the old very brown 1980, 5 spd trans problem
11-09-2013 | 07:04 PM
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the old very brown 1980, 5 spd trans problem
You may recall late last year the very brown 1980 928 lost first and 2 nd gear. Being busy with other car things like The Car Chasers TV show it became driveway art...
So last Tuesday I drove it over to Greg Brown's Precision Motorwerks plan was to see what was locking out first and second. I somewhat hopefully was thinking shift forks. And yes I drove it starting in third as it is only 18 miles and I had driven it 60 miles from the Fontana track to home plus to Van Nuys and then home 90 miles or so.
I was allowed to "help" with dropping the rear suspension and extracting the gearbox which Grant did in very little time
Next Greg popped off the top cover and said something like "what the hell happened to this thing" . Both first and second gear syncros had come off and were loose on the pinion shaft...which should NOT be possible
So he proceeded to blow the box apart and eventually discovered that the needle bearings under both 1st and 2nd were destroyed and had ruined the pinion shaft in the process... There was no fixing that gearbox
Digging around the back room Greg found an 03 gearbox he had as a "core" so he took it all apart and determined that parts of it,a couple pieces from my now dead box and a couple other used parts a gasket set and some new syncros should be all good. Of course he pulled apart the limited slip to check the wear on the friction discs and yes they were toast as well. So while we were in there seemed like the time to add those.
Wednesday was clean all the parts day before Greg carefully examined each and every bit dropping sliders onto the syncros to determine the amount of wear. When finally satisfied he assembled it which was amazing to watch as I really think he could do it blindfolded such is his familiarity with these transaxles. All the time he is talking to me and pointing out what and why he was doing things. The fifth gear (inputshaft) looked like new splines were perfect.
I then was looking at the end of the torque tube driveshaft and started thinking it was not in great shape splines showed a lot of wear asked Greg to look at it (knowing what he would say ) so time to drop the tube and run it over to Mark @928 International for a replacement drive shaft and rebuild.
getting the central tube out required dropping the aftermarket headers so I played with that for a long time before asking Grant to get the last couple bolts (the nearly impossible to reach ones) . So starter motor is off clutch slave off headers off and the clutch comes out pretty easily.
It is then obvious that disc 2 is completely destroyed on one face, so make a note to get a good used one when I pick up the tube from 928 International.
Looking at the engine which is covered with oil it is painfully evident that the oil pan gasket is leaking very badly plus the engine is resting on the crossmember....so seems like a good time to put on $400 of early motor mounts and the pan gasket since the starter is off and it would be a shame to let that oil blow back on the nice clean "new" transmission.
After the pan came off it was into the dishwasher for a good cleanup. After it was done I noticed a small burr near the drain plug hole as I looked closer I then noticed that the threads were nearly gone....Greg then pointed out that the factory Helicoil was missing an a trans drain plug was threaded in but really did not fit. Back to the back room to find another oil pan.
Oh nearly forgot the steering rack bushingsfell out so Greg had some of Roger's plastic replacements. Good time to do that !
I then noticed Greg checking the clutch discs including the like new used one from Mark and he and Grant are talking.....the clutch short shaft is pretty badly worn and good chance it is going to hang up not allow the disc to retreat properly and drag, dragging is very hard on the syncros. Not good for my "like new" gearbox. However Porsche has the priced at about $600.
Good news is Greg has had a guy making them for him Bad news they are not finished yet. Grant and I at lunch time swing by the machine shop to try to get the sample good used part from the guy but his workers can not find it. However they have a nearly finished new one made from the heavy duty steel so we take one back to Greg. A few minutes on Greg's lathe and I have a new super clutch shaft ready to go back in.
As I left Precision at about 6:30 Friday night everything is back together except for the clutch and hanging the exhaust. I did opt to go back to stock cast iron manifolds so I can put the cat on and get it smogged. Monday it will be done although it does need a new oxygen sensor......
It was quite an education for me to see how things are supposed to be done and the torque wrench is used for EVERTHING you hear beep, beep all the time.
So last Tuesday I drove it over to Greg Brown's Precision Motorwerks plan was to see what was locking out first and second. I somewhat hopefully was thinking shift forks. And yes I drove it starting in third as it is only 18 miles and I had driven it 60 miles from the Fontana track to home plus to Van Nuys and then home 90 miles or so.
I was allowed to "help" with dropping the rear suspension and extracting the gearbox which Grant did in very little time
Next Greg popped off the top cover and said something like "what the hell happened to this thing" . Both first and second gear syncros had come off and were loose on the pinion shaft...which should NOT be possibleSo he proceeded to blow the box apart and eventually discovered that the needle bearings under both 1st and 2nd were destroyed and had ruined the pinion shaft in the process... There was no fixing that gearbox
Digging around the back room Greg found an 03 gearbox he had as a "core" so he took it all apart and determined that parts of it,a couple pieces from my now dead box and a couple other used parts a gasket set and some new syncros should be all good. Of course he pulled apart the limited slip to check the wear on the friction discs and yes they were toast as well. So while we were in there seemed like the time to add those.
Wednesday was clean all the parts day before Greg carefully examined each and every bit dropping sliders onto the syncros to determine the amount of wear. When finally satisfied he assembled it which was amazing to watch as I really think he could do it blindfolded such is his familiarity with these transaxles. All the time he is talking to me and pointing out what and why he was doing things. The fifth gear (inputshaft) looked like new splines were perfect.
I then was looking at the end of the torque tube driveshaft and started thinking it was not in great shape splines showed a lot of wear asked Greg to look at it (knowing what he would say ) so time to drop the tube and run it over to Mark @928 International for a replacement drive shaft and rebuild.
getting the central tube out required dropping the aftermarket headers so I played with that for a long time before asking Grant to get the last couple bolts (the nearly impossible to reach ones) . So starter motor is off clutch slave off headers off and the clutch comes out pretty easily.
It is then obvious that disc 2 is completely destroyed on one face, so make a note to get a good used one when I pick up the tube from 928 International.
Looking at the engine which is covered with oil it is painfully evident that the oil pan gasket is leaking very badly plus the engine is resting on the crossmember....so seems like a good time to put on $400 of early motor mounts and the pan gasket since the starter is off and it would be a shame to let that oil blow back on the nice clean "new" transmission.
After the pan came off it was into the dishwasher for a good cleanup. After it was done I noticed a small burr near the drain plug hole as I looked closer I then noticed that the threads were nearly gone....Greg then pointed out that the factory Helicoil was missing an a trans drain plug was threaded in but really did not fit. Back to the back room to find another oil pan.
Oh nearly forgot the steering rack bushingsfell out so Greg had some of Roger's plastic replacements. Good time to do that !
I then noticed Greg checking the clutch discs including the like new used one from Mark and he and Grant are talking.....the clutch short shaft is pretty badly worn and good chance it is going to hang up not allow the disc to retreat properly and drag, dragging is very hard on the syncros. Not good for my "like new" gearbox. However Porsche has the priced at about $600.
Good news is Greg has had a guy making them for him Bad news they are not finished yet. Grant and I at lunch time swing by the machine shop to try to get the sample good used part from the guy but his workers can not find it. However they have a nearly finished new one made from the heavy duty steel so we take one back to Greg. A few minutes on Greg's lathe and I have a new super clutch shaft ready to go back in.
As I left Precision at about 6:30 Friday night everything is back together except for the clutch and hanging the exhaust. I did opt to go back to stock cast iron manifolds so I can put the cat on and get it smogged. Monday it will be done although it does need a new oxygen sensor......
It was quite an education for me to see how things are supposed to be done and the torque wrench is used for EVERTHING you hear beep, beep all the time.
11-09-2013 | 09:53 PM
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The work was over 4 days, Tues thru Friday , I did very little. Greg did all the trans rebuilding limited slip setup. Grant was like a machine just going and going to get things done. They also managed to get a some work done on customer cars as well in spite of how my "simple quick trans rebuild" just kept growing and growing....
Monday it should be a short day Yea right, felt that way on weds, Thursday and Friday. Greg just started saying "It is a slippery slope " as the old very brown 1980 kept asking for more love.
Monday it should be a short day
Yea right, felt that way on weds, Thursday and Friday. Greg just started saying "It is a slippery slope " as the old very brown 1980 kept asking for more love.
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11-10-2013 | 09:10 AM
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Wow, the car should feel like new after all that! Amazing how much work was done over such a short time.
BTW love season 2 of Car Chasers. It is one of the better car shows. Are you going to be in any of them? Try to get them to buy a 928 for resale (although Meg is pretty sharp so that might not fly ;-)
BTW love season 2 of Car Chasers. It is one of the better car shows. Are you going to be in any of them? Try to get them to buy a 928 for resale (although Meg is pretty sharp so that might not fly ;-)
11-10-2013 | 01:28 PM
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Wow, the car should feel like new after all that! Amazing how much work was done over such a short time.
BTW love season 2 of Car Chasers. It is one of the better car shows. Are you going to be in any of them? Try to get them to buy a 928 for resale (although Meg is pretty sharp so that might not fly ;-)
BTW love season 2 of Car Chasers. It is one of the better car shows. Are you going to be in any of them? Try to get them to buy a 928 for resale (although Meg is pretty sharp so that might not fly ;-)
