Over-filling gearbox oil

[gunner93]

Thought I'll update this.

I have used RL Lightweight Shockproof aka Smurf Blood for about 2 months include 2 track days and a number of spirited drives. My synchros started to crunch and very difficult to engage in most gears.

I then took advice from my RL dealer to use RL MT-90 (75w90 GL4). Had it replaced, run it in for 50 to 100 km and my gear shifts are smooth again. Seems the Smurf Blood may work for some newer gearboxes but it doesnt on mine.

Open for sharing?

 

[Yakozan]

I've heard that RL shockproof can be hard on synchros in some boxes. But I thought that only applied to the heavyweight.
I've been using Motul Gear300 in my S15 and the gearchanges has been smooth all the time (used gear300 for about 3 years now).

 

[Ozone]

Just as I was going to go for the RL stuff...
Looks like Motul Gear300 then, I think my mate runs this in his 106GTi and e30 M3.

My gearbox has a 2nd gear that is difficult to engage in cold weather unless you consciencely change slowly. Only on up change and only in cold weather, the rest of the time it is fine. I haven't overfilled the oil yet but figured I might as well change and overfill at the same time.

 

[mook]

Interresting, mine's notchy into third and fifth when cold and tricky to get into 6th at all. When warm it can then be tricky to get into 3rd and 5th when I'm giving it the gun.

Think I'll have to get some of that Motul and overfill it too, hopefully that'll help

 

[Yakozan]

I have no notchiness what so ever and no problem selecting any gear at any given time. No crunching at all.

But I haven't put much mileage on the gearbox oil. Changed first time at about 50000km and then a second time at about 65000km when I had the clutch and flywheel changed. So only about 15000km with the same oil.

 

[Fro-Daddy]

So much better when it is over-filled!

 

[Scotty]

Hey mate, don't use lightweight shockproof, i was crunching after about 100km, just street use down in NZ, its made for dogboxes,

im using mt-90 now, and my car only has a small notch into second gear, other than that its fine, im going to overfill the box tomorrow, with some gulfwestern ultraclear, and see how that goes.

anyone tried it?

 

[Nicely]

Hey mate, don't use lightweight shockproof, i was crunching after about 100km, just street use down in NZ, its made for dogboxes,

And yet, I ran it for 20k miles without issue...

 

[Fro-Daddy]

Yea I'm not having any issues so far, only ~5,000kms though...

 

[Scotty]

Yeah, thats werid, mine was pretty soon, at the start it was ok, then after about a week, it crunched, then slowly got worse, was in the car 2000kms max.

 

[Darren_S15]

Im using lightweight shockproof too with no issues

 

[gunner93]

Yeah, thats werid, mine was pretty soon, at the start it was ok, then after about a week, it crunched, then slowly got worse, was in the car 2000kms max.

Is it due to the RL different formulation in these part of the world or is it the weather? Very puzzling.

 

[yc86]

Hi guys!.. sorry to hijack this thread.
Can anyone confirm if the drain plug is a square key or a bolt? Looking at the logical position of where the plug should be, it's a 22-24mm bolt (rather large one). And the filler plug also looks to be a large bolt too. Am I looking at the right bolts or are they somewhere else?

I can't find a square key anywhere.. even though the manual shows its a square too, but doesn't show where.

oh, and about overfilling the box. If the filler plug is on the left, would it help by tilting the car to the right? that should allow an extra 200ml to fit in, shouldn't it?

Thanks!

 

[GR1FTA]

I use RL heavy and light in boxes with syncros and not had a problem in the past a lot of people say the viscosity is too thick and doesnt get around the syncros but its all bull, if you use fluids with the intended purpose in mind then everything will be fine. heres a old box of mine with rl heavy covered everypart of box never had a problem cold or warm, although some people who couldnt operate a clutch properly said it crunched like mad