PDA

View Full Version : Gearbox problems SIII, Advice needed



Tank
9th June 2008, 05:38 PM
My son, has a 1980 SeriesIII 109 2.25D, he has replaced clutch Master and Slave cylinders, BUT he is still having troubles changing 1st to 2nd and 2nd to first, crunching synchro's, OK if he double clutches.
Also has a hard time getting into 4th (Top) once over 60Klm/h, under that speed, no problems. Gearbox runs 90 grade Gear oil.
Plenty of oil in Gearboxes.
My 1975 Series III 2.25D 109 has Auto trans fluid (ATF) in it's box, as I have not driven it yet, (still rebuilding engine), I can't comment on what difference ATF makes to gearbox changes and longevity of gears and bearings over the standard EP90 gear oil. Anyone with any experience with different oils and the problems my son is having, I would be much obliged for any help in this matter, Regards Frank.

PAT303
9th June 2008, 07:44 PM
Tank just remember you MUST run castrol oil in series box's.ATF is OK but phosphor bronze bearings will re-act with additives,I can't remember which one in other oils.I ruined a new box that way and when I pulled it to bits the bearings were like dryed soap.Owen Rumble,the second oldest LR dealer-mechanic in Australia told me that. Pat

Blknight.aus
9th June 2008, 08:52 PM
stock non exotic 80/90 is the go. but not the synthetic stuff, castrol is good but there is other stuff that meets the spec... sounds like generic gearbox syncro wear to me with perhaps a touch of support bearing failure between input and output shafts...

you might try a nulon oil stabaliser on the next change but thats just a bandaid fix.

isuzurover
9th June 2008, 09:40 PM
Tank just remember you MUST run castrol oil in series box's.ATF is OK but phosphor bronze bearings will re-act with additives,I can't remember which one in other oils.I ruined a new box that way and when I pulled it to bits the bearings were like dryed soap.Owen Rumble,the second oldest LR dealer-mechanic in Australia told me that. Pat

Castrol is just a brand, any 90wt GL4 rated oil will do. Normal 80W90 is GL5. The only GL4 Oil I have used (in the IIA) is VMX80, and it is too thin IMHO. So I have normally used 80W90 GL5, and I have pulled the box open a few times since rebuilding it, and the broze parts look like new.