Getrag Overheat

[Andrew.Y]

Hi there,

My 34 Getrag is really hot when running for long period of time. After a cruise last Sat night on the hills the knob get so hot that I need to keep fingers away from the metal part otherwise it will get burnt. Outside temp is sub 15C.

Later on a friend drove my car and first thing he noticed is the hot gearbox. I had a 34Gtt and the never noticed any heating issues with the 5-speed-manual.

Is it normal for a getrag to be so overheated compared to other gearboxes? What's the ideal street/track temperature for a getrag?

Thanks.

Andrew

[MrStabby]

Sorry no idea about the heat, but you may as well make sure its got the correct fluid as the most basic maintenance. Oddly, the getrags actually require synthetic auto transmission fluid, like castrol transmax Z. IIRC redline superlight shockproof is an alternative. You could open the fill hole and put your finger in to see if its the usual transmission fluid red, but if you havent changed the transmission fluid since you got the car you might as well do it for peace of mind.

[Moodles2]

If it's hot it's possible it's low on fluid and you're getting metal on metal contact

[Andrew.Y]

Sorry no idea about the heat, but you may as well make sure its got the correct fluid as the most basic maintenance. Oddly, the getrags actually require synthetic auto transmission fluid, like castrol transmax Z. IIRC redline superlight shockproof is an alternative. You could open the fill hole and put your finger in to see if its the usual transmission fluid red, but if you havent changed the transmission fluid since you got the car you might as well do it for peace of mind.

Thanks very much Adam. Changed the gear box oil with Castrol Transmax Z however it's green instead of red. Gear change feels so much more smooth now and I doubt workshop which rebuilt my gearbox has put regular 75-90w gearing oil in it before. Because Transmax Z is a really light oil, is it sufficient to protect the gearbox?

The mechanic mentioned that the front bearing is a bit worn out and making noises. Is it a serious issue? Currently running Excedy twin plate clutch.

[Beer Baron]

if you have a worn gearbox bearing that will be generating heat (due to friction). there is also an insulator between the shifter mount thing and the box. sometimes they get left out. if that's missing you definitely will get more heat transfer into the shifter and gearknob. can't remember in 34 GTR but in 32 GTR the shifter actually goes into the transfer case anyway and not the gearbox.

[Andrew.Y]

if you have a worn gearbox bearing that will be generating heat (due to friction). there is also an insulator between the shifter mount thing and the box. sometimes they get left out. if that's missing you definitely will get more heat transfer into the shifter and gearknob. can't remember in 34 GTR but in 32 GTR the shifter actually goes into the transfer case anyway and not the gearbox.

Thank you Richard. Will look into it.

[MrStabby]

Is the temperature any different with the new fluid?

Did you say transmax Z is now green (or was green the colour of the old fluid)? It was red when i used it in my powersteer about 18 months ago.

If you're running 350+kw it might be worth using superlight shockproof instead. I have no direct experience tho, just what's bounced around my skull after lots of reading. BeerBaron or TO4GTR etc would know.

[R31Nismoid]

You cannot use the redline in the Getrag IIRC...

You must use one of the two:

Castrol - Tranzmax Z

Royal Purple - Synchromax

[Andrew.Y]

Is the temperature any different with the new fluid?

Did you say transmax Z is now green (or was green the colour of the old fluid)? It was red when i used it in my powersteer about 18 months ago.

If you're running 350+kw it might be worth using superlight shockproof instead. I have no direct experience tho, just what's bounced around my skull after lots of reading. BeerBaron or TO4GTR etc would know.

Did another hill run last night. Temp is definitely lower after oil change. Syncho is much more smooth. Thin oil helps.

Yes the Transmax Z is green. The old oil is regular yellowish color.

With 286awkw it's a mild gtr.

Thank you very much Adam.

[Andrew.Y]

You cannot use the redline in the Getrag IIRC...

You must use one of the two:

Castrol - Tranzmax Z

Royal Purple - Synchromax

Thanks. Noted/

[MrStabby]

You cannot use the redline in the Getrag IIRC...

Pretty sure it has been mentioned here that superlight (ONLY superlight) is recommended by Redline for that box. I found it hard to believe at the time, but IIRC the poster had called Redline. Would definitly be worth confirming with them before trying it.

Anyway Andrew at that power, stick with the transmax Z.

[R31Nismoid]

mmm perhaps, i don't know either way.

The two above are what all the other Getrag owners are using, so seems fit to go with whats working rather than whats perhaps... not

[SkylineSky]

As Beer Baron said the shifter goes into the transfer case not the gearbox, make sure the fluid level is ok in the transfer case, if it is ok then the clutch pack in the transfer case is shagged.. or a worn bearing but this is unusual..