Ok, don't fry me to hard here Bin driving standards all my life. All Japanese cars sorry to say. Last one I had was a 5 speed Accord coup. When I would thrash it around I would down shift on the fly while blipping the throttle to match the RPM's. Worked awesome, and the Accord loved it. Never a grind or a complaint noted. Now, ( this is my first vintage 4 speed car ) when I tried this with the Vette, the Jo racer move did not go to smooth. The tranny complained, the engine complained, the whole thing was complaining like a union shop on a long weekend. So I did not do it again. You Tube shows guy's just down shifting with out the blip and letting the RPM catch up. Very crude IMO. Can you down shift these cars smoothly with the blip, or just drop the clutch in a lower gear and forgetabout it. Are the Vettes tough enough to handle some shenanigans? Looking at that rear end I am skeptical about that. Just don't want to brake something out of sheer stupidity. Cheers.

 

My guess is your transmission is due for a rebuild.
Think about it the parts are 35 -40 years old and the bearings / brass synchronizer / possibly the gears them self are wore out.

 

Are you saying you don't use the clutch pedal when you down shift? When I down shift my 79 4 speed I give it a blip, but I also step on the clutch when I change gears. I can shift up and down my Colorado 5 speed with out the clutch pedal, but i don't do it very often. Just match engine speed to road speed and it goes right in. Never tried it in the Vette though.

 

I down shifted my 72 with a mild 454 and my 66 with a hotter 327 sometimes doing this "blip" never an issue for me, but I also down shift my vw trike and the shifter on it sticks out the left side,

I splattered 2 sticks in my 72 I would assume from acting like the 17 yo dork I was, I liked to have it in first or second and in a combo of blipping and clutching I could do wheel chirps, lol really sounds stupid in hindsite,
The first time I busted it I had it fixed, the shop that fixed it took blame for the second time and I was all careful with it after that...

I beat the heck out of the 66 never broke anything on it....

 

I always match engine revs with downshifting never had a problem with my Corvette or Camaro.

 

When I down shift from say 4th to 3rd, the through seems to be very slow. I do have the clutch in, do the blip but the stick seems to take for ever to come out of 4th and engage 3rd. By that time the RPM has fallen again and I am missing the turn in point. There is no grinding, just slow shifter movement. Cant seem to do the switch quickly. So I was wondering what most do, the blip or down shift and let the clutch out to match the rpms. ( my tranny was rebuilt a few years ago, have the invoice of the work. Cost the PO $2500. ) I guess I have to practice it a bit more. Just not sure how robust the Vette is? Hope they are somewhat tough.

 

Muncie transmissions are tough, you can break them if you try hard enough, but in everyday normal use they hold up well. Take your time shifting until you get to know your car a little better and make sure the linkages and clutch are adjusted correctly.

A Honda Accord it's not...

 

I don't blip the throttle until I have shifted from 4th to 3rd, or whatever lower gear I want to go to. That's what synchros are for the throttle blip is to match the engine speed with the higher revs needed to make a smooth shift.

Now in my truck I don't have synchros so I have to put it in neutral and blip the throttle to down shift and to up shift you have to pull it out of gear wait a second or so and put it in the next gear.

 

These transmissions can handle it. (If, that is, there is nothing mechanically wrong that needs fixing.)

As pointed out above, you don't need to double clutch or rev-match since they are synchroed, but feel free to do so if you want to. They will be noisier and make more vibrations than your honda transmissions did, however.

For something different, try shifting slower than you're used to. I had a flight instructor tell me: "you gotta be smooth to be fast, you gotta start slow to get smooth."

Man he was absolutely right!

 

Smooth and easy definitely wins the race. Personally, I heel-toe the throttle while simultaneously double clutching my downshifts. It gets easy with practice. Very racy and helps everything get to the same speed.

My car, I have found, is reluctant to go into a gear while downshifting if the revs are way off. This happens most during slow putters around the neighborhood when I am trying not to wake everyone up with my loud exhaust.

I have found that the car is MUCH happier with a smooth road race upshift...Danny Popp style...than a boy racer slam shift.

Hope this helps answer your question.

 

Is your clutch adjusted correctly and fully disengaged when shifting? That makes a big difference. Lots more compression at work than "a 5 speed Accord" and if the clutch is dragging it's a whole lot harder to move from one gear to the next. And that is saying nothing about 40 year old synchros.

 

Still not sure if you're talking about getting into the right gear quick enough or how things behave after the fact...?

You downshift to keep the engine in the proper RPM range, for a given vehicle speed, in a given gear. In street driving it's nice to allow the engine to 'brake' and decel the vehicle whereas if racing you should be accelerating, then braking, then accelerating (no coasting). So for a given engine, each gear will have a happy vehicle speed. I think you already knew this, but if not, google 'slipper clutch' and read up on its benefits.

If you're having trouble downshifting quick enough, I'd ask if you're having trouble disengaging the clutch or with the actual gear changing. If the former, I'd look at z-bar/clutch linkage; maybe even clutch pedal movement. If it's the latter, you might have synchro or actual trans issues (I'd think synchros first).

Matching the engine speed by 'blipping' the throttle simply gets the crank speed closer the trans input shaft speed (for a given gear at a given vehicle speed). If matched, no clutch is needed, but it's likely not the best habit regarding gear engagement.

Modern cars will have hydraulic throwout bearings that eliminate all clutch linkage found in your car and will likely have improved shifter linkage. The condition of your trans is a possible factor as well.

 

This is an interesting discussion about driving technique in general. I wish folks could post quality videos on the subject. I'm not following all the lingo and descriptions.

I would guess that many on here would love to learn more about driving/shifting techniques. I know how I drive but would have a hard time describing it. I like downshifting for the reason above i.e. To decelerate the car and not use brakes as much.

Or perhaps I'm all wet....

 

I rev match my m-21 car with no problems. Keep in mind that internals of muncie have alot more mass that those of a modern FWD car so you do need the give the synchros a bit more time to speed up/slow down all the parts.

BTW I typically rev match but leave the heel-toe stuff for very spirited driving. I was surprised at how decent the pedal placement/travel was for a 40+ year old car. By no means Miata good but all in all alot better than expected.

 

This is exactly what seems to happen. " not getting into the right gear quick enough" So I am bombing towards a nice highway on ramp in 4th gear doing about 60MPH In goes the clutch, as I am pushing up on the shifter I do the blip but it does not go in to 3rd!! I am meeting resistance, so I don't push to hard on the shifter. By this time I am in to the corner already coasting in neutral. So I try again blip the throttle and try 3rd, still resistance, now I am slowed right down to like 40 and need to catch 2nd. With a bit of complaining I get second gear and off I go swearing and frustrated. Mostly saying WTF!!!!! I have bin doing this on my bikes and standard cars for years. I got that technique figured out. It's like the tranny is lazy or something. Other than this the tranny works very nice, clutch works very nice. Shifts very smoothly all the time. I tried doing this maybe 2 or 3 times then gave up. I guess I will practice a bit mote to see if this car need a little trick to get it going.
The 454 blips so nice though, just makes the best sound ever. Love the big blocks.

 

I am not an expert nor can I explain technique the way some can but it seems to me that the clutch isn't fully disingaging. I would start with the basics, making sure I have proper adjustment. .. doesn't cost any $$$
Mine down shifts very smoothly.
Regrads,
Pete

 

Does the same problem happen when downshifting from 3rd to 2nd, 2nd to 1st? If so, your clutch is not disengaging completely. If not, there is a problem with the trans. Throttle blipping and rev matching have nothing to do with getting the trans from one gear to the other.

 

I suspect that your shift linkage rods and bushings are nearly shot. That puts a lot of slop in the system and shifting becomes more ragged.

The rod ends (inside the bushings) wear once the bushings are shot. So, repair usually requires new bushings and new rods.

Pretty easy fix, though. Your shifting will likely improve in both directions.

 

Is your shifter set on the short or the long throw?

In the long throw, the gears can effortlessly be engaged on my m20. In the short throw, you have to push a bit harder on the shifter. Short throw setting is a nicer shift in my opinion.

 

First do you have OEM shifter or aftermarket? If OEM as mentioned what is the throw position? If OEM or after market was it been rebuilt when transmission was rebuilt? I have abused Muncies since the early 70's and they just keep giving. I rarely shift by "rev matching" unless shifting without disengaging the clutch.

A couple of things, I have noticed in those years that people think they have a transmission problem may have either a clutch adjustment or shifter adjustment issue.

Been abusing these Muncies forever and shifting up or down is never an issue. Just shift and let go!

John