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  #1  
Old 19-08-14, 09:33
Ken Hughes's Avatar
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Question crash gear box changing gear

Hi people,Im having trouble changing back thru the gears from top gear.
I have to almost stop to select third or second gear,im pretty sure its technique and ive tried the three finger shift that i remember from an old army instructional film that i had once viewed .
I seem to do a very good impersonation of Jiff polishing gears,any thoughts,thanks in advance.
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  #2  
Old 19-08-14, 10:24
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Default Gear changing

You should see the video with Tony in the cab 12!

It's a matter of practice - double declutching takes a while to get used to and easier in a Chev than a Ford. It's a matter of not changing down when you're still too fast... back off throttle, disengage clutch, shift to neutral, give it a rev as you engage clutch, then disengage and go to lower gear. You need to go to the lower gear fairly smartly as blipping the throttle synchronises the gears and if you hesitate they slow down again causing a crunch.

Once you get the hang of it you can try doing it without the clutch. Very satisfying when they just snick in beautifully.

Changing up is similar but without blipping the throttle, and you can take it a bit more slowly - keep at it - the gearbox is strong!
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  #3  
Old 19-08-14, 11:13
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As Keith said it is all practice, you will eventually develop an ear for the right revs for the changes. Once you get the hang of it you wont forget, I learnt to drive a crash box when I was seven, by the time I got my licence we had updated to synchro boxes in the truck but 30 years later when I got the blitz it all came back in a couple of miles. Down changing while going up hill is easier to master than when you are going down hill. Enjoy a long drive and have fun learning.
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  #4  
Old 19-08-14, 13:51
jack neville jack neville is offline
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I think the biggest mistake is thinking you have to change after you have revved the engine out and built up speed as we do in modern vehicles. Do all the changes at low speed. I was always told the side whackers like to lug down low. Funny how my son Jake at 27 is better at it than me. But then again he virtually learnt to drive in these things. We've both polished our fair share of gears though.
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  #5  
Old 19-08-14, 14:04
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Gearing down is easier without using the clutch. Let off the gas a bit and pull it out of high. Then rev it up a bit as you put it into 3rd. When the revs are right it slips right in. It's all a matter of matching the engine and tranny speed.
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  #6  
Old 19-08-14, 14:53
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Default Sounds like a GoPro Film Challenge

Hi Ken

First off don't think you are going to damage the transmission with those little crunches. Because you are not likely to hurt these transmissions unless you really grind them or use a lot of force. If you are having problems shifting lets check a couple of things:

  • Does your clutch fully disengage?
  • With the transmission warm and clutch disengaged can you shift through the gears without excessive force on the lever?

Everybody is correct it is just a matter of practice the more you shift the better and smoother you will get.

Sounds like we need GoPro Film Challenge, for those of you with a GoPro or other small video camera that you can mount to show the gear shift and the peddles lets see who can come up with a good video. Think we should have couple of goals:

  • Best technical video in that it most clearly shows the feet and hands
  • Best actual shifting how smoothly can you shift up through the gears and back down. (no editing the sound tracks)
Cheers Phil
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  #7  
Old 20-08-14, 01:00
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Default GoPro

What a great idea Phil!

Just to add another point about things which make changing difficult, particularly when changing up is a weak throttle return spring. You really want to have the revs die right down when lifting the clutch pedal in neutral on changing up.

Quote:
Originally Posted by Phil Waterman View Post
Hi Ken

First off don't think you are going to damage the transmission with those little crunches. Because you are not likely to hurt these transmissions unless you really grind them or use a lot of force. If you are having problems shifting lets check a couple of things:

  • Does your clutch fully disengage?
  • With the transmission warm and clutch disengaged can you shift through the gears without excessive force on the lever?

Everybody is correct it is just a matter of practice the more you shift the better and smoother you will get.

Sounds like we need GoPro Film Challenge, for those of you with a GoPro or other small video camera that you can mount to show the gear shift and the peddles lets see who can come up with a good video. Think we should have couple of goals:

  • Best technical video in that it most clearly shows the feet and hands
  • Best actual shifting how smoothly can you shift up through the gears and back down. (no editing the sound tracks)
Cheers Phil
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  #8  
Old 21-08-14, 08:57
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Thumbs up

Hi Guys,thanks for the info,practice is the answer by the looks of it.
The ford has a good return spring on the throttle so the revs do drop of quickly.
The clutch etc is all new and adjusted correctly,i think im to heavy on the throttle when doubling the clutch.
A while back a friend went with me to give me some pointers and said that i would be ok with practice ,but sadly he has since passed away,i have driven his Dodge command car on occasion and not had to many problems with it.
I look forward to some videos on the subject,it would be interesting to say the least.
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  #9  
Old 21-08-14, 09:31
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Kenny, Same gearbox ratios in the Command car as your Ford truck. only the diff ratios are different.
In fact, many of the gearbox internals will inter change.
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  #10  
Old 25-08-14, 09:12
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yes Lynn, the internals are the same,the late Murray Obens Dodge command car was the one i drove to warbirds at Wanaka,must around 4 years ago with a friend sharing the driving .
Murray said his gear box parts were pretty much Ford.
Yes also gear changes are better once the truck trans has warmed up,i drove it over to work on saturday to fit some new tires to it and noticed it got better as i went.
Thanks for all your imput guys cheers.
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  #11  
Old 25-08-14, 11:04
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Ken, I never met Murray, but had a couple of phone conversations with him some years back. A gentleman and helpful chap. I wish I'd had the honour of meeting him.
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  #12  
Old 29-08-14, 10:22
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Yes Lynn,a great loss as a friend and a very active club member,i owe him a lot for the help he gave me over the years.
Most of his collection will be sold at some later date.
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  #13  
Old 30-08-14, 00:30
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Default Gday Ken

I must confess to not posting as I was hoping for another (and more embarassing) bit of film of someone doing worse gear changes than your's truly.

Alas it has not eventuated, or in any case, it may not have been humanly possible.

Well done on getting it sorted..

Do you have a picture you could post of your throttle return spring setup?

Bit rude I know, having not helped, then asking for it... but I am from West Island.
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  #14  
Old 30-08-14, 23:14
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Default Got some video to post

Hi Tony

I had some fun this week doing road test on my Pattern 12, with the Go Pro mounted. Been trying to get camera angle right to show clutch, gas, pedal, lever and view of the road.

Now I'm trying to figure how to down load the video to YouTub.

One thing is very certain as a cause of gear crunch, any clutch drag at all. My Pat 12 Chevy had a problem in that the surface of the clutch was sticky and that really screwed the shifts unless you got a perfect match on speeds. With a new really clean clutch it shifts like a dream. Only real crunches are going down from 3rd to 2nd.

Will work on the video.

Cheers Phil
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  #15  
Old 31-08-14, 08:48
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Have had quite a lot of practice lately, as my F15A is back on the road after many years in storage. I did not have any previous experience driving non-synchromesh gearboxes before driving my CMP. Apart from the theory I have had very little guidance, so it's just a matter of practice.

What I learned till now is that the engine idle settings have to be right, too high and you'll grind when shifting. Also, take your time between shifts. If you try to shift too quickly, you'll grind the gears. Shifting up can be learned quickly, shifting down is more difficult. Here I find that the engine revs need to be much lower than expected. This is all due to being accustomed to synchromesh gearboxes which can shift very quickly of course.

Another point is that I find the pedal setup ideal, with the throttle pedal in the middle and lower than the brake pedal, it is very easy to use your heel to blip the throttle during downshift.

I have been reading this thread with great interest as there are some very good pointers which I will try out. Also I am looking out for the videos Phil has made.

H.
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  #16  
Old 31-08-14, 09:23
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Hi Tony,my extra throttle return spring is two bits of wire tied to carb throttle leaver and the other one mounted to the oil filler tube with a small spring in between,not very authentic i know but it works,and i think i have a heavy foot on the throttle and am in too much of a hurry when changing gears,so i need to improve MY skills a lot,well this is what i have arrived at after reading all the good advice from everyone,thanks guys.
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  #17  
Old 31-08-14, 10:56
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Default Hi Tech

Quote:
Originally Posted by Ken Hughes View Post
Hi Tony,my extra throttle return spring is two bits of wire tied to carb throttle leaver and the other one mounted to the oil filler tube with a small spring in between,not very authentic i know but it works,and i think i have a heavy foot on the throttle and am in too much of a hurry when changing gears,so i need to improve MY skills a lot,well this is what i have arrived at after reading all the good advice from everyone,thanks guys.
Ken, great to hear your throttle return set is the same as mine
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