Return to Website

NG Owners Club Forum

Welcome to the NG Owners Club Forum.

This forum is intended for members of the NGOC, if you are not a member
please consider joining  it only costs £15 a year...

The views & comments expressed on this forum are the views and comments of the person that posted them. The NG owners club does not take any responsibility for any views or comments made on the forum. The NG owners club reserves the right to remove any posting from the forum.

NG Owners Club Forum
Start a New Topic 
Author
Comment
View Entire Thread
Re: Overdrive on a Marina based TA

Hi Jeremy and thanks for responding so quickly. I guess I'll have to buy a Triumph gearbox then if I want overdrive. My research suggests that I need a Spitfire or Dolomite 1500 single rail overdrive gearbox with a cast iron bellhousing if I' want to have overdrive, finding one at a reasonable price and quickly will be a challenge. Any out there in the club? Also, anyone need a MG overdrive box (dipstick model) lol?
Cofion/Regards
Dafyddcoch

Re: Overdrive on a Marina based TA

Hi Dafydd,

If the gearbox was fitted to the Spitfire then I presume the same box was fitted to the MG Midget 1500. If so the Wrexham based MG spares/breakers might be worth a call. I know its the other side of north Wales to you but probably the most handy possible source!

The Marina 1275 gearbox I have here has a cast bell housing, and a flat steel plate on the top. I was keeping it as a spare for my mates MG Midget 1500 but if its not the same I may as well get rid of it.

They might take your MGB box in exchange - is its 3 or 4 syncro box by the way? (If its a 3 syncro box I might be interested if its going spare)

Cheers
Jeremy

Re: Overdrive on a Marina based TA

This is the place:

http://www.welshmg.co.uk/wordpress/

They have two Midget 1500 gearboxes on thier ebay list - £100 and £150 but neither have overdrive.

(Look just like the gearbox I have).

Cheers
Jeremy

Re: Overdrive on a Marina based TA

Thanks. I think the 1500 midget box is a single rail Triumph box also so it should look the same. I have a 4-speed non-overdrive box now but could really do with an overdrive or 5 speed solution as the car is going to be my everyday car and used on dual carriageways/motorways. Regarding the MG overdrive box I purchased in error, the guy I purchased it from (Classic Rides her in Wales) is a really helpful chap and has said he'l look for an Triumph single rail overdrive box for me. As long as he doesn't want it back I would be happy to come to an arrangement with you regarding price and getting it to you somehow. it is complete with the overdrive and is apparently all good.

Re: Overdrive on a Marina based TA

Hi Dafydd,

Sounds like you do need the overdrive if you are going on dual carriage ways etc., it does make the cars a little more long legged. The wheel size and the rear axle ratio will also have an impact.

I run on 14 inch wheels although many TA's are on 15's as are other models, it will run happily at 70mph.

The axle ratio on my car is stock MGB I think its 3.9:1 for an overdrive car with a banjo rear axle. Not sure what Marina's are but they ran on smaller 13 inch wheels originally so it might be different.

If the MGB box is spare and is a 3 syncro box then I would be interested at the right price. Let me know - no rush. I'm pretty sure the 4 syncro boxes are a different length - but someone with more knowledge can put me right if that not true.

Cheers
Jeremy

Re: Overdrive on a Marina based TA

I'll measure the MG box and see if either of us can find out the information we need. BTW it was out of a 1971 model.
cofion/regards

Re: Overdrive on a Marina based TA

Hi All,

Just to add my two pence worth. Have you looked at the Sherpa option? My understanding is that the late 1800 'B' series /early 'O' series shared the same engine back plate which means that you could fit the 5 speed LT77 gearbox directly on the back of the 1800 'B' series engine. There is also some compatibility between the Sherpa and the TR7 regarding gearboxes. There are a couple (maybe more?) different lengths of gear change remote so this would also be something to look out for. Also the bell housing differ in size with the 3500 bell housing being the smaller more compact unit.

One thing to watch out for is that the spigot bearing in the end of the crankshaft differs between Marina and MGB (MGB being bigger. So just consider this when looking at different options.

I have a Marina based TF with the LT77 gearbox fitted running on 15" wheels. It has been in this configuration for the last 20 years. This makes cruising at 50-60MPH very relaxed and can run at 70MPH no problem although things do get a bit draughty at that speed.

I hope this helps rather than confuses but I am happy to talk things through with you on the phone if that would help. Send me a direct email and we can exchange numbers

Regards

Paul

Re: Overdrive on a Marina based TA

Thanks for that Paul, I have discovered today that the spigots are a different size but think that swapping the bearing around will fix this> I will indeed get on the phone and ring you up. I have a friend with 3 scrap 200 series Sherpas but they are Perkins engine models and the gearboxes seem huge. but wonder if a bell housing from a O series engined Sherpa would bolt onto an Perkins engined gearbox and give me a 5 speed box that would fit.

Regards

Re: Overdrive on a Marina based TA

Ooops, I forgot to give you my email address which is dafyddcochparc@hotmail.co.uk
Regards

Re: Overdrive on a Marina based TA

Hi Guys,
I have a Marina based TF (Pastiche) and decided another gear was required, I looked at getting the leyland overdrive unit but as mentioned that is a pretty rare item,

I managed get an LT177 box for the right price (nothing) but the bell housing proved to be the stumbling block for a bolt together answer.

Then I discovered another option a Marlin owner had done a really good job of fitting the Ford type 9, 5 speed box to his marina based Marlin Kit car,

He sells a Kit including gear ratio calculations, a machined adaptor plate and good instructions with dimension for the bell housing machining etc, it retains the marina clutch complete but does require the rear mounting to be changed and the gear lever moves backwards a couple of inches. I ran it on my car for a season before the engine started burning more oil than petrol.

I hope to get my act together and get the new engine sorted and the car back on the road before the end of the year.

Cheers Chris

ps I have the details on my computer at work but I think his website is 5speedmarina.com

Re: Overdrive on a Marina based TA

thanks for that Chris. I have come across the website and noticed that a Type9 is an option and the bolt together advantage is tempting as despite having welders etc my garage floor is earth with flippin huge rocks sticking up and no ramp or pit. I'm not a Ford fan but tehy did make good gearboxes generally so I can see why they're popular.Did you have to do any fibreglass re-working? Regards

Re: Overdrive on a Marina based TA

Just to be clear -

1) You have a Marina gearbox that needs a refurb

So - rebuild the gearbox - I've used Klassic Transmissions for my Sprite box - Ken is a nice guy and on 'your' side of Birmingham - http://www.klassiktrans.co.uk

2) You have the MGB engine and overdrive gearbox ?

All you need is a propshaft to suit the MGB gearbox flange to Marina rear axle and maybe a mod to the NG gearbox mount ?

I did a quick search - these guys are near me - http://www.premierpropshafts.co.uk - never used them, but a custom propshaft is a common fix for custom cars - lots of people can do it.

With regards to changing gearboxes :-

The LT77 box has a load of ratios to choose from, you need to get one from a Rover SD1 - otherwise you will a really low first ratio - so low as to be unusable.

For the good LT77's - i.e. the later 'D' suffix boxes you will be competing with all the MGB V8 owners and V8 kit car owners, so you'll pay for a good box - god help you if you need the same bell housing as the V8's - the bell housing alone will fetch £250 on eBay.

The LT77 is a notchy box on cold days and to be honest, not that strong even in D suffix version - I've had two rebuilt - so any box you buy second hand will need a rebuild. - cost's about £500

For the Ford type 9 box, you will competing with all the Midget/Sprite owners - this is very popular conversion - and all the Westfield type cars - again you will be paying a premium for a good box.

For my money and to get you running I'd get Ken to have a look at your Marina box or find out exactly what need to happen to get the MGB od box in - somebody like Moss Europe or http://www.fastmarinamagazine.com might help - I don't think I'd tell them you have a kit car - just ask "how do i fit an MGB overdrive box in my 1800 Marina.

Malc

Re: Overdrive on a Marina based TA

Thanks Malc. Measured the MG overdrive box today. The box with overdrive unit is a bit longer. The gear lever would actually end up more central in the aperture of the tunnel than the Marina on!!The MG mounting is a few centimetres nearer the engine on the MG box but the hanger but a fabrication that bolted onto teh TA chassis gearbox mounts and the torsion bar mounting might make it an easyish modification. Only potential problem I can think think of is the increased length of the box and teh subsequent shorter prop would make the already sharp angle on the prop even more severe and maybe chew up the rear UJ. Not sure but worth considering, What do you think?

Thanks again, much appriciated
Regards

Re: Overdrive on a Marina based TA

Hi Dafydd,

The MGB propshaft is 31 inches long for comparison purposes.

Cheers
Jeremy

Re: Overdrive on a Marina based TA

Thanks again Jeremy. Will have a look over teh next few days and see what can be done. I now have a good Marina 4 speed box so may go with that for now so we can start useing the car ASAP and then work out what to do re 5speed/overdrive later on. I have teh engine bits coming this week (big end and main hells, top and bottom gasket set, timing chain etc) so it will be ready to put back in soon and I need it working and ready for MOT within a couple of weeks. I must say however, w"hat a bunch of helpful and informative owners in this club/forum", Thanks or Diolch as we say here in North Wales.