Things I learned at a Dr. Evil Transmission Clinic, (McMarks Coffee Sucks) |
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Things I learned at a Dr. Evil Transmission Clinic, (McMarks Coffee Sucks) |
ConeDodger |
Dec 13 2009, 02:29 PM
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#1
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Apex killer! Group: Members Posts: 23,612 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California |
First of all, my transmission had just been rebuilt a year or so before and at that time had a billet intermediate plate and Guard Torque Biasing Differential installed at that time. Issues discovered during that rebuild were the bearing in the stock intermediate plate had a cracked race which I hear is common, and synchro replacement was needed in gears 1 through 3.
So, I was opening a fresh box and should expect to find fresh parts without wear. right? My first gear synchro which again was new, showed pretty significant wear. My first gear dog teeth were pretty worn as well. The dog teeth wear would never have gotten by the guy who rebuilt it. He would have replaced it during the rebuild. Lesson one: never downshift your 901 into 1st gear while you are moving. It seems that even though it has a syncho it will not tolerate that. I changed to M 3rd and S 4th gears. I left the Zd 5th on the advice of the learned DNHunt who knows a bit about teeth in humans as well as transmissions. Lesson two: this is a very nice gear set for street driving in traffic with lights and stop signs. I expected it to be a great autocross/DE transmission but what I didn't expect was to be able to cruise down Sunrise Blvd. in 4th gear without any urgency to downshift. In short, it isn't so "busy" in traffic. Lesson three: with all due respect to the Capn who says transmission gear oil does not need to be changed, I have to agree with the Evil Dr. My fresh gear box had a little metal Chia Pet attached to the magnet after only a few thousand miles. The Dr. says change it after the first thousand miles. I agree. |
davep |
Dec 14 2009, 09:45 AM
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#2
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914 Historian Group: Benefactors Posts: 5,152 Joined: 13-October 03 From: Burford, ON, N0E 1A0 Member No.: 1,244 Region Association: Canada |
My first gear synchro which again was new, showed pretty significant wear. My first gear dog teeth were pretty worn as well. The dog teeth wear would never have gotten by the guy who rebuilt it. He would have replaced it during the rebuild. Lesson one: never downshift your 901 into 1st gear while you are moving. It seems that even though it has a syncho it will not tolerate that. Apparently there is a solution, of a sort, for this. You notice that the dog tooth ring and the associated synchro parts are different for first gear? Try using all the parts from the 2nd through 5th synchro sets. First gear original synchro was designed to work in one direction only, while the rest are bi-directional. Probably not a perfect solution, but is is a step in the correct direction from what I understand. This was something I got from Grady Clay. |
Dr Evil |
Dec 14 2009, 10:49 AM
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#3
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Send me your transmission! Group: Members Posts: 23,002 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
My first gear synchro which again was new, showed pretty significant wear. My first gear dog teeth were pretty worn as well. The dog teeth wear would never have gotten by the guy who rebuilt it. He would have replaced it during the rebuild. Lesson one: never downshift your 901 into 1st gear while you are moving. It seems that even though it has a syncho it will not tolerate that. Apparently there is a solution, of a sort, for this. You notice that the dog tooth ring and the associated synchro parts are different for first gear? Try using all the parts from the 2nd through 5th synchro sets. First gear original synchro was designed to work in one direction only, while the rest are bi-directional. Probably not a perfect solution, but is is a step in the correct direction from what I understand. This was something I got from Grady Clay. You would have learned it from me at the clinic you attended as well (IMG:style_emoticons/default/dry.gif) It doesnt solve the wear problem, it gives you an option to save some coin because good used 2-5 teeth are readily available and 1st ones are not. |
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