by deceleration in 1st gear. After that I knew the tranny status was critical. I continued to drive it for about 2 wks until I could get it back to Florida, making through a couple of near tranny lock ups that turned out to be pieces of metal wedging between gears.
I submitted the pictures to a Saab tranny builder since that's what the F40 originated in and he attributed the failure to fatigue and guessed without any hints that I was running a solid flywheel and solid clutch disc which is correct.
His recommendation is to run a sprung hub clutch disc and a flywheel in excess of 14 lbs if not dualmass. Apparently 1st, 2nd and 6th gear are on the same axis and that's why I had chronic problems and associated noises with those gears.
He also mentioned that the cure for the difficult cold shifting is to run the tranny at near half capacity as some how the proper fluid level contributes to the shifting difficulty. He runs his F40 at 2qts instead of the recommended 3.1 and uses Redline 85W, behind 400 lb/ft.
The first brief abberant sound is the clutch disc noise, apparently the little springs vibrating in it.
The first sign there was a serious problem was when a gear whine developed after a boosted run that sounded like cupped tire noise at first but coincided with acceleration load in 1st through 3rd gear.
On one particular evening the 6th gear scrape became more pronounced and shortly after that a loud whine occured that was aggravated by deceleration in 1st gear. After that I knew the tranny status was critical. I continued to drive it for about 2 wks until I could get it back to Florida, making through a couple of near tranny lock ups that turned out to be pieces of metal wedging between gears.
I submitted the pictures to a Saab tranny builder since that's what the F40 originated in and he attributed the failure to fatigue and guessed without any hints that I was running a solid flywheel and solid clutch disc which is correct.
His recommendation is to run a sprung hub clutch disc and a flywheel in excess of 14 lbs if not dualmass. Apparently 1st, 2nd and 6th gear are on the same axis and that's why I had chronic problems and associated noises with those gears.
He also mentioned that the cure for the difficult cold shifting is to run the tranny at near half capacity as some how the proper fluid level contributes to the shifting difficulty. He runs his F40 at 2qts instead of the recommended 3.1 and uses Redline 85W, behind 400 lb/ft.
The first brief abberant sound is the clutch disc noise, apparently the little springs vibrating in it.
Attached Files
Comment