Quote:
Originally Posted by cwitt
I asked the owner about it, and he said the trans still needs to "break in". The local shop that rebuilt it (a reputable place, by the way) is also claiming the need for break-in, and added that they think the short shift kit and it's adjustment could be part of the problem. Another reputable local shop said that the break-in theory is at least plausible.
To me, this is just counterintuitive. Shouldn't a rebuilt trans shift best right after the rebuild, and then slowly degrade again as the new synchros get milled down by the sliders? Or is there truly a break-in period after a rebuild? If so, how long should break-in take? (it's already got ~4K post-rebuild miles on it.Curtis
|
Curtis, I'm sorry to hear about your difficulty. Extended break in usually occurs when something is overlooked. As others have posted, the installed dimension of every new synchro must be measured, and every new synchro must be mated to a new slider. That's my rule, and my transmissions are often broken in before the end of a 5-mile test drive. They never require more than 20-30 miles to become comfortable.
There is a lot to be learned from the comments made by Marc, John and Matt, and if you have to time, I urge you to read my 915 repair Tutorial at...
Welcome to Red Line Porsche Wiki - Porsche Wiki
...simply locate "Page Tags" and click on "915."
Regarding your transmission, today, your old sliders are carving away friction material from your new synchros. That material loss will shorten the effective life of your synchros, and make your next refresh happen sooner than it should. I, like Marc, have returned out-of-spec synchro rings to a supplier; one can only imagine how difficult shifting might be with a new, egg-shaped synchro combined with a used, worn sliding sleeve.
About your shifter. Try to determine if you have stock 1985 shifter pieces (10% shorter than '84 and earlier original shifters), or if you have a super-short shifter (20% shorter than '84 and earlier original shifters) introduced in 1986. The '85 set-up should serve you well, but I've removed SS shifters because of complaints of unusually heavy motion (not to be confused with poor shifting characteristics).