View single post by Tony Hollart
 Posted: 08-05-2006 04:37 am
PM Quote Reply Full Topic
Tony Hollart

 

Joined: 03-21-2005
Location: Waitomo Caves, Otorohanga, New Zealand
Posts: 40
Status: 
Offline
I see you have the 5 speed Getrag box so the following does not apply but seeing I already typed it all in, I will my say about the four speed box.

I dont have the answer about slipping out of first gear, but my JH does have the same problem. When I am in first going down hill ( we have a steep driveway ) When the gearbox has warmed up not as much of a problem. However the gearbox is a really simple unit to work on as long as you make up three selector fork removal rods and a layshaft removal tool. The fork selector rods have indents in them so that the fork stays in the right position for the particular gear, there is a small amount of latitutude where these rods get position in the gearbox, so I thinks the problem with my car jumping out of gear probably a combination of the position of the selector rod and possibly worn selecting forks or the spring that hold the ball bearing ito the indent. The gearbox is similar ( same ) as the Hillman Hunter, with different ratios, ie JH has higher ratios for 1st, 2nd, 3rd with top being the same at 1:1.

I have got another gearbox to rebuild the original JH gear clusters onto so that I have the benefit of the higher ratios through the gearbox, but in the mean time I have the Hillman Hunter gearbox fitted. I have some phots of the process if you need encouragement.

The other topic about the gearbox is what sort of oil you use. The JH hand book says to use a  20w/50 oil  ( normal motor  oil )  if someone has put in  Hypoid oil 80w this may couse problems. It may be useful to drain existing gearbox oil out into a clear container to see whats suspended in the oil, hopefully nothing but you may see flakes or bits etc. Takes about 2 litres of oil to full the gearbox up.

By all accounts the gearbox is a robust easy gearbox to work on and is well suit to the JH. Regards Tony H.

Last edited on 08-05-2006 04:41 am by Tony Hollart