| Author | Message | ||
     Ron Lewis New User Username: great48 Post Number: 12 Registered: 01-2009 |
Hi, all - hope you can help me with this. Was getting my Mark VI (Steel Body) ready for carrier transport and have just experienced a problem where it appears the selector lever inside the gearbox has slipped out of the selector rod, leaving 3rd gear permanently engaged. The driver's gear lever has no resistance whatsoever when in the 3rd gear position - it just flops around there. However, there is resistance when I try to select Reverse, first and second gears so the external driver's gear shifter is working fine. My query is whether I can fix this problem externally (or at least by leaving the gearbox in situ) and somehow re-engage/re-install the internal gearbox selector lever correctly. To compound matters, the car is currently stored at an interim house (with bare minimum of garage facilities) and with a car carrier booked in one week's time to transport it to our new home in interstate QLD. Ron Lewis | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 425 Registered: 07-2018 |
Have a look at the fourth last post in this thread. See the first photo in that post. There's an access port there with 4 studs sticking up and in some models, that access port is accessible through the floor. Once the cover is removed, you can access the shifting rods and put things back as it should be. Has someone been messing around with your trans. ? There are locking balls to keep one from selecting more than one gear and it sounds like they may be missing in your case. If third gear is selected, then the gear selector fork should still be in the shift rod, did you remove the shift lever and try to correct this ? If the gate bolted onto the frame is not synchronized to the gate inside the trans, that can also cause problems. The shifting gate is adjusted by shims between it and the frame. The gate itself is also adjustable so the shift lever lines up with the gate inside the trans. You may have to remove the floor to see what's going on, if you're not familiar with the innards of the trans. it's difficult to visualize how things go. If the locking balls are not in place I think it would be possible to install them, but you would be working up-side-down with oil dripping all over _ it would be very difficult. With the access cover removed as well as the shift lever you would be able to slip third gear back into neutral with a large screwdriver, but the question is, how did it get that way in the first place ? http://au.rrforums.net/forum/messages/16999/41017.html?1661678835 https://rrtechnical.info/mkvi/02_mkvi_02.html | ||
| ChristopherCarnley Unregistered guest Posted From: 217.39.245.39 |
The only way to proceed is either to remove the floor, 42 rusted in 1/4" BSF screws and then the small square inspection cover on top of the gearbox, 1/4" BSF nuts, or to take the gearbox out. WM Section"F". The drop lever may have come out of the selector jaw, or the 3rd speed thrust washer had broken up. I do not think that you will have any joy in emptying the oil and removing the 7 nut bottom cover. 3 No. detent springs and 3 No 1/2" steel balls. Be careful that the 3/4 interlock ball has not come out of its hole. These gearboxes have been badly neglected for many years. (Message approved by david_gore) | ||
| Ron Lewis New User Username: great48 Post Number: 13 Registered: 01-2009 |
Thank you Chris and Jeff for your replies - very much appreciated. Due to the tight time constraint and the total absence of any workshop facilities in my daughter's garage, the top inspection cover has to be my first exploration call. The car has been laid up for 4 plus years while I did a heap of mechanical and electrical repairs (on and off) to put reliability into the car. Gearbox looked fine when I had the side cover off while fitting some new external gaskets and then the EP80 gear oil with new; other than that it's always performed perfectly, even on the recent short 25km drive to its current address. But... An acquaintance who was toying with buying the car may have accidentally done something with the gear lever whilst stationary/engine off to cause the problem (as the car was unregistered and couldn't be driven on the road). I don't know if that's a possibility, but it's all I have at the moment. Anyway, will see what the top inspection cover discloses. Thanks again, guys, for the detailed responses once again. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 426 Registered: 07-2018 |
Are you able to "rock" the engine from side to side, if yes, then the rubber mounts on the torque stabilizer have perished ? I'm not sure if enough movement would cause the gear selector fork to become disengaged from the gate within the transmission though. Just a thought. | ||
| Ron Lewis New User Username: great48 Post Number: 14 Registered: 01-2009 |
Another good point that sounds worth checking out, thanks, Jeff. The gearbox mounting is new, as are the torque arm rubbers also. I will probably recheck adjustment of the torque arm once the selector arm is sorted out. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 427 Registered: 07-2018 |
If the torque arm rubbers are new, then that has not caused the problem. I suppose if they are very out of adjustment, that might be the cause, but the engine would be sitting severely to one side. There's something going on in the trans that has to be looked into. | ||
| ChristopherCarnley Unregistered guest Posted From: 86.159.149.222 |
Ron, I see that you have an early B series 1947 car, the gearboxes up to the middle of the D series in 1949 had several design flaws. Apart from the rear main bearing, these are located around the 3/4 synchronising mechanism. The early main shafts had milled out weak splines that crack and break up under synchro cone lug action, jamming the sliding piece, this problem along with a fragmented weak 3rd speed thrust washer may be at the root of the matter, in this case. Your friends vigorous levering may have caused a total jam, but although I have heard of the drop lever coming out, I have never seen it myself. Replacement gearboxes are hard to find, and dismantlers are not reliable enough to provide you with a serviceable replacement. (Message approved by david_gore) | ||
| Ron Lewis New User Username: great48 Post Number: 15 Registered: 01-2009 |
Thanks once again for this latest information, Christopher and Jeff, it's all most helpful. Engine is level and pretty firm on its mount. The design flaws are a concern, but hopefully more should be revealed (and hopefully solved???) after I remove the top inspection cover when I'm down in Melbourne in the next couple of days. Will post an update after something eventuates. | ||
| Ron Lewis New User Username: great48 Post Number: 16 Registered: 01-2009 |
Got down to Melbourne and was fortunate enough to solve the stuck-in-gear problem with a simple fix, albeit a temporary one. The best part was the fix was achieved without removal of the gearbox, which I was dreading due to lack of available time and facilities. From the beginning, the driver's gear lever still moved sideways in its neutral gate in 1/2 and Reverse planes, so I just tied it across to one side to retain it in its neutral position. The easiest and quickest elimination step was to then drain the gearbox oil, remove the bottom cover and selector balls and springs to try my luck there. The three selector shafts were exposed, with the 3rd-4th shaft, naturally, in third gear selected position. It was just a case of gently prising the 3-4 selector shaft back so its gate was in line with the other two and do a careful selection check to ensure each gear could be engaged individually without problems, which they all could. After refitting the bottom plate and refilling, all gears were rechecked with detent balls in place - all moved okay, so road tested (on private road) and everything was operating as it should. So, the vehicle is now driveable and the car carrier's schedule can be met, averting at least one crisis for me. Another positive is that the problem now appears to be narrowed down to being external to the gearbox, otherwise I doubt that I could have resolved it without gearbox removal and dismantling. Obviously, more investigation is required of the original cause, but that is for a later time and better facility. Many thanks to Christopher and Jeff for all the information they provided - it was a great benefit in helping me get my head around the best and worst case scenarios. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 432 Registered: 07-2018 |
Go talk to your friend Ron, ask him what he did to disengage the gear lever out of the 3rd/4th shift rod ? |
