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MGB Red Line Oils MGB Transmission?

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PAUL161

PAUL161

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Can Red Line oil be used in an MGB transmission with over drive?
Ever since I rebuilt the transmission in the 72, it shifts a little stiff, not uncomfortable, but stiff. It's had 20/50 in it since 2006 and it's still the same today as it was back then. Could Red Line synthetic be put in it to replace the 20/50? What impact would there be on the over drive? If there's the slightest question, I'll leave it as it is. PJ
 
Find some straight 30-weight, Paul. Pennzoil come to mind.
 
Doc, think the straight 30W will make it shift a little easier? That's my main concern and I don't want to put anything in there that could cause the brass syncros to wear faster. I'm getting different opinions, as someone else told me to use Red Line MTL as it's a little thinner than MT90. Kinda confused here. I have MT90 in the TF, but the trannies are different, especially the B with the overdrive, which is another concern. It was also said with the MTL, the OD will shift a little faster. :concern: PJ
 
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Not sure it'll shift any 'easier' with the 30W, but a four-synchro box still has the layshaft needle bearings to consider. Haven't had experience with MTL, would like to see a box apart after extended use before switching.


Also: Some of the synth lubes are a bit too slick and defeat the friction needed by the baulk rings to do their job.

If it doesn't leak with 20/50, it likely won't change.
 
Thanks Doc! I'm going to rethink this. The car doesn't get driven much, so the transmission hasn't had a lot of running time. I'm going to a show in Arkansas in September and driving the B. I'll see how things are when I get back. PJ
 
Paul - I've run both 20W50 and the straight 30 non-detergent in the 4-syncro MGB box and couldn't tell the difference. It was a deliberate shift either way, it's not that delicate of a gearbox.

If I still had that car I'd have stuck with the 20W50 just to be able to stock one kind of oil for engine and transmission.
 
My curiosity was Drew, I have MT90 on the shelf for the TF and thought it might make the B shift a little easier, which was the reason for the questions. I think I'm going to leave it alone with the 20/50 in it until I make this 200 mile run next month. Should get things warmed up a bit. PJ
 
Just found out I can use it in an MGB transmission with OD! I already have some on the shelf, so another quart should do it. Doug on the Healey forum has been using it in his Healeys for quite some time with no issues in his OD units. Says his transmissions shift smoother, run quieter and cooler. All good stuff! PJ
 
So I'm a dinosaur!

May need to rethink and try the Redline lubes. :wink:
 
Hey Doc, Talk about dinosaurs, when we were kids, this was the oil of choice! I think it was 2 bucks for a 2 gallon can at Pep Boys! That re processed oil was expensive stuff! Cheaper when on sale! :highly_amused: PJ

 
I recall as a teen buying the recycled oil in quart "Mason" jars with their own pointed cone shaped lids, for 35 cents apiece.
 
Many people have used this with OD without problems, and Redline says it is OK with ODs, BUT if you put a lot of torque through the gearbox, you can get slip and trash an OD unit. We never use anything but straight weight non-detergent in the race cars.
 
I agree, if you change from what the manual suggests, put 30W ND in, usually Warren, found at the local can gas station, not the redline. The redline will work and works ok with overdrives, but the molecule sizes are much smaller. if you don't have a gearbox leak now, you will later.

The Non Detergent oil doesn't have the ability to encapsulate the dirt molecule's and therefore the dirt sinks to the bottom of the gearbox. If you had a filter, like an engine encapsulated dirt molecule's would float around and get caught in the filter. That's why you use ND in a LBC transmission. If the gear change is still a little stiff, try using 1/2 a measuring cup full of automatic transmission fluid. This has worked well for me in the past.

www.britishcarmechanic.com
 
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