WHICH 5-SPEEED TRANNY FOR MGA

Good evening all-
I've finally given up nursing my MGA 1500 tranny past 1st gear everytime I stop for a traffic light, etc. I have an rb MGB parts car with a nicely running 1800 and an ok 4 spd tranny (yes, I have a strong dislike for electric overdrive).
I'm collecting the parts necessary to install a 5 speed box. Should I use a 280z box, or a T5/T9. All the assembled kits seem to be overpriced for what they actually give you, and i have access to a transmission rebuilder with more than a few years experience.

Let you know your choice of 5 speed box, particularly if you presently have one installed in your MGA.

Regards all, Lee B.

I have both MGA and MGB. MGA first seems easier to go to from 2nd gear. Guess I have a shift habit. I am a purist and plan to keep my MGA and MGBGT pure as I can.

I have a Sierra 5speed in my MGA with an 1800 engine. Perfect fit with no modifications to the car. I say it is the way to go since you will keep an original car.

If you can get a T-9 and want a few parts for the conversion call Peter Gamble at HiGear and you can surely get the bits you need. Peter will be most helpful in your project. I got my custom kit from him.

Unlike you Lee, I actually enjoy the vintage feel of the MGA and Mk1 MGB gearboxes. For me it actually ads to the entire experience. What I never liked in either car though is the perpetual sensation of wanting another gear after fourth at anything over 45-50 mph. Hence my MGB received a 3-synch O/D box (a very simple conversion) many years ago and I've just bought one of Pete Gamble's 'Hi Gear Engineering' Ford Sierra (T-9) based conversions for my MGA. It arrived from the UK this week and is going into my MGA next week! Again the choice was based on the reputed ease of the change-over; it's all worked out; everything needed for the installation's supplied, and there's no metalwork modification or fabrication needed. Many here in Australia fit Toyota Celica, Toyota Supra or Nissan gearboxes, but I haven't the time or inclination to try to engineer my own solution to the jig-saw puzzle.

Another vote for the Ford T9 gearbox. I put one of the Hi Gear Engineering kits in my car several years ago. As other have stated, it is a very straight forward and completely reversible conversion...although I honestly can't imagine why anyone would want to go back.

Thomas-
Thanks for your input. We share a liking for the clickety-clackety of the old BMC boxes. I've been shifting MGA/MGB's since around 1958 and like yourself, yearn for another gear to shift into when you're doing 65mph or so on the highway. I want to try and come close as possible to replicating the 'feel' of the BMC boxes, hence this posting.
Cheers, Lee B.

So here is the question then (maybe one for Barney):

What gearboxes are there out there in the world that will mate up to a BMC engine? 4-speed or 5-speed, with or without overdrive...

1) Ford "Sierra" T5 or T9

2) Datsun/Nissan ??? p/n

3) Toyota Supra/Celica ??? p/n

4) earlier model MGB gearbox without overdrive

5) later model MGB with overdrive

What else? I plan to find myself another engine to tear down and rebuild, and will try to put a 4-speed box that works at 70mph or a 5-speed box on it when the time comes. What are all of my "easy" options, or at least relatively easy options, given that I will be likely looking around in bone yards for the parts, not buying nice shiny new kits.

There have to be a million pre-1975 Toyota Celica gearboxes out there to be had...or something similar.

JIM in NH
Thanks.

Overdrive or 5-speed is a luxury option, generally not cost justified. I have 385,000 miles on my MGA with a 4-speed, so obviously it can get on okay that way, just a matter of getting used to the vintage tunes.

There is no easy bolt-in 5-speed gearbox for the MGA.

People sing praises for the Hi-Gear T9 "bolt-in" kit because it comes with all of the custom made adapter parts included. Stands to reason when you figure that 3/4 of the kit price is for the expensive adapter pieces.

If you would like to swap some sweat equity in place of the commercially available adapter parts, you could spend a LOT of hours re-engineering the job. You also need a milling machine and lots of "free" time (two things that do not often go together). I've never done it, so I don't have the spec's or the drawings. I have a funny feeling that even if I did have the drawings the time required to make one each of all the required parts could have you working for less than minimum wages.

Some time ago a club friend did exactly that with a Nissan 5-speed, and we have some photos and notes here: http://mgaguru.com/mgtech/gearbox/gt401.htm
This should give you some idea of what's involved. He has made the adapter parts for a few other people.

So a later 1800 5-bearing block with a 4-speed MGB gearbox is probably the best alternate engine and transmission option, then if I were to look for something to play with. Barney, what do you do about the high revving in 4th gear problem - fit a different final drive ratio in the pumpkin?

JIM

Jim and Barney-
Thanks for your posts continuing my thread. Are there any recently posted photos of a 5 bearing MGB 1800 w/4 spd box being installed in an MGA. I'll looking for what to do with the MGA rear tranny mount, and the fabrication and installation of the necessary (new) MGB mount.
Thanks, Lee B.

One of the guys in our club has the Sierra box in his A and loves it.

Lee

I put a late model 1800 with od tranny in my MGA MK2 a few years ago. Pros, able to cruise the Interstate at 80mph all day. Syncros in all gears. Fool a lot of people who thought you might have a 1622. Cons, still can get whipped by a soccer mom in a minivan, watch your knuckles when you speed shift.

The rear transmission mount varies depending how you want to mount it, weld a new mount in place or make a transition plate that bolts to the crossmember. Regardless you have to cut off the dog ears but I saved mine just in case I want to return to MGA stuff. Bigger issue was to make the tunnel fit over the od. Lots of work there, then there is the speedo cable and r-angle drive. Had to bend the handbrake handle to make it fit since I had to enlarge the tunnel. Have to move the shifter hole a few inches fwd as it comes out close to the dash. Cut off the shifter by about 2 inches and then your knuckles clear the dash. Also have interference with getting to the overdrive solenoid and filter screen. Need to use a MGB speedo since there is no tach drive. Need to find a place for the overdrive switch, firewall clearance is tight and starter position. Those are some of the things I remember.

Since I had to modify the tunnel extensively I used a spare one, and saved the orig. In hindsight I recommend making the tunnel fit over the floorboards to make removal much easier.

If I had to do it again I mingt reconsider a 5 speed, even though I like the 1800 with a od gearbox. Since I already had a rebuilt hi performance 1800 and a spare gearbox with od it was the cheapest route for me but the time and laobr to make it fit might make it a wash vs buying the kit.

Ron

Ron-
Good morning-
Wow, you certainly undertook a lot of work to get the 1800cc overdrive box into your mga.
I could probably go the 1800cc 4spd (non-OD) box route with one of my extra trannys. I had seen a post in an older thread claiming you can use the front of an 1800 box with the rear of a MGA 1600 box, and simply remounting the 'new' box in the existing 'dog ears' MGA rear mount. Do you think this is feasible/practical?
Regards, Lee B.

I have also heard that you can put 1800 transmission in MGA by swapping the reare housing and shifter from the mga to the mgb tranny. Think i saved the rear part off a 1600 tranny.

There's a fair amount of 5-speed vs. OD discussion on the MGB forum. You might want to check it out. May or may nor pertain to the MGA, but possible.:)-D

Lee

You can pretty much swap MGA/MGB bits around anyway you want. If you use a A box then I would install a MGB clutch along with the B engine. Sure is nice to have syncros in all gears though. The major factors to consider follow: Engine, rear plate, flywheel, clutch, crank bushing, gearbox splines, etc. It is a personal choice and all of it somewhat a compromise between originality and making improvements.

Barney

You are much more informed on the MGA than I am. I do agree that these high revving engines can run all day at 4000rpm plus. I just feel better when they dont have to, I have a personal comfort level of about 3500+/-rpm. On my MK 2 with 4.1 rear axle ratio and OD I was comfortable. RPM's were similar to driving a MGB with overdrive.

But for a road car my MGC does it even better. I like driving the Interstate and usually want to put some miles on the car in a given amount of time. Maybe someday I will be able to slow down and smell the roses and drive the back roads and screw the clock but I am not quite there yet. Patience is a virtue I am working on.

Love you website.

Ron

Gil-
Do you recall if your MGA 1600 tranny tail piece actually had a flanged output shaft vis-a-vis splined shaft.
If it did, and you can find it and wish to donate it to science, I'll pay the shipping and let you know what happens.
Regards, Lee B.

Barney-
Thanks again for the info in your latest post.
Is the larger layshaft the only way to recognize the late '67 MGB gearbox.
Exactly where is it larger than the layshaft in an ordinary MGB 4spd box.
Regards, Lee B.

For late 1967 production only, the layshaft changed from 0.645 to 0.668 diameter and went to four bearings. Shaft, bearings and gear can be changed as a set, but you need to ream out the hole in the case to accept the larger shaft.

Maybe its easier to learn how to ease the mga transmission into first gear. I usually am downshifting to 3rd and 2nd when stopping and it will slip right into first form me. Anyway I want mine original as possiple and not have to put it in MGA1800 or modified class.

Gil-
Good morning.
I have to replace my mga tranny because there is a lot of excessive wear- 1st gear howls and chatters. At the moment, I usually skip first altogether and start off in 2nd gear like an F600 truck.
I've already 'modified' my MGA with push-button electric start, and 2 speed wipers. The extra oomph of an 1800cc might even be fun. I think TR6 wire wheels are next.
For what a good rebuilt MGA tranny costs, I can just about have my choice of upgrades.
It just comes down to which tranny should i use.
Regards, Lee

The answer to cost is to rebuild your existing gearbox, as parts are pretty cheap. If you have a broken gear, then you buy a complete used gearbox for less than the cost of a new gear. I just rebuilt one last week. New layshaft, couple of synchro rings, gaskets and seals, a few miscellaneous bits, and parts were less than $150. Good used replacement gears would be extra if needed.

Barney-
Good afternoon and thanks for the post.
Sounds like good advice and a solid plan.
Thanks again, Lee B.

Ok Lee good luck.
Is your laygear the big problem.

Lee

I agree with Barney, easy to rebuild and parts are cheap. When you start swapping engines and gearboxes sometimes it gets out of hand and costly.

Ron

Barney-
Is there a part number embossed on the MGB to identify a late '67 tranny with the thicker diameter layshaft.
I couldn't locate a late 1967 MGB tranny, but found many '71-74 and some '77-80 MGB boxes. Can the later tranny layshaft, laybearings and laygear be transferred as a unit into an MGA 1600 flanged transmission casing after reaming it out to accept the larger layshaft, etc.
Thanks, Lee B.

listen to Dave Headley..he is building kits for the Bs that will probably work in the A's also,and for a real fair price as compared to ....others.

Wyatt-
is there a particular thread on the MGB forum you have in mind. When it comes to 5 spd boxes, the emphasis seems to be on t5 vs t9, etc., and presently offered kits are really "quite dear" as our cousins across the pond would say.
regards, lee

actually Dave stopped by for a visit and he said he was in the process of setting up kits for Chevy or Ford 5 sp trans for the MGB.....talk to Dave.He's real sharp for an old guy.....Hee Heee. Fab-Tek.

Ok, Wyatt, will do.
Lee

I really like the mga gear box.

I love the tight shifting pattern. But I really like the the fact I need to come to a full stop to put it in first gear. I have saved a bunch of money on California stops at stop signs. I drive it every day and every day I see cops generating revenue at stop signs.

Power is no problem since I have larger valves and a reworked #15 head and a 3.9 rear end and can drive 75mph all day if they let me.
I feel the cost for the 5 speed is way too much for what you get. and in 20 years will you be able to rebuild that transmission?

In my bugeye I converted over to a 5 speed from a rebuilt datsun 210 which was a very easy conversion by comparison and way cheaper. The original shifting in the bugeye was very sloppy so the 5 speed was definitely a better up grade.

My advice is to find someone with the conversion you want and take it for a spin to make sure you like it. You may find the shifting is sloppier than the stock mga.

Just my 2c.

Liam

Liam, it's been some number of years since I've driven a 3-synchro B, much less an A. But IIRC. a 4 synchro B shifts and feel a little nicer than a 3-synchro B and the T5 Mustang I put in the B shifts noticeably nicer than the 4-synchro. Just sayin!:devil:

PO had shortened the shifter on my 57 with original transmission. It made for even shorter throws and without making shifts difficult. I like the mod - more room between shift knob and ehater control. Shifts very nice and crisply.

Jack-
what do you think is the height of the cut-down shift lever, measured to top of knob.
thanks, lee