TwoLaneBlackTop

Well, this has been a problem sence the day I bought my 1985 911 with 52K miles. The 915 trans when I downshift into first likes to grind. Any other downshifts are fine but from second to first I get a grind unless I am going like 5mph or slower when I downshift. Any advice?

steve911

the first gear synchros in the 915 are not all that good to begin with. you might try double clutching when going 2nd to 1st, or just not go into first at all unless at a complete stop.

pbs911

I had the same problem with the 915 in my 78 when I bought it. Under 5 mph it grinded going into 1st, so I never did it. I would wait till I came to a stop to shift into first. I later flushed the transaxle with cheap gear oil and refiled with Swepco. From that point on there has been no grinding going to first, even at about 15 mph.

So, when is the last time you checked the gear oil?
Have you tried Swepco?
Have you checked the shift coupler bushings?
Of course, it could be a syncro going bad.

Good luck.

Howard

Once the synchro begins to wear the dog teeth also go, then the shifter sleeve. Double clutching is your only recourse until you rebuild it. I know, I just did this 2 weeks ago, new synchro hubs at 1st and 2nd, new synchro rings and new sleeve between 1st and 2nd.
And as usual......" while I had it apart"....bearings...gears...seals...and lots of $$$$ .

TwoLaneBlackTop

I changed to swepco about 300 miles ago. Things did seem a little better after that and sometimes it does not grind at all. I will start doubble clutching next time I take the car out. Can't go out driving today though. Dang TN vally weather with all it's rain