Gearbox Problem

[brian bax]

Has anyone recent experience of rebuilding a TC gearbox? I think that the sliding hub springs currently being supplied are much too strong resulting in second gear synchro becoming effective while you are still disengaging first gear. Can anyone supply an original set of springs? Any advice would be gratefully received before I take it apart for the sixth time! Brian Bax TC3550

[Charles Hill]

brian bax wrote:

> > Has anyone recent experience of rebuilding a TC gearbox? I think that the sliding hub springs currently being supplied are much too strong resulting in second gear synchro becoming effective while you are still disengaging first gear. Can anyone supply an original set of springs? Any advice would be gratefully received before I take it apart for the sixth time! > Brian Bax TC3550

Brian, I rebuilt my TC gearbox last year. Wasted most of the driving season with the car in pieces. I don't think your problem is with the springs. The original ones are pretty strong. I sure had a hard time them and those little balls together. There should be quite a thread on that subject in the archives. If everything is OK, there is no way that 2 gears can be engaged at the same time. My first guess would be that the 2nd gear split washer is worn allowing the gear to ride too far back. I'm sure that others with more experience with the TC box may have a better idea on what the problem might be. Regards, Charles Hill

[Eric Worpe]

Hi Brian and Tabc listers, You have highlighted one of the idiosyncrasies of the TB/ TC gearbox. You are quite right in believing that as you start to disengage first gear ( first gear needs to be displaced almost 7/8 of an inch to either engage or disengage its mesh with the laygear) the outer sliding ring / first gear can drag the inner sliding hub due to the friction from the spring loaded balls. The inner sliding hub only moves about 1/8 of an inch on the splines of the mainshaft before its synchro recess engages with the synchro cone on the second gear assembly. At this point first gear is still partially engaged, but only a limited amount of force engages the 2nd gear synchro cones. As first gear continues to be disengaged, the syncro balls drop into a groove by which time first gear is completely disengaged. Further displacement of the sliding ring / first gear applies greater force to the synchro cones until the balls are forced out of the groove and the outer sliding ring's internal splines are allowed to slide into mesh with the "dog teeth" on second gear. First and second gears cannot be engaged together but as I hope the above description suggests, it is possible for the second gear synchro cones to become engaged albeit with a limited force, at the same time that first gear is partially engaged. Usually the ability of the synchro cones to "lock" up with only a small applied force is not significant as the teeth in the synchro recess have to bite through an oil film before mating with the synchro cone. However I've come across some synchro cones that seem to lock up easily with only a little applied force and I'm not at all sure why other than a perfect match between surfaces being responsible. I'm sorry not to be of any help in overcoming the problem which seems to be due to a rather efficient set of synchro cones "jumping the gun", the irony is that many would be glad to have a set of second gear synchro cones that weren't worn out. Regards, Eric Worpe.

[harry van malder]

Hello My TA was always jumping out of 2nd gear and reverse . Therefore I toke the selector off, regulated so that the distance between the pin under the lever and the pin wich goes into the box is a little bit bigger ( 0,5 cm each side), and this works now. Another problem wich remains is the following: By coming down from 2nd to neutral,the selector block of the 2nd ( on the right top axle) is not coming back far enough, so when I take reverse, the reverse block ( on the left top axle) is going to reverse, but same time, the box is also taking 2nd gear at the same time.and the car keeps movin forward in 2nd . As the pin wich selects the position of the gears in the box is gone to the position of reverse, it is impossible to put the box out of 2nd, and the thing is completely blocked.The only solution is to take off the seats, carpets, etc, finally the selector plate,and then with a screwdriver pushing the selector block of the 2nd gear in the right position . As far as I can see , there is no real problem with the gearbox itself, and I think now that the problem is caused by the interlock balls on the top 3 axles, who dont work properly( maybe they are not even in.) Can I move out one of the 3 axles a little bit towards the engine side , just to see if the balls are in ( then I dont have to take off the end plate( propshaft side) Are the springs and balls mounted under the axle( the gaps in the axle are there ), because on a drawing in a moss catalogue, they are shown to being mounted above the axle( wich seems very strange). In the catalogue, they mention 5 balls and 3 springs.( page 46 part 21 and 22 ), 3 springs and balls are going in the holes on the frontside housing of the box, but where do i have to fit the other 2 ? On the drawing they show them placed at each side of the middle axle. I indeed see a screw on the right side of the box to fit them in, but are there no springs required ? Any answer can help Thanks Harry [Non-text portions of this message have been removed]

[D & J Edgar]

> In the catalogue, they mention 5 balls and 3 springs.( page 46 part 21 and 22 > ), 3 springs and balls are going in the holes on the frontside housing of the > box, but where do i have to fit the other 2 ? On the drawing they show them > placed at each side of the middle axle. I indeed see a screw on the right side > of the box to fit them in, but are there no springs required ?

Harry, The three balls and 3 springs do come down from the top and are used to indent the 3 axles as you call them (Moss refers to them as selector shafts - items 1, 2 and 4 in catalog). The two remaining balls go between the sector shafts. They in effect only allow one selector shaft to move at a time (which you seem to be having problems with). The moving selector shaft will push the ball off to the side and lock the adjacent selector shaft into place. You can see the other two balls in the Moss diagram near the top where the selector shafts are drawn. The two balls are labeled #22 (same number as diagramed further down in the drawing where the springs are). If they are missing you have to remove at least the middle selector shaft far enough to fish in the two balls and then move the selector shaft back and thus trapping them into position. David Edgar, TC 5108 El Cajon, California