Changed the fluid on the GDU for the first time today. I read an older report on Piston Heads suggesting that the only way to ensure the GDU had sufficent fluid was to:
1. Fill with fluid to level bung.
2. Jack car up and run car through gears.
3. Add more fluid now that the gearbox has seen some work.
Does anyone else follow a procedure this complicated? We just filled to the level bung and called it good.
I have never hear of or done this. I just fill it until it starts to flow out of the fluid level hole. One time I tried over filling it a little thinking it would help to have some extra oil... This was not a good plan. When there is too much oil it comes out of the vent and makes a big mess.
Here is the GDU filling instructions from the SR3 Owners manual which should be helpful.
That's the process we followed.
On a side note, how much metal is usually stuck to the magnet on the level bung?
There should only be traces on the magnet. This is what the magnet on mine looked like when I changed fluids right before I had the engine overhauled after 40 hours. I suspect that the previous owner didn't overhaul the GDU at the previous overhaul because I did have to change some gears when I did my overhaul. After it was overhauled I changed the fluid every 10 hours and there was very little on the magnet.
The manual suggests opening the case and draining the fluid that way. Rather than do that and worry about the seal on the case each time, we tend to just remove the lower hose from the case and let drain through the hose. Not perfect I believe it's a fairly common way to drain the fluid.
The manual suggests opening the case and draining the fluid that way. Rather than do that and worry about the seal on the case each time, we tend to just remove the lower hose from the case and let drain through the hose. Not perfect I believe it's a fairly common way to drain the fluid.
Garrett...thanks. That is what we ended up doing. We managed to coax 800ml out of the lower hose. The fluid coming out didn't look too worse for the wear. We will do a full fluid swap and gear change over the winter so this should do the trick for 1 event.
P.S. I am bringing some goodies down to TX for ya.
I do it the same way Garrett explained. I also flush the old fluid out of the oil cooler a bit. Flushing the cooler is easy to do when the rear wheels are off of the ground. Simply put the oil return line, that goes into the filler of the GDU, into a container and then rotate the rear wheels and the GDU will pump the clean through the cooler and you can catch it in the container. I do that until fresh fluid comes through.
Charley
Screw in an air fitting into the top and give it a blast with some air pressure and anything in the oil cooler will drain out the bottom hose fitting.
If flushing gear oil from the oil cooler, does this require adding oil somewhere besides the top of the GDU, or a procedure to make sure the GDU ends up with sufficient oil?
One more question -- should the black reinforced hose from the case and hose clamps be replaced at a certain interval?
If flushing gear oil from the oil cooler, does this require adding oil somewhere besides the top of the GDU, or a procedure to make sure the GDU ends up with sufficient oil?
One more question -- should the black reinforced hose from the case and hose clamps be replaced at a certain interval?
@davidf No, you fill it from the top like you normally do. After you complete the flush you take out the side plug on the GDU and fill until it just starts to run out the side. Do not over fill the GDU because when they are even a little over filled they excess will come out of the vent and make a mess.
Regarding the life of the reinforced hoses, I am not aware of a stated replacement time. I would check for signs of pending failure and replace if you see anything that could lead to a failure. These hoses are not under great pressure so there isn't much chance of a surprise failure as long as you to thorough inspections.
Charley
Hi @charleyhradicalsportscarregistry-com The owner's manual on the forum doesn't have that page, do you happen to have a link to the full manual that page is from?
Lastly what oil would you recommend? Neo Synthetics 75W90 RHD?
Hi @tertre-rouge, take a look at page 30 and 31 on the latest SR3 manual. Here is a link. 🙂 https://radicalsportscarregistry.com/sr3xx-gen-4-2020-owners-manual/
Yes, Neo Synthetics 75W90 RHD is the best GDU fluid. If you Reach out to Neo Synthetics USA and tell them you would like to get the Radical Sportscar Registry Discount they will reduce the price by 10%. Here is a link. https://neosyntheticoil.com/contact-us/
@charleyhradicalsportscarregistry-com Fantastic on all fronts, that manual has all the missing torque settings I've been hunting around for and a discount is always appreciated! Thank you.
