steamy Posted January 17, 2017 Report Share Posted January 17, 2017 I have a 67 TR4A IRS and am a newbie as only had it for 5 months. It had all the usual oil leaks but acceptable. After trolling through all the preferred gearbox oil info on this forum settled on changing the oil to Redline MT-90 Synthetic. I have only done one 40 mile run since (up on stands now as re trimming and carpeting, dash etc) and in the morning I was greeted by a large puddle of oil on floor. No further leaks for a couple of weeks and then bizarrely started to drip like a tap from the bell housing area for a few hours then stop. It has done this a few times with engine not started or car moved. I am baffled!! but have read that this oil might increase possibility of leaks? Can any one tell me if this is so and what thicker oil to use short term as am reluctant to drop gearbox at present with all new trim and wool carpet although I know I will have to replace 'front seal' ? eventually. Thanks in advance for any advice from more knowledgeable owners. Quote Link to post Share on other sites
Lebro Posted January 17, 2017 Report Share Posted January 17, 2017 (edited) Questions: Is it dropping gearbox oil or engine oil Do you have overdrive fitted How much gearbox oil did you put in Is the drain plug sealing How much engine oil have you got in (where on the dipstick) Too much of either oil is not good. Initial thoughts were - bell housing leak suggest to me leak from drain plug running down to bottom of bell housing, rear crank seal failure, or overfilled gearbox Bob. Edited January 17, 2017 by Lebro Quote Link to post Share on other sites
Fireman049 Posted January 17, 2017 Report Share Posted January 17, 2017 Hi Steamy ~ If I were you I'd remove the engine and gearbox and fit a new gearbox front oil seal and the 'Mad Marx' rear crankshaft oil seal. This is what I did with my 3A. The 'Mad Marx' oil seal doesn't require the crankshaft scroll seal removing and you end up with two oil seals! I used my crankshaft to centralise the oil seal (see photo). Tom. Quote Link to post Share on other sites
marko Posted January 17, 2017 Report Share Posted January 17, 2017 That gearbox oil may well "eat" the phosphor bronze baulk rings / internals in the gearbox causing catastophic failure of the GB and OD (or both) and a very expensive repair bill! I would get it out pretty damn quick. We have rebuilt many many gearboxes where unsuspecting owners with good intentions have put a modern synthetic oil in, however the contents of some of the synthetic oils and cleaning agents were not designed for "old" gearboxes / engines so problems may well occur as a result... I would only ever recommend a mineral based 80/90 GL4 for TR boxes - this has come from my gearbox man that has been rebuilding these for over 40 years! Others may disagree but I can show you several invoices for large sums of money where this failure has occured after unsuspecting owners have changed the gearbox oil to something modern, co-incidence? I don't think so.... What do I know Quote Link to post Share on other sites
RogerH Posted January 17, 2017 Report Share Posted January 17, 2017 Hi Steamy, what does Marko know!! - quite a lot and more. Follow Toms advice eventually. Follow Bobs advice now. Penrite GB40 is thinner than the 80 or 90 grade oils but not a great deal - and works well. Engine oil will be black with not too much smell GB oil will look new(ish) and have a strong smell. Occasional spurts sound like the engine rear scroll seal letting out oil then allowing an air bubble to pass by, then more oil. A bit odd though. Check all the levels. You may well need to remove all your carpets and things to check all the GB for leaks with the tunnel removed. Roger Roger Quote Link to post Share on other sites
mike ellis Posted January 17, 2017 Report Share Posted January 17, 2017 I can't see why the Redline MT-40 should cause a problem. At 75W90 it is the correct viscosity and it is to GL4 spec which means it does not have the brass eating additives. It is marketed for this application, the fact that it is synthetic should not be a problem. Quote Link to post Share on other sites
steamy Posted January 17, 2017 Author Report Share Posted January 17, 2017 Many thanks to all for your inputs. Bob, Definitely GB oil (colour and smell).Engine dipstick shows about 1/16" above full line and on removing GB filler about egg cup of oil came out so was overfilled. It has OD fitted. When oil was leaking..it's stopped now..it was dripping from bottom of bell housing and more significantly from middle engine sump nut but definitely GB oil! Tom, I know I might have to bite the bullet sooner than later. Will the engine and transmission drop out from bottom with GB cover in place? If 'thinness' of oil is making it leak more any suggestion for a short term replacement oil especially regarding Marko's thoughts?. Thanks Ian Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 17, 2017 Report Share Posted January 17, 2017 I have a 67 TR4A IRS and am a newbie as only had it for 5 months. It had all the usual oil leaks but acceptable. After trolling through all the preferred gearbox oil info on this forum settled on changing the oil to Redline MT-90 Synthetic. I have only done one 40 mile run since (up on stands now as re trimming and carpeting, dash etc) and in the morning I was greeted by a large puddle of oil on floor. No further leaks for a couple of weeks and then bizarrely started to drip like a tap from the bell housing area for a few hours then stop. It has done this a few times with engine not started or car moved. I am baffled!! but have read that this oil might increase possibility of leaks? Can any one tell me if this is so and what thicker oil to use short term as am reluctant to drop gearbox at present with all new trim and wool carpet although I know I will have to replace 'front seal' ? eventually. Thanks in advance for any advice from more knowledgeable owners. When you changed the gearbox and overdrive oil how much did you drain out? As much or less than you put back in? Perhaps overfill is the issue. My own gearbox (Stag with TR6 mods) has a top dip stick filler from a TR3 (I drilled it when fitting the gearbox) and the original side filler plug. I remove the side plug for level purposes, fill through the top with the car on level ground. Go for a cup of tea then replace the plugs when I consider all levels have stabilised. Is this overkill? My car drips from the selector rods, just like Roger's. Peter W Quote Link to post Share on other sites
RogerH Posted January 17, 2017 Report Share Posted January 17, 2017 Hi Ian, get your levels where they need to be. Even when on the full mark it may be too much. For the engine stay below the full. If the enginbe quickly gets to a level below full and stays there for a reasonable period before topping up then that level may be the place to be. Allow the GB to drain before refitting the level/fill plug. 40 or 90 grade get thin when hot and will leak. OK 90 grade may leak a little less, but!! 40 grade shouldn't leak - thus you have a leak somewhere that needs sorting. There is a seal in the bell housing that should stop the oil flow but it isn't very manly - have you got the GB vented ? Are you certain it is coming from the front of the bell housing little drain hole. Could it be coming from elsewhere and running forwards - that bottom of the bell housing is the lowest point. When you can, have a look at the area around the selector rods (on to of GB) - this is a common leak area (it's common on mine ) What do you mean by middle sumps nut? more significantly from middle engine sump nut but Good luck Roger Quote Link to post Share on other sites
Fireman049 Posted January 17, 2017 Report Share Posted January 17, 2017 Hi Ian ~ I'm afraid that you will have to remove the gearbox cover inorder to release the rear gearbox/overdrive mounting. I took my engine/gearbox out from the front ~ much easier. Tom. Quote Link to post Share on other sites
RogerH Posted January 17, 2017 Report Share Posted January 17, 2017 Hi Ian, having read your post again. The engine and gearbox can be taken out through the engine bay and out the top. OR you can unbolt the GB from the engine and pull the whole box out backwards and out through the cabin and doorway. The GB will not drop down with or without the engine. I prefer, Like Tom in the previus post, taking both engine and GB out together but have recently removed the GB on three occasions last summer with not a lot of trouble (it gets easier the more you do it). Roger Quote Link to post Share on other sites
steamy Posted January 17, 2017 Author Report Share Posted January 17, 2017 Not sure about the quantity of oil drained verses renewed Peter but certainly was 'overfilled' as per previous post. Don't know about breather on GB but has 'A' overdrive which should have breather but not checked! Where is breather on GB...is it just a hole? The breather would be for pressure build up but if it leaks periodically when just standing there I am baffled. The drips are around the drain hole of bell housing and around the bolts holding the sump between bell housing and engine. Most seems to be from around the bolt heads on sump. As you say Roger it might not be from front seal but from selectors and running forward? When it does leak it really flows and drips constantly for about 30 mins. It really is a mystery I really can't get my head around why it could be OK for several days and then bang but learning more from all your inputs. Thanks again Ian Quote Link to post Share on other sites
Fireman049 Posted January 18, 2017 Report Share Posted January 18, 2017 Hi steamy ~ If I were you I'd remove the engine and gearbox and carry out the necessary work on the gearbox oil seal and engine rear oil seal and be done with it once and for all. Tom. Quote Link to post Share on other sites
steamy Posted January 18, 2017 Author Report Share Posted January 18, 2017 Hi Tom, Yes you are right I have come to the same conclusion it's the only way to see what's going on. Thanks for the pics in your previous reply....very useful. Ian Quote Link to post Share on other sites
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