• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Spitfire spitfire transmission and j type O/D oil question

Share this page

Re: spitfire transmission and j type O/D oil quest

Thanks for the input, Randall. And, you're probably correct in stating that Triumph tested more gearboxes than a repair shop in Connecticut. /bcforum/images/%%GRAEMLIN_URL%%/thankyousign.gif /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

As we know, lubricants have improved dramatically since Triumph tested these cars/gearboxes. Triumph's suggested lubricants are not optimal nowadays. Thus, we're having this informative discussion about gearbox oil.

As one said, each to his own . . .

Good luck and best wishes with your car!
 
Re: spitfire transmission and j type O/D oil quest

vagt6 said:
As we know, lubricants have improved dramatically since Triumph tested these cars/gearboxes.
Click to expand...
I guess I'm just having trouble with the concept that non-detergent motor oil has improved substantially in the last 40 years (since Triumph reported excessive gearbox failures with it). IMO the only improvement in ND 30 has been that it's not used any more.

But you're quite right, to each his own. TTFN & all that.
 
Re: spitfire transmission and j type O/D oil quest

I recommend 30wND;Not every car & every driver has the SAME habits about good maintience,SSSooo its better to go with the guy with the MOST experience.Its kinda like the human body what goes in is directly related to HOW LONG YOU LIVE.
Cheers Mates
Ken&Whitelightning
PS;The world is FULL of no it alls.Experience is the BEST TEACHER.;-)
 
Just to clarify a few things

GL5 gear oil most certainly has upper limits for additives, starting with the milspec.

Non-detergent oils will specifically say non-detergent on the label. In engine oils, these are typically labeled as lawnmower oil.

The issue with sulfur in the gear oils is a "yellow metal" issue, not simply brass. Copper and bronze suffer from it as well. And it is specific to the formulations of the yellow metals. Some survive quite well, others do not. Triumph transmissions are not particularly vulnerable, but the copper differential washerss are.

As a former test lab engineer for a major manufacturing firm, I'd strongly suspect John at Quantum Mechanics has in fact tested more gearboxes than Triumph did. Particularly overdrive gearbox units. In fact I rather doubt that Triumph ever conducted an internal test or inspection a single overdrive unit.

Remember, Laycock did not specify what oil to use in their units, and that they were compatable with just about anything, and were run in cars using anything from gear oils to ATF's, to engine oils, depending on what vehicle they were put into.
 
foxtrapper said:
Just to clarify a few things

GL5 gear oil most certainly has upper limits for additives, starting with the milspec.
Click to expand...

Ah yes, very clear. Starting with the fact that the API GL series is not a Mil spec; and is only a performance specification. It does not even specify what additives are to be used, let alone how much of each additive can be present. This is why synthetic gear oils, which use different additives (and amounts) can still meet the same specification.

Why don't you post a copy of it for us all to read ? My scanner is down ...

In a very real sense, Triumph (Leyland, et al) did a field test on every single gearbox and overdrive that they ever delivered. If there was a failure during the warranty period, they not only heard about it, but tore the offending box down to determine what failed. There are numerous TSBs on the subject including one dated Oct 1954 where they advise that Laycock (maker of the overdrive unit) specifically warned against using "hypoid" oil. They also made a great many incremental changes to the gearbox over the years, obviously to reduce future failures.

Opinions vary, obviously. You guys think lawnmower oil is the best thing for your overdrive gearboxes, that's fine with me. If you baby it as John suggests, probably it will work fine. (Personally, I like to drive my Triumphs.)

But please, let's stick to the facts instead of making things up.
 
TR3driver said:
You guys think lawnmower oil is the best thing for your overdrive gearboxes, that's fine with me.
Click to expand...
I certainly never said that.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]But please, let's stick to the facts instead of making things up. [/QUOTE]
Please, do so. For no where did I advocate lawnmower oil as being the best thing for overdrive gearboxes.

And btw, a 1954 service bulletin predates the Spitfire by a good bit. The Spitfires came with the later D and J type overdrives. Leyland had already made a number of changes in the overdrives in the decade plus since that bulletin.
 
foxtrapper said:
And btw, a 1954 service bulletin predates the Spitfire by a good bit.
Click to expand...

Gee, you think so ? /bcforum/images/%%GRAEMLIN_URL%%/jester.gif

However, it shows you are wrong about Triumph never inspecting overdrive gearbox units; and about Laycock never specifying what oil to use. I didn't bother to look up all the other TSBs discussing their examinations and conclusions, but there were several of them. Including their decision to go back to EP gear oil after having excessive gearbox failures under warranty.

Personally, I don't even use 30 weight non-detergent in my lawnmower; but I can't think of any other application for it offhand. Come to think of it, I've been running that same little one-lunger mower for over 25 years now and it still cuts my grass. Obviously because I'm using the wrong lubricant /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

Would anyone like a scan of the official Triumph workshop manual, saying that the J-type OD was designed to be shifted at full throttle, behind a 145hp V8 ? I came across it the other night while assembling the gearbox for the Stag. And the only substantial difference between the Stag & Spit J-type is that the Stag runs a higher pressure in OD (to handle the increased torque).
 
Okay, has anyone here contacted the other overdrive supplier that might be able to offer some input on fluids and updating the odrive.

Gear Vendors in El Cajon, Calif.

Sell an updated Laycock type overdrive for rods, motor homes, etc.

Just curious?
 
RonMacPherson said:
Okay, has anyone here contacted the other overdrive supplier that might be able to offer some input on fluids and updating the odrive.

Gear Vendors in El Cajon, Calif.

Sell an updated Laycock type overdrive for rods, motor homes, etc.

Just curious?
Click to expand...

Yes. Gear Vendors specifically, as well as several others. None of them recommend a single specific fluid because the units are capable of operating with a wide variety of lubricants. That's why in OEM installations they operate with engine oils, gear oils, ATF's and probably several other types of oils I'm not thinking of at the moment.
 
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

It'd be interesting to compare details, but I never got that far in my talks with them. After learning the price, I figured there was no way it would ever pay for itself on my motorhome.

But somehow, I imagine their unit is a bit more rugged than an ordinary J-type ... can't quite imagine a J-type shifting under full throttle in 1st gear behind a 7.2 V8 pulling a 12,000 pound motorhome. That shaft is no bigger than my thumb. But Gear Vendors swore it was no problem (and GV ODs come standard on many more powerful rigs).
 
Back
Top