ATF in a manual box?

[adidasandy]

My friend has a golf tdi and it's quite hard to change gear when motoring on (crunches sync), so spoke to a gearbox tech and he reckons to change oil with AFT although it's a manual box. He then told me that most car including Ford and GM's use ATF in there manual boxes as it's so thin which gets to all the oil ways. He did also say that Ford and GM use different names for there gear oil but it is only Dex II.
So before going ahead to try this has anyone heard of doing this?

 

[aragorn]

I have, but its not really that great an idea. ATF isnt a proper lubricant. Its not designed for high shear loads that you get in a manual box. As you say its thinner, so it can sometimes let a weak synchro do its job, but its a bodge at best imo.

I'd try some new fresh Manual transmission oil of the correct grade, but tbh, it probably needs a new gearbox.

 

[adidasandy]

Oil has been changed but still the same, most new cars run ATF but they are designed to. The gearbox lad says ATF is as good if not better than GL-4. If the gearbox ihas had it anyway then no real harm changing it to ATF.

 

[aragorn]

I wouldnt say most cars run ATF. Some do, some dont, and those that do dont neccesarily run it because its the best for the job.

Landrovers R380 box for instance was originally specified to run ATF, due to a weak synchro design on 2nd gear, however in the mid 90's they put out a TSB advising that all R380's should now be run on a specially developed MTF (Texaco MTF94) which was designed to give the proper levels of protection the box required, but had a low enough viscosity to allow the poor synchro to work effectively enough.

Some info here:
ATF vs. gear oil - Bob Is The Oil Guy

In your mates case, its probably worth a go.

 

[adidasandy]

Mm, interesting read, may put some ATF in my S4 as looking at the posts it helps massively on fast shifting(always an good thing) and some ATF's ARE GL-4 equivelant. Time to test the water now.