Gearbox woes

[michael47]

G'Day All
I drove my new Roadster home today and really enjoyed the trip. The previous owner/builder had told me the gear box was getting old and I would need to double clutch going into 3rd well even double clutching it still clunked and it will not downshift from 4th even double clutching.So I guess I will have to replace it or have it rebuilt , the car came with tons of spares (owner had a couple of Marina parts cars)there is a spare gear box but it is not an overdrive unit like the one in the car . Is the overdrive unit something that is just bolted on to the gear box? Is the gearbox a triumph unit and if so from which triumph cars? With Roadsters can the gearbox come out without having to remove the motor? I hope to drive it until the snow comes and then tackle the gearbox
Thank you for any information you can supply
Michael the very happy Marlin owner

[stevejgreen]

Re: Gearbox woes

The good news, and the bad news.
The Marina gearbox is essentially identical to a Triumph Spitfire 1500 and a few others, but let's keep it simple. The chances of finding a Marina parts supplier in Canada I guess will be zero, more chance of a Triumph restorer, though there are a few Marina owners in the US.
There are some variations and differences between the Marina and Spitfire box, primarily the 1800 input shaft that is significantly longer on a Marina but it can be built into the Spitfire box. There have been several variants especially with reverse gear over the years, until you get the box on the bench, you won't know what you have got.
Otherwise a strip down will be needed. It sounds as though it's all down to synchro ring wear, but until you have it out, you will never know.

[b_caswell]

Re: Gearbox woes

To answer the other half of your question the overdrive is mounted onto the back of the gear box but is driven by a different mainshaft so you cant just swap the box on its
own. Also some Triumph gear boxes are three rail (with reverse press down left and forwards) and some single rail(lift right and forwards) The most probable arrangement you have is a Triumph Dolomite 1850 O/D box that has the long input shaft but would still use the Marina clutch housing. Or as Steve says the Marina input shaft has been transplanted into a Spitfire or Dolomite 1500 gear box. Also depending on where the box came from it could have a "D" type or a "J" type overdrive.

If possible take a couple of pictures from underneath of the gear box and overdrive and I may be able to ID which one you have.

[michael47]

Re: Gearbox woes

Thank you STEVE /BEN
I will get under and get some photos of the Gear box.Can the GB dropped out without removing the motor.Took it for a drive this am(42 Deg F) and just went from 2nd to 4th the car is so light that it was not a problem for just cruising around the country side.

[stevejgreen]

Re: Gearbox woes

Engine has to be tipped at a crazy angle to drop the box from below and that means disconnecting everything(almost) and straining the engine mounts. If you are a competent mechanic take the engine send gearbox out as one, it's so much easier to reassemble clutch and gearbox at workbench height.
Ben is right, but if it's just a gear change problem, deal with that once you base the box on the bench.

[tony.branson76]

Re: Gearbox woes

I agree with Steve. As a trials driver I have had to change gearboxes more than more than once. I did once try to take it out without the engine and gave up as you have to twist the engine mountings past breaking point. In my experience the most difficult bit of engine removal is the rear mounting for the gearbox. My friend who has an O/D gear box has a bar welded across the chassis and we managed with much twisting to get the flange at the back over this and then drop the engine. On my roadster there is an H shaped mounting that is bolted to the tunnel with 6 8mm bolts and nuts. Getting it out is not too bad, replacing it has taken several hours on occasion. I have now made it easier bit fitting rivnuts. My usual engine removal method involves removing the engine mountings and dropping the power unit onto a wheeled dolly. I then lift the front of the car with the engine hoist and wheel the power unit out. Good luck

[michael47]

Re: Gearbox woes

Thanks guys not the news i was hoping for I was hoping it was going to like a TR4 but I will get some experienced friends over and pull the whole unit this winter.
MichaelIMG_2357_Fotor.jpg

[cameronfurnival]

Re: Gearbox woes

Dont despair michael, the engine/ gbox will come out quite quickly - certainly do-able within a day at a leisurely pace. Tips I would recommend are to replace the bonnet nuts (the ones holding the bonnet to scuttle and nose cone) with rivnuts so you can whip it off at a moments notice without dropping the nuts into eh engine bay!
Once you have whipped off the nose cone and rad it all becomes straight forward. worth doing as you will be able to give it all a spruce up and check over on the bench...If you are stuck give a shout on here and someone will help you out with good practical advice.

[michael47]

Re: Gearbox woes

Dont despair michael, the engine/ gbox will come out quite quickly - certainly do-able within a day at a leisurely pace. Tips I would recommend are to replace the bonnet nuts (the ones holding the bonnet to scuttle and nose cone) with rivnuts so you can whip it off at a moments notice without dropping the nuts into eh engine bay!
Once you have whipped off the nose cone and rad it all becomes straight forward. worth doing as you will be able to give it all a spruce up and check over on the bench...If you are stuck give a shout on here and someone will help you out with good practical advice.

Thanks for the encouragement Having only owned the car for a few days I assumed that engine removal would be like a MGB up and out ,your comment about removing the rad and nose cone was a surprise but now that you said it it makes sense much like working on a moggie
Thanks again
Michael

[dcunn]

Re: Gearbox woes

Michael, I think I have identified your car as a YKC built Marlin Roadster - YKC took over production of the car from Marlin.

Could you please confirm the chassis(kit) number ends in 48
Here's a pic to show you where to look, in front of the front suspension, drivers side on a LHD car.
Rgds DC

[andyf]

Re: Gearbox woes

Thanks for the encouragement Having only owned the car for a few days I assumed that engine removal would be like a MGB up and out ,your comment about removing the rad and nose cone was a surprise but now that you said it it makes sense much like working on a moggie
Thanks again
Michael

You can avoid that by dropping the engine and box out the bottom of the car.

[Michael Turpin]

Re: Gearbox woes

You can avoid that by dropping the engine and box out the bottom of the car.

Out of the bottom is by far the easiest way and as Steve has said having it on the bench/floor makes parting the engine and G/box far easier, I say this as I have recently done this on my roadster albeit with a V8.
Look at page 10/11 in latest Pitstop which describes the "crazy angle" method, in which again as Steve said you have to disconnect almost everything apart from the engine mounts (which can easily be damaged by the tilt angle required), and the issues I encountered doing this way. You will see the dropout method in Part two of the article but be assured it is the best way.
good look
Michael

[andyf]

Re: Gearbox woes

I have done it both ways. More recently I've take the box out on it's own. All I had to disconnect was the top radiator hose. Compared to getting the box out of an escort or the sunbeam the angle isn't that crazy but then that could be because I have the Ford engine and box in there.

I went for that approach because I couldn't face trying to get the manifolds off!

[michael47]

Re: Gearbox woes

Michael, I think I have identified your car as a YKC built Marlin Roadster - YKC took over production of the car from Marlin.

Could you please confirm the chassis(kit) number ends in 48
Here's a pic to show you where to look, in front of the front suspension, drivers side on a LHD car.
Rgds DC

Hi Dave
You are right it is a YKC car it was delivered in early 1994.I know this because there was a briefcase full of paper work (build manual , Bill of sale from YKC etc) that came with the car that I started reading today .There were several letters from one Steve Himsworth who seemed very helpful to the previous owner/builder when ever he had a question.How did you know it was a YKC car ? I am very happy with the car it has 15000 miles on it since it was built. That # looks like it could be 201048.My only concern aside from rebuilding the gear box is the 13 inch rims I think 14s would look a lot better.Thanks to you and this club for all the help

Michael

[dcunn]

Re: Gearbox woes

Thanks for the confirmation Michael. We (Ben and I) are still spending hours trying to identify all the cars, it was an educated guess that 48 is the one you have.
You can't imagine the number of unidentified red Roadster pics we have, yours being green has helped.
FWIW my experience has shown it sensible to take nose cowl/rad etc off and engine/box out together from underneath, lower them to the floor then lift the car off.
Suggest you search this forum and the Roadster Tech Tips for advice and info about 14" wheels
Rgds DC