915 gear Shift Pop

msk1986911 · 07-07-2006, 06:36 PM

The transmission in my '86 911 (75K miles) typically shifts with no problem at all. Occasionally, I feel a distinct pop from the gear shift when going from 1st to 2nd. I am not pushing the car, probably revving at around 2,500. This only happens very rarely. Any idea as to what might be causing this? The car does not have a short shift kit (if that matters).

Many thanks, as always.

Mike K.

Oh Haha · 07-07-2006, 07:23 PM

A couple of things to check into:

Coupler adjustment-could neeed to be tweaked a bit

Engine/trans mounts- could be allowing the trans to move when applying torque causing the linkage to bind a little.

Shifter bushings--could be getting old and worn causing some slop

Either way, it seems to happen a lot on these cars. It should be a simple fix.

Paulporsche · 07-08-2006, 12:41 PM

There is another possibility: If your mixture is a little rich, when you shift to the next gear you can get a sort of a burst as if the car is "exploding" into the new gear. Without experiencing the car itself, it's hard to tell, but I thought I'd mention it just in case the above tranny related fixes don't work.

Oh Haha · 07-08-2006, 06:54 PM

That's a new one, Paul. I never thought of that.

I had the same shifting "issue" as Mike tonight while out and about.
I was just going through town about 30-35 in stop and go traffic. I left a light and when I went from 1st to 2nd it "popped" like there was a binding and then it let go. I wasn't paying attention so I don't know what I did differently than all of the other shifts tonight. My shifter has new bushings and has been adjusted. I also have new trans and motor mounts. Strange.

Jim Sims · 07-08-2006, 07:14 PM

Notch on 1/2 operating sleeve?

Hoss3.0 · Hoss3.0's Garage

Mine does the same thing with new bushings and just adlusted. I am going to pull the shifter and lube the reverse lockout plate.

msk1986911 · 07-08-2006, 07:44 PM

Thanks for the responses. I will have to take some time in the garage, armed with these responses, and Wayne's book, to see if I can figure this out.

Mike

keez · 07-08-2006, 09:42 PM

This actually happened to me a couple of times tonight as well. I have a newly installed wevo shifter with a wevo coupler too. It seems to happen when stopped, sitting in neutral and when I shift into 1st to take off and shift into 2nd it seems like it just pops, almost like it wasn't entirely in first gear. Regularly shifting from 1st to 2nd there's no pop and shifts nice and smooth.....I'll have to make a mental note next time it happens to see what I am doing different from any other time. Just one of those quirks I guess.

Palum6o · Palum6o's Garage

This is interesting, I've had my 915 now for about 6 months, and I've noticed that if I clutch just a slight hair too late, that happens, its only happend a couple times for me and usually when I'm not paying attention. Considering how quirky the 915 really is, I wouldn't be surprised if it was the humidity in the air. Its funny how some days the shifting works like a symphony, and yet other days its not in the mood... sort of like a woman.

tiwebber · 07-08-2006, 11:14 PM

Happens on my 915 too. It seems that if it happens at all, it will be on the one of the first shifts from 1st to 2nd from when the car is started. I almost always notice that its a bit sticky shifting into 2nd from 1st gear though maybe this is unrelated.

Good luck. I am very interested in what you find out.

keez · 07-09-2006, 05:12 AM

Palumbo may be onto something about timing when clutching or just the 915 attitude.
Mike you don't happen to have a red or dark gray 911 do you....saw a couple running around yesterday afternoon.

Zeke · 07-09-2006, 07:15 AM

Sounds to me like the dogteeth are not completely locked when the torque is applied to the gears. An Adjustment should fix that. Make sure your linkage allows the forks to travel fully into gear. A more severe misadjustment and the gear would POP out. Now that is a nasty sound. AMHIK

keez · 07-09-2006, 07:24 AM

Milt you just put into words about my thoughts on this...almost not like fully engaged and when you add torque to the mix and shifting to 2nd at the same time....pops it out of first and by that time you're already shifting into 2nd. I wonder if you weren't manually shifting if it would pop out into neutral?

84toy · 07-09-2006, 07:31 AM

I would suspect the "late clutch" or "lazy foot" as well. Easy test.....get on it hard but be deliberate and concentrate on your clutching making sure the clutch is depressed fully before shifting. If it works fine then but not when you are thinking about chicks, you will know if it is mechanical or "mental"

I suspect the gears are just still loaded with engine torque when you take it out of gear.

dezzmo · 07-09-2006, 04:30 PM

This "popping out of gear" problem has been happening to me also. When I shift from 1st to 2nd I have to let the rev's drop down before I can move the shifter or it will really "Pop" out of gear. It act's like I'm pulling the shifter out of gear without letting off the gas pedal.

I replaced all my shifter bushings and my clutch and clutch cable are so for me it must be both the shift linkage and clutch cable that needs adjusting.

I'm gonna keep an eye on this thread. For me it's a good one.

msk1986911 · 07-09-2006, 05:33 PM

A response that I saw on PCA's website for a similar post was as follows:

"I would first check all of the bushings in the system. There is a coupler in the rear tunnel that attaches to the transmission that could be the issue. If you have excessive play in the handle look here for the cause.

If everything is aligned and correct then I would run the car by a dealer or mechanic and have him take a look. The other issue which would involve a little more work is the syncros and dog teeth.

This would explain why it doesn't happen twice. By the time you get it in to gear the syncro has slowed down and the car will slip back into gear."

Hoss3.0 · Hoss3.0's Garage

I readjusted the coupler and greased the shifter assembly. It works great now. Give it a try.

Rodsrsr · Rodsrsr's Garage

I just had my 915 completely rebuilt. All synchros were replaced, and I notice that mine does the same thing from time to time. I previously had a weltmeister short shift kit and the problem was much more severe, (almost forcefully popping out of 1st) I threw the weltmeister in the trash and installed a factory short shift kit and it works beautifully. Every now and than it still happens, but it is very very slight, not at all the way it was with the weltmeister. All the bushings are new as well, along with a new coupler. Indeed a very strange mechanical anomaly