Does anyone have any recent experience with swapping their transmission for a 5 Speed?

I have a '63 3.8 and the trans leaves much to be desired. (others may differ, lol). I do like the idea of a highway gear as I do drive the car often. I have done this to a first generation Mustang and it was the best thing I ever did, but it seems so much more expensive for an E-type. Suggestions? Comments?Insults?


There is TONS of info on this, in the archives.

No insults, but what are your main issues with the original gearbox? After really learning how to use mine I found it quite satisfactory, so satisfactory that after many years of using it I decided to actually spend the money to do a proper rebuild on it, and it turned out there was a lot wrong with it. It still hasn’t gone back in the car so I don’t know how much improvement there will be, but if it was satisfactory before it should be at least satisfactory+ now, hopefully more than that.

Getting highways revs down is a reasonable goal but that alone is far more easily/cheaply resolved by changing the final drive ratio with none of the inherent hassles of trying to fit a new gearbox, plus the benefit of maintaining originality and value. I’ve been somewhat surprised lately to see the emphasis buyers are placing on original components. It wasn’t much of a thing when I bought my car, but it seems to be more of a thing now. So if I’m going to spend time and money I try to do it in a way that it will add value.

Unfortunately, the original gearbox is long gone, and a 4.2 syc is in it’s place. It feels horrible going into first, even at a dead stop. If I’ve been driving the car for a bit, sometime it is just plain impossible to slip it into first gear. It just doesn’t have a crisp feeling shift. I’m sure it needs a rebuild, but I was thinking perhaps to do the swap instead. I was offered a brand new Cosworth MT75 transmission for $3500 that had been siting in a garage for 2 years, but still in it’s original carton. As long as there aren’t any permanent altercations to the car needed to fit it, I’m interested.

My only suggestion would be to try a known good sync box and see if you like it. The sync box is much beloved by a lot of people and best of all, it’s way cheap to rebuild and quite easy also for a DIYer, unlike my Moss which set me back 2k in parts alone.

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have you tried a better gear oil in it? I had the same exact problems with my 1st gear synchro until I switched to Red Line MT-90. There was a recent thread about a Ford synthetic oil that is also good, but its pricey. You need a quart and a half of oil, so before spending $3500 try a better gearbox oil.

Thanks Bob, great suggestion. I’ll try it this weekend.


For the Moss box, Redline MTL works MIRACLES! In proper working order, the Moss box shifter is short, quick, and very crisp. If only the synchros actually worked. For getting into first from the stop:

  1. Depress clutch FULLY
  2. Shift into 2nd.
  3. Shift into 1st.

Whether up or down shifting, shift into neutral, wait 1/2 second, then shift into the next gear. If down-shifting, try to RPM-match. DON’T downshift into 1st, unless you’re moving at a crawl.

A Moss box, no matter how good it is, will NEVER allow you to slam it from one gear into the next - the synchros were never that good. But with the 1/2 second delay, it will shift quietly every time, except for 1st. The one real advantage of the Moss box is it is darned near indestructible.

Ray L.


I’m going to try MT-85 this time. I think it’s newish. Before there was MTL which is 75W80 and MT-90. This one should be right in between. I just put it in my VW and it’s seriously outperforming the factory labelled fluid.

sorry then, I got the impression his car had a 4.2L synchro trans from a newer car. I dont know my Moss transmissions, I am a one trick pony.

Yes Bob,

I do have a 4.2 synchro trans from a newer car. The Moss box is long gone. You are saying to use the Red Line MT-90 oil in this trans?


In that case, there is something very wrong in your box. A properly working all-synchro box shifts very nicely, and has no trouble at all going into first. A rebuild would be a LOT cheaper than a 5-speed.

Ray L.

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Brian, Yes!!

The Red Line MT-90 has been tried and used by a number of people with synchro trans on this forum with great results. myself included. I had the exact issues you describe. put in the MT-90 and drive it, the more you drive the better it will get too. I thought something was very wrong in mine, but this has made a significant improvement. not saying a rebuild wouldnt be the best option. but for 40 bucks or so you can sure try this cheaply


There was a very recent post about some synthetic Ford trans oil, but I have been very happy with the MT-90. the Red-Line isnt cheap either as its about $20 a quart, you need two quarts to do the job.

You’ve made some really good points on this thread, but I would argue that a 5-speed would probably add value to the majority of E-types out there, especially if the original trans were supplied as a spare.

The only exceptions I can think of would probably be cars that had strong potential to win major concourse events.

Brian definitely try the Red Line MT 90 first, it transformed the shifting and especially selecting first gear in my 4.2 all syncro box. I don’t know what oil was in there when I bought the car but I hated the box and now it’s far better. I use the Ford XT gear oil in my T9 5 speed in my MGA and it works far better than the MT 90 did. So if there’s no improvement with the MT 90 try the Ford XT; both far cheaper than a 5 speed.

However I’d still like to install a 5 speed in my car just for the high speed cruising and quieter operation,

I might have to try that in the T9 in my ‘67 MGB.

I’ve tried MT-90, a GL-4 gear oil from Brad Penn, and now a GL-4 by Driven/Joe Gibbs. It’s not been terrible with any of them, but I’ve always felt there was room for improvement.

Your clutch may be dragging causing your first gear (lack of) engagement issue. Have your clutch adjusted so you can shift into first or better yet reverse w/o grinding. Then decide if your trans is that bad.


Dave is right, I bet. Saved me more typing, too.

Holy crap! I rebuilt everything on mine including the rearend, but the tranny is way beyond me. And there is one point in reassembly IIRC where there are three balls that need to simultaneously get seated. Took my buddy, whose specialty was English transmissions quite some time and an extra
pair of hands as we tried to maneuver that together.

Yeah same on the Moss except it’s 5 balls/springs! There are a couple options. A large hose clamp can be strapped lightly around to hold the balls compressed as you squish the sleeves together, kind of like pushing assembled pistons into the cylinders. Or you can lay the assembly in a press, and apply a tiny force. Push the balls in, apply a bit more pressure, push the balls again etc.

I hired someone to do mine because I was too tired and busy but I’m certain I could have done it. There isn’t much magic in there, just a lot of really heavy steel that I can’t lift.