I rebuilt the Superwinch (Fairey type) overdrive this afternoon. I had rebuilt it 18 months ago, but dispite initial smooth running a problem quickly became apparent. The selector lever gained a serious vibration on over-run, accompanied soon by a tooth-meshing noise. The OD was removed instantly and awaited investigation in the garage.
The end float on the mainshaft and output gear were excessive (approx 1mm). Stripping and rebuilding indicated no missing or damaged parts, but the float persisted. Shimming the rear end of the mainshaft eliminated the mainshaft end float, but had no effect on the output gear. The output gear is retained by the mainshaft, so this pointed towards the thrust bearing between the two. It transpired that the new bearing supplied for the original rebuild had one incorrect thrust washer – one should be approx 1mm thick, while the other is nearly 3mm thick (with a bevel on the inner circumference to allow for the mainshaft’s radiussed section change). The bearing had been supplied with 2 thin washers. This has now been rectified, and the OD is now fully refurbished and ready for fitting. Another space in the garage cleared and (potentially expensive) job ticked off the list! Very pleased about it too, as I was wary of shelling out another £7-800 for a Roverdrive.
Nick,
Very cool site.
I read with interest your entry where you describe the rebuild of your Superwinch OD. I also have one of these items fitted to my 109″ SIII.
Could you advise on where you sourced a service kit for it.
Although I can perform most jobs on my landy I have yet to tackle a gearbox related problem. Would I need any special tools, presses etc.
Your advice would be greatlt received.
Regards
Andy Withers
Hi Andy,
Thanks for your compliment on the site.
I got most of the parts for the OD from http://www.legs.co.uk , who also sell gearbox parts and kits. They don’t carry a full stock of OD parts, most notably the needle thrust bearings and the smaller shims for the rear end of the main shaft. Superwinch still have some spare parts in their Tavistock (Devon) UK headquarters and were able to help with the shims. It’s unlikely that you’d need to replace the needle bearings, so these two sources should suffice. One tip on the OD work – to get the main shaft out (and back in) the layshaft must be free-floating, so remove the layshaft cluster’s shaft from the casing before trying to remove the mainshaft. On reassembly, fit the layshaft cluster, complete with all shims and bearings, to the casing but do not insert the shaft until after fitting the main shaft. This makes lining up all the layshaft shims and bearings a little tricky, but it’s the only way to do it.
The tools you’ll need are a set of spanners, a rubber or copper mallet, a wooden drift (for tapping in the bearings), some circlip pliers and an allen key for the selector shaft detent retaining screws. If you need to replace the clutch sleeve on the gearbox’s mainshaft (the collar with the fine splines), you’ll need a screwdriver to un-bend the lockwasher and a suitable drift (a chisel works well) to loosen and later tighten the special nut on that shaft. The lock washer should be replaced with a new one. There is a special version for ODs which has slightly shorter locking tabs than the original – the standard washer’s legs are too long and foul the inside of the OD mainshaft on refitting, but these can be filled down 1mm to fit.
Good luck,