drovers Posted September 13, 2009 Share Posted September 13, 2009 Any help regarding the following would be really appreciated. I have an original Series 1 1951 80 inch. It has a later 2.0ltr engine which I've rebuilt BUT I know very little of gear boxes... Problem with my gear box is as follows:- When driving and when I let off the accelerator. i.e on the over run in 3 or 4th The gear box and/or the transfer box makes a high pitch metalic rattle, bit like a loose panel or a broken internal exhaust baffle. If I apply power it stops. This noise has only started recently but is getting progressivly louder and more regular. Sorry for such a brief description, but is there a common fault that might explain this noise. I've been told that Lay shafts are weak Basically I do not know enough about gear boxes (Probably a good time to get involved now) Any advice appreciated, or the name of someone who knows / can rebuild S1 boxes "nicely" One comment a guy made was to swap it for a SII box, but I'm not sure if there are changes in ratios or fitting issues. Help much appreciated Regards Mike (Worcester/Gloucester Area) Quote Link to comment Share on other sites More sharing options...
paulnb57 Posted September 14, 2009 Share Posted September 14, 2009 Mike Dunno about the noise, but I think the Series gearboxes with the red/yellow knobs are interchagable and just had upgrades through the different models they were fitted to over the years ie synchromesh on first/second in the S3. My S1 88 has Series 3 engine and box on the same engine/gearbox mounts as the originals. I suppose it depends how original you want to keep it......... Paul Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted September 14, 2009 Share Posted September 14, 2009 I would hazard a guess at the following: if it's happening in fourth then it might not be the layshaft, I would look at the mainshaft bearings and possibly check the transfer box for oil. Take the bottom cover off the transfer box and look forwear in the three gears. Once you've eliminated that then it points towards the layshaft, and either the small bearin on the gearbox bellhousing or the phosphor bronze bush which can fracture around the step on the middle of the layshaft. they are not particularly hard, I managed one as a 16yr old and am still using it in my 109" Series 1. I would take a little look on the OLLR.net forum where there's a handy guide on how to rebuild one of these boxes Quote Link to comment Share on other sites More sharing options...
landmannnn Posted September 14, 2009 Share Posted September 14, 2009 Agree with rusty-w, once you have got it out (hard work) these boxes are simple to overhaul. Not expensive if you want a professional to repair it either. Quote Link to comment Share on other sites More sharing options...
Anderzander Posted September 14, 2009 Share Posted September 14, 2009 I have a '51 80" too. You could look on LRSOC.com too - there may be some more gearbox info on there too. Quote Link to comment Share on other sites More sharing options...
sean f Posted September 15, 2009 Share Posted September 15, 2009 Most series gearboxes are interchangeable with a bit of work... BUT the bellhousings aren't. A 2.0 lt side valve engine has a different stud pattern to a 2 1/4 engine. The bellhousings can be unbolted and swapped over from and early S2 box, later boxes used a bigger diameter lay shaft so a bit more fiddling is required. As far as I am aware all series boxes have the same ratio's (except possible origional 1 tonne boxes??). It can all be done but as others have said they are pretty basic boxes, if you are happy to rebuild an engine an old LR gearbox should hold many problems, many old school mechanics would be able to help or offer usefull advice. Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted September 16, 2009 Share Posted September 16, 2009 Start with the basics and make sure it isn't something transfer box related Oil level correct Handbrake not releasing fully Forward output disengaging properly in high ratio (do you have free-wheeling hubs fitted?) Loose bearing adjustment on the rear output shaft If it is the main gearbox then check the following Oil level correct The castellated nut on the rear of the mainshaft, behind the PTO cover, should be tight and not letting the mainshaft float forwards & backwards (has it got or had an overdrive fitted as the nut may have been disturbed?) Does it have a tendancy to jump out of gear on the over run in 2nd or 3rd - suggests a worn bronze bush on the mainshaft Is the stop for reverse gear set correctly More detailed investigation will require the gearbox out of the vehicle. At that stage a rebuild isn't difficult. Most parts are available from decent stockists. Series boxes are very simple to work on, particularly if reference is made to the factory manuals. Attention to detail when setting up clearances, end floats, etc pays dividends. Quote Link to comment Share on other sites More sharing options...
drovers Posted September 17, 2009 Author Share Posted September 17, 2009 Thanks for all the info and advise. The OLLR.net gear box guide really helps to make sense of the old Land Rover WS manual, that assumes you have done it all before! Cheers for the link Rusty-W Checked all I could in situ. Noise still coming from the Box. So the whole lot is now out and starting to spread out across my garage... They come apart nicely....All in all it looks pretty tidy so far...Mind you I havn't put it back together yet! Thanks again for all the advise, when I find the "rattley bit" I'll post a reply!. Cheers Mike Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted September 17, 2009 Share Posted September 17, 2009 they really are wonderful little things. A masterclass in simple engineering basics. Quote Link to comment Share on other sites More sharing options...
secondjeremy Posted September 18, 2009 Share Posted September 18, 2009 If it makes the noise in top its unlikely to be the layshaft as its idling and not part of the drive train (these gearboxes get top by locking the mainshaft so it acts as a solid shaft) I'd look at the transfer box intermediate shaft and bearings which wear badly on these boxes. In fact you can change it without removing the gearbox. To check take off the top cover of the transfer box and with a back wheel jacked up and the main box in gear (2wd - so transfer box in high) push and pull on the handbrake drum. If you can see the front end of the intermediate gear move around - you've found your problem. While you've got the cover off see if the strange looking nut of the back of the main gearbox is tight. It should be 100lb ft. On just about every box I've dismantled its loose. If its severely loose the mainshaft will move backwards and forwards but I don't think this is your problem as it would probably jump out of gear rather than make the noises you describe and the lever would tend to feel as though it was moving in your hand as you changed from drive to overrun. To replace the intermediate shaft - remove the handbrake backplate and the transfer box bottom cover. The end of the shaft can be seen locked by a bolt and plate. Undo the bolt and lever the shaft out, catching the gear as it falls out. In fact you may have to turn the transmission to get it out. The bearings will probably need replacing as well and the thrust washers should be checked. The noise is probably there in second - its just you don't notice it or decelerate much in second. Later boxes have a much larger shaft which seems much more robust. Quote Link to comment Share on other sites More sharing options...
drovers Posted October 1, 2009 Author Share Posted October 1, 2009 Thanks for all the advise. Transmission all back in now and no rattles and is fine. Nasty bits where "transfer box intermediate shaft and bearings which wear badly on these boxes" "the phosphor bronze bush which can fracture around the step on the middle of the layshaft" Thanks for all your advise and encouragemnt Replaced loads of other bits on the way, As per your comments, there nice to work on and I won't shy away from a early series box again!! Mike P.S doesn't leak any oil.....yet! Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted October 1, 2009 Share Posted October 1, 2009 P.S doesn't leak any oil.....yet! Have you put any in? BTW: It isn't a leak, merely marking its territory Quote Link to comment Share on other sites More sharing options...
sean f Posted October 1, 2009 Share Posted October 1, 2009 P.S doesn't leak any oil.....yet! Are you sure there's any in it!!. Normally when it stops leaking oil you need to put more in. Quote Link to comment Share on other sites More sharing options...
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