with those interested in the cars from Bradford, England. If you want to post on this forum you need to register. The site uses cookies and uses security certificates when you are logged in.
As headline indicates our Jupiter has stuck in, I believe, 1st gear.
Leaver can be moved up and down, but does not select different gear.
Out and in motion is impossibble, and it is not possible to press "button" to select reverse gear.
Been "in under ( )" bonnet to investigate, and also under car, and only thing I can see is that the most forward rod has worn rubber hose under radiator.
Other than that - any "tips or tricks" greatly appreciated - before we start taking things appart.
I fear problem same as Keith had when he visited Porsgrunn, Norway a few years ago!?!?
Speak to Ib he had the same problem in Scotland last month! Looks like there is a Jowett virus!
Please check it is actually the column and not the box by seeing if the actuator arm and rod are moving or not.
By actuator arm you mean the two rods going across top of gearbox with linkage either end?
If so, the one to the front (closest to radiator) seems stuck. The one to the rear seems free.
Will have to try and phone Ib .... if I find his phone number.
Will send him a PM.
....The Titanic was built by professionals, KonTiki by amatures !!...
What do you mean by 'stuck'?
If the column is broken then you will be able to move the column, but the arm will not move, which is i think what you meant by it moves up and down. Can I assume without the normal feeling of moving the selector forks in the gearbox?
If you cannot move the column in and out or push the button it is because the selector shaft that moves up and down in the gearbox cannot move because it is not 'in the gate' and the box is stuck out of neutral. You could try pulling or pushing on the arm that goes to the shaft coming out of the top of the box until you select neutral (about half way).
The rod that connects to the lever at the side of the box is the one which selects either 1st or 2nd selector fork or 3rd and fourth selector fork or the reverse gate. It is probably the ball bearing mechanism inside the column that translates up and down into radial movement that has broken.
Have a look at TOPIC in the Gallery which should show you how to fix the column.
Some of the pics are blurred but I was taking them as I was doing the job to remember how it came apart. I modified the Javelin bits to suit the Jupiter. The hardest bit is aligning the arms with the shaft when welding the arm on.
Oh dear! I am surprised that you have not been snowed under by advice on this! You have unfortunately joined the fraternity of Javelin and Jupiter owners who have experienced this problem and from my experience this includes just about everyone at some time or other!
Getting stuck in either first gear or less commonly reverse gear, is a hazard I am afraid we all have had to bear! I know that at least two club members had this problem during the Rally at Crieff!
Most times you can get out of the situation by some judicious ‘waggling’ of the gear lever, but take care, the gear change columns are delicate pieces of design and must not be forced.
If this has not cleared the problem, I recommend the next action might be to undo the ball joints on the tops of the two movement arms on the top of the gearbox. Probably the easiest way of doing this is to take off the nuts on the bases of the ball joints, to save ‘popping’ the ball joints.
This will then allow you to see if the column change mechanism has free movement and isolates the problem as either within the gearbox or with the column change mechanism, as mentioned in an earlier post.
From this point, it is either time to repair the column or sort out the gearbox, depending on what you find when you separate the two possible sources of the problem.
In my experience, it has always been the gearbox which has been at fault. If this is what you find, then I would suggest starting by taking off the side plate from the box and examining the selectors and the two sliding bars.
The causes of the box jamming ( if this is what has happened ) can be various, but are usually a combination of wear in the moving parts of the selector mechanism. The rivets in the selector arms work loose and these can be tightened. However, I suspect that you will, by opening the box, be able to get things working again and I recommend that you then check and reset the length of the operating rods upon reassembly by the method given in the workshop manual. This is crucial and must be followed to the letter.
It maybe that by readjustment of the rods, that your problem can be cured, but if the problem is due to wear in the box, then I am afraid that it will reappear again and further reconditioning work on the gearbox or replacement will be needed if you want to avoid it happening again.
Thanks folks for most helpfull guidance in my days of trouble.
As I am stuck at work in Norway, and the Jupiter is in Sweden, I am relying on info from my brother Peter who is in Sweden for the summer (a teacher - boy they have long summer holidays!?!), who now has a question I have been asked to pass on:
Peter has found two complete gearboxes among spare parts for our Javelin.
Can we use one of these just for the summer (condition unknown!), as we would like to use the car some in good weather and rather go for a proper recondition on the original gearbox over the winter, for a better "long-term" soultion and be ready for next summer?
If possible or not - what to look for?
Thanks again!
....The Titanic was built by professionals, KonTiki by amatures !!...
You must first establish whether it is the gearbox or the gearshift column, or indeed whether it is just the adjustment of the actuator rods.
Step 1.
Since you say you can move the gearshift lever up and down through the 1st second gate, check whether the actuator rod is moving and the vertical shaft entering the gearbox is rotating through about 60deg. Just make sure the shaft is turning and not that the arm has worked loose.
If it is doing rotating then the fault is likely to be the gear selector fork in the box. This can easily be changed on the roadside. I have done this on at least two occasions when I was lucky to locate a spare fork closeby. For many years carried a pair as spares.
Step 2.
Sometimes the lock up is due to incorrect adjustment of the up and down movement of the vertical shaft. This is usually freed by disconnecting both arms at the bottom of the column and wiggling in either a random fashion or by reasoned movement from understanding how the box works! The cause is that the 3rd/4th selector forks have moved out of the neutral position preventing the vertical shaft from moving to engage them. The fact you say you cannot move into reverse gate suggest this may not be the case which is why I put my money 1st/2nd fork having broken and preventing return to neutral position.The reverse gate lock might be preventing this though.
You can interchange forks between boxes; but there are some differences so I will not guarantee they will always work. You can weld up the broken fork; although this must be done carefully, as it is a weak point.
Other faults could cause lock up; such as broken washers or synchro balls popping out. But if the fork is not broken, you will know to investigate.
Simply drain oil, take side off box and replace fork. Some jiggling will be needed to locate it properly with the vertical shaft 'finger'. Chcek for any 'bits' in the oil or bottom of box!
Make sure you adjust the detent plungers on the forks.
Last edited by Forumadmin on Sat Jul 12, 2008 12:51 pm, edited 1 time in total.
Your interest in the forum: How to do repairs restoration buy spares have 3 jupters OTB73 runs others under restoration. Have 1947 Austin8 also restored could be for sale
I have just had this problem twice, once in the old gearbox and also in a brand new Bill Lock one .
The lockup is because two gears are selected at once but the actual reason for this is that the rod lengths were wrong.
By removing the gearbox side you can free the box
You know it is right if you can "plunge" the selector arm and put a 4mm drill bit into the hole at the underside of the selector mechanism
Then follow keiths instructions ie use the handbook to refit the rods using the drill bit and fitting the thick rod first. Dont forget to check for wear whilst you have the gearbox side off
)" bonnet to investigate, and also under car, and only thing I can see is that the most forward rod has worn rubber hose under radiator.