| Author |
 Topic  |
|
kimber
United Kingdom
1529 Posts |
 Posted - 11/04/2011 : 17:54:12
|
quote:
Originally posted by trainsimple
Ok, so I'm getting the upshifts. Just a slight noise in 2nd, nothing in 3rd or 4th. I can't downshift into 2nd to save my life. This could pose a problem when driving in more traffic.
Almost certainly either insufficient or excessive revs when in the neutral phase. Takes some practice. Easier done at slower speeds to learn the technique first. Its all about timing and instinctively knowing what are the appropriate revs for speed. Only comes with practice and by experimentation. Those gearboxes are pretty tough. If it doesn't want to go into gear, don't force it but repeat the ddc process using different revs (more/less) until you 'hit the spot'. Find a quiet road somewhere and experiment. |
 |
|
|
Robin Macmillan
United Kingdom
415 Posts |
Posted - 11/04/2011 : 20:54:05
|
| you need to rev the engine more and change while the engine is going fast enough to match the rev/min that you will be in at that road speed |
|
|
|
bahnisch
Australia
674 Posts |
Posted - 12/04/2011 : 01:58:04
|
| I am convinced that preselector gearboxes were adopted to overcome the difficulties of changing gears (particularly in competition) with crash-type gearboxes! This, to some extent, coincided with road circuits coming into vogue. At places like Brooklands it was possible to get into top gear and just hang on but on road circuits gear changing became much more necessary. Preselector gearboxes must have been a great boon but robbed engine power, quite critical in small cars such as MG's! |
|
|
|
Bob Stringfield
United Kingdom
854 Posts |
Posted - 12/04/2011 : 09:31:05
|
My late mother, a fast and effective driver of any car, both pre-war and post-war, taught me to drive a 'crash' 'box.
She held that both self-changing pre-selector and synchromesh 'boxes were undesirable, in that they enabled people with little mechanical sense to drive a car so equipped.
It is arguable that present-day parking and traffic sensors facilitate driving by people with no sense of distance.
Automatic transmission by Sensaud and by Hayes existed in the 'thirties but were both unsuccessful owing to problems with metallurgy and available oils.
The thing about a 'crash' 'box is that even experienced drivers get it wrong every so often which keeps us alert, not that nodding off is often an option while driving a MMM.
|
|
|
|
Colin McLachlan
United Kingdom
991 Posts |
Posted - 12/04/2011 : 10:08:22
|
You're getting there - just keep practising. I find second from third requires more revs than you expect, initially. After 22 years driving my PA I get about one change in three perfect, the other two are acceptable :-). Every so often I get it badly wrong, but I'm told it doesn't sound so bad from outside the car. The next challenge is second to first, while braking hard for a hairpin bend! That requires a so-called "heel & toe" technique (which doesn't actually involve heels and toes!), but you don't need to worry about that now. Don't worry, everyone struggles initially, but you'll get the hang of it in the end. In my experience these gearboxes are nearly bulletproof, so just keep on crunching.
Colin
PA 0613 - MG3242 |
|
|
|
MaGic_GV
United Kingdom
868 Posts |
Posted - 12/04/2011 : 11:32:41
|
As an illustration of how robust the gears are, here is a pic of the gear cluster (left in pic) that was in my car when first acquired (late '60s) It made a dreadfull piercing noise when in second... It didn't get noticably worse as I crunched my way through its first year or so in my hands. Cluster on right illustrates more acceptable degree of wear...
For what its worth, the car seems to have been continually taxed up until my ownership, when it became somewhat less regular, so it had done a fair few miles...
Graham |
|
|
|
trainsimple
USA
8 Posts |
Posted - 21/04/2011 : 21:44:19
|
Ok, I got some nice weather today and started practicing. I was able to downshift into 2nd twice, so that's a start. Don't know how good I'll be in more traffic, so I need more practice.
A couple of questions. It was only 52(F) degrees out today, the car temp was in the 80 - 100 (C) range. Does that sound right? Granted I was going up a few hills again and again, it rarely got it above 30mph ... I'm just concerned when it's 85(f) this thing may boil over, or no, should I be ok?
Also, I think I can feel the body flex every now and then ... is that normal? And it gives a pretty bumpy ride on less than perfect roads, which I'm ok with, I just want to know if it's normal and ok for the car.
Finally, I have to go down a fairly steep hill to get out of my house. I really have to pull hard on the hand brake to stop. Is that ok? I know it's better than smashing into someone, but again is this ok for the car to do on a fairly regular basis?
Thanks again! |
Edited by - trainsimple on 21/04/2011 21:45:41 |
|
|
|
bahnisch
Australia
674 Posts |
Posted - 22/04/2011 : 00:50:29
|
| I sympathise with you, old cars can be a bit of a headache on the road, alertness and anticipation are absolutely paramount in today's traffic! Body/chassis flexing is par for the course, "ladder" chassis design can never be torsionally rigid. As for brakes, I remember relining my M-type some time back and the brakes were hopeless (nowhere near as good as they were pre-relining!) until I got the adjustments even. I recommend carefully adjusting the individual wheels at overhaul and then only using the wing nut under the driver's floor. That way even application is ultimately achieved and maintained although I doubt whether effectiveness will ever rival modern cars. My PA used to run at 95C on most days but I cannot remember it boiling. If your radiator core is clean it is probably OK. I have modern cores in both of my prewar MG's (as well as in a couple of "veteran" cars that I have), my F-type (surprisingly) sits on about 80F and never goes above 90F. |
|
|
|
DickMorbey
United Kingdom
3677 Posts |
Posted - 22/04/2011 : 06:43:07
|
Hello Matt,
Regarding the brakes, Barry is quite correct about getting th adjustment correct. Another thing to look out for is to ensure that the angle between the brake cables and their operating levers at the four brake back plates is less than 90 degrees. Anything more denotes wear or a lack of adjustment and will make a huge difference in braking effort. Don't forget that as the handbrake is on the same system as the footbrake, you can in extremis give some assistance to the foot pedal by hauling on the handbrake!
Best wishes
Dick |
|
|
|
bahnisch
Australia
674 Posts |
Posted - 23/04/2011 : 01:34:53
|
| Dick has raised another couple of critical issues. I have been amazed at the number of restored prewar MG's with "over the centre" drum brake levers. From memory left and right are interchangeable but if wrongly fitted the levers adopt "backward" angles. This is difficult to explain but factory photos of the front brakes, for example, show the cable attachment end of the lever very close to the front of the backing plate (if not forward of it!). I have never driven a car with the levers "wrongly" angled so I do not know if, or how much, difference it makes. All I can say is that it seems everything must be 100% for optimum effectiveness. In my P-type days (my first car, well over 50 years ago!) I often had to resort to pulling like hell on the handbrake! Much more leverage than the little brake pedal! |
|
|
|
Dow
United Kingdom
490 Posts |
Posted - 23/04/2011 : 05:47:18
|
I used to have trouble with noisy gear changes on my J but once you get your "ear in" to the revs required for the next gear, 95% of the time you get it right and it is a joy to drive.
The only problem now is getting in and out in order to drive it. Has anyone else noticed that our cars shrink over the winter ?
Regards
David D |
Edited by - Dow on 23/04/2011 05:48:08 |
|
|
|
Oz34
United Kingdom
2539 Posts |
Posted - 23/04/2011 : 09:30:51
|
Barry,
I think what you're trying to say is that the cables should be pulling the lever TOWARDs a 90 degree angle at which point there is maximum mechanical advantage. If, going back to Dick's post, the angle between cable & lever at rest is 90 or greater, the cables wiil be pulling AWAY from this 90 dgree point with less & less effectiveness the further they pull.
Dave |
|
|
|
bahnisch
Australia
674 Posts |
Posted - 23/04/2011 : 11:18:53
|
| Dave, You are quite right! There is some principle of physics (levers?) involved but it is too long ago for me to remember! I have wondered how drivers get on with levers in what I would call the "over-the-centre" position. As a matter of interest my M-type brakes are quite good (light car, etc.) but my F-type (12" drums) not as inspiring! Perhaps the linings are still bedding in. |
|
|
|
MGB
Netherlands
114 Posts |
Posted - 26/04/2011 : 17:50:06
|
Also regarding driving a J2:
How many miles/kilometres can I drive with a full tank on a motorway or in the city?
Also hints on how to take as much luggage as possible?
Regards,
Maurice
Still looking for the perfect J2, PA, PB or K3 |
|
|
|
Topic |
|
Forum Locked
Topic Locked
