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Transmission Oil

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Thamil

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I have read many posts/discussions on the right oil for transmission of 62 3000 MKII. I was told castrol syntec 75w90 but when reading label is states its "limited Slip" so now I am confused as I thought that you didnt want any friction additives. Your help is appreciated.

Thanks

TH
 
Transmission or differential? I've just replaced the oil in my diff with standard 80W-90W gear oil, and the g'box with 20W-60W Penrite mineral oil (same as engine).
 
Syntec 75w90 is gear/differential oil; do not use it in a Healey transmission-O/D. The shop manual says 30W non-detergent, but many of us--myself included--prefer a modern synthetic like Redline MTL or MT-90.
 
Is there any reason NOT to use a g'box&Diff additive? I bought one for the diff, but havent put it in yet. It also claims to be good in manual g'boxes. Contains P.T.F.E and is compatible with all lubricants...
 
CanberraBJ8 said:
Is there any reason NOT to use a g'box&Diff additive? I bought one for the diff, but havent put it in yet. It also claims to be good in manual g'boxes. Contains P.T.F.E and is compatible with all lubricants...
Click to expand...

1) none are called-for or necessary
2) the gearbox synchros and O/D cone clutch may be adversely affected by PTFE or other (claimed) 'slippery' additives ('limited slip' is a friction modifier for, well, limited slip differentials, which Healeys don't have unless modified)

Owners generally either run 30W non-detergent, 20W-50 engine oil of their choice, or Redline MTL or MT-90 (90 is a little thicker) in the gearbox/OD. The synthetics usually leak a little more. Any good gear oil is fine for the diff (I use Redline).
 
Thanks Bob. I had the tube of additive and I have put in the g'box, but haven't run the car yet. I felt the gear change felt like the oil was a little 'thin' or something after replacing it (first time that I've done it in my car). The old oil looked pretty gooy! I'm going for a run with the boys this morning, and I'll replort back as to whether it makes any noticeable difference. (it felt 'thin' when cold - the gears tending to catch slightly and not engage like they can when warmer. The additive claims that esp. when cold it will help...).
 
Not much to report as yet. The 'box was cold at the beginning of the run and felt like it - but the additive hadnt had a chance to mix in. Bob, I hadn't read your post when I mixed the additive in. Hopefully it won't be a problem for the OD. It was feeling fine for the rest of the drive this morning, and showing the rest of the cars (Porsches) a thing or two... hahaa. And sounding louder and better! I think they were surprised at the acceleration and pace...
 
All things being equal, you should find that the overdrive is less aggressive when shifting into OD under full power. That is assuming the magic teflon-y stuff does actually reduce friction. If it is really slippery then the engage clutch will have a hard time hanging up under power which would be both good and bad. Good because it would be evidence that all the crazy claims additive companies attach to their products may have some basis, and bad because you won't be able to shift into OD under full power without eventually damaging the clutch.

I suspect nothing will change.

Andy.
 
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