88V8 Posted December 10, 2007 Report Share Posted December 10, 2007 I'm sure this is a daft question, but the shop manual is no help, and I have searched on the forum but I keep getting side-tracked into other interesting topics, there's enough knowledge here to restart the Triumph factory... How do I drain the back axle oil? Surely I don't have to disassemble the diff mount and remove the rear cover - do I ? No particular reason for draining - just doing a full fluid change. Ivor Quote Link to post Share on other sites
foster461 Posted December 10, 2007 Report Share Posted December 10, 2007 I'm sure this is a daft question, but the shop manual is no help, and I have searched on the forum but I keep getting side-tracked into other interesting topics, there's enough knowledge here to restart the Triumph factory... How do I drain the back axle oil? Surely I don't have to disassemble the diff mount and remove the rear cover - do I ? No particular reason for draining - just doing a full fluid change. Ivor Hee hee. Ivor, for reasons I cannot explain they decided to eliminate the rear axle drain plug and the only way to drain it is to remove the rear cover. Many of us tap the case and fit a drain plug. Of course many of them leak through the pinion seal and the axle seals so they naturally drain without the need for a plug.. Stan Quote Link to post Share on other sites
88V8 Posted December 10, 2007 Author Report Share Posted December 10, 2007 Hee hee. Ivor, for reasons I cannot explain they decided to eliminate the rear axle drain plug and the only way to drain it is to remove the rear cover. Many of us tap the case and fit a drain plug.Of course many of them leak through the pinion seal and the axle seals so they naturally drain without the need for a plug.. Stan Arrrrrgh! Quote Link to post Share on other sites
Jersey Royal Posted December 10, 2007 Report Share Posted December 10, 2007 Arrrrrgh! Ivor. Could try sucking it out through the fill plug with a ?, canthink what they are called like o gease gun with a tube on the end.. Did mine that way. Regards Guy Quote Link to post Share on other sites
foster461 Posted December 10, 2007 Report Share Posted December 10, 2007 Ivor. Could try sucking it out through the fill plug with a ?, canthink what they are called like o gease gun with a tube on the end.. Did mine that way. Regards Guy A pump ? :-) only problem with that approach is you dont get all the metalic crud out that is grinding up your bearings, crownwheel and pinion. Stan Quote Link to post Share on other sites
piman Posted December 10, 2007 Report Share Posted December 10, 2007 Hello Stan, surely if that stuff is damaging the differential, then it has to be in suspension and sucking it out will remove it? Anything lying in the bottom will not cause damage, I would think? Even with a drain plug fitted you will not be sure of getting all or even most of that rubbish out? Alec Quote Link to post Share on other sites
ianc Posted December 10, 2007 Report Share Posted December 10, 2007 If the car has had a good long journey in summer, the diff oil should be nice and warm and, with both the filler plug and the drain plug removed, the oil should drain as quickly as possible. A drain plug with magnetic insert will remove most of the metallic stuff. The lack of a drain plug is yet another of these short-term economies adopted by manufacturers - but they never expected us to be driving their products some 40-50 years on! Ian Cornish Quote Link to post Share on other sites
BrianC Posted December 10, 2007 Report Share Posted December 10, 2007 (Never having done this myself) I would have thought it should be possible to drill a drain hole without removing the diff (taking care to not use an electric drill for the final breakthrough), drain the oil, tap and fit magnetic plug, refill with a suitable thin oil, take for a short run to warm it up, drain and refill with correct oil - or is that all too simplistic? Quote Link to post Share on other sites
marvmul Posted December 10, 2007 Report Share Posted December 10, 2007 The cover is a steel pressing, only about 0.1" or less : too thin for tapping for a plug. Welding a nut after drilling a hole is a surer way to get a drain plug. The drain plug in the side screen TR's is scewed in a boss that is welded on the cover. Removing the cover is not a big job, and it's an opportunity to clean and inspect the differential. Quote Link to post Share on other sites
foster461 Posted December 10, 2007 Report Share Posted December 10, 2007 The cover is a steel pressing, only about 0.1" or less : too thin for tapping for a plug. Welding a nut after drilling a hole is a surer way to get a drain plug.The drain plug in the side screen TR's is scewed in a boss that is welded on the cover. Removing the cover is not a big job, and it's an opportunity to clean and inspect the differential. The diff rear cover is a pretty substantial cast aluminum piece that has the wings on it for the rear mounts. It is thick enough to tap for a small plug but it would not be the lowest point in the diff so would not be entirely effective for this purpose. If I recall there is an identifiable location on the bottom of the cast steel case where a drain was originally fittect and you can just whack a hole right there and tap it for a plug. I'll take a picture of mine later this evening. Stan Quote Link to post Share on other sites
88V8 Posted December 10, 2007 Author Report Share Posted December 10, 2007 The diff rear cover is a pretty substantial cast aluminum piece that has the wings on it for the rear mounts. It is thick enough to tap for a small plug but it would not be the lowest point in the diff so would not be entirely effective for this purpose. If I recall there is an identifiable location on the bottom of the cast steel case where a drain was originally fittect and you can just whack a hole right there and tap it for a plug. I'll take a picture of mine later this evening.Stan Thankyou That would be excellent. I could drain it with an oil gun as Guy suggests, but better to let it all drain out I think. Quote Link to post Share on other sites
marvmul Posted December 11, 2007 Report Share Posted December 11, 2007 The diff rear cover is a pretty substantial cast aluminum piece that has the wings on it for the rear mounts. It is thick enough to tap for a small plug but it would not be the lowest point in the diff so would not be entirely effective for this purpose. If I recall there is an identifiable location on the bottom of the cast steel case where a drain was originally fittect and you can just whack a hole right there and tap it for a plug. I'll take a picture of mine later this evening. Stan The early TR's (until TR4) had a pressed steel cover and the drain plug is located in this cover. During TR4 or rather at the start of TR4A production, the cover became a cast aluminium. The main casting has a filling plug, but I think it never had a drain plug. Quote Link to post Share on other sites
foster461 Posted December 11, 2007 Report Share Posted December 11, 2007 ThankyouThat would be excellent. I could drain it with an oil gun as Guy suggests, but better to let it all drain out I think. Here's where my drain is installed. http://i38.photobucket.com/albums/e119/fos...ts/DSC_0023.jpg This is in the case and not in the rear cover. There is an obvious location for it once you clean the **** off the bottom of the case. Stan Quote Link to post Share on other sites
88V8 Posted December 11, 2007 Author Report Share Posted December 11, 2007 This is in the case and not in the rear cover. There is an obvious location for it once you clean the **** off the bottom of the case.Stan Thankyou Super that looks like a 1/2" plug I'll add this near the top of the 'things to do' list Something missing from your car, you know Important period feature Rust Ivor Quote Link to post Share on other sites
foster461 Posted December 11, 2007 Report Share Posted December 11, 2007 Something missing from your car, you knowImportant period feature Rust Ivor I wish. I did the rear end last winter although the TA's will be coming off again soon to swap out the poly bushes for Nylatron. The frame forward of the T-shirt is very solid but has surface rust that is on my list to fix this winter. Stan Quote Link to post Share on other sites
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