Fast Marina Magazine

Bren, I quoted all the part numbers earlier in the topic.

Here’s an original BL one on EBay

https://www.ebay.co.uk/itm/MG-Midget-15 ... ng-13H6968

I have been doing some more research and turned this up on the net, dated 1975. It confirms the engine number for the change of bearing and the order of fitment of the earlier bearing and spacer. The spacer definitely is fitted onto the main shaft before the bearing.

If the old spacer is trapped in the first motion shaft, I have found that old dental picks are really useful. You can pick them up at autojumbles and on eBay.

The way I read the TSB its the early small diameter, but wide bearing did not have a spacer fitted. I would fit a new 13H6968 bearing and put it back together as it came apart. Having another close look at the photo what I thought initially looked to be wear. could well be assembly grease
Dave

True David, deffo need to buy a spacer and small caged bearing.

Thanks again both, David, that is correct the score marks are actually assembly grease that I applied, it is only a 40k box and it looks to have had quite an easy life. It looks to me like that is correct, the earlier caged bearing looks to have not had a spacer fitted, I have bought the caged bearing that Chris found for me so I'll fit that and assemble it again hopefully that will be the solution. I'm going to try and find some data on the earlier 1st motion shafts and see if I am correct that the earlier types are machined differently to the later types.

Yes the motion shafts are different


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I'm now at the point of refitting the speedo drive ring, can anyone give me some advice on how to fit this without breaking it? I broke the original getting it off and I broke a new one trying to refit it, they are extremely tight.

Cheers

I would get a nice snug metal tube, that contacts the inner metal ring of the worm gear, not the plastic. Use that to drive the gear home. I would also help fitting if the gear is heated up in hot water prior to fitting.
Dave

Well I am more than ready to give up on this now. I have ordered two ring gears from Rimmer bros and they have both split. It seems to me that the inner diameter is too small, I had the gear only 3mm away from its seated position before it split, the same as the other I tried to fit. I have asked them to replace them as at £15 a pop they aren't cheap, especially as they seem to be quite prone to failure. So what do I do now? The marina has been off the road since december because of this and it needs much more work than this but this is holding it all up. What other BL boxes can be fitted to them as I am inclined to replace it now, which is a shame but this is just taking the p**s.

loads of 1.3 gearboxes here sadly no 1.7/1.8 could you fit a 1.3 clutch plate and then a 1.3 gearbox I know the gearing in top gear is the same
barry

Hi Barry,
Not too sure about that, would it be possible to build one good one out of the two? I could switch the first motion shaft with the one on mine although this would have to be on a gearbox with an early type mainshaft and roller bearimg (pre 1974 I think)

again mate not sure I've heard somebody did put a 1.3 in a bigger engined car and just used a 1300 clutch plate I've got 5 or 6 1300 gearboxes

Neither am I if I'm honest, not a clue what the differences are. I'll see if I can find out as it may be easier going down this route. I could try ordering one more ring gear and grinding the inner diameter to help ease it on but I don't know how effective or easy that'll actually be. I want to find who has the hoard of 1.8 boxes, it's unbelievable how much harder to find they are!

If you strugle to get the spacer out of the first motion shaft try filling the spacer hole with grease and tap the main shaft in to where the grease is as this may hydraulic the spacer out. This technique is used very sucessfully on the spigot bear in the fly wheel. Saves damaging surfaces trying to pick it out.

This is third-hand information, but if you pore-through the lists from the parts retailers, they specify for the spitfire & TR-7 to count the number of teeth on the gears. This is from the Marina-sourced single-rail, it's because the early TR-7 used the Spit's box, that didn't go well (the 7's 2L had too much torque, at some point I heard that the US dealers insisted on only selling 5-speed cars.) The final Spits had gears with stronger/larger teeth, and you had to know which kind you had. I think the Spit inherited them, they would've been redesigned for repairing warranty-repaired 7 boxes, the whole set of gears was swapped, not piece-by-piece (because old & new won't mesh). Perhaps some bearings/hardware was also upgraded?