Thread: 51 MG restoration.

Totally agree Tom. Only at the start of the research.
But yes, I take off in second strong currently so am comfortable dropping to the 3.7, as it’s available and if I do that first, like end of this season, and run on it for a while I can then upgrade later to the fully synch’d Tmmc 5 spd. Haven’t seen a 3.44 option out there for this diff so far in my research.
This chart shows those specs, in mph, not km’s, my 4 spd vs the 5 spd with the same 3.7 rear gears.

At first glance, seems to be about where I wanna be, cruising around 2.5k rpm at 60 mph and look at that top end in 5th at red line.
Do not ever intend to get this 1300 lb car going that fast, but wowee!
And if I do stay with my 4 spd, seems to be a good spread as well, 3000 rpm @ 60 mph would not be too screamy I don’t think, as long as it still has the torque.
Ideally an assortment of ring and pinions would be nice and a track to play on, but seeing as how neither are possible, I’ll have to pick a lane and evolve slowly I figure.
Here are the tranny gear ratios for both

What you have going on Tom sound perfect.
Good luck figuring all that out Mike.

Chasing classic cars….was watching this today….had an MG on it…though you would enjoy this episode

Had a bit of a deal fall into my grasp this week.
The gent I got my mgb front end had the rear end still from same mgb, a 68 tourer with a 3.909 rear end.

tear down in progress, mine on the right.
Not the ultimate ratio, but will get me way closer, and still should give me a fairly strong low end.
The best part is I have it in hand, and will not have to align shims etc as I am changing the entire pumpkin and it’s already shimmed and balanced for its gears. Just need to swap sun gears for the half shafts.
Should be installed today after work.
And he has a couple very cool cars, one a fiat, I’m not familiar with.


And this sweet, one of a kind project..

An Aston Martin DB5. Brand new, fully fiberglass body. Going on a z3 frame..
Gonna be gorgeous..

Great find. Much better than having to tear it down completely. Good luck.

Yes, at least you can learn what that much will do for you.
If it's not quite what you want, at least you will have a more exact idea how much more you might go.

Having another 3rd member would be great in that respect. Re-gearing a spare will result in little down-time.

Zactly my thinking Tom.
A simple test, relatively cheap, and a spare pumpkin to rebuild with the new gears, if I need that extra .2 advance.
This’ll get me to the point I can plan and find a w58 for fully synced gears and an overdrive.
If I could get out early it’s be done today.
Damn pay heck earning requirements.

Not the most difficult of swaps once the drift pin was removed.
Took my time, made sure things went back the way they came out and now I’m waiting on the silicon gasket material to set up overnight before I refill the oil and test her out.
Can’t wait!

So no spanner adjusters on the carrier bearings? Looking good!

The carrier bearings were undisturbed during the swap, as were the shims used to align them originally, so my gaps and lash are all as tight as the factory made them still. Once assembled I have 15 thou backlash between the crown and pinion gear and everything feels loose, not sloppy, but free spinning.
Verified my reduction @3.909 and am filling up the 75w90 gear oil and checking for leaks.
Road test later.

Maybe 4 hrs to do the job in and out so really, an easy swap all things considered.