Living with the Triumph TR4A 2018
So, we had a few interesting issues during 2017. You rebuild a Triumph TR4A front the ground up and you hope everything will just work - it often doesn't. Right now we have a watchful eye on the alternator and hope that it does not fry like the last one.
Locking petrol cap - January 2018
I met Marco on the TR Register forum. He has fabricated a locking petrol cap insert. It is really discrete and does not detract from the originality. I have ordered one at £60. The picture on the left was taken by Marco to show how it sits inside the LeMans Petrol Cap that is standard issue on a Triumph TR4A.
The gallery below shows our locking petrol cap from Marco installed on our TR4A. Takes 2 seconds to fit and works a treat! We are really pleased with it. Superbly made and comes with a spare key.
A new (old) petrol cap seal.
Marco noticed that my petrol cap did not have the seal in place (He's a petrol cap geek). You can't buy them new. The size is 60mm outside diameter, the width is 3mm making the inside diameter 54mm. Interestingly it appears the seal is actually made up of three seals. 2 of them are 2mm deep and the other is 1 mm deep making a total depth of 5mm. It maybe that these 3 were originally 1 seal and it has delaminated with age? You can get 'O' rings in similar sizes but the seal is a flat washer type. I bought an old fuel cap on Ebay that had the seal in place. I then put the cap in a pan of simmering water to soften the rubber to get the seal out. I went around the outside edge with a very sharp knife and that released the seal. I then put the seals back in the water to continue to soften them. My plan is to sell the cap on Ebay as it is in good condition and works well - minus the seal. As I can't get a replacement seal I will reuse these here starting with the split seal at the very bottom working my way up to have the one that is in the best condition touching the cap when it closes.
Seals in place
3 seals came out but I could only get 2 back in. I guess it was because they were old. Still, they are pliable enough now and the inner spring loaded cap has sat the seal in securely. Another job finished!
Overdrive not disengaging? January 2018 (Started in November 2017)
The picture above was found online. It shows the fill and drain points on a Moss box. This is NOT correct on a Triumph TR4A. The fill plug is correct but the drain on a TR4a is the brass spinner that sits at the bottom of the box. Behind the spinner you'll find the brass filter.
I have been looking in to this issue. The overdrive engages well but it takes a 'blip' of the throttle to disengage it. There are many theories. Firstly, the electrics were checked and they are all fine. Secondly, the solenoid operates fine on the switch/stalk. So, in the hope that it is nothing serious inside the overdrive itself, I will be investigating the oil as I do know it was seeping a little from the brass turn screw/plate at the bottom of the the box. It could be, without the right amount of oil, the pressure is not enough to disengage the overdrive.
I am using Castrol Classic EP90. The box holds about 2 litres. I also bought a pump for £8.95 on Ebay that allows you to feed in or remove oil. ideal for filling gearboxes and differentials that are often hard to access.
Below you can see the TR4A up on axel stands. We do have a ramp but there is another car on it with the engine out - pain!!!
The overdrive investigation starts - January 2018
So I spotted leaks from front and rear seals as well as the seal where the OD joins the box. There is only one way to fix this - take the gearbox out and dismantle it and replace the gaskets/seals. This is a home workshop task but it is a bit of a mission. It could be done in a weekend but I will need the use of my ramp. You can see the transmission oil leaking at the lowest points in the pictures below. It is a gentle seep but you can see where it lands on the exhaust (This would burn off in seconds once the engine is running so good to see it here as it gives a clue to the problem). The fill plug is in very, very, tight and I don't have the square spanner that gets a tight fit around the plug. So, I have ordered one and will continue once the right tool for the job is here. The car has done 3,oo0 mies on the gaskets and seals, so one would hope that they would be more resilient than that??? My plan is to check the oil level and then drain the box and refill it with EP90. I can only imagine that in another 3,000 miles it would need doing again so I maybe able to hold off taking the gearbox out until next winter? The oil is probably the cause of the overdrive issues as there would not be enough pressure for the overdrive to disengage. In many ways this is good news as it points to nothing sinister in the overdrive causing the problem.
Overdrive Wiring diagram TR3A - covers TR4A
Overdrive advice from CCK Historic
I was down at CCK historic and managed to chat to the very knowledgeable Graham (He rebuilt my TR engine). On hearing my issue, he thought the most likely cause was a blocked filter not allowing the oil to run back. So, I will start there and see what we have?
The right tool for the job
I managed to find this Girling Square Socket Spanner that was used to remove the drain and filler plugs on gearboxes, overdrives and brakes. Great find as now I have the right tool for the job. The drain and fill plugs are in tight and a conventional spanner is not doing the job.
Overdrive February 2018
I've not had much time to get on with this task but I finally found the time to get stuck in. The Girling plug spanner worked a treat - everyone should have one. I used my finger to check the oil level and could not feel any oil. So I used a coffee stirrer and managed to get a slight level. So, I am guessing that oil has dripped out. Next, I checked the filter by undoing the brass spinner at the bottom of the box. A lot of gloop came out and the filter did have deposits blocking it up. So, I cleaned out the filter and cleaned everything up. Lastly I started to refill the box using the pump I bought. The pump is not so great. In fact pretty useless, so I am trying to find another plan. The pictures below show the Girling spanner, the beautifully clean filter and the spinner that is made of brass that sits at the bottom of the box.
Making a Gravity Fed Gearbox Oil Filler February 2018
So, the next mission was how to get the fresh oil into the gearbox. The pump I bought was rubbish. I was pump furiously and nothing much was happening. After half an hour a quarter of the oil had gone in to the box and my arm and given up with cramp. So, after sleeping on it, I came up with a gravity fed system. So easy to do and I have to say it works a treat.
1: Drill a hole in the gearbox tunnel from inside. This is easily done as you only need to pull the carpet back.
2: I used a transmission jack to hold a funnel with a filter in it.
3: A plastic tube was slipped on to the funnel and pushed through the hole in the tunnel and pushed into the gearbox from underneath the car - it was on axel stands.
4: The oil was placed in the funnel and I went for a walk as it slowly drained in to the box.
5: On pulling the tube out of the box oil started to pour out which means I had overfilled it. This is a good thing as when the oil stops dripping out you know the box is full. Worth remembering to have your car level on the axel stands.
6: Cleaned up the oil that had dripped down the box.
7: Refit the oil filler plug in the box with the Girling tool.
7: Put a rubber cover in the hole in the gearbox tunnel.
8: Replace the carpet.
It is that easy:-). I have a small video here to show how it all worked.
Test-drive to check the overdrive
The problem of the overdrive not disengaging still exists so I'll have to think on to try and resolve this. Still. it was great to get out in the TR4A for a drive - the first of 208 and the first great day of weather we have had. Went driving at night too - 6pm at this time of year!