How should a 1981 SC shift?

Poohsan · 01-20-2007, 04:25 PM

How should a 1981 SC shift?

At this time shifting in to 1st and 2nd requires some tugging and pulling, more than what seems reasonable. 3rd, 4th, and 5th go in to gear with ease.

I have not driven another SC for comparison. But the force needed for 1st and 2nd make me feel that something is not right. My daily drive is only 8 miles in Los Angeles with stoplights at every corner, so I tend to live in 1st 2nd and 3rd gears and my elbow is taking a beating.

When I purchased the SC the shifter was a total mess. I¡Çve been working on fixing the PO¡Çs mess. The current set up is a factory short shift kit with new bushing. I made an adjustment to the coupler and that made a difference.

I¡Çm wondering if the coupler is still misadjusted or if it is something in the Transmission.

I found this during a search
¡ÈIf you can get it into 1st/2d, and also 5th/reverse, without having to tug overly hard to one side or the other with the shifter to make this work, you should be good.

If you are off some at the coupler in terms of rotation, this will usually show up as being hard to get into gear in one or the other of the two outer planes. If you have it set up so 1st/2d are really hard to select, you can even find that you can force it into 5th/rev with the hook on the shift lever to the left of the tab it is supposed to hook over, rather than to the right (where it holds against the spring tension).¡É

Zeke · 01-20-2007, 04:51 PM

A lot of what you quote there has to do with the fore and aft alignment. IOW, having to pull hard against the side of the shifter housing to rotate the shaft enough to get into that shifter plane. I don't think this is what your problem is, but you should check that anyway. There can be internal problems, or perhaps some other shifting mechanism faults like bad bushings.

Basically, the trans should shift into gear with the car not running w/o much difficulty unless you just happen to have things aligned in a certain way. Slightly rocking the car back and forth should help get things aligned. If the trans is balky like this, the next thing to do is remove the coupler and see if the binding is in the linkage or internal. The trans is not easy to shift at the shift rod on the tail, but it will shift with a rag around the shaft and a pair of pliers. Again, you may have to raise the rear wheels or rock the car.

One or the other is messed up and you might as well figure out which one. The linkage I think you can sort out yourself. If it's in the tranny, maybe take it to your favorite shop. Might be a simple adjustment for one of the maestros on this forum.

Do you have a copy of 101 Projects by our host, or another manual?

dentist90 · dentist90's Garage

My 2nd was balky because of this...

SLO-BOB · 01-21-2007, 06:30 AM

I can't guide you on repair, but I'll add this to think about-

How long have you had this 911? Have you driven any other 911s? What is your reference for good shifting?

To some people used to a relatively "good" shifting car, ie, Honda, BMW, Daihatsu, Mack truck

, the 915 can be difficult. My first experience was in my 77. It seemed difficult to engage into second based on my experience. It would slide back, but the last 1/2 inch to inch of travel was usually difficult to engage. I asked a number of 911 savvy people to drive it and they proclaimed it a "perfect" shifting 915 transmission.

I would take it to a mechanic to evaluate.

RarlyL8 · RarlyL8's Garage

How should an '81 SC shift?
Exactly as described unless everything is new or rebuilt to new.
There are two things critical to the "feel" of your shifter, bushings and alignment. How old are all of your shifter bushings? Pelican sells a kit that contains every bushing from the shifter to the coupler. Replace them all and adjust the alignment. Any remaining shift issues will be isolated to the tranny and much easier to diagnose or work around. If your tranny has a lot of wear you may be able to make it "feel" better with Swepco fluid or some other brand that is more viscous.

Jim Sims · 07:33 AM

The 915 on my '76 (100,000 plus miles) shifts smoothly into all gears (including down into 1st if going less than 25 mph). Too many have only driven a worn out (and possibly abused) 915 and gained their "calibration" from those experiences. There is also some "rationalization" going on to justify the deferring of repairs. Its likely the first and second gear syncronizer parts are worn in your transmission or there are other adjustment or wear problems with linkages (shift coupler bushings?) or the operating sleeve spider (inside the transmission). That being said, the 915 doesn't respond well to speed shifting but should be shifted deliberately with a momentary pause as it passes through neutral between gears. Cheers, Jim

Zeke · 01-21-2007, 08:09 AM

Well said so far. In fact, another "test" would be to use the double clutch and rev matching process to see if the trans is the culprit. I'm still motivated to believe what i do by this statement, "I made an adjustment to the coupler and that made a difference."

jmohn · jmohn's Garage

It should be noted that a "short-shift" kit will require more "force" to move the gear lever than the stock shifter (due to simple mechanical advantage).

Jerry M
'78 SC

dentist90 · dentist90's Garage

The short shift does require a bit more effort than stock, but the big difference here is that ALL gears should feel a bit more resistant. In my case 1st was way too easy to engage because synchro ring and slider teeth had worn excessively. I could get it into 1st while rolling but not without crunching the gears. Synchro wasn't doing it's job. However my 2nd gear was wayy too resistant and would leave me coasting in neutral while I struggled and eventually went back to 1st or up to 3rd. Synchro ring had expanded past it's nominal diameter (due to broken teeth) and slider couldn't get around it. 3rd, 4th and 5th were still my happy gears, shifted crisply up and down with little pause at all.
Poohsan... do try to adjust the coupler first as it is a simple thing to do. Make sure the shift lever is rotating the coupler all the way over to 1-2 plane ( ie, shifter knob is all the way to the left while coupler is rotated to the right in neutral plane, then tighten). Do this even at the possible expense of not being able to get properly into 5-R plane. If your 1-2 shifts improve... Bingo! It was a coupler adjustment. While you're in there also give the shift rod in the tunnel a wiggle with your hands to see if the guide bushing is wearing out. If you move the shifter knob while looking at the coupler there should be immediate and positive movement of the coupler. Freeplay indicates worn bushings, cup or even shifter housing bores. If your shift linkages all seem tight the next step would be to drain the tranny and look for Jimmy Hoffa's ghost (or metal bits, whatever...)

hytem · 01-21-2007, 05:32 PM

You have to shift deliberately with these cars--don't get ahead of the synchros. It takes a few months to get the feel. And you never take your mind off your shifting. Concentrate. 2nd to 3rd was the toughest for me to get used to. Downshifting from 5th to 4th is notoriously difficult--shifting to 3rd from 5th is easier, and many do that.

Jim Sims · 01-21-2007, 05:42 PM

"And you never take your mind off your shifting."

No, once you learn the feel of the car (clutch, transmission and shifter) and the sound of the engine, shifting becomes an automatic reflex if the car is your daily driver. One doesn't even have to mind the tach - one can tell the engine speed from the sound and the car's response (the peak torque band is so obvious). All you have to mind is the speedometer as it tends to creep upward.

hytem · 01-21-2007, 06:13 PM

Quote:

Originally posted by Jim Sims
"And you never take your mind off your shifting."

No, once you learn the feel of the car (clutch, transmission and shifter) and the sound of the engine, shifting becomes an automatic reflex if the car is your daily driver. One doesn't even have to mind the tach - one can tell the engine speed from the sound and the car's response (the peak torque band is so obvious). All you have to mind is the speedometer as it tends to creep upward.

Sorry. I should have said I only drive about once a week. I also have a stick Jeep as a main car which shifts more easily. It did take a few months to get the feel, and sometimes those gears aren't in the same place. A tad balky on occasion. But, heck we're talking 25 years old.

Jim Sims · 01-21-2007, 06:18 PM

"and sometimes those gears aren't in the same place."

The same thing happens to me when I put the 911 up for the winter and I'm reduced to driving a 325 - who moved reverse gear!?

Poohsan · 01-21-2007, 07:47 PM

Quote:

Originally posted by SLO-BOB
I can't guide you on repair, but I'll add this to think about-

How long have you had this 911? Have you driven any other 911s? What is your reference for good shifting?

To some people used to a relatively "good" shifting car, ie, Honda, BMW, Daihatsu, Mack truck , the 915 can be difficult. My first experience was in my 77. It seemed difficult to engage into second based on my experience. It would slide back, but the last 1/2 inch to inch of travel was usually difficult to engage. I asked a number of 911 savvy people to drive it and they proclaimed it a "perfect" shifting 915 transmission.

I would take it to a mechanic to evaluate.

I have been driving this 911 for 3 months.

For most of that time I was driving it with a butchered shift lever. The PO had what he believed was a short shifter installed. In actuality it was a cut down shift lever, (someone was taken by their mechanic). Other problems included over an inch of slop in the shift pivot housing. The set screw on the front of the shifter housing was not set correctly. Lastly the coupler was also misaligned.

I sorted all of this out by installing a factory shift kit, replacing the bushings, and aligning the coupler. This made a HUGE difference. But I still think that the shifting is rough. This is the only 911 I have driven so I do not have point of reference.

I think it would help if another SC owner came over and gave it a spin to check it out.

JV911SYDNEY · JV911SYDNEY's Garage

Quote:

Originally posted by jmohn
It should be noted that a "short-shift" kit will require more "force" to move the gear lever than the stock shifter (due to simple mechanical advantage).

Jerry M
'78 SC

+1

I've got a rebuilt box with less than 5000km on it with a short-shift kit.

You have to make a very deliberate & positive shift from 1 to 2 when driving "normally". If you are going hard and match the revs it seems to be smoother.

2-3 & 3-4 is much easier.

5-4 is a tricky one until you get used to it. Careful not to get reverse by mistake

1st wont engage until you come to a complete stop.

The 915 box is difficult for those who havent driven them before but very rewarding when you get it right

VA911 · 01-21-2007, 11:54 PM

my 915 box on my SC is great. shifts perfect. is very tight and can down change into 1st at about 45km/h. In saying that my box has been rebuilt like new. this was done about 50000ks ago though

toddu · 01-22-2007, 07:36 AM

I just completed the install of a factory short shift kit this weekend. Along with the kit, I replaced all of the bushings. Previously, my shift lever was sloppy, loooong, and at times I also had a hard time "finding" 2nd gear. Looking at the old bushings, they didn't appear THAT worn, but I suppose a combination of them all being a little worn = a lot worn.

I have yet to drive the car (raining last couple of days), but with it just sitting in the garage, and running through the gears, it feels great. I can feel it go into gear precisely, not having to hunt around for the sweet spot.

There was a lot of play in the rear coupler when I took it out. The new (Pelican) bushings took all play out of it.

911pcars · 01-22-2007, 08:11 AM

Assuming most of our cars were not bought new, we can blame the previous owners who may or may not have treated the gearbox with the care necessary for longevity.

Our cars are usually driven more aggresively than the usual Toyota. That means quite a few more full-throttle up-shifts and more high-speed downshifts. That, coupled with a less-than-stellar synchromesh design means more shifting issues down the road (now, by the tone of many threads in this forum). If the previous or current owner didn't/doesn't double-clutch when downshifting, if gear changes are forced when shifting, if the gearbox lube isn't changed at reular intervals and/or the recommended gear lube isn't used, if there are over 100K miles on the car, if the shift linkage bushings are worn, then all these factors stack up.

Before it's too late, repent and modify your gearshifting style and/or maintain and fix what you can before you reach the point of no return (rebuild time).

MHO,
Sherwood

Kraftwerk · 01-22-2007, 10:14 AM

When I shift my car I am reminded of its great heritage: a tractor! My brothers Kubota shifts smoother. I often wonder how much better if at all the SC felt on its first day out of the showroom. I know the first owner traded this car for a corvette. I don't envy that guy one bit!

Hetmann · 01-22-2007, 10:53 AM

I've owned my car for 12 years. In that time the shifting has gone from pretty good to abysmal to ok to really good. I've been through 3 different shifters. Current one is the factory short shift. There are several factors that can affect the feel of the shifter. Make sure your bushings are in good shape and everything is adjusted. Shift slowly, deliberately and gently.