Stiff 1-2 shift

[ckelly]

Okay, got a simple question...maybe. My '80 SC has a non factory short shift installed, but I don't think this is the problem. When in normal driving, 1-2 shift is fine, but when under heavy acceleration or high rpm, 2nd is VERY, VERY stiff, doesn't grind, just won't go in for like ....1-2 seconds, which doesn't seem long, but it feels like an eternity when your corvette buddy leaves you in the dust. I've tried to just "pull" it into gear and it feels like the shift rod is going to bend or something. All other gears seem fine. Anyway, is this a shifter related problem or some kind of transmission problem, or normal?? This is my first 911 so I don't have anything else to go on

Thanks

[Silveresrty911S]

Ckelly,

Do a search on "shifting" or " shifter bushings" and you'll have plenty of reading on the sutulties of the 915 transmission.

[nostatic]

the harder you pull, and the faster you try and hit second, the more it will complain. I find the 1-2 shift to be the defining moment for the 915 owner. Whenever I try and get antsy, it lets me know who's boss. When I play nice, it slides right in.

Oh great, now I'm writing porn scripts...

[RoninLB]

Originally posted by ckelly
is this a shifter related problem or some kind of transmission problem, or normal??

sounds more like as the engine twists under acceleration [more porn] the linkage binds

[nostatic]

Originally posted by RoninLB
the linkage binds

Ron, I didn't know your were on Joe Millionaire

[ckelly]

Also, I've replaced all the bushings in the shifter as well as checked the shift coupling.
So how can the engine be twisting enough to cause bind if the clutch is in? Drag from transmission, wheels, etc?
Nostatic, you're correct, the faster I try it, the more it fights me. This can't possibly be normal,,,, can it?

[RoninLB]

Originally posted by nostatic
Ron, I didn't know your were on Joe Millionaire

man.. had to think.. not easy/try not to..
must be tube stuff.. try again, LOL

[nostatic]

normal? My car has 49K miles on it, the tranny feels great, but if I force it, she fights back. It just doesn't feel like a "modern" tranny. On the upside, when you shift you can actually feel what's going on inside, and engagement is pretty positive, as opposed to more "modern" trannies that can be pretty vague.

It's an aquired taste...

[RoninLB]

Originally posted by ckelly
So how can the engine be twisting enough to cause bind if the clutch is in? This can't possibly be normal,,,, can it?

OK.. you have 2 sets of rubber bushings.. one set on the tranny and one set on the engine mount.. not expensive and doable.. I usually loosen the eng mount to engine bolts after doing bushings to reset the engine

[ckelly]

I like the feel, I just don't like having to wait for the engine to come down to almost idle again before I can get it into 2nd. The weight has completely shifted forward at this point. I have a dodge diesel pickup that shifts similarly, but I'm not going anywhere fast with that anyway.
I want to go to my first DE events this year and I'm concerned about it, how often are you in that 1-2 gear range? Would Swepco transmission fluid help at all? How about solid mounts? Suggestions.....?

[speeder]

I would check your linkage to make sure that it is adjusted precisely and check all motor and trans mounts. Swepco is good oil, but would make no difference in your situation, IMO. Any miracle stories associated w/ Swepco involve cars that were half full w/ 20 year old goop previously.

[jrb964]

I just rebuilt my tranny on my '80SC. Have the same problem, shift from 1 to 2 under 3k rpm - smooth as glass, over 3.5K - its like pulling teeth. I've followed a couple of threads regarding the tranny and motor mounts. One of major forces at higher rpms that change is the stress provided by the inertia of the higher rpms. If that stress could be minimized (held in check) it would cause the engine and tranny not to move out of their normal plane thus continue to shift smoothly.

The general consensus on mounts is to have solid mounts on the engine with sport mounts on the tranny. This tends to stablize the engine and tranny while not transmitting the excessive noise provided with solid mounts at the tranny.

Or the other solution is the always shift under 3k. NO WAY!!!!!!

Also, when I rebuilt put in an aluminum flywheel and the SACH's power clutch. Rev's to 5K real quick!!!

Just my thoughts on the issue.

[RoninLB]

Originally posted by jrb964

Just my thoughts on the issue.

good reply

[Botman]

To address your DE concerns,

You will shift from first to second pulling out onto the track during a warm-up lap, but at most tracks, you will never be in first gear again. At some, you will never even be in second gear again until you are pulling back into the pits with "the big grin" on your mug.

[ckelly]

Anyone tried the solid/sport mount combination with any success in curing a shift problem? I've seen the opposite advertised, solid trans and sport motor mount in pelican, is this the best or should I try to find the solid motor and sport trans?

JRP, you've described my problem exactly, did you find any resolve? I'll certainly order up the mounts if this helps, the motor does seem quite "loose" to me, I'm sure the mounts are all original.

I need to do a clutch change soon also and I'm considering the aluminum flywheel/Sachs clutch combination. Any considerations on this that I should be aware of regarding my shift problem or other driveability issues?

Thanks guys, this is a huge help...

[stealthn]

EXACT same problem here, but it's funny it didn't show up until I had 1st & 2nd rebuilt. If I rip it to 5-6K I have to double clutch to get it in second, and same if I go slow or shift with no load no problem.

If anyone has fixed this with tranny mounts I would love to hear about it, as my mechanic isn't sure why this happened after the rebuild.

Cheers

[RoninLB]

Hey guys... IMO, engine/tranny mounts are a maintance item.. just do it.. and as I said before, I reset the engine in its cradle by loosening the "engine support" 4 bolts.. I run the engine w/the loose bolts and rev a few times to seat it......... Ron

[Doug Zielke]

Just re-read what nostatic wrote. Nuff said. Deal with it; it's never going to shift like a Honder.

The solid engine mounts/sport trans mounts conversion make a noticible difference in *overall* shift quality, but you still have to relax when going 1-2.

[Joe911]

I have also had the stubborn 1-2 shift. Finally switched to SWEPCO and the sports engine/trans mounts and the problem is reduced by about 50%. Definately worth the effort - about a 2 hour job in total.

[Gordo2]

Same deal here,

In addition to the rough one-two punch mine is flakey going back into 1st. I practically need to be at a complete stop to get it back into 1st.

I changed to Swepco, replaced all my shifter bushings and re-adjusted my linkage. I did it step by step to see if I could notice any positive changes with each fix.

My shift linkage bushings that I replaced were in pretty good shape. Changing them made no difference, but I could definitely see how worn bushings would negatively impact shifting.

The transmission fluid that I dumped was like mud. Changing to Swepco made a slightly noticable improvement. I don't think this was due to Swepco entirely. I think replacing the old gunk with any quality proper weight tranny fluid would have had the same effect.

I goofed around with linkage adjustment. I found a few things I liked:
-I moved the forward-back shifing adjustment back further (so I didn't have to lean forward when shiftin 1st and 3rd). This was a nice improvement.
-I adusted side to side to try to get it to slide into 2nd better. Found it was either good or outright wrong (shifted same or couldn't get it into gear (either 1-2 or 5th).

I don't get any grinding on the 1-2 shift, just as you stated... I need to milk it to make it smooth.

Bought the car in October 2002 and have accepted the fact that there is nothing more I can do to make it better. The real power and beauty of the car comes into play from 2nd through 5th.

Gordo