Originally Posted by John Haggard
some say they run Synthetic transmission fluid in the G.V. units. the manual says not to.
I have checked under the coach several times while on the road and the G.V. casing is to HOT to touch. do they run Hot ?
can a Transmission cooler be Plumbed Into the system ?
John, how hot is hot? If you were to check the trans or engine block they also get hot. Do you have the deep sump on your GV? That adds a little more oil and a little more cooling. I just added the deep sump to mine while doing the first oil change. There was no sign of burnt or overheated oil without the extra oil of the deep sump. If you have one of the infra red thermometers you could get a good temp read and check the trans as a comparison.
The oil pick up is through a pick-up tube and screen inside the bottom cover. As far as I know the only oil port is at pump pressure which is around 700 psi. If you want to add a cooler you will probably have to tap the bottom cover/sump and add an external pump to circulate the oil through a cooler and back to the sump.
The original Laycock OD units on European cars shared the oil with the transmission being coupled to the back of the trans as a single unit. When GV took over they built a coupler to separate the GV oil from the original trans oil I would guess so they don't have to deal with approval and warranty issues from the vehicle manufacturer. They seem to have been very successful with this approach.
Good luck, Dan