Gearbox oil

[vincent]

Hi out there can anyone tell me what is the best oil for gearbox,A.T.F.oil?.sraight 40,? EP 90.???and also best for primary side....?all the best Vincent..

[LJ.]

I use Hypoid 90 in my gearbox and Castrol XXL40 in the primary... works for me!

[old PJ]

Hi out there can anyone tell me what is the best oil for gearbox,A.T.F.oil?.sraight 40,? EP 90.???and also best for primary side....?all the best Vincent..

Hi Vincent i use EP 80 /90 gearbox oil in my A10 and its been ok for 15 years and i use Castrol GTX in the engine and primery . Hope this helps.

PJ   

[Beezageezauk]

Hi Vincent,

I think everybody could be right on this one no matter what sort of oil they use.   Let me explain by quoting from the Roy Bacon "BSA Twin Restoration" book.

Pre-unit models simply used engine oil in both the gearbox and primary chaincase.  This situation changed with the advent of the unit construction engines, with the gearbox using SAE50 oil and the chaincase SAE20.

From 1967 the box changed to EP90 gearoil which had a similar viscosity to the engine grade used before but was better able to cope with the increased stress levels.  Thus EP90 would be a good choice for all gearboxes.

I've heard a lot of reports of guys using ATF in the primary chaincase with no ill effects.  Is anybody on this forum using it??  And if so, how about some feedback?  I could be tempted to start using it myself on the A10 that I am rebuilding. ????

Beezageezauk.

[a101960]

I use ATF in my primary chain case to good effect. I also have the SRM alloy clutch cover and radial release bearing fitted. The clutch works very well, it does not drag or slip, and neutral can be selected easily. As for the gearbox I use straight 50 grade oil, be careful with EP oils, some fromulations will attack 'yellow ' bearings. In the engine I use fully sythentic. As with everything, you pays your money, and you makes your choice!

[vincent]

Hi There Thanks for all replys,i have just managed to get hold of Steve Mcfarlane (S R M Founder )Who does work on my bikes  in Cardiff.and yes A T F is good in Primary Side.use the cheap stuff.!and EP 90 can also be used in Gearbox,its more important though to keep them topped up!whatevers in there. all the best Vincent .I fear the Salt is Approaching!!

[G/F DAVE]

I use ATF in primary case of my 52 gold flash no problems last 18+ yrs. I also run clutch open with no top hat doesnt slip & never had a problem with it either, As for g/box  EP80/90 seems the oil everyone uses also with no problems. Dave.....

[BSA500]

Well I use sae 140 in the A7 to prevent leakage.The box still leaked after replacing the bearing with a sheilded type and a new oil seal so in went the thicker oil.Prob leaks between the mainshaft and the bearing it runs in.I did also try ATF in the chaincase but that made the clutch slip alot!!

[groily]

Hi, Yes, I use 90 grade in the box too, and it's very sweet. A10 1960 is the second person recently to say 'be careful' with gear oils and bronze bushes, though, and I wonder what is it in the mix that causes the problem? Having just trued up the mainshaft and made a new sleeve gear bush to suit a diameter which is about 12 thou down on standard, don't want to find it gets eaten alive and have to do it again any time soon . . . especially as the hardening can't be all that thick now. . . . Groily

[DazSeaton]

Hi, Yes, I use 90 grade in the box too, and it's very sweet. A10 1960 is the second person recently to say 'be careful' with gear oils and bronze bushes, though, and I wonder what is it in the mix that causes the problem? Having just trued up the mainshaft and made a new sleeve gear bush to suit a diameter which is about 12 thou down on standard, don't want to find it gets eaten alive and have to do it again any time soon . . . especially as the hardening can't be all that thick now. . . . Groily

I was pointed to this page, see number 8:
http://www.morrislubricants.co.uk/lubricants/company.asp?wp=91

[muskrat]

 I'm with ATF in the plunger A7 and A65. GFDave the "top hat" also stops the basket from spreading. OldP gtx has friction modifiers which upset clutches.
 I use straight 50 and nulon in the box. And cheap 20/50 with nulon in the motor.
Cheers