Royal Purple Synchromax
Discussion
Googling around I'm quickly finding gearbox oil for Tremec T56s to be hotly debated. There seems to be a lot of talk of royal purple shearing (losing viscosity in the long term?) and damaging paper blocker rings, although it's not always clear whether that's RP ATF or RP synchromax. It would also seem that was a historic issue that I assume isn't going to be applicable to monaros ( carbon blocker rings). Some of the people who slate RP seem to be people who do a lot of launches for 1/4 miles, so whether their input is useful or not is also unclear. The RP stuff does seem universally agreed (or at least not contested) to give improved cooling...and I'm sure it's better than the aged ATF currently residing in my gearbox.
Apologies if this has been done to death, my google-fu didn't lead me back to this forum. Obviously monkfish is trusted and pushes the royal purple, but most yanks seem to go for Mobil Dexron or Pennzoil Synchromesh.
Apologies if this has been done to death, my google-fu didn't lead me back to this forum. Obviously monkfish is trusted and pushes the royal purple, but most yanks seem to go for Mobil Dexron or Pennzoil Synchromesh.
Yeah, that's exactly why I stopped googling and came here to see if there was a definitive (or at least encouraging) answer to stop the automotive hypochondria.
My box is a bit notchy, if nothing else hopefully it'll smoothen it slightly. Plenty of testamonials to that effect, though naturally a bit qualitative/subjective.
My box is a bit notchy, if nothing else hopefully it'll smoothen it slightly. Plenty of testamonials to that effect, though naturally a bit qualitative/subjective.
L2VXR said:
monkfish1 said:
Probably worth pointing out that nearly all the gearbox failures we have seen are as a result of spigot bearing failure, so nothing to do with the gearbox!
So what are the early warning signs if any ?
When my spigot bearing went it was hard to get in gear and made a crunchy noise. I think I was lucky as my shaft was still tight in the box and I've done about 1500miles since replacing it with no problems.
L2VXR said:
monkfish1 said:
Probably worth pointing out that nearly all the gearbox failures we have seen are as a result of spigot bearing failure, so nothing to do with the gearbox!
So what are the early warning signs if any ?
The signs are difficulty selecting 1st - 4th. Sadly, they are not early warning signs, just a sign it is now knackered. There is not early warning.
KMud said:
monkfish1 said:
Not really. Id say its more of an age related thing.
Aren't all vauxhall monaros about the same age?!

Yes hence all the gearboxes are starting to break lol
Any opportunity that you get to replace the bearing do it, ive just been bit and it aint pleasant. Clutch change, box oil seals anything that involves the box out do the bearing, money well spent.
I looked into the difference between Dexron 3 and "Royal Purple" after another question was posted a few weeks ago. Royal Purple appears to be a brand rather than a specific oil, but they do appear to market an oil for manual transmission applications. Data:
www.royalpurple.com/prod-pdfs/sync
Shows it to be very similar to a generic Dexron 3:
http://www-static.shell.com/static/ca
Viscosity at 40 deg C, 38 vs 34.35, at 100 deg C,7.7 vs 7.23, viscosity index 175 vs 195, API 34 vs 32.5, assuming measured to the same standard. Obviously both have text extolling their virtues in subjective relative terms. What would be good to know is how critical these numbers are to the performance of a manual transmission, and so hold advantage for one or other in the T56 application. What can make the gearbox "much smoother".
The main difference appears to be Royal Purple is 4 times more expensive, making a quick check on eBay.
www.royalpurple.com/prod-pdfs/sync
Shows it to be very similar to a generic Dexron 3:
http://www-static.shell.com/static/ca
Viscosity at 40 deg C, 38 vs 34.35, at 100 deg C,7.7 vs 7.23, viscosity index 175 vs 195, API 34 vs 32.5, assuming measured to the same standard. Obviously both have text extolling their virtues in subjective relative terms. What would be good to know is how critical these numbers are to the performance of a manual transmission, and so hold advantage for one or other in the T56 application. What can make the gearbox "much smoother".
The main difference appears to be Royal Purple is 4 times more expensive, making a quick check on eBay.
L2VXR said:
monkfish1 said:
KMud said:
Is there a typical mileage at which spigot bearings start going?
Not really. Id say its more of an age related thing.
So is the replacement an uprated better quality item or are they destined to the same fate?
destined to the same fate. looking into an alternative, but its not quite as simple as it seems.
granada203028 said:
I looked into the difference between Dexron 3 and "Royal Purple" after another question was posted a few weeks ago. Royal Purple appears to be a brand rather than a specific oil, but they do appear to market an oil for manual transmission applications. Data:
www.royalpurple.com/prod-pdfs/sync
Shows it to be very similar to a generic Dexron 3:
http://www-static.shell.com/static/ca
Viscosity at 40 deg C, 38 vs 34.35, at 100 deg C,7.7 vs 7.23, viscosity index 175 vs 195, API 34 vs 32.5, assuming measured to the same standard. Obviously both have text extolling their virtues in subjective relative terms. What would be good to know is how critical these numbers are to the performance of a manual transmission, and so hold advantage for one or other in the T56 application. What can make the gearbox "much smoother".
The main difference appears to be Royal Purple is 4 times more expensive, making a quick check on eBay.
Given the amount that Mobil/etc spend on research I was sceptical that Royal Purple would have magical properties...but I forked over my hard earned this time for an easy life. I've little doubt there's an equivalent generic that's as good if not better, but given the T56 appears to be a weird old lump I'm not about to mess with mine.www.royalpurple.com/prod-pdfs/sync
Shows it to be very similar to a generic Dexron 3:
http://www-static.shell.com/static/ca
Viscosity at 40 deg C, 38 vs 34.35, at 100 deg C,7.7 vs 7.23, viscosity index 175 vs 195, API 34 vs 32.5, assuming measured to the same standard. Obviously both have text extolling their virtues in subjective relative terms. What would be good to know is how critical these numbers are to the performance of a manual transmission, and so hold advantage for one or other in the T56 application. What can make the gearbox "much smoother".
The main difference appears to be Royal Purple is 4 times more expensive, making a quick check on eBay.
Think I'll stick £100/month into a savings account and get a new clutch, remote bleed line and new spigot bearings next service.
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