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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - New 4.1 Rear

Just opened the crate, actually the goody box from Dave Clark. Took the 4.8 out today and the new one will go in tomorrow with the new hard axles. Nice. PJ


Paul161

It will be interesting to hear if you notice significant loss in acceleration - I use a 4.3 when I am supercharging a car; I've never tried a 4.1.

Tom Lange
MGT Repair
t lange

Are you using the MGA saddles under the U bolts & the breather mushroom PJ? Cheers
Peter TD 5801
P Hehir

Peter - No need to use MGA saddles - Dave Clark modifies the existing TD/TF rear axle with the innards modified with the MGA parts.
Cheers - Dave
DW DuBois

Peter, new saddles and breather came with the rear, along with new axle seals and spring rubbers. The bearings I bought separately.PJ



Paul161

Nice one PJ .. Cheers
Peter TD 5801
P Hehir

You won't be sorry. I put the 4.3 in and am glad I did... just be ready to rev a bit higher when shifting, there is zero juice at <2000 RPM. I just hang in 3rd on twisty roads (a lot of them around here) a bit more than before. But, these engines live best at 2,500 to 4,000 anyway.....
MAndrus

I just drove the car with the new rear in it and what a difference! Plenty of power and the rear is as quiet as a church mouse.

As my transmission was very noisy in first gear, I was talking about it to a friend who is deep in car racing, NAS car and Formula 1, you should see his Formula one car, he has both. He told me that all racing transmissions are straight cut gears because their much stronger than the helical cut gears. He told me there has been a tremendous amount of research on their transmissions on what oils they use and gave me the formula he uses to not only quiet the gears but shifting is easier and the transmissions last longer. I mixed 70% of 80/85/90 API rated GL-3-4 & 5 with 30% Lucas oil stabilizer. Drained my Red Line 90 out and added his mixture, the results are amazing! Smoother shifting in all gears and first gear is only half as noisy, hardly any whine to it at all. Needless to say I'm very happy with everything. Dave Clark did a wonderful job building this rear for me, it was the best move I've made on this entire car! He is top shelf! PJ

I forgot to ad, there was no metal in the drained oil!
Paul161

PJ is there any possibility that the GL 3-4 in your mix might affect the brass synchros? I got the impression from the archive that GL 5 is the only compatible lubricant for the T series boxes. Just curious is all. Cheers
Peter TD 5801
P Hehir

Peter, my racing friend and I discussed this on the brass synchros and he said no. The oil has all three API ratings on the container and as he said, why would this oil damage anything in the GL-3/4 ratings if it also meets GL-5 ratings? He also said, why would we as race car owners put anything in a 20K transmission that would potentially damage it? And he also said, you guys are using 60 year old transmissions that has had every kind of oil imaginable in them over that many years and probably most of them still have the original synchros in them and your worried that a modern oil will damage them? If you rebuild your transmissions, put new synchros in it and you won't live long enough to see anything go bad he said! He laughed. Regardless, I'm running his oil mixture, I'm not downgrading Red Line oils, I'm just saying that the mixture I'm using now is a lot better. The transmission is much quieter and shifts much smoother. I'm not recommending anyone change what their happy with, I'm just stating how my transmission is working now in relation as how it worked before the oil change. PJ
Paul161

Glad box is now quiet. It is the GL-5 that is of concern with the brass supposedly. I agree that we will likely be long gone before even straight 5 did any damage. Our boxes have likely been run with whatever gear oil was available for years, and some likely engine oil or even squashed bananas (as Tom and Ray would suggest!) over the years. George
George Butz

PJ thanks for the reply & I'm happy you're box seems to have been improved. I suppose as nobody these days in Formula 1 or NASCAR would be running a 1950's T series gearbox, the modern mix wouldn't be a problem. George I thought the 5 was the go & the 4 was the problem but I'm happy to be corrected. It seems GL-5 is the preferred lubricant & the GL-4 apparently is what is not compatible with the 60 year old brass syncros. Anyhow I'm sticking with the Redline MT 90 but I'm still very interested in what others have to say on PJ's racing friend's mix of the 3, 4 & 5 for use in our cars. Cheers
Peter TD 5801
P Hehir

Keep in mind that there are additives in oils for all kinds of reasons, and some oils don't have them for all kinds of reasons too.

Soft parts like 60 year old syncros need special care, and certain additives combat the absorption of humidity inherent in open systems that may remain in service for years unlike race cars that only have to survive the current race.

Also, any oils that tout anything like a detergent should be avoided for unfiltered systems as they are specifically designed to hold particulates in suspension so they can be filtered out. We need the crap to fall to the bottom of the case and stay there.

Our transmissions were designed for certain oils, and given the closed spaces oil needs to get to and the passages it needs to fit through in order to do its job..... just be careful about making things too quiet, especially if you run your car in cold weather. Some thickeners might stay a little too thick. Great for quieting gears on the race course where temps might climb to 'too hot to touch', maybe not great for flowing through to the small parts at winter temps.

....
MAndrus

Well, I do appreciate all the comments and technical support, but all I can say is this transmission is quieter and shifts much smoother. If the sinchros blow out of it in my lifetime, which I doubt, I'll rebuild the transmission. For now, I love how it's performing and with the new 4.1 rear, the car is now a joy to drive and no one riding my back bumper because I'm running too slow. With my rebuilt XPEG engine, I have plenty of power also. PJ
Paul161

I will say this, should my transmission need rebuilding, I would probably shelf it and go with a High Gear setup. The parts for our transmissions, if you can get them, has gone out of site on prices and availability for new is nil on a lot of the parts. There is a solution to any problem, it just depends on how far you want to go with it or how much the pocket allows. PJ
Paul161

Hi PJ, et al,
I've been watching this with interest, as I expect some others have. (it's off-subject now, so the archives won't find it later) Seems to my leaky mind, new brass synchros are among the unobtainium. I'm greatly tempted to shift from my Redline oil to the mix -- for the amount of use our TF gets, it oughta last well past my limited lifetime. And, like PJ says, if it didn't, I'd go to a 5-speed.
best to all,
Al
54TF Emma
A W Parker

As I want to keep my old girl looking as original as I possibly can, (subscribing to the custodian "do no harm" rather than the owner "it's my car I can do what I want" philosophy), I'm keeping the original box. As the change from the 5.25 to the 4.1 or the 4.3 is almost invisible I went with the 4.3. On the gearbox it's still possible to pick up an original unreconditioned one here for about $500 AUD. Also Al there is a guy in Sydney who replaces worn T type synchros & when I finally get the TD on the road I plan to recondition my spare box & have him do the synchros if needed. Because the Red Line does no harm I'll certainly be staying with that. Cheers
Peter TD 5801
P Hehir

Hi Peter,
That sounds reasonable, can you give us info on the synchro source down there? Does he supply new ones, or refurbish the old ones? Years ago (about 50) I was into my TD's gearbox, twice I think, not too bad a job. Synchros in Emma's are pretty bad now, but I'm lazy.
thanks,
Al
54 TF Emma
A W Parker

Al there is a business in Dural on the outskirts of Sydney called Sprite Parts run by Colin Dodds. The guy who refurbishes the synchros can be contacted through Colin. Cheers
Peter TD 5801
P Hehir

Al, I just looked them up, here's their web site. PJ

http://www.spriteparts.com.au/
Paul161

Thanks Peter & PJ
I'll check Mon. and let you know what I find.
Al
A W Parker

The Redline MT-90 is actually GL-4, and has the best rating for yellow metal friendliness. The GL-5 spec is for newer rear pumpkins with extreme loads, generally. GL5 therefore, generally, has more of the copper eating sulpher/phosphorus compounds. Not always, though.
See this link for a number of different gear oils, and a couple of MT oils with the best ASTM D-130 (copper protection) ratings.

http://xlforum.net/vbportal/forums/archive/index.php/t-1533539.html

The link erroneously states Delo ESI gear oils are not yellow metal friendly-- with a 2a rating. In fact a 2a rating is 3rd best, and meets a strict Military Spec where yellow metals are present. Only 1a, 1b and 2a meet that Mil Spec.

Only the GL-5 75w-90 gear oils listed at the bottom should be avoided from this list. The Lucas, Royal Purple and the LSD additive.

As this list was written up with yellow metals in mind, the best rated oils for yellow metal are listed. Note many are GL-5 synthetic. If they are not listed, I would assume they are copper eating, if GL-5. Similar to the three at the bottom.

The Valvoline High Perf, the Castrol Hypoy C and the DELO Gear ESI are the only non-synthetics listed. I happen to know the DELO ESI also comes in 75w-140.

140W GL4 gear oil is sometimes available in gallons at places like O'Reilley's.

D mckellar

My post above included the statement "It seems GL-5 is the preferred lubricant & the GL-4 apparently is what is not compatible with the 60 year old brass syncros." This misstates the situation & should have read "GL-4 is the preferred etc". Thanks to D McKeller for the clarification. Glad to see a further endorsement of the Redline MT 90 in relation to the synchros. Cheers
Peter TD 5801
P Hehir

While changing the transmission oil, I noticed that there is not a drop of oil dripping from the back of the engine. Hard to believe this is happening. I was always told, if it's not leaking, there is no oil in the engine, but it's there, I checked. Grin. PJ


Paul161

This thread was discussed between 14/10/2015 and 22/10/2015

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.