SteveP TR3A Posted February 2 Report Share Posted February 2 Good Morning, I would be grateful for some help and pointers on how to replace the small pin that links the throttle rod to the lever please. The throttle pedal just went flat to the floor when I started the car (luckily the car was in my garage at the time). If moved manually it just spins in the lever. I assume this means the pin is broken or fallen out. The car is RHD. Any guidance on the best way to fit a new pin would be gratefully received. Thanks, Steve Quote Link to post Share on other sites
Lebro Posted February 2 Report Share Posted February 2 (edited) If this is the pin which is on the end of the rod inside the engine compartment, then the 1st task will be to remove the remains of the broken one, then replace with a correct size mills pin. The old one should just tap out using a suitable size punch, the replacing of a new one just requires small hands, & a lot of care getting it in the hole ! Truimph part number is 500555, https://rimmerbros.com/Item--i-DS1312 Good luck Bob Edited February 2 by Lebro Quote Link to post Share on other sites
SteveP TR3A Posted February 2 Author Report Share Posted February 2 Thanks Bob, I thought this may be a bit tricky. I have ordered the pin - waiting for it arrive. Just a follow up question please as I am very much on a learning curve here. Is it possible to access the pin from the engine side? Or from inside the car? Thanks, Steve Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 2 Report Share Posted February 2 It is in the engine compartment Access is limited If the lever is turning on the pedal shaft it will all be able to be removed and the broken bit of pin removed on the bench. The new pin is fitted with the lever and pedal shaft assembled on the car. Quote Link to post Share on other sites
SteveP TR3A Posted February 2 Author Report Share Posted February 2 Thank you. Having cleaned all the muck off the lever, I can see the pin now, which runs vertically through the lever and rod. Quote Link to post Share on other sites
Motorsport Mickey Posted February 2 Report Share Posted February 2 (edited) The Mills pins are torture. A tapered pin, they are originally fitted from on top with the large diameter of the taper obviously being on top,’ and you can beat them in. When they shear there is normally a faff to get access to it, and some disassembling normally results. Take advantage and drill the sheared Mills pin out through the shaft and housing with a suitable drill, (parallel,... I think I used 3mm) and then replace the pin with a C pin which is harder and doesn’t shear in use. Also being parallel if needing to be stripped later, you can just drive it out from on top, and then replace it again from on top. Mick Richards Edited February 2 by Motorsport Mickey Quote Link to post Share on other sites
stuart Posted February 2 Report Share Posted February 2 1 minute ago, Motorsport Mickey said: The Mills pins are torture. They are originally fitted from on top with the large diameter of the taper obviously being on top,’ and you can beat them in. When they shear there is normally a faff to get access to it, and some disassembling normally results. Take advantage and drill the sheared Mills pin out through shaft and housing with a suitable drill, ( I think I used 3mm) and then replace the pin with a C pin which is harder and doesn’t shear in use. Also being parallel if needing to be stripped later, you can just drive it out from on top, and then replace it again from on top. Mick Richards You think its difficult on a TR2/3/4 you should try it on an Italia! Their footwells are slightly wider and the bonnet wont lift high enough to even see it! Quote Link to post Share on other sites
greasemonkey Posted February 3 Report Share Posted February 3 On 2/2/2024 at 11:47 AM, Motorsport Mickey said: The Mills pins are torture. A tapered pin, they are originally fitted from on top with the large diameter of the taper obviously being on top,’ and you can beat them in. When they shear there is normally a faff to get access to it, and some disassembling normally results. Take advantage and drill the sheared Mills pin out through the shaft and housing with a suitable drill, (parallel,... I think I used 3mm) and then replace the pin with a C pin which is harder and doesn’t shear in use. Also being parallel if needing to be stripped later, you can just drive it out from on top, and then replace it again from on top. Mick Richards Mick - Aren't Mills pins the parallel hardened steel pins with a longitudinal split and a chamfer on each end ? They're made from spring steel & rely on their compression in the hole to secure. Phil. Quote Link to post Share on other sites
Motorsport Mickey Posted February 3 Report Share Posted February 3 (edited) 1 hour ago, greasemonkey said: Mick - Aren't Mills pins the parallel hardened steel pins with a longitudinal split and a chamfer on each end ? They're made from spring steel & rely on their compression in the hole to secure. Phil. Nope...damn things are softish metal (that's why they shear), which are tapered and in the original build where they connect the accelerator pedal rod which travels horizontal from drivers footwell into the engine compartment, they have to be accessed vertically UPWARDS to remove. Miserably because they are tapered, and you can only access the wide end of the taper it means they are impossible (well I never worked out how to do it) to remove when fitted and joining the rod and linkage together. Drill out and fit a parallel pin. When I bought Trevor the TR my TR4 back in 1973 from Manchester it sheared it's pin after about 5 miles driving and I had to butcher the radio wiring to get a piece of wire long enough to pass from the drivers seat through the bulkhead and onto the carb linkage operating it by hand. A long journey across to Nottinghamshire in the dead of night, the throttle was pretty much an "on off" switch due to the return spring pressures. As you describe the parallel pins are called C pins ...cos it's their shape when looked at from the end, are hardened and can be driven out from above when you want to split the horizontal throttle rod from carb linkage rod. If I bought another TR it's the first thing I'd check had been "upgraded", not an easy get around at the side of the road. Mick Richards Edited February 3 by Motorsport Mickey Quote Link to post Share on other sites
Lebro Posted February 3 Report Share Posted February 3 I sure you are correct Mick, but everywhere I look on the internet describes the Mills pin as being the "C" type you describe. & that is what Rimmers are selling to do this job. Maybe the definition has become corrupted over the years. Bob Quote Link to post Share on other sites
Motorsport Mickey Posted February 4 Report Share Posted February 4 It's easily identified Bob, if it won't come out when it's hit from on top, it's that blasted tapered pin version. If it does drift out then somebody has already changed it for a C type pin and thank goodness for that. Mick Richards Quote Link to post Share on other sites
Lebro Posted February 4 Report Share Posted February 4 Agreed, I changed mine for a "C" pin years ago. Just saying that almost everyone calls the "C" pin a Mills pin these days. Bob Quote Link to post Share on other sites
SteveP TR3A Posted February 5 Author Report Share Posted February 5 (edited) Here is a photo of mine taken from the top after I cleaned it up. From what I have read above, it is the original type pin. The one I have on order is the 'C' type one. Edited February 5 by SteveP TR3A Quote Link to post Share on other sites
Motorsport Mickey Posted February 5 Report Share Posted February 5 (edited) Yep, that’s an original tapered Mills pin, showing it’s larger dia towards you… hopeless ! Undo the carb linkage and then the accelerator shaft housing holding the bearing, and the throttle pedal bracketry inside the car. See if you can get to it from the engine side, I think you’ll struggle but if you can get it to point more into the engine compartment so it points front to back you may be able to get to it and drill it out from there. Mick Richards Edited February 5 by Motorsport Mickey Quote Link to post Share on other sites
SteveP TR3A Posted February 5 Author Report Share Posted February 5 Thanks Mick, much appreciated. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 5 Report Share Posted February 5 If the. Pin is sheared then once the spring ang throttle link are removed the lever might slide off the shaft and be worked on at the bench Quote Link to post Share on other sites
john minchin Posted February 5 Report Share Posted February 5 After a pin sheared on me I use a masonry nail. Its hard, wedges in tight and long enough to get hold of to pull out. Quote Link to post Share on other sites
stuart Posted February 5 Report Share Posted February 5 I still call the taper ended pins Mills pins and I think Burlen do as well as theyre used on other parts of carb linkages. The "C" shaped ones Ive always known as roll pins. Stuart Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 5 Report Share Posted February 5 (edited) 14 minutes ago, stuart said: I still call the taper ended pins Mills pins and I think Burlen do as well as theyre used on other parts of carb linkages. The "C" shaped ones Ive always known as roll pins. Stuart They hold the oil caps on the end of your rocker shaft and cam driven gear on the oil pump/distributor drive shaft. Grooved taper pins. The c pin is a dowel scroll pin in Triumph parlance and as it is general hardware has a meaningful prefix (DS) followed by numbers that denote size. Think 6cylinder manifold alignment pins originally being DS something now sold under a RPS (roll pin scroll) number. That’s due to factory parts system mergers and amalgamation of stock and MG being the dominant volume of parts sales (unreliability ?). Guaranteed to annoy a Triumph trained parts man, all this Austin Morris BMC numbering. Edited February 5 by BlueTR3A-5EKT Quote Link to post Share on other sites
stuart Posted February 5 Report Share Posted February 5 2 minutes ago, BlueTR3A-5EKT said: They hold the oil caps on the end of your rocker shaft and cam driven gear or the oil pump/distributor drive shaft. Grooved taper pins. The c pin is a dowel scroll pin in Triumph parlance and as it is general hardware has a meaningful prefix (DS) followed by numbers that denote size. Think 6cylinder manifold alignment pins originally being DS something now sold under a RPS (roll pin scroll) number. That’s due to factory parts system mergers and amalgamation of stock and MG being the dominant volume of parts sales (unreliability ?). Guaranteed to annoy a Triumph trained parts man, all this Austin Morris BMC numbering. I think I got the roll pin description from previous Jaguar parts nomenclature experience or even god forbid Healey Stuart. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 5 Report Share Posted February 5 Yep that makes complete sense. Two kit car companies fitting what comes to hand. Quote Link to post Share on other sites
stuart Posted February 5 Report Share Posted February 5 Just now, BlueTR3A-5EKT said: Yep that makes complete sense. Two kit car companies fitting what comes to hand. Stuart. Quote Link to post Share on other sites
SteveP TR3A Posted February 12 Author Report Share Posted February 12 Thanks again for all the help; it is really appreciated for me being new to my TR3a. After a lot of faffing and thinking, I managed to remove the lever arm from the accelerator rod while still attached to the car. I found a small puller at Halfords that is intended for wiper arm removal. It just about fits round the lever arm with enough grip. It was then straightforward to punch out the two broken pieces of the pin from the lever on the bench; and the middle piece from the accelerator rod. The new split dowel (C pin) needs to be fitted yet, but I feel well on the way to having an accelerator pedal that works. I also realised that there wasn't a pedal stop bolt fitted, so will be putting one of those on too before going on the road again. I wanted to share the method used to get the lever arm off with others on the forum who may encounter broken pins in the future. Steve Quote Link to post Share on other sites
Motorsport Mickey Posted February 12 Report Share Posted February 12 (edited) Hi Steve, So that little puller was fitted upside down onto the linkage housing and with the knob underneath then wound it up and it pushed the Mills pin (spit) out from underneath great result. I'm off to Halfords to buy the tool. Mick Richards Edited February 12 by Motorsport Mickey Quote Link to post Share on other sites
Z320 Posted February 12 Report Share Posted February 12 16 minutes ago, SteveP TR3A said: Hi Steve, is / was this a copper pin? Ciao, Marco Quote Link to post Share on other sites
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