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#1 Engaging first gear
Posted: Thu Jun 11, 2020 11:06 pm
by Tony
Can anybody suggest why when my car gets really warmed up it is difficult to engage first gear. The car is a 1962 series 1 3.8 convertable running with a 5 speed Getrag box. It makes driving tiresome particularly when driving stop start in traffic and engaging first gear. When the engine is not fully warmed up there is not a problem. Do I need to consider a different oil.
Tony
#2 Re: Engaging first gear
Posted: Thu Jun 11, 2020 11:50 pm
by abowie
I have no personal experience with Getrag boxes.
It has been suggested to change from an EP80 oil to ATF if you have shifting difficulties. As to which ATF I can't advise but others may know.
A previous thread:
viewtopic.php?t=8816
#3 Re: Engaging first gear
Posted: Fri Jun 12, 2020 6:20 am
by Joes66
This is age old problem
The problem is that some manufacturers recommend different oil types for getrag gearboxes
I looked into this once and rule of thumb is that if your having great selection problems then there are 2 choices
Either DX3 ATF or a fully synthetic 75-90 gear oil
It's a pecularity of the getrag box that it can develop gear selection problems
And there are a few different models of the getrag box as well
If you look you will see that different manufacturers will recommend either the ATF or ep75-90 for the same gearbox!
But you can use either oil in the getrag
ATF oil in my opinion is not as good in a manual gearbox as EP75-90 as a lubricant so I would use that if I had no gear selection problems
If I did I would try the ATF
If no change then back to the EP75-90 and accept you have a troublesome box
One last note
Have you tried selecting 2nd gear first before you select 1st?
The usual way of using a non synchro gearbox?
So at a stop you select 2nd and then into 1st
Joe
#4 Re: Engaging first gear
Posted: Fri Jun 12, 2020 8:54 am
by abowie
Joes66 wrote: ↑Fri Jun 12, 2020 6:20 am
It's a pecularity of the getrag box that it can develop gear selection problems
Joe
That's interesting. What is the actual problem with the box?
#5 Re: Engaging first gear
Posted: Fri Jun 12, 2020 7:06 pm
by Tony
Going into second is what I do to get over the problem but it something I feel I should not have to do with a gearbox that has only done 22k. I shall have to try a different oil and see it if that makes a difference.
So at the moment the suggestion is DX3 ATF for a troublesome box .Any other comments or options.
Thanks all so far
Tony
#6 Re: Engaging first gear
Posted: Sat Jun 13, 2020 9:52 am
by Joes66
The getrag gearbox is well known for premature synchro wear
And is also well known for gear selection problems
This may well be because most manufacturers recommend using ATF fluid which doesn't have as good film strength and lubrication properties in a manual gearbox
This may well have been a trade off with the gearbox by the manufacturers getrag themselves
I actually got in touch with getrag and asked what oil you should use in their gearboxes they and they told me to use ATF fluid
BMW gearboxes which are getrag are all atf fluid
My opinion is that the fifth gear is the problem as it uses molybdenum on its load bearing surfaces which getrag seem to think runs better on ATF fluid
Where as the other gears use a different metal which I cant remember off hand
This is why I think its first 4 gears and the ones shifted in and out of the most wear faster
But as I say it's a common problem on getrag boxes
#7 Re: Engaging first gear
Posted: Sat Jun 13, 2020 6:25 pm
by cactusman
May not be appropriate for getrag boxes but I know the people who build the boxes for Jaguar Heritage and Woodham Mortimer race cars (and others) They use redline MTL gear box oil. 75W80 GL4 spec..