TR4A1965 Posted February 18, 2018 Report Share Posted February 18, 2018 Hi all. Can you look at the attached vid and let me know what you think of the operation of my overdrive solenoid. https://youtu.be/TDWjssyI5zo It looks good to me but I want to rule it out as a source of my overdrive not disengaging issues? Many thanks, Paul. Quote Link to post Share on other sites
Hamish Posted February 18, 2018 Report Share Posted February 18, 2018 Looks ok to me. Positive action on the solenoid. Quote Link to post Share on other sites
RogerH Posted February 18, 2018 Report Share Posted February 18, 2018 Hi Paul, the solenoid looks as though it is doing the correct thing. However there is always a small amount of play in the fork attached to the solenoid plunger. This may allow the operating shaft/cam to remain engaged. Reset the plunger/fork and alignment arm and see how it goes. It has been posted that some people do not go solely by the rigging position and add an extra bit of alignment arm rotation Roger Quote Link to post Share on other sites
Drewmotty Posted February 18, 2018 Report Share Posted February 18, 2018 If your overdrive is slow to disengage take a look at the pushrod under the cap on the right hand side. Remove the cap, spring, plunger and ball with a small magnet and then withdraw the pushrod. The rod is hollow and when the overdrive disengages the oil escapes through a small hole in its side. Blow it through to ensure that its clear as it is easily blocked by the smallest piece of debris. Quote Link to post Share on other sites
TR4A1965 Posted February 19, 2018 Author Report Share Posted February 19, 2018 Thanks all, I'll try all of that and see where we go. Best. Paul. Quote Link to post Share on other sites
RogerH Posted February 19, 2018 Report Share Posted February 19, 2018 Hi Paul, what grade of oil are you using.? Having read the 'Foaming OD Oil' saga, one of the write-ups suggested that 90 grade (i would suggest they mean EP90) was too thick and the pressure could not be released by the appropriate valve. Many people use EP90 and it may be that it is just on the cusp of operation. On my 4A GB/OD I use Penrite GB40. Roger Quote Link to post Share on other sites
TR4A1965 Posted February 20, 2018 Author Report Share Posted February 20, 2018 Hi Roger, I have just completed an Oil Change to Castrol Classic EP 90. Pictures attached:-) When I dropped the filter out the oil was quite dark and it seemed lumpy. The filter did have some crud in it but I cleaned it all out then performed a change with my new invention a 'Gravity Fed Triumph TR4A Gearbox Oil Filler Upper.' (Hole drilled in gearbox cover and accessed from inside the car - Oh and I am the proud owner of a Girling square bung spanner - sexy) So, I have a feeling that the Solenoid could be binged up?. I am crossing everything in the hope it is. The box and overdrive were rebuilt by Mike Papworth 3000 miles ago and his work by all accounts is of the highest quality so I am ruling out anything too sinister at this stage????? Best Paul Quote Link to post Share on other sites
RogerH Posted February 20, 2018 Report Share Posted February 20, 2018 Hi Paul, on the 'Foamy Oil' thread there is a suggestion that EP oil can break down with high temp. This may put lumps in the operating valve. This valve has a number of small holes to allow the pressure to drop off. If the holes are bunged up then the pressure hangs around. This valve is located on the off side of the OD and is a hex bolt head. You need a magnet on a stick to get it out. Regarding your 'gravity oil feed' - that luverly red roof looks very close. I use this and it works well https://www.machinemart.co.uk/p/cgg500-500cc-oil-suction-gun/ If you make the hole, in the side of the tunnel, the same size as the rubber bung in the floor then you will have more than enough room to access the plug etc. Roger Quote Link to post Share on other sites
Fireman049 Posted February 20, 2018 Report Share Posted February 20, 2018 (edited) I opened up that tiny hole for the gearbox oil filler to enable easier access to the plug. The hole is covered in one of the floor jack rubber bungs. Tom. Edited February 20, 2018 by Fireman049 Quote Link to post Share on other sites
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