sixtwoeight Posted March 24, 2018 Share Posted March 24, 2018 (edited) 1980 Series 3, has been unused for nearly 30 years, I have replaced the rear half chassis, recomissioned brakes and generally tidied it and thought I was home and dry. Drove it for the first time today and when engaging first gear 95% of the time unless you hold the gear lever forward it will half jump out of gear when pulling away leaving a gear on gear grating sound, reverse engages nicely and pulls away no problem. As far as I can tell all other gears seem ok. Any ideas on the problem? Low range works ok. Yellow knob..the external linkage moves but it doesn't seem to positively engage anything, moving from hi to low and back does not release the yellow linkage, so it isn't doing whatever it should internally?? Where do I start with that? Any pointers will be appreciated...oh the engine smokes, a lot....? (Oily, petroly not white). Thanks Edited March 24, 2018 by sixtwoeight Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 24, 2018 Share Posted March 24, 2018 (edited) Re the smoke - is the choke sticking? Carb flooding? Burning oil gives blue smoke, too rich a mixture gives black smoke. 1st gear - could be worn detent springs on the synchro. Yellow knob - is the spring in place? It doesn't really feel if it engages anything normally. Does 4 WD engage OK in low ratio? To test if 4 WD is engaged, park up with the handbrake on, lift a front wheel off the ground and try turning it by hand. If you can't then 4 WD is engaged. Expect some backlash, engage free-wheeling hubs if fitted!! Edited March 24, 2018 by rtbarton Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 24, 2018 Author Share Posted March 24, 2018 Thanks for the reply, Its a brand new carb but I will check the choke, I have a feeling its burning oil, anything I can do? I assume the MOT man wont like it? what sort of a job is it to replace the detent springs? Yellow knob, The spring and the small cover where the lever comes through are missing, maybe I'm jumping the gun a bit if they aren't fitted? Il jack it up tomorrow and see if it engages. Does anyone have any pictures of how the lever should look with the spring etc..? Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 24, 2018 Share Posted March 24, 2018 (edited) If it's oil it could be piston rings or the rubber seals on the valve guides, you need to do a compression test to see which. Remove the rocker cover and do a visual inspection of the valve stems - you might see the O-rings are damaged or missing. It will fail the MOT on excessive smoke. Replacing the synchro detent springs is a gearbox overhaul. It may be worth a look to see if the gear lever selector detents are OK, if the gear lever is dropping out of position it could disengage the gear, but unlikely. When you hold the gear lever in place can you feel it pushing against your hand as it drops out of gear? The spring and that little cover are essential for the correct operation of the yellow knob. The bottom of the spring sits on the little cover, the top goes under the knob itself. IIRC there should be a ferrule that the spring sits on. You can download parts and maintenance manuals from t'web. Edited March 24, 2018 by rtbarton Correction Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 24, 2018 Author Share Posted March 24, 2018 Thanks again, il check the compression. I cannot feel the gear lever pushing back against my hand, it only needs a little pressure to hold it there. Il obtain the missing parts for the 4 wheel drive selection lever before I jump to any more conclusions. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 24, 2018 Share Posted March 24, 2018 Worth mentioning - don't drive it on tarmac if you're not certain it's in 2 WD, you could cause transmission damage. Have a look at the selector detents, you can get at those from outside the gearbox. Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 24, 2018 Author Share Posted March 24, 2018 Only been on a gravel farm track so far. I will have a search for what the selector detents look like as I havnt a clue! Many thanks for your replies. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted March 24, 2018 Share Posted March 24, 2018 Also, try the main shaft nut, access from the PTO hole, if loose can cause gears to pop out. It's a castle nut, so is often tightened by chisel, and is a serious torque setting. Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 8 hours ago, Gazzar said: Also, try the main shaft nut, access from the PTO hole, if loose can cause gears to pop out. It's a castle nut, so is often tightened by chisel, and is a serious torque setting. Thanks gazzar I will try that today. I was searching last night and found a thread which I think was by you, which was rebuilding a series 3box but very annoyingly photobucket has well and truly ruined it. I'm guessing you don't have the time/inclination to rehost the photos? Quote Link to comment Share on other sites More sharing options...
Gazzar Posted March 25, 2018 Share Posted March 25, 2018 Time, mostly. And finding the photos. How much is photo bucket? If it was a tenner a year I'd pay it. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted March 25, 2018 Share Posted March 25, 2018 But I'll be doing another box soon, and the photos will be hosted here. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 25, 2018 Share Posted March 25, 2018 $399 per year. Use Chrome and install photobucket fix extension, problem solved, on desktop at least. Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 A rip off, yeah it's complete pain having to 're host, find photos etc.. No worries The main shaft nut accessed through the pto hole, I have a dowty hydraulic pump so I dont think i can get to that without removing the pump?? . Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 I have taken the top off the gearbox and everything to my untrained eye looks ok with the springs and balls, the springs seem to have good tension. I don't know the correct terminology so apologies for that but here goes. Looking at the middle selector shaft (for first and second), and looking back down into the box the selector fork locates onto a ring with internal teeth, the teeth are not the shape I would have thought, although they do look regular so wondering whether it looks correct or not. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 25, 2018 Share Posted March 25, 2018 The teeth are shaped that way so that the sliding bit can slide into the other bit easily. If they were shaped like conventional gear teeth there's a chance they could engage point to point and not slide in. Once the sliding bit is home it's held in place by detent balls and springs inside the synchro hub and it sounds like these may be weak. Gazzar's point about the mainshaft nut is well worth investigating especially if the pump you mention if fastened to the back of the transfer box (rather than underneath). I suspect there will be a special nut-cum-driving dog to drive the pump (like on an overdrive) and this may not have been tightened properly by whoever fitted the pump, or the locking tab omitted. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 25, 2018 Share Posted March 25, 2018 @sixtwoeight You have a PM Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 2 hours ago, rtbarton said: The teeth are shaped that way so that the sliding bit can slide into the other bit easily. If they were shaped like conventional gear teeth there's a chance they could engage point to point and not slide in. Once the sliding bit is home it's held in place by detent balls and springs inside the synchro hub and it sounds like these may be weak. Gazzar's point about the mainshaft nut is well worth investigating especially if the pump you mention if fastened to the back of the transfer box (rather than underneath). I suspect there will be a special nut-cum-driving dog to drive the pump (like on an overdrive) and this may not have been tightened properly by whoever fitted the pump, or the locking tab omitted. Ok so its not the teeth then, I suppose I was clutching at straws. The pump is indeed on the back, so I will take that off and hope my problem is there rather than internally. Many thanks for your help. 1 hour ago, rtbarton said: @sixtwoeight You have a PM Replied, and thanks. Quote Link to comment Share on other sites More sharing options...
steve b Posted March 25, 2018 Share Posted March 25, 2018 What does the pump run ? a winch or something more exotic? The pump and pto housing will come off as a unit , best to remove the selector box off the top first , then the 6 bolts into the transfer case , if possible leave the hyd. pipes connected as otherwise you will need to drain the tank. When it's off check the needle roller brg. inside the pto. shaft as well as the mainshaft nut cheers Steve b Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 The pump just has a hose out the back to connect whatever you want. So I took the pump off and the control lever and found the castle nut, the locktab was doing it's job and the nut seemed tight - I couldn't get it tighter. But I have noticed on reassembling everything that the selector rod cover has a brass plug with a spring underneath, now should there be a ball bearing between the spring and the selector rod??? I'm not sure whether there never was one or whether it dropped out without me seeing it or there shouldn't be one? . Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 25, 2018 Share Posted March 25, 2018 Yes there should be one - it's the detent for the centre selector rod, you can see the three corresponding slots in the rod. Remove the drain plug and see what drops out and have a good look round the inside of the box with a torch. Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 (edited) 45 minutes ago, rtbarton said: Yes there should be one - it's the detent for the centre selector rod, you can see the three corresponding slots in the rod. Remove the drain plug and see what drops out and have a good look round the inside of the box with a torch. Didn't find the ball but did find these, can you identify them? (obviously one is a tooth) Edited March 25, 2018 by sixtwoeight Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 25, 2018 Share Posted March 25, 2018 Can't help there There's a good chance there may be more you haven't found, looks like a gearbox strip-down, I wouldn't like to risk more damage. Quote Link to comment Share on other sites More sharing options...
steve b Posted March 25, 2018 Share Posted March 25, 2018 The spring plates are the synchro-detent springs for 3rd/4th synchro-hub , I don't recognise the nut though . cheers Steve b Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 25, 2018 Share Posted March 25, 2018 ^^ Ah yes, LR gearboxes have those silly springs instead of balls. I think the nut is the drain plug. Quote Link to comment Share on other sites More sharing options...
sixtwoeight Posted March 25, 2018 Author Share Posted March 25, 2018 Looks like I have no choice but to strip it and learn in the process of doing so. Yes it is the drain plug. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
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