HA1 Gearbox oil

[RSM]

Does anyone know what the best oil is for a HA1 5 speed gearbox.

I am currently using 80w90 and the result is a scratchy change into 3rd gear. If I do a slow change it is as if internal components starts to turn as the gear is being engaged, grating, forcing me to disengage, wait for the cluster or whatever to stop spinning and then doing the change.

If I do a quick gear shift, the problem is not as evident. It is as if I havent given, whatever is turning, the chance to gain momentum. Logic tells me the oil may be too thick causing parts that should be turning independently to turn together????????

Any advice?

 

[wb6nvh]

I ran both straight 90W and the same oil you are using in mine and never had that issue. I don't think my temperatures in coastal California are much warmer than South Africa so the results should have been about the same.

If you could even find any, I don't think I would go much below 80W gear oil in that application.

You might try one of the oil additives on the market but I am thinking a worn synchro or bearing is the inevitable cause of this. You didn't say if it was shifting up into 3rd or down into 3rd which has the issue, or both. I am presuming the throwout bearing freeplay has been adjusted correctly.

Unrelated to the issue you mention, if you ever drain and refill the transaxle, make sure to only refill it with the refill quantity stated in the shop manual. If you continue to refill until oil runs out the filler hole, you have overfilled it and the seal at the input shaft will leak and ruin the clutch.

 

[RSM]

Thanks for the info. The key here that you brought to my attention is that I always filled to the filler hole! I will drain and fill the stated amount. Its is 2Litres I think........

Thanks

 

[RSM]

I ran both straight 90W and the same oil you are using in mine and never had that issue. I don't think my temperatures in coastal California are much warmer than South Africa so the results should have been about the same.

If you could even find any, I don't think I would go much below 80W gear oil in that application.

You might try one of the oil additives on the market but I am thinking a worn synchro or bearing is the inevitable cause of this. You didn't say if it was shifting up into 3rd or down into 3rd which has the issue, or both. I am presuming the throwout bearing freeplay has been adjusted correctly.

Unrelated to the issue you mention, if you ever drain and refill the transaxle, make sure to only refill it with the refill quantity stated in the shop manual. If you continue to refill until oil runs out the filler hole, you have overfilled it and the seal at the input shaft will leak and ruin the clutch.

Just for info.Its a low mileage box so I dont suspect wear being the issue. Im sure its just overfilled. Thanks for pointing that out!