Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing plus 8 gearbox

Hi folks

I have a pretty strong 5 litre motor in my car and I'm looking to swap the LT77 gearbox before it breaks. The R380 looks like a simple swap but is not a lot stronger.
Has anyone tried the Quaife straight cut gear kit in the R380? The ratios are as described in gomog (http://www.gomog.com/allmorgan/gearboxes2.html#CLOSE). They are a good match for a light car, but I'm worried that it might be too noisy ...I don't mind the straight cut whine, but you can have too much of a good thing.

Anyone have experience of this? Or can suggest another way to go?

Regards
Terry
(Canberra, Oz)

Try New Elms, Tim Ayres has lots of experience of racing and +8's and is pretty helpful.

If its for a road car just dont have straight cut gears they will drive you nuts!! if I was you I would go down the T5 route which will be much cheaper than Quaife internals? There is a Class A Morgan running in the Morgan Challenge race series in the UK which is pushing out about 360/380 BHP quite happily on a T5 but this would be very close to the limit!!!
Talk to Peter Mulberry at Mul fab he can supply the bits to connect the T5 and might even have a box?? (UK) 02476 397666 or pmulberry@aol.com
www.mulfab.co.uk
Racer

2nd the T5 route.

For regular road work semi helical or helical gears won't get on your nerves like the whine of straight cut race-set and the T5 is a well trodden path.

Both my modified 4/4's run Quaife straight cut clusters, nice but you have to know what your getting into in terms of cash and living with parts designed for the circuit rather than touring.

Thank you all for the advice

I've weighed it up and had a word with Peter Mulberry (helpful as ever). T5 it is, but I want to get the semi-helical close ratio version. I have also looked at G-Force and I'm a little confused as to differences between G-Force 5 speeder and gearboxman T5 semi-helical. I've made enquiries and now wait patiently for replies from suppliers

Terry

Hi Terry,

when i rebuild my +8 from 76 with a 4.6 Stage 3 engine i lok also for a better gearbox. I used a Tremec TKO with a JDS Bell Housing.
The shifter is 15 mm out of the original position, it has a mechanical tacho output, the ratio is very close to the original gear box, the 5th is 0,68 as an overdrive.
Importend is also the rear axle, i used a Ford 9" build by Moser.

Regards Manuel

here you can find pictures

http://www.talkmorgan.com/ubbthreads.php/galleries/161555/Gear_Box

Manuel
Thank you for this. That is a heavy duty car! Well done, I'll bet it's a lot of fun
I looked at a Tremec tko 600. They are very strong and will work with my engine. I also know they are as heavy as an R380 at roughly 50kg, and very bulky - I would accept that if I could get one to fit the space. However I have also heard that they have a very slow gearchange, especially 2nd into 3rd.
I would like your comment on two matters:
1. Is the gearchange something you needed to "get used to" in your car?
2. Do you find the wide spread of gears to your liking? (there is no close ratio option from Tremec)
Regards
Terry

Terry
it is the 3550 TKO. The weight is 45 Kilo without the bell housing.
The gear change is very fast, only 60 mm from gear to gear.
For my use is this a perfect gear box.
Go to the pictures, i added some more informations.
Manuel

Thank you to all for the advice

I'm pretty settled on a T5 with Quaife semi-helical internals (http://www.gearboxman.co.uk/infot5.html). It uses the original Sierra Cosworth ratios (2.9 1st, 1.9 2nd ....)which will, as Peter Mulberry pointed out, lead to a drop in revs of less than 2000 when changing at 6000. That looks quite OK to me.

I have heard that this Quaife box has been known to break in Class A cars, but the grip at the rear on a typical road means you can't put more than 400 ft lbs or so through the propshaft, so I'm going to try it.

We'll see.

In case anyone is thinking of upgrading the gearbox, I've done it now. Various factors pushed me back to a 380 and I got the close ratio straight cut one from Dave Ashcroft. It was a bit of a fiddle to fit, but it is beautifully made and changes sweetly. It does whine (not in 4th of course) but I like it. Open cars tolerate noise.
The speedo now reads low (50 mph indicated is 57mph according to the phone GPS)... I think swapping drive gears is going to be too tricky with the box in, unless someone tells me how
I am happy with it, and the car now goes and sounds the way I like it. I don't intend to tour in it, I think it might not suit that very well but it suits the car.... Aero screens and twin roll hoops behind headrests, stripped down look. About to get its Tillet B6 seats fitted

Terry