Rover V8 Brand New Two Wheel Drive Gearbox Options

The LT77 and R380 gearboxes have been the main two wheel drive gearbox options on the Rover V8 for a long time. However, at their core they are modified Land Rover gearboxes and often don't provide the right experience wanted for a two wheel drive car such as an MG B or kit car. What's more, as time goes on more and more of them are starting to show their age (with even the newest ones being over 20 years old), and parts are becoming harder and harder to get hold of to rebuild them.
But now there are two options on the market for brand new two wheel drive gearboxes. One is the superb and well proven Tremec T5, and new in to us at RPi is a Mazda gearbox kit, recently seen in use and performing excellently on the 4.6 stage 3 MG B GT we've had in our workshop. In our eyes, the Mazda box is now the best value for money gearbox option for almost all two wheel drive Rover V8 powered cars.

[@sidecarbod1441]

The T5 box is available in two forms, world class and non-world class, the former has differences in the shaft bearings and synchro's, I believe. You can also get Quaife close ratio gears which are straight cut, or at least a straighter cut than the standard gears which reduces side thrust. (but they are noisy). It could be argued that a V8 in a light car does not need close ratio gears but the main difference is the taller first gear which is really useful rather than having to shift into second when you have only moved 10 feet from stationary. Using a gear calculator tool I worked out the following top speeds at 6k RPM for my Cobra replica running a stage III 4.6 (with a 100 BHP NOS shot)....1st gear=53 MPH (not that I rev it out in first), 2nd gear=80 MPH, 3rd=107 MPH, 4th=135 MPH, 5th=155 MPH. I have not worked top speed out for reverse!

[@kennyh5083]

Great except the guy in the backseat has to do all the shifting!

[@bryanphipps8654]

What clutch splines do you use on the Mazda gearbox ? Does it use the same spigot bearing ? I know the T5 is a metric spline, and uses a different spigot Thank you

[@RPIEngineering]

Hi Bryan, The clutch setup is all OE Mazda parts including the needle bearing. All done to mate up to the Rover V8 engine.

[@mddaly6082]

@@RPIEngineering Does the Rover flywheel need to be re-drilled or does the OE Mazda pressure plate bolt up to the standard V8 flywheel? Cheers.

[@RPIEngineering]

@@mddaly6082 Sorry since my last reply I later discovered its not OE Mazda. The pressure plate is made specially as to match the mazda splines and rover clutch cover size. No drilling of the Rover 2 wheel drive fly wheel is required though. It bolts straight on.

[@mddaly6082]

@@RPIEngineering thanks for the reply; I couldn't find anything OE that would fit so that makes sense.

[@vincentmarino9825]

Does the Mazda gearbox require a custom bellhousing or does any Mazda 5 speed bolt directly to a Rover v8?

[@RPIEngineering]

Its a custom bell housing which is only available along side the purchase of a gearbox / clutch setup.

[@trevorquinnell8515]

Hi mate does the shaft from the mazda gearbox and t5 fit straight into rover 3.5l what work am expecting to do from auto to manual conversion please i need this information

[@RPIEngineering]

With the correct bearing in the end of the crank shaft yes direct fit. You can see more in the shop here shop.v8engines.com/manual-gearboxes-and-parts-14-c.asp

[@ratziism]

is this conversion strong enough for a TVR 5.0 Engine, with roundabout 350HP and 500NM? Thanks :)

[@RPIEngineering]

You would want the T5 for that power output. Many TVR's got the T5 as standard though so it would be worth while checking to see what box you currently have.

[@rockinnathan]

Do you do bell housing kit and bits

[@RPIEngineering]

Sorry but we only supply the gearbox complete with the bell housing and parts.

[@rockinnathan]

@@RPIEngineering how much are these

[@mjelkin89]

Hi is there a Mazda 6 speed rover V 8 conversion also ?. Thanks.

[@RPIEngineering]

No it is not. A 6 speed is not really needed either with the torque of a V8

[@user-fd1sd7hr9o]

What is the measurement difference between Mazda and lt77?

[@RPIEngineering]

Unfortunately we have not been in a position to measure one. i.e we have not remembered or needed to whilst having a 77 or 380 our of a car.

[@user-fd1sd7hr9o]

@@RPIEngineering shame as it the measurements of the lt77 both these replace would be useful information for those considering a swap that don’t have mg. 👍🏻

[@trevorquinnell8515]

You fail to mention if holden or ford t5 there is difference and i need to no please

[@RPIEngineering]

We are not familiar with all the T5 box variants as its the Rover V8 engine we focus on and these gearboxes are options that we have sourced over the years to be able to supply 2 wheel drive manual options.

[@petyrkowalski9887]

I wonder what the weight differences are between the two?

[@RPIEngineering]

around 23KG saved between a R380 and the Mazda gearbox

[@petyrkowalski9887]

I thought it would be significant. Thanks

[@lucasarredondo1429]

​@@RPIEngineeringgreetings and blessings. I had surgery on the cervical spine, I have screws and plates in the spine. Driving with a manual transmission is not an option for me. The most affordable transmissions I have where I live are the 4L60E in V6 and V8 versions. Could you give me advice beyond the adapter plates? The engine is from a 2000 Range Rover 4.6 to be used as 2WD. Thanks in advance for your answer and for your videos that I enjoy so much.

[@grzegorzluterek6308]

How much for new gear box

[@RPIEngineering]

Hi, we have them listed in our shop shop.v8engines.com/manual-gearboxes-and-parts-14-c.asp