Strange 5 Speed Conversion - Will it Work?

[PAUL161]

Hap, I've always taken your expert advice. The article you just wrote is very enlightening. The Moss conversion was the first I gave a lot of consideration to due to the completeness of their kit. It seems that no modifications have to be made to the chassis, which I don't want to do, thus taking the car back to original is merely a bolt off bolt on job. Thank you for your input on this. It was very informative. PJ

 

[PAUL161]

Just read the complete Moss installation instructions and was sad to see the chassis does have to be modified/cut in a couple places for their conversion. I won't cut the chassis on this matching number car. Oh well, on to the next. I guess it'll be the gearing in the rear. PJ

 

[drooartz]

Is this for your MGB or the TF? If for the B, there's always sourcing a proper OD gearbox (https://www.quantumechanics.com/). I'm assuming this is for your TF though...

 

[PAUL161]

Is this for your MGB or the TF? If for the B, there's always sourcing a proper OD gearbox (https://www.quantumechanics.com/). I'm assuming this is for your TF though...

It was an idea I had for the TF Drew. The B has OD and is in like new condition. The TF has a 4.8 rear and in first gear you can climb trees or pull stumps in first gear. First is actually useless. With the Moss setup, the chassis has to be modified and that is a no no. So, I have an early B banjo rear with 3.9 gears that will fit into the TF housing, but it might be a bit too tall for the 1500 engine, even though my engine has been totally rebuilt. PJ

 

[drooartz]

I'd imagine the TF 1500 would be able to pull the higher rear gear just fine. That's a pretty popular swap from what I've read, and does make first gear usable -- though doing some rock crawling in a TF would be exciting for certain.

 

[billspohn]

It was an idea I had for the TF Drew. The B has OD and is in like new condition. The TF has a 4.8 rear and in first gear you can climb trees or pull stumps in first gear. First is actually useless. With the Moss setup, the chassis has to be modified and that is a no no. So, I have an early B banjo rear with 3.9 gears that will fit into the TF housing, but it might be a bit too tall for the 1500 engine, even though my engine has been totally rebuilt. PJ

Why not just fit an MGA ratio to the MGB diff casing? Need the right spiders (most MGA = coarse spline except later 1600/Mk2)? The 4.3 ratio is a nice compromise and you won't need to bugger about with the trans.

 

[PAUL161]

It was an idea I had for the TF Drew. The B has OD and is in like new condition. The TF has a 4.8 rear and in first gear you can climb trees or pull stumps in first gear. First is actually useless. With the Moss setup, the chassis has to be modified and that is a no no. So, I have an early B banjo rear with 3.9 gears that will fit into the TF housing, but it might be a bit too tall for the 1500 engine, even though my engine has been totally rebuilt. PJ

Why not just fit an MGA ratio to the MGB diff casing? Need the right spiders (most MGA = coarse spline except later 1600/Mk2)? The 4.3 ratio is a nice compromise and you won't need to bugger about with the trans.

I'm sort of going back and forth with a transmission conversion. My transmission is in near perfect condition and has given me a lot of doubt about changing it out. I know a 5 speed would make the car more pleasant to drive with all syncro gears, but taking away it's originality bothers me. I think, (not sure), that changing the rear ratios , which is undetectable to the eye, would be the way to go. I can get a rear from Arizona already converted and give him mine as a core for around $1200. Easy bolt out bolt in job. We'll see. PJ

 

[drooartz]

Forgot that the common swap was the 4.3 not the 3.9... I'd vote for doing that 4.3 swap in your TF. Keeps the originality (you can always swap back) while giving you some better cruising ability. Cheaper, too.

 

[Hap Waldrop]

First off Moss is by no means the inventor of the T9 kit, that honor goes to Peter Gamble of the UK, and a bunch of folks sold the T9 kits a decade or more before Moss jumped into the game, one the first in the US to do it with MGs was Butch White, who was friend of mine, although I didn't get to know him long enough, before we lost him to cancer. I sell T9 5 speed kit as well,and all them are using gambles parts and pieces, and I only sell them for MGBs and the ocasional MGA, mostly because with the MGB, what the T9 kits was originally designed was for, it is the Cadillac of MGB 5 speeds, by leaps and bounds, no drilling, no cutting, no oddball custom conusmable parts, all the clutch parts are 100% MGB, even the disc, and the cross member and drive shaft are improvements over the stock MGB parts,and are more user friendly. It's a win-win all the way around, the other kits don't even come close in design.

OK with that said, the UK folks also use the T9 kits for the Spridgets, but I don't offer this kit for sale, even though is available to me, for the reasons you have to butcher the car by cutting out the permanent crossmember and tranny tunnel to make it work, I can't think a lot of US Spridget owners are going to do this this to their chassis when the Datsun 210 kit are avaialable to them, and recommend Spridget owners go with that kit.

The T9 kits have now been appiled to alot of applications, but none of them are enarly as slick as the MG fitment. I don't know about T series cars, probably never will, so it sounds like there is lot of room for improvment in design compared to what is currently offered, common sense would tell me T series owners would be even less inclined to cut on the bodies and frames than the Spridget crwd, based on the rarity, and age of the T series cars. A Suzuki Samari is RWD desgn and it has a samll size to it's tranny, about the same size and length as a Spridget gearbox, who knows that too might be a tranny to look at for the T series.

 

[Hap Waldrop]

Drew I'll tell you this firsthand there is no camparision between a good 5 speed and the OD, the 5 speed is much, much, much better, if your OD ever implouds don't look back, go with a T9 5 speed, going with a T9 and rebuilding a OD is very simular money and it's a no brainer.

 

[drooartz]

Drew I'll tell you this firsthand there is no camparision between a good 5 speed and the OD, the 5 speed is much, much, much better, if your OD ever implouds don't look back, go with a T9 5 speed, going with a T9 and rebuilding a OD is very simular money and it's a no brainer.

I don't doubt that the 5-speed is a better box than the OD, I just like the vintage feel of the OD setup -- it's just cool to reach a finger over and flick that switch. It's part of why I have an MGB instead of a Miata or similar. I'm more of an originality guy than I thought, I guess.

That said, I'm still saving my pennies for an engine build some day...

 

[billspohn]

I will have to respectfully disagree with Hap on this one.

The factory OD offers instant shifts between 3rd and 3rd OD with the flick of a switch - no rowing around. On winding roads (i.e. the best sort) that is a very useful feature, the equivalent of shifting between 3rd normal and 4th normal, but by just flicking a finger to do it.

That may not sound like much, but if you've ever experienced it, no 5 speed can match it.

Are the modern 5 speeds better transmissions than the original MG boxes? Of course, but having said that, just how much of the original car are you prepared to throw away for the sake of making it 'modern' or 'better'? All of it? If not, then where do you draw the line? The factory OD box does the job very well and does not cry out for replacement. The only reason that the 5 speed conversion is popular here is that for some odd reason, while most home market cars had the OD, relatively few were shipped that way to North America, where we really needed it!

 

[drooartz]

while most home market cars had the OD, relatively few were shipped that way to North America, where we really needed it!

I never really got this, though I sorta maybe kinda understood their approach -- OD made the cars more expensive, I suppose, and in the US these were always the "cheap" sports cars (though I think Americans would have paid the extra for the OD). Cars in the UK were always more expensive in general, so folks were be more willing to pay the extra to have all the options.

Did seem strange, though, as the US is a *big* place with lots of open stretches. But then again many US cars in the 60s didn't have any overdrive gearing either...

Different horses for different courses I guess. I'm happy with my OD and one will stay in my car for as long as I own it (it's a UK home market car and had the OD from the factory). As to this thread's original question, had I a TD or TF I would do the MGA rear gear set swap and call it good though I wouldn't turn down a car that had one of the 5-speed swaps if it was done well.

Just as long as you drive them, it's all good.

 

[Hap Waldrop]

I won't get in a big debate with Bill on this one, as we would never agree , but I throw a couple of pros out there as for the T9 5 speed vs OD, or a MGB 4 speed for that matter.

Much improved upon cross member design, much better tranny mount set up, and it bolts in place the same as the stock cross member, the T9 crossmember is piece of artwork.

Slip jointed driveshaft on the front, this should be biggie to anyone thats had to deal with original MGB driveshaft's front side.

No electrics to deal with on the 5 speed.

The T9 trannys are pretty much bullitproof

The cost of pro built OD and the complete T9 kit (including a guaranteed for 1 year gearbox) is $100

I think one of these deals as to what folks have, is what they like or prefer, I've had both, and far prefer the T9 5 speed.

 

[billspohn]

1 - only the generally inferior MGB had a so-so mount design. The MGA used a giant metelastic joint that prevented forwad motion and never failed on lateral location. The MGB replaced that with a pair of pad joints and a fore/afet steady rod, and had to add another bracket for the top of the motor mount when even that jerry-rigged assembly failed to match the performance of the MGA single mount.

2 - I hate slip jointed driveshafts and much prefer one that won't dump a pool of oil on the floor when I remove it. MGAs used to have a slip jointed shaft early on, but came to their senses and improved it by 1958.

3 - if you want to sell me a T9 with guarantee for $100, I'm your man, though!!!

Just so you don't get the wrong idea, the T-9 is a far better more modern transmission, and a nice swap for anyone that really wants to go that way. But there isn't a whole lot wrong with just using the stock stuff if that's what you want to do.

 

[Hap Waldrop]

Bill I ponder your points, as I'm driving a MGB GT with a new engne, carbs and T9 5 speed up I-85 Sunday to take it back to the owner

 

[DNK]

while your on the forum
Dang Hap,...you are good

 

[billspohn]

Bill I ponder your points, as I'm driving a MGB GT with a new engne, carbs and T9 5 speed up I-85 Sunday to take it back to the owner

And I have no doubt at all that it is a joy to drive (and that the conversion was carried out to the very highest standards, of course).

And I enjoy the T5 in my Jamaican, the all synch MG OD in my MGC and the non-synch close ratio OD in my race car as well (possibly the last is the very best of all). :thumbsup:

 

[JPSmit]

There is a lot out there about T5 transmissions - they also have interchangeable tail pieces for shifter location. Just a sample:
Many faces of T5 transmission
Ratios of different T5 transmissions
shifter location

 

[billspohn]

The T5 is readily available in North America, has a higher torque capacity, but is slightly larger and requires a bit of massaging of metal to fit in MGs (pretty easy, though). The T9 has the advantage of being enough smaller that it slips into the stock space in the MGs and unless you are also running an engine conversion, you don't need the added torque capacity anyway.

The downside of the T9 is that it didn't come in any cars with great availability in the North American market, so unless you get lucky and find one of the odd cars that did have it here (Merkur XR4Ti), you'll need to import from the UK.