Hello, The drive pinion on my Ransomes Marquis is broken and I want to replace it. However I don't succeed in taking off the broken one. Can somebody help me? Thank you,
Last edited by CyberJack; 18/07/1602:29 AM. Reason: Topic heading.
Hi keith2001, and a warm welcome to the forum. It's great to have you aboard. I can't help with the pinion removal, but have found a manual for you.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl
Keith, it is a bit of a mystery so far, and I haven't found anything in the parts list which Deejay found, to clarify it. Can you post some pictures showing an axial view of the end of the shaft, from close-up, and various lateral views of the damaged sprocket in various rotational positions please? Also, your picture shows that the end of the shaft has either been center-drilled, or has an internal thread - can you tell us which it is?
I found out that it was screwed. I got it off and also from my spare shaft. But as you can see on the picture there is one "ball" missing on the bearing. Is that a problem? If so, how can I take the bearing from my spare shaft? Thank you.
The bearing isn't usable with a ball missing. We need the dimensions of the bearing: the inside (or shaft) diameter, the outside diameter, and the width. If your bearing is the same as on the Model 51, those dimensions will be 17x47x22.2 mm. If they are the same, you can replace it with a standard ballrace called a 5303. However you might do better to use a sealed bearing instead of an open one, so that lubrication is assured. Then it would be called a 5303-2RS. Just look that up on the internet and you'll find several vendors available.
To remove the bearing, the usual method is to remove the sprocket, then use a gear puller to pull the bearing off the shaft.
Thank you. I did find the bearing 1203 and replaced both. It works.
But now I have another problem: There's a knocking noise coming from the flywheel. It seems that the drive shaft from the engine isn't fixed for 100% to the flywheel. if you turn the flywheel for a few millimetre, the drive shaft isn't turning. Screw nr 3 on the flywheel seems not to be tightened for 100%, when i tighten the screw there no knocking noise anymore for 1 minute, then it comes back. Changing the screw nr 3 and nr 2 doesn't help. How can I fix this? Thank you.
The engine's output shaft, or PTO (power take-off), has a keyway, and the clutch has a matching one. There should be a tight-fitting key in that keyway, so that the engine can drive the clutch. There are two grub-screws in the clutch body, numbers 2 & 3 in your picture. They are at right-angles to each other. One of them bears on the top of the key, to keep it from moving axially along the shaft, and the other grub-screw bears on the shaft, to keep the whole clutch from moving axially along it. The symptom you describe (shaft will rotate a few degrees in the clutch, but this stops temporarily if you tighten the grub screws) means that either the key is missing, or the shaft and/or clutch is damaged so that the key is now loose-fitting.
You need to remove the engine from the mower, and inspect the PTO, the key, and the keyway in the clutch. If you are lucky, the previous tenant lost the key and has been trying to drive the clutch with the grub-screw by screwing it down into the keyway. If that is all that is wrong you can fix it by cleaning up the mess with a file, then fitting a key. If the correct-sized key is there but has come loose through wear, the problem is more serious. Please post some pictures of the parts after you remove the engine, so we can see whether there is no key, an undersized key, or a damaged key and shaft. Once we know that, we can talk about putting it right.
The mark on the top of the key has been made by the grub-screw. This is normal and appropriate: the screw has to bite into the key to securely keep it from sliding longitudinally in service. However the key should be a firm fit, in both keyways - the external one in the shaft, and the internal one in the clutch bore. If it is a slack fit laterally, it will not work properly.
The engine appears to be a Briggs and Stratton, which is built to inch dimensions, not metric. A 3/16" key would be 4.76 mm square, not 4.4 mm. I expect this would apply equally to the Ransome mower, which I believe would have been made in Britain some years ago, presumably using inch dimensions. If you actually have a 4.4 mm square key, it is probably not the original one, and not of the required size.
I first tried to replace the key. As I live in Belgium they have no stock of imperial keys only metric, so I bought a 5 x 5mm oversized and filed until it fitted on the crankshaft. Stange,it did not fit on the flywheel, so I filed half of the key to fit the flywheel. Strange that it is not a square size. The key fits now in both, but is asymmetric.
The engine doesn't make a knocking noise anymore on a first test. As it rains today I hope to cut the grass tomorrow, let's hope it stays ok. I will let you know in a few days if everything is working. Thank you very much for your help.
Hi Keith, glad to see you got a good outcome, and good luck with the testing.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl
Stepped keys are a standard engineering solution to mismatched parts, Keith, so what you have done is quite legitimate. Occasionally they are made stepped both sides, but it is far more common to only have a step on one side, as you have done. However it should not have been necessary: I think it unlikely that the mower had a stepped key when it left the factory. Most likely it had some kind of British engine originally, and the Briggs and Stratton was fitted as a replacement. Provided you have achieved a good firm fit in both keyways, it should now be effective and reliable for as long as the mower lasts.